bluuebunny/crossref_metadata_2025 huggingface dataset:
A Binary Salt Mixture LiCl–LiOH for Thermal Energy Storage
Authors: Hassan Naveed , Minakshi Manickam , Ruprecht John , Liew Willey Yun Hsien , Jiang Zhong-Tao
Published: February 2023

For thermal energy storage, the most promising method that has been considered is latent heat storage associated with molten salt mixtures as phase-change material (PCM). The binary salt mixture lithium chloride—lithium hydroxide (LiCl–LiOH) with a specific composition can store thermal energy. However, to the best of our knowledge, there is no information on their thermal stability in previous literature. The key objectives of this article were to investigate the thermophysical properties, thermal repeatability, and thermal decomposition behavior of the chosen binary salt mixture. FactSage software was used to determine the composition of the binary salt mixture. Thermophysical properties were investigated with a simultaneous thermal analyzer (STA). The thermal results show that the binary salt 32 mol% LiCl-68 mol% LiOH melts within the range of 269 °C to 292 °C and its heat of fusion is 379 J/g. Thermal repeatability was tested with a thermogravimetric analyzer (TGA) for 30 heating and cooling cycles, which resulted in little change to the melting temperature and heat of fusion. Thermal decomposition analysis indicated negligible weight loss until 500 °C and showed good thermal stability. Chemical and structural instability was verified by X-ray diffraction (XRD) by analysing the binary salt system before and after thermal treatment. A minor peak corresponding to lithium oxide was observed in the sample decomposed at 700 °C which resulted from the decomposition of LiOH at high temperature. The morphology and elemental distribution examinations of the binary salt mixture were carried out via scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS). X-ray photoelectron spectroscopy was conducted for surface analysis, and their elemental composition verified the chemical stability of the binary salt mixture. Overall, the results confirmed that the binary salt mixture is a potential candidate to be used as thermal energy storage material in energy storage applications of up to 500 °C.
Investigation on the Electrical Conductivity of Graphene/Cement Composites by Alternating Current Method
Authors: Jin Ming , Li Wenwei , Ma Yuefeng , Zeng Haoyu , Huang Minghui , Lu Chao , Yang Guo
Published: February 2023

This paper is concerned with an analysis of the electrical conductivity of graphene/cement composites by means of DC (direct current) and AC (alternating current) techniques. Moreover, the micrograph and element composition of composites have been characterized through SEM (scanning electron microscopy) and EDS (energy-dispersive spectrometers) techniques, respectively. Results revealed that a percolation transition region Φ2–Φ1 (Φ2 and Φ1 values are determined as 0.8% and 1.8%, respectively) can be observed in the S-shaped curve. In addition, the logistic model has been recommended to characterize the relationship between the conductivity and the graphene concentration, which ranged from 0.001% to 2.5%. The micrographs obtained by SEM technique clearly indicate a complete conductive network as well as agglomeration of graphene slices when the graphene content reaches the threshold value. Furthermore, graphene slices can be distinguished from the cement hydration products by means of the analysis of element composition obtained through the EDS technique. It is promising to apply the graphene/cement composites as intelligent materials.
Measuring and Predicting the Effects of Residual Stresses from Full-Field Data in Laser-Directed Energy Deposition
Authors: Polyzos Efstratios , Pulju Hendrik , Mäckel Peter , Hinderdael Michael , Ertveldt Julien , Van Hemelrijck Danny , Pyl Lincy
Published: February 2023

This article presents a novel approach for assessing the effects of residual stresses in laser-directed energy deposition (L-DED). The approach focuses on exploiting the potential of rapidly growing tools such as machine learning and polynomial chaos expansion for handling full-field data for measurements and predictions. In particular, the thermal expansion coefficient of thin-wall L-DED steel specimens is measured and then used to predict the displacement fields around the drilling hole in incremental hole-drilling tests. The incremental hole-drilling test is performed on cubic L-DED steel specimens and the displacement fields are visualized using a 3D micro-digital image correlation setup. A good agreement is achieved between predictions and experimental measurements.
Removal of Methylene Blue from Wastewater by Waste Roots from the Arsenic-Hyperaccumulator Pteris vittata: Fixed Bed Adsorption Kinetics
Authors: Mazzeo Leone , Marzi Davide , Bavasso Irene , Piemonte Vincenzo , Di Palma Luca
Published: February 2023

Phytoremediation of arsenic-contaminated water was successfully conducted by means of the perennial fern Pteris vittate, which is an arsenic-hyperaccumulator plant able to grow in hydroponic cultures. In order to avoid the costs linked to the disposal of As-contaminated biomass, in this work, Pteris vittata waste roots were tested as a low-cost bio-adsorbent for the removal of methylene blue (MB) from water in a fixed-bed adsorption configuration. As a matter of fact, methylene blue can negatively impact the growth and health of algae and plants by blocking light from reaching them in water, which can alter their normal biological processes. Previous works have already shown the potentiality of such material toward the uptake of methylene blue; however, all the studies conducted were just focused on batch-mode experiments. In this work, column runs were carried out at 20 °C, evaluating the bed void fraction for each test and hence estimating the apparent density of the material (300 g/L). The breakthrough curves collected were fitted by means of a mathematical model based on the linear driving force (LDF) approximation to obtain information on the mass transfer mechanism occurring in the system. A relation for the product between the LDF mass transfer coefficient and the solid specific surface (kLDFas) with respect to the Reynolds (Re) dimensionless number was obtained (kLDFas=0.45Re). The range of validity of such expression was Re<0.025. Its applicability was deeply discussed: in such conditions, the technology is ready to be tested at larger scales.
Experimental and Numerical Analysis of Triply Coupled Vibration of Thin-Walled Beam with Arbitrary Closed Cross-Section
Authors: Yang Jianglin , Xu Ting , Zhong Haolong , Sun Meng , Gao Fei
Published: February 2023

In this paper, a numerical experimental study about coupled vibration and natural frequency of thin-walled beams with an arbitrary closed cross-section is presented. A new thin-walled beam dynamic transfer matrix method, named TDTMM, is presented in the frequency domain for the thin-walled beam, which expands the advantages of the general dynamic transfer matrix method (GDTMM). The theory takes into account the influence of warping effect, that is, both the bimoment B and the rate of twist ϕ(x) of the beam are considered, and the TDTMM is derived by solving the governing differential equations of motion for coupled bending and torsional vibration of the thin-walled beam. Finally, two numerical examples and one experimental example are given and compared with the GDTMM and the finite element method (FEM) results to validate the developed theory.
A Single-Loop Framework for the Reliability-Based Control Co-Design Problem in the Dynamic System
Authors: Zhang Qi , Wu Yizhong , Lu Li , Qiao Ping
Published: February 2023

When solving the control co-design (CCD) problem using the simultaneous strategy in a deterministic manner, the uncertainty stemming from the stochastic design variables is ignored, and might have a negative influence on the performance of the dynamic system. In attempting to overcome the undesirable effect of the uncertainty, this research investigates the reliability-based control co-design (RB-CCD) problem and presents a single-loop framework for RB-CCD based on the modified RB-CCD model and single-loop approach (SLA). Specifically, the modified model is deduced by introducing additional design variables and equality constraints (state equations and algebraic equality constraints) so as to transform the probabilistic constraints into inequality constraints. Meanwhile, to enhance the solution efficiency, SLA transforms the modified RB-CCD model into an equivalent single-loop deterministic CCD model by incorporating the approximate reliability information of the stochastic design variables into the deterministic optimization. Finally, a numerical example and an engineering example are implemented to verify the feasibility and effectiveness of the single-loop RB-CCD optimization framework. The results demonstrate that the suggested single-loop framework dramatically improves the reliability of the dynamic system, and significantly increases the solving efficiency without compromising accuracy.
Integro-Differential Boundary Conditions to the Sequential ψ1-Hilfer and ψ2-Caputo Fractional Differential Equations
Authors: Sitho Surang , Ntouyas Sotiris K. , Sudprasert Chayapat , Tariboon Jessada
Published: February 2023

In this paper, we introduce and study a new class of boundary value problems, consisting of a mixed-type ψ1-Hilfer and ψ2-Caputo fractional order differential equation supplemented with integro-differential nonlocal boundary conditions. The uniqueness of solutions is achieved via the Banach contraction principle, while the existence of results is established by using the Leray–Schauder nonlinear alternative. Numerical examples are constructed illustrating the obtained results.
Optimizing Service Areas in 6G mmWave/THz Systems with Dual Blockage and Micromobility
Authors: Golos Elizaveta , Daraseliya Anastasia , Sopin Eduard , Begishev Vyacheslav , Gaidamaka Yuliya
Published: February 2023

The modern 5G millimeter wave (mmWave) New Radio (NR) systems as well as future terahertz (THz) radio access technologies (RAT) will heavily rely on beamforming to combat the excessive path losses. Additionally, both RATs target similar bandwidth-greedy non-elastic traffic and are affected by the blockage phenomena. To improve service reliability in these systems multiconnectivity can be utilized to dynamically hand over the ongoing sessions between two technologies. In this article, we investigate the association strategies in collocated deployments of mmWave/THz systems and evaluate the impact of the utilized antenna arrays. Our results show that accepting sessions to THz BS that may experience outage in blocked conditions is preferable when multiconnecitvity is utilized as compared to accepting them to mmWave BS. However, extending the coverage of THz base station (BS) by increasing the number of antenna elements slightly affects performance metrics. Nevertheless, there is still non-negligible probability of dropping sessions accepted for service, implying that in 6G deployments the support of fully reliable microwave technology such as sub-6 GHz NR is vital.
Adaptive Fuzzy Predictive Approach in Control
Authors: Romanov Anton A. , Filippov Aleksey A. , Yarushkina Nadezhda G.
Published: February 2023

This article studies the approach to solving the problem of controlling the complex organizational and technical systems based on hybrid models. We propose a new component of intelligent decision support that is integrated with control systems. The proposed component is based on fuzzy logic and knowledge engineering. We present a model of ontology to form the context of data analysis and time series modeling. The ontological context allows us to represent trends of the analyzed object indicators. An expert can add a set of fuzzy rules to the ontology for systems control based on the fuzzy inference. The proposed approach allows reducing the time of analysis and interpretation of the results. Experimental results confirm the correctness and effectiveness of the approach proposed in this article.
Runge–Kutta–Nyström Pairs of Orders 8(6) for Use in Quadruple Precision Computations
Authors: Kovalnogov Vladislav N. , Matveev Alexander F. , Generalov Dmitry A. , Karpukhina Tamara V. , Simos Theodore E. , Tsitouras Charalampos
Published: February 2023

The second-order system of non-stiff Initial Value Problems (IVP) is considered and, in particular, the case where the first derivatives are absent. This kind of problem is interesting since since it arises in many significant problems, e.g., in Celestial mechanics. Runge–Kutta–Nyström (RKN) pairs are perhaps the most successful approaches for solving such type of IVPs. To achieve a pair attaining orders eight and six, we have to solve a well-defined set of equations with respect to the coefficients. Here, we provide a simplified form of these equations in a robust algorithm. When creating such pairings for use in double precision arithmetic, numerous conditions are often satisfied. First and foremost, we strive to keep the coefficients’ magnitudes small to prevent accuracy loss. We may, however, allow greater coefficients when working with quadruple precision. Then, we may build pairs of orders eight and six with significantly smaller truncation errors. In this paper, a novel pair is generated that, as predicted, outperforms state-of-the-art pairs of the same orders in a collection of important problems.
A Review on Business Analytics: Definitions, Techniques, Applications and Challenges
Authors: Liu Shiyu , Liu Ou , Chen Junyang
Published: February 2023

Over the past few decades, business analytics has been widely used in various business sectors and has been effective in increasing enterprise value. With the advancement of science and technology in the Big Data era, business analytics techniques have been changing and evolving rapidly. Therefore, this paper reviews the latest techniques and applications of business analytics based on the existing literature. Meanwhile, many problems and challenges are inevitable in the progress of business analytics. Therefore, this review also presents the current challenges faced by business analytics and open research directions that need further consideration. All the research papers were obtained from the Web of Science and Google Scholar databases and were filtered with several selection rules. This paper will help to provide important insights for researchers in the field of business analytics, as it presents the latest techniques, various applications and several directions for future research.
Explicit Identification of Pointwise Terrain Gradients for Speed Compensation of Four Driving Tracks in Passively Articulated Tracked Mobile Robot
Authors: Jeon Haneul , Lee Donghun
Published: February 2023

Tracked mobile robots can overcome the limitations of wheeled and legged robots in environments, such as construction and mining, but there are still significant challenges to be addressed in terms of trajectory tracking. This study proposes a kinematic strategy to improve the trajectory-tracking performance of a PASTRo (Passively Articulated Suspension based Track-typed mobile robot), which comprises four tracks, two rockers, a differential gear, and a main body. Due to the difficulties in explicitly identifying track-terrain contact angles, suspension kinematics is used to identify track-terrain contact angles (TTCA) in arbitrarily rough terrains. Thus, the TTCA-based driving velocity projection method is proposed in this study to improve the maneuverability of PASTRo in arbitrarily rough terrains. The RecurDyn-Simulink co-simulator is used to examine the improvement of PASTRo compared to a tracked mobile robot non-suspension version. The results indicate that PASTRo has a 33.3% lower RMS(Root Mean Square) distance error, 56.3% lower RMS directional error, and 43.2% lower RMS offset error than the four-track skid-steer mobile robot (SSMR), even with planar SSMR kinematics. To improve the maneuverability of PASTRo without any information on the rough terrain, the TTCA is calculated from the suspension kinematics, and the TTCA obtained is used for both TTCA-based driving velocity projection methods. The results show that PASTRo, with the TTCA-based driving velocity projection method, has a 39.2% lower RMS distance error, 57.9% lower RMS directional error, and 51.9% lower RMS offset error than the four-track SSMR.
Marine Compounds from the Far Eastern Organisms
Authors: Dyshlovoy Sergey A. , Malyarenko Timofey V. , Zhuravleva Olesya I. , Tomoda Hiroshi , Zhidkov Maxim E.
Published: February 2023

The term “Far East” implies a huge geographical region that consists of Eastern and Southeastern Asia, Eastern Russia and includes the waters of two oceans—the Pacific and Indian [...]
Anion Effect on Forward Osmosis Performance of Tetrabutylphosphonium-Based Draw Solute Having a Lower Critical Solution Temperature
Authors: Moon Jihyeon , Kang Hyo
Published: February 2023

The applicability of ionic liquids (ILs) as the draw solute in a forward osmosis (FO) system was investigated through a study on the effect of the structural change of the anion on the FO performance. This study evaluated ILs composed of tetrabutylphosphonium cation ([P4444]+) and benzenesulfonate anion ([BS]−), para-position alkyl-substituted benzenesulfonate anions (p-methylbenzenesulfonate ([MBS]−) and p-ethylbenzenesulfonate ([EBS−]), and methanesulfonate anion ([MS]−). The analysis of the thermo-responsive properties suggested that the [P4444][MBS] and [P4444][EBS] ILs have lower critical solution temperatures (LCSTs), which play a beneficial role in terms of the reusability of the draw solute from the diluted draw solutions after the water permeation process. At 20 wt% of an aqueous solution, the LCSTs of [P4444][MBS] and [P4444][EBS] were approximately 36 °C and 25 °C, respectively. The water flux and reverse solute flux of the [P4444][MBS] aqueous solution with higher osmolality than [P4444][EBS] were 7.36 LMH and 5.89 gMH in the active-layer facing the draw solution (AL-DS) mode at osmotic pressure of 25 atm (20 wt% solution), respectively. These results indicate that the [P4444]+-based ionic structured materials with LCST are practically advantageous for application as draw solutes.
Effect of the Synthesis Route on the Microstructure of HfxTi(1−x)NbVZr Refractory High-Entropy Alloys
Authors: Moussa Maria , Gorsse Stéphane , Huot Jacques , Bobet Jean Louis
Published: February 2023

In the present work, the effects of (i) Ti replacement by Hf and (ii) the synthesis method on microstructure and crystal structure evolution in the high-entropy alloy HfxTi(1−x)NbVZr are reported. The results of scanning electron microscopy and X-ray diffraction analysis of alloys prepared by both arc-melting and induction-melting are compared with theoretical thermodynamic calculations using the CALPHAD approach. The non-equilibrium thermodynamic calculations agree well with the experimental observations for the arc-melted alloys: a mixture of body-centered cubic (BCC) and cubic C15 Laves phases occurs for low-Ti-concentration alloys and a single BCC phase is obtained for high-Ti alloys. The agreement is not as good when using the induction-melting method: equilibrium solidification calculations predict that the most stable state is a phase mixture of BCC, hexagonal close-packed, and a cubic C15 Laves phase, while experimentally only one BCC and one hexagonal C14 Laves phase were found. The estimation of the exact cooling rate and the lack of a thermodynamic database can explain the difference. In addition, for both methods, the thermodynamic calculation confirms that for a high Ti concentration, the BCC phase is stable, whereas phase separation is enhanced with a higher Hf concentration.
Investigating the Effect of Ni Loading on the Performance of Yttria-Stabilised Zirconia Supported Ni Catalyst during CO2 Methanation
Authors: Omoregbe Osaze , Majewski Artur J. , Steinberger-Wilckens Robert , El-kharouf Ahmad
Published: February 2023

CO2 methanation was studied on Ni-based yttria-stabilised zirconia (Ni/YSZ) catalysts. The catalysts were prepared by the wet impregnation method, where the amount of Ni content was varied from 5% to 75%. Thereafter, the prepared catalysts were analysed by BET, XRD, SEM and H2-TPR. BET results showed an initial increase in the surface area with an increase in Ni loading, then a decrease after 30% Ni loading. The XRD results revealed that the Ni crystallite size increased as the Ni loading increased, while the H2-TPR showed a shift in reduction peak temperature to a higher temperature, indicating that the reducibility of the catalysts decreased as the Ni loading increased. The activity of the synthesised catalysts for CO2 methanation was studied by passing a mixture of H2, CO2 and N2 with a total flow of 135 mL min−1 and GHSV of 40,500 mL h−1 g−1 through a continuous flow quartz tube fixed-bed reactor (I.D. = 5.5 mm, wall thickness = 2 mm) containing 200 mg of the catalyst at a temperature range of 473 to 703 K under atmospheric pressure and a H2:CO2 ratio of 4. The tested Ni/YSZ catalysts showed an improvement in activity as the reaction temperature increased from 473 K to around 613 to 653 K, depending on the Ni loading. Beyond the optimum temperature, the catalyst’s activity started to decline, irrespective of the Ni loading. In particular, the 40% Ni/YSZ catalyst displayed the best performance, followed by the 30% Ni/YSZ catalyst. The improved activity at high Ni loading (40% Ni) was attributed to the increase in hydrogen coverage and improved site for both H2 and CO2 adsorption and activation.
InGaN Laser Diodes with Etched Facets for Photonic Integrated Circuit Applications
Authors: Gibasiewicz Krzysztof , Kafar Anna , Schiavon Dario , Saba Kiran , Marona Łucja , Kamińska Eliana , Perlin Piotr
Published: February 2023

The main objective of this work is to demonstrate and validate the feasibility of fabricating (Al, In) GaN laser diodes with etched facets. The facets are fabricated using a two-step dry and wet etching process: inductively coupled plasma—reactive ion etching in chlorine, followed by wet etching in tetramethylammonium hydroxide (TMAH). For the dry etching stage, an optimized procedure was used. For the wet etching step, the TMAH temperature was set to a constant value of 80 °C, and the only variable parameter was time. The time was divided into individual steps, each of 20 min. To validate the results, electro-optical parameters were measured after each step and compared with a cleaved reference, as well as with scanning electron microscope imaging of the front surface. It was determined that the optimal wet etching time was 40 min. For this time, the laser tested achieved a fully comparable threshold current (within 10%) with the cleaved reference. The described technology is an important step for the future manufacturing of photonic integrated circuits with laser diodes integrated on a chip and for ultra-short-cavity lasers.
Incidence and Risk Factors for Clostridioides difficile Infections in Non-COVID and COVID-19 Patients: Experience from a Tertiary Care Hospital
Authors: Markovic-Denic Ljiljana , Nikolic Vladimir , Toskovic Borislav , Brankovic Marija , Crnokrak Bogdan , Popadic Viseslav , Radojevic Aleksandra , Radovanovic Dusan , Zdravkovic Marija
Published: February 2023

(1) Background: The aim of this study was to assess the incidence and the risk factors for healthcare-associated Clostridioides difficile infection (HA-CDI) in patients with COVID-19 and without this infection. (2) Methods: A single-center, prospective observational study was conducted at the University Clinical Hospital Center in Belgrade, Serbia, from January 2019 to December 2021. The entire hospital was a COVID-dedicated hospital for 12 months during the study period. The incidence density rates and risk factors for HA-CDI in patients with and without COVID-19 are presented. (3) Results: The incidence rates of HA-CDIs were three times higher in patients with COVID-19. The HA-CDI–COVID-patients were younger (69.9 ± 12.6 vs. 72.5 ± 11.6; p = 0.017), admitted from another hospital (20.5% vs. 2.9; p < 0.001), had antimicrobial therapy before CDI (99.1% vs. 91.3%, p < 0.001), received two or more antibiotics (p = 0.030) during a longer period (p = 0.035), received proton pump inhibitors (95.9% vs. 50.0%, p < 0.001) during a longer period (p = 0.012) and steroids (32.8% vs. 20.4%, p < 0.001). During the last month before their current hospitalization, a higher percentage of patients without COVID-19 disease were hospitalized in our hospital (p < 0.001). Independent predictors for HA-CDIs in patients with COVID-19 were admission from another hospital (p = 0.003), the length of antibiotic administration (0.020), and the use of steroids in therapy (p < 0.001). The HA-CDI predictors in the non-COVID patients were older age (p = 0.017), advanced-stage renal failure (p = 0.005), chemotherapy (p = 0.003), and a low albumin level (0.005). (4) Conclusion: Higher incidence rates of HAI-CDIs in COVID-19 patients did not occur due to reduced infection control precautions and hygiene measures but due to antibiotic therapy and therapy with other drugs used during the pandemic.
Exploring the Potential of Sustainable Acid Whey Cheese Supplemented with Apple Pomace and GABA-Producing Indigenous Lactococcus lactis Strain
Authors: Mileriene Justina , Serniene Loreta , Kasparaviciene Beatrice , Lauciene Lina , Kasetiene Neringa , Zakariene Gintare , Kersiene Milda , Leskauskaite Daiva , Viskelis Jonas , Kourkoutas Yiannis , Malakauskas Mindaugas
Published: February 2023

This study aimed to utilize two by-products, acid whey and apple pomace, as well as an indigenous Lactococcus lactis LL16 strain with the probiotic potential to produce a sustainable cheese with functional properties. Acid whey protein cheese was made by thermocoagulation of fresh acid whey and enhancing the final product by adding apple pomace, L. lactis LL16 strain, or a mixture of both. The sensory, the physicochemical, the proteolytic, and the microbiological parameters were evaluated during 14 days of refrigerated storage. The supplementation of the cheese with apple pomace affected (p ≤ 0.05) the cheese composition (moisture, protein, fat, carbohydrate, and fiber), the texture, the color (lightness, redness, and yellowness), and the overall sensory acceptability. The addition of the presumptive probiotic L. lactis LL16 strain decreased (p ≤ 0.05) the concentration of glutamic acid, thus increasing γ-aminobutyric acid (GABA) significantly in the acid whey cheese. The supplementation with apple pomace resulted in slightly (p < 0.05) higher counts of L. lactis LL16 on day seven, suggesting a positive effect of apple pomace components on strain survival. The symbiotic effect of apple pomace and LL16 was noted on proteolysis (pH 4.6-soluble nitrogen and free amino acids) in the cheese on day one, which may have positively influenced the overall sensory acceptance.
Colonization and Healthcare-Associated Infection of Carbapenem-Resistant Enterobacteriaceae, Data from Polish Hospital with High Incidence of Carbapenem-Resistant Enterobacteriaceae, Does Active Target Screening Matter?
Authors: Pawłowska Iwona , Ziółkowski Grzegorz , Jachowicz-Matczak Estera , Stasiowski Michał , Gajda Mateusz , Wójkowska-Mach Jadwiga
Published: February 2023

The objective of the study was to analyse the incidence of carbapenem-resistant Enterobacteriaceae (CRE) at a provincial hospital from 2019–2021. Multiplex PCR was used to detect the presence of carbapenemase genes. There were 399 cases of CRE detected in total in the analysed period, including 104 healthcare-associated infections. Out of the isolated CRE, 97.7% were Klebsiella pneumoniae with OXA-48 or KPC genes. Overall, among the identified CRE genes, the most frequently present genes were the ones mediating oxacillinase OXA-48 (71%) and KPC (26%), and significantly less often New Delhi NDM metallo-β-lactamase (2.5%). Moreover, two isolates produced two carbapenemases, i.e., OXA-48 and KPC. The conducted research demonstrates that there is a constant need for continuous monitoring of the occurrence of CRE strains and the hospital antibiotic policy, as well as the implementation of procedures to prevent CRE transmission by medical personnel and hospital support staff.
Performance of Composite Portland Cements with Calcined Illite Clay and Limestone Filler Produced by Industrial Intergrinding
Authors: Irassar Edgardo F. , Bonavetti Viviana L. , Cordoba Gisela P. , Rahhal Viviana F. , Castellano Claudia Cristina , Donza Horacio A.
Published: February 2023

The performance of five composite Portland cements (CPCs) with limestone filler (LF = 10%–25% by mass) and calcined illite clay (CIC = 10%–25% by mass) elaborated by intergrinding was analyzed in paste, mortar, and concrete. Hydration was studied by isothermal calorimetry, bound water, and XRD. Flow and compressive strength (2 to 90 days) were determined in standard mortar. Concretes (w/b = 0.45; binder content = 350 kg/m3; slump = 15 ± 3 cm) were elaborated to determine compressive and flexural strength, water penetration, and chloride migration. Intergrinding CPCs have a large specific surface area when LF + CIC increases, with a similar size range of clinker particles. Supplementary cementing material replacements decreased the heat rate, prolonged the dormant period, and decreased the acceleration rate at early ages. According to the Fratini test, all CPCs had positive pozzolanicity after 28 days, but XRD analysis showed Ca(OH)2 associated with monocarboaluminate phases. Mortar flow was slightly reduced when the proportion of CIC was increased. Mortar strength decreased when the sum of LF + CIC increased. CPC strength class was limited by compressive strength after 28 days. Concretes were workable, and the compressive strength after 28 days depended on the LF + CIC, and CIC contributed after 90 days. After 28 days, the water penetration depended mainly on the LF + CIC content. The chloride migration coefficient was also reduced when CPC contained more CIC and less LF.
Frothing Performance of Frother-Collector Mixtures as Determined by Dynamic Foam Analyzer and Its Implications in Flotation
Authors: Batjargal Khandjamts , Guven Onur , Ozdemir Orhan , Karakashev Stoyan I. , Grozev Nikolay A. , Boylu Feridun , Çelik Mehmet Sabri
Published: February 2023

In recent years, most of the studies have been adapted to determine the optimum conditions for the flotation of very fine minerals. In this context, besides parameters such as particle size, morphology, and pH, the effects of frother type and its concentration present a very significant role in optimizing the flotation conditions. Therefore, the effects of froth stability during flotation can be considered one of the most important issues. Considering that knowledge in mind, in this study, the foamability and froth decay rate of six frothers (PPG200, PPG400, PPG600, BTEG, BTPG, and BDPG) having different molecular weights but similar polyglycol structures were investigated. In addition, methyl isobutyl carbinol (MIBC) which is a well-known frother type in the industry was also used as a reference. Additionally, a series of tests were also performed in the presence of collectors (Dodecylamine hydrochloride, DAH, and sodium oleate, NaOL) + frother mixtures to mimic the flotation conditions. The results of these tests indicated that the bubble size became finer at even low concentrations of PPG600 and PPG400 frothers. Following that, a significant decrease in bubble size was also found for the collector + frother mixtures system regardless of the concentration of the frothers.
Citrus Waste as Source of Bioactive Compounds: Extraction and Utilization in Health and Food Industry
Authors: Maqbool Zahra , Khalid Waseem , Atiq Hafiz Taimoor , Koraqi Hyrije , Javaid Zaryab , Alhag Sadeq K. , Al-Shuraym Laila A. , Bader D. M. D. , Almarzuq Mohammed , Afifi Mohamed , AL-Farga Ammar
Published: February 2023

The current research was conducted to extract the bioactive compounds from citrus waste and assess their role in the development of functional foods to treat different disorders. The scientific name of citrus is Citrus L. and it belongs to the Rutaceae family. It is one of the most important fruit crops that is grown throughout the world. During processing, a large amount of waste is produced from citrus fruits in the form of peel, seeds, and pomace. Every year, the citrus processing industry creates a large amount of waste. The citrus waste is composed of highly bioactive substances and phytochemicals, including essential oils (EOs), ascorbic acid, sugars, carotenoids, flavonoids, dietary fiber, polyphenols, and a range of trace elements. These valuable compounds are used to develop functional foods, including baked products, beverages, meat products, and dairy products. Moreover, these functional foods play an important role in treating various disorders, including anti-aging, anti-mutagenic, antidiabetic, anti-carcinogenic, anti-allergenic, anti-oxidative, anti-inflammatory, neuroprotective, and cardiovascular-protective activity. EOs are complex and contain several naturally occurring bioactive compounds that are frequently used as the best substitutes in the food industry. Citrus essential oils have many uses in the packaging and food safety industries. They can also be used as an alternative preservative to extend the shelf lives of different food products.
Experimental and DFT Research on the Effects of O2/CO2 and O2/H2O Pretreatments on the Combustion Characteristics of Char
Authors: Zhang Lei , Xu Jie , Sun Rui , Wang Zhuozhi , Wang Xingyi , Yuan Mengfan , Wu Jiangquan
Published: February 2023

The use of a coal-based energy structure generates a large amount of CO2 and NOx. The numerous emissions from these agents result in acid rain, photochemical smog, and haze. This environmental problem is considered one of the greatest challenges facing humankind in this century. Preheating combustion technology is considered an essential method for lowering the emissions of CO2 and NO. In this research, the char prepared from O2/CO2 and O2/H2O atmospheres was employed to reveal the effects of the addition of an oxidizing agent on the combustion characteristics of char. The structural features and combustion characteristics of preheated chars were determined by Raman, temperature-programmed desorption (TPD), and non-isothermal, thermo-gravimetric (TGA) experiments. According to the experimental results, the addition of oxidizing agents promoted the generation of smaller aromatic ring structures and oxygen-containing functional groups. The improvement in the surface physicochemical properties enhanced the reactivity of char and lowered its combustion activation energy. Furthermore, the combustion mechanisms of the char prepared from the O2/CO2 and O2/H2O atmospheres were investigated using the density functional theory (DFT). The simulation results illustrated that the combustion essence of char could be attributed to the migration of active atoms, the fracture of the benzene ring structure, and the reorganization of new systems. The addition of oxidizing agents weakened the conjugated components of the aromatic ring systems, promoting the successive decomposition of CO and NO. The results of this study can provide a theoretical basis for regulating the reaction atmosphere in the preheating process and promoting the development of clean combustion for high-rank coals.
Analysis of Furan and Its Derivatives in Food Matrices Using Solid Phase Extraction Coupled with Gas Chromatography-Tandem Mass Spectrometry
Authors: Tsao Wen-Xuan , Chen Bing-Huei , Lin Pinpin , You Shu-Han , Kao Tsai-Hua
Published: February 2023

The objective of this study was to develop a simultaneous analysis method of furan and its 10 derivatives in different food commodities. The results indicated that furan and its 10 derivatives could be separated within 9.5 min by using a HP-5MS column and gas chromatography–tandem mass spectrometry (GC-MS/MS) with multiple reaction monitoring mode for detection. Furthermore, this method could resolve several furan isomers, such as 2-methyl furan and 3-methyl furan, as well as 2,3-dimethyl furan and 2,5-dimethyl furan. The most optimal extraction conditions were: 5 g of the fruit or juice sample mixed with 5 mL of the saturated NaCl solution, separately, or 1 g of the canned oily fish sample mixed with 9 mL of the saturated NaCl solution, followed by the equilibration of each sample at 35 °C for 15 min, using a carboxen-polydimethylsiloxane SPME arrow to adsorb the analytes for 15 min at 35 °C for subsequent analysis by GC-MS/MS. For method validation of all the analytes in the different food matrices, the recovery was 76–117% and the limit of the quantitation was 0.003–0.675 ng/g, while the relative standard deviation (RSD%) of the intra-day variability range from 1–16%, and that of the inter-day variability was from 4–20%. The method validation data further demonstrated that a reliable method was established for the analysis of furan and its 10 derivatives in commercial foods.
Rapid LC-MS/MS Bosutinib Quantification with Applications in Metabolic Stability Estimation
Authors: Attwa Mohamed W. , Alanazi Mohammed M.
Published: February 2023

Bosutinib (BOS) is FDA approved drug for the treatment of chronic phase (CP) Philadelphia chromosome-positive (Ph+) chronic myelogenous leukemia (CML). We report a fast, sensitive, and simple LC-MS/MS method, validated for the determination of BOS in human liver microsomes, utilizing tofacitinib (TOF) as the internal standard. The separation of BOS and TOF was done using a 1.8 μm C18 column (2.1 × 50 mm) at room temperature using the isocratic elution system of acetonitrile–water (30:70, v/v) containing 0.1 M formic acid at a flow rate of 0.15 mL/min, and a triple-quadrupole tandem mass spectrometer (TQD-MS) with an electrospray ionization (ESI) source that was operated in the positive ion mode. The method was validated according to the European Medicines Agency, and the rapid and specific quantification of BOS in human liver microsomes was achieved in the range of 5–200 ng/mL, with a determination coefficient of 0.999. Intra- and inter-day accuracy and precision values were <4% in all cases. The procedure is rapid, specific, reliable, and can be applied in metabolic stability evaluations since it is the first LC-MS/MS method specific to BOS quantification. The metabolic stability assessment of BOS showed high CLint (34.3 µL/min/mg) and short in vitro t1/2 values of 20.21 min, indicating that BOS may be rapidly eliminated from the blood by the liver.
NO2 Physical-to-Chemical Adsorption Transition on Janus WSSe Monolayers Realized by Defect Introduction
Authors: Ju Lin , Tang Xiao , Li Xiaoxi , Liu Bodian , Qiao Xiaoya , Wang Zhi , Yin Huabing
Published: February 2023

As is well known, NO2 adsorption plays an important role in gas sensing and treatment because it expands the residence time of compounds to be treated in plasma–catalyst combination. In this work, the adsorption behaviors and mechanism of NO2 over pristine and Se-vacancy defect-engineered WSSe monolayers have been systematically investigated using density functional theory (DFT). The adsorption energy calculation reveals that introducing Se vacancy acould result in a physical-to-chemical adsorption transition for the system. The Se vacancy, the most possible point defect, could work as the optimum adsorption site, and it dramatically raises the transferred-electron quantities at the interface, creating an obviously electronic orbital hybridization between the adsorbate and substrate and greatly improving the chemical activity and sensing sensitivity of the WSSe monolayer. The physical-to-chemical adsorption transition could meet different acquirements of gas collection and gas treatment. Our work broadens the application filed of the Janus WSSe as NO2-gas-sensitive materials. In addition, it is found that both keeping the S-rich synthetic environments and applying compression strain could make the introduction of Se vacancy easier, which provides a promising path for industrial synthesis of Janus WSSe monolayer with Se vacancy.
Recent Advances in the Synthesis of 3,n-Fused Tricyclic Indole Skeletons via Palladium-Catalyzed Domino Reactions
Authors: Fan Liangxin , Zhu Xinxin , Liu Xingyuan , He Fangyu , Yang Guoyu , Xu Cuilian , Yang Xifa
Published: February 2023

3,n-fused (n = 4–7) tricyclic indoles are pervasive motifs, embedded in a variety of biologically active molecules and natural products. Thus, numerous catalytic methods have been developed for the synthesis of these skeletons over the past few decades. In particular, palladium-catalyzed transformations have received much attention in recent years. This review summarizes recent developments in the synthesis of these tricyclic indoles with palladium-catalyzed domino reactions and their applications in the total synthesis of representative natural products.
Safe and Effective Antioxidant: The Biological Mechanism and Potential Pathways of Ergothioneine in the Skin
Authors: Liu Hui-Min , Tang Wei , Wang Xiao-Yi , Jiang Jing-Jing , Zhang Wei , Wang Wei
Published: February 2023

Ergothioneine, a sulfur-containing micromolecular histidine derivative, has attracted increasing attention from scholars since it was confirmed in the human body. In the human body, ergothioneine is transported and accumulated specifically through OCTN-1, especially in the mitochondria and nucleus, suggesting that it can target damaged cells and tissues as an antioxidant. It shows excellent antioxidant, anti-inflammatory effects, and anti-aging properties, and inhibits melanin production. It is a mega antioxidant that may participate in the antioxidant network system and promote the reducing glutathione regeneration cycle. This review summarizes studies on the antioxidant effects of ergothioneine on various free radicals in vitro to date and systematically introduces its biological activities and potential mechanisms, mostly in dermatology. Additionally, the application of ergothioneine in cosmetics is briefly summarized. Lastly, we propose some problems that require solutions to understand the mechanism of action of ergothioneine. We believe that ergothioneine has good prospects in the food and cosmetics industries, and can thus meet some needs of the health and beauty industry.
Urea Decomposition Mechanism by Dinuclear Nickel Complexes
Authors: Martins Christian O. , Sebastiany Leticia K. , Lopez-Castillo Alejandro , Freitas Rafael S. , Andrade Leandro H. , Toma Henrique E. , Netto Caterina G. C. Marques
Published: February 2023

Urease is an enzyme containing a dinuclear nickel active center responsible for the hydrolysis of urea into carbon dioxide and ammonia. Interestingly, inorganic models of urease are unable to mimic its mechanism despite their similarities to the enzyme active site. The reason behind the discrepancy in urea decomposition mechanisms between inorganic models and urease is still unknown. To evaluate this factor, we synthesized two bis-nickel complexes, [Ni2L(OAc)] (1) and [Ni2L(Cl)(Et3N)2] (2), based on the Trost bis-Pro-Phenol ligand (L) and encompassing different ligand labilities with coordination geometries similar to the active site of jack bean urease. Both mimetic complexes produced ammonia from urea, (1) and (2), were ten- and four-fold slower than urease, respectively. The presence and importance of several reaction intermediates were evaluated both experimentally and theoretically, indicating the aquo intermediate as a key intermediate, coordinating urea in an outer-sphere manner. Both complexes produced isocyanate, revealing an activated water molecule acting as a base. In addition, the reaction with different substrates indicated the biomimetic complexes were able to hydrolyze isocyanate. Thus, our results indicate that the formation of an outer-sphere complex in the urease analogues might be the reason urease performs a different mechanism.
Activity and Thermal Aging Stability of La1−xSrxMnO3 (x = 0.0, 0.3, 0.5, 0.7) and Ir/La1−xSrxMnO3 Catalysts for CO Oxidation with Excess O2
Authors: Drosou Catherine , Nikolaraki Ersi , Nikolaou Vasilios , Koilia Evangelia , Artemakis Georgios , Stratakis Antonios , Evdou Antigoni , Charisiou Nikolaos D. , Goula Maria A. , Zaspalis Vasilios , Yentekakis Ioannis V.
Published: February 2023

The catalytic oxidation of CO is probably the most investigated reaction in the literature, for decades, because of its extended environmental and fundamental importance. In this paper, the oxidation of CO on La1−xSrxMnO3 perovskites (LSMx), either unloaded or loaded with dispersed Ir nanoparticles (Ir/LSMx), was studied in the temperature range 100–450 °C under excess O2 conditions (1% CO + 5% O2). The perovskites, of the type La1−xSrxMnO3 (x = 0.0, 0.3, 0.5 and 0.7), were prepared by the coprecipitation method. The physicochemical and structural properties of both the LSMx and the homologous Ir/LSMx catalysts were evaluated by various techniques (XRD, N2 sorption–desorption by BET-BJH, H2-TPR and H2-Chem), in order to better understand the structure–activity–stability correlations. The effect of preoxidation/prereduction/aging of the catalysts on their activity and stability was also investigated. Results revealed that both LSMx and Ir/LSMx are effective for CO oxidation, with the latter being superior to the former. In both series of materials, increasing the substitution of La by Sr in the composition of the perovskite resulted to a gradual suppression of their CO oxidation activity when these were prereduced; the opposite was true for preoxidized samples. Inverse hysteresis phenomena in activity were observed during heating/cooling cycles on the prereduced Ir/LSMx catalysts with the loop amplitude narrowing with increasing Sr-content in LSMx. Oxidative thermal sintering experiments at high temperatures revealed excellent antisintering behavior of Ir nanoparticles supported on LSMx, resulting from perovskite’s favorable antisintering properties of high oxygen storage capacity and surface oxygen vacancies.
Synthesis of MnSe-Based GO Composites as Effective Photocatalyst for Environmental Remediations
Authors: Jevtovic Violeta , Khan Afaq Ullah , Almarhoon Zainab M. , Tahir Kamran , Latif Salman , Abdulaziz Fahad , Albalawi Karma , Zaki Magdi E. A. , Rakic Violeta
Published: February 2023

In this work, a manganese selenide/graphene oxide (MnSe/GO)-based composite was prepared for wet-chemical assisted method against organic dye; herein, methylene blue (MB) dye removal from the water was employed as a metal selenide-based photocatalyst. The synthesized MnSe/GO composite was systematically characterized by X-ray diffraction (XRD), Fourier transform electron microscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and UV-visible diffuse reflectance spectroscopy (UV-vis. DRS). The structural characteristic revealed the adequate synthesis of the sample with good crystallinity and purity of the obtained products. The morphological analysis indicates the formation of MnSe nanoflakes composed of tiny particles on their surface. At the same time, the GO nanosheets with high aggregation were formed, which may be due to the van der Waals forces. The bond interaction and compositional analysis studies confirmed and supported the structural findings with high purity. The optical analysis showed the bandgap energies of MnSe and their composites MnSe (1.7 eV), 7% GO-MnSe (2.42 eV), 14% GO-MnSe (2.6 eV), 21% GO-MnSe (3.02 eV), and 28% GO-MnSe (3.24 eV) respectively, which increase the bandgap energy after GO and MnSe recombination. Among different contents, the optimized 21% GO-MnSe composite displayed enhanced photocatalytic properties. For instance, a short time of 90 min was taken compared with other concentrations due to the narrow bandgap of MnSe and the highly conductive charge carrier’s support, making the process to remove MB from water faster. These results show that the selenide-based photocatalyst can be an attractive candidate for future advanced photocatalysis applications.