bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of JFET Region Design and Gate Oxide Thickness on the Static and Dynamic Performance of 650 V SiC Planar Power MOSFETs
Authors: Zhu Shengnan , Liu Tianshi , Fan Junchong , Maddi Hema Lata Rao , White Marvin H. , Agarwal Anant K.
Published: August 2022

650 V SiC planar MOSFETs with various JFET widths, JFET doping concentrations, and gate oxide thicknesses were fabricated by a commercial SiC foundry on two six-inch SiC epitaxial wafers. An orthogonal P+ layout was used for the 650 V SiC MOSFETs to reduce the ON-resistance. The devices were packaged into open-cavity TO-247 packages for evaluation. Trade-off analysis of the static and dynamic performance of the 650 V SiC power MOSFETs was conducted. The measurement results show that a short JFET region with an enhanced JFET doping concentration reduces specific ON-resistance (Ron,sp) and lowers the gate-drain capacitance (Cgd). It was experimentally shown that a thinner gate oxide further reduces Ron,sp, although with a penalty in terms of increased Cgd. A design with 0.5 μm half JFET width, enhanced JFET doping concentration of 5.5×1016 cm−3, and thin gate oxide produces an excellent high-frequency figure of merit (HF-FOM) among recently published studies on 650 V SiC devices.
Nanomechanics of Retained Austenite in Medium-Carbon Low-Temperature Bainitic Steel: A Critical Analysis of a One-Step versus a Two-Step Treatment
Authors: Zhou Songbo , Hu Feng , Wang Kun , Hu Chengyang , Zhou Wen , Yershov Serhii , Wu Kaiming , Zhang Zhicheng , Pan Xianming
Published: August 2022

A two-step bainitic treatment with a final isothermal temperature below MS was adopted to obtain bainitic steel with abundant retained austenite (RA). Nanoindentation testing was used to investigate the stability of RA in bainite steel and clarify the effect of RA on the deformation of medium-carbon steel. The results showed that, in contrast to the traditional one-step approach, a greater amount of nanoscale RA film was obtained using the two-step treatment. This was due to a lower final bainitic transformation temperature, which induced a higher carbon concentration in the untransformed austenite in the stasis stage; this resulted in untransformed austenite with a higher carbon content existing as RA rather than forming martensite in the subsequent cooling process. In addition, it was determined that the increased stability of RA during the two-step transformation delayed the pop-in point.
Development of a Portland Cement-Based Material with Agave salmiana Leaves Bioaggregate
Authors: Rosas-Díaz Felipe , García-Hernández David Gilberto , Mendoza-Rangel José M. , Terán-Torres Bernardo T. , Galindo-Rodríguez Sergio Arturo , Juárez-Alvarado Cesar A.
Published: August 2022

Depending on the morphology of the natural fibers, they can be used as reinforcement to improve flexural strength in cement-based composites or as aggregates to improve thermal conductivity properties. In this last aspect, hemp, coconut, flax, sunflower, and corn fibers have been used extensively, and further study is expected into different bioaggregates that allow diversifying of the raw materials. The objective of the research was to develop plant-based concretes with a matrix based on Portland cement and an aggregate of Agave salmiana (AS) leaves, obtained from the residues of the tequila industry that have no current purpose, as a total replacement for the calcareous aggregates commonly used in the manufacturing of mortars and whose extraction is associated with high levels of pollution, to improve their thermal properties and reduce the energy demand for air conditioning in homes. Characterization tests were carried out on the raw materials and the vegetal aggregate was processed to improve its compatibility with the cement paste through four different treatments: (a) freezing (T/C), (b) hornification (T/H), (c) sodium hydroxide (T/NaOH), and (d) solid paraffin (T/P). The effect of the treatments on the physical properties of the resulting composite was evaluated by studying the vegetal concrete under thermal conductivity, bulk density, and compressive strength tests with a volumetric ratio between the vegetal aggregate and the cement paste of 0.36 and a water/cement ratio of 0.35. The hornification treatment showed a 15.2% decrease in the water absorption capacity of the aggregate, resulting in a composite with a thermal conductivity of 0.49 W/mK and a compressive strength of 8.66 MPa, which allows its utilization as a construction material to produce prefabricated blocks.
Effect of Bonding Protocols on the Performance of Luting Agents Applied to CAD–CAM Composites
Authors: Hilgemberg Bruna , Siqueira Fabiana Suelen Figuerêdo de , Cardenas Andres Felipe Millan , Ribeiro Josiane Loch , Dávila-Sánchez Andrés , Sauro Salvatore , Loguercio Alessandro Dourado , Arrais Cesar Augusto Galvao
Published: August 2022

This in vitro study aimed to evaluate the effect of different bonding strategies on the micro-shear bond strength (μSBS) of luting agents to CAD–CAM composites. Surface scanning electron microscopy (SEM) and spectroscopy by energy-dispersive X-ray spectroscopy (EDS) were performed to analyze the surfaces of the composite before and after bonding treatment. Three CAD–CAM composites were evaluated: Lava Ultimate restorative (LU), Brava Blocks (BR), and Vita Enamic (VE). The LU and BR surfaces were sandblasted using aluminum oxide, while the VE surfaces were etched using a 5% hydrofluoric acid gel according to the manufacturers’ recommendations. All surfaces were subjected to the following bonding strategies (n = 15): adhesive with silane and MDP (ScotchBond Universal, 3M Oral Care, St Paul, MI, USA); adhesive with MDP (Ambar Universal, FGM, Joinville, Brazil); adhesive without silane or MDP (Prime&Bond Elect, Dentsply Sirona, Charlotte, NC, USA), pure silane without MDP (Angelus, Londrina, Brazil), and pure silane with MDP (Monobond N, Ivoclar Vivadent, Schaan, Liechtenstei). Afterwards, tygons were filled with RelyX Ultimate (3M Oral Care), AllCem (FGM), or Enforce (Dentsply Sirona), which were light-cured and subjected to the μSBS test. Data were analyzed using two-way ANOVA and Bonferroni’s post hoc test (α = 0.05). Additional blocks (n = 15) were subjected to scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) before and after the surface treatment. The μSBS values on VE surfaces were higher than those observed on LU and BR surfaces (p < 0.001). Silane without MDP (Allcem) promoted the highest μSBS values, while silane with MDP (RelyX Ultimate) provided the highest values among all bonding strategies (p < 0.001). Enforce promoted no significant difference in μSBS values. SEM and EDS analyses detected noticeable changes to the surface morphology and composition after the surface treatment. The effectiveness of the bonding strategy may vary according not only to the CAD–CAM composite but also to resin cement/bonding agent/silane used.
Deep Learning-Based Software Defect Prediction via Semantic Key Features of Source Code—Systematic Survey
Authors: Abdu Ahmed , Zhai Zhengjun , Algabri Redhwan , Abdo Hakim A. , Hamad Kotiba , Al-antari Mugahed A.
Published: August 2022

Software defect prediction (SDP) methodology could enhance software’s reliability through predicting any suspicious defects in its source code. However, developing defect prediction models is a difficult task, as has been demonstrated recently. Several research techniques have been proposed over time to predict source code defects. However, most of the previous studies focus on conventional feature extraction and modeling. Such traditional methodologies often fail to find the contextual information of the source code files, which is necessary for building reliable prediction deep learning models. Alternatively, the semantic feature strategies of defect prediction have recently evolved and developed. Such strategies could automatically extract the contextual information from the source code files and use them to directly predict the suspicious defects. In this study, a comprehensive survey is conducted to systematically show recent software defect prediction techniques based on the source code’s key features. The most recent studies on this topic are critically reviewed through analyzing the semantic feature methods based on the source codes, the domain’s critical problems and challenges are described, and the recent and current progress in this domain are discussed. Such a comprehensive survey could enable research communities to identify the current challenges and future research directions. An in-depth literature review of 283 articles on software defect prediction and related work was performed, of which 90 are referenced.
Beta-Blocker Use after Discharge in Patients with Acute Myocardial Infarction in the Contemporary Reperfusion Era
Authors: Hu Mengjin , Hu Song , Gao Xiaojin , Yang Yuejin
Published: August 2022

Background and objectives: The effect of beta-blocker use after discharge on patients with acute myocardial infarction (AMI) in the contemporary reperfusion era remains ambiguous. By applying meta-analysis, we sought to assess the role of beta-blockers in the contemporary reperfusion era. Materials and Methods: Randomized controlled trials (RCT) and observational studies using propensity score matching, comparing use of beta-blockers with non-use of beta-blockers, in patients with AMI after discharge. The primary outcome was all-cause mortality. Odds ratios (OR) and associated 95% confidence intervals (CI) were calculated. Results: One RCT and eight observational studies, containing 47,339 patients with AMI, were included. Compared with non-use of beta-blockers, beta-blocker use after discharge may have reduced the risk of all-cause mortality (OR: 0.70, 95% CI: 0.61 to 0.80, I2 = 14.4%), cardiac death (OR: 0.63, 95% CI: 0.44 to 0.91, I2 = 22.8%), myocardial infarction (OR: 0.73, 95% CI: 0.62 to 0.86, I2 = 0), and revascularization (OR: 0.92, 95% CI: 0.85 to 0.99, I2 = 0). No significant differences were found in major adverse cardiovascular events (MACE, OR: 0.88, 95% CI: 0.66 to 1.17, I2 = 78.4%), heart failure (OR: 0.56, 95% CI: 0.29 to 1.08, I2 = 0) or stroke (OR: 1.13, 95% CI: 0.92 to 1.39, I2 = 0). For patients with preserved left ventricular function, beta-blocker use after discharge may have also reduced the risk of all-cause mortality (OR: 0.61, 95% CI: 0.44 to 0.84, I2 = 0). Conclusions: Use of beta-blockers after discharge may still be beneficial for AMI patients in the contemporary reperfusion era, with or without preserved left ventricular function.
Factors Related to the Progression of Clinically Isolated Syndrome to Multiple Sclerosis: A Retrospective Study in Lithuania
Authors: Balnytė Renata , Matijošaitis Vaidas , Čelpačenko Ieva , Malciūtė Miglė , Stankevičiūtė Radvilė , Laucius Ovidijus
Published: August 2022

Background and Objectives: Multiple sclerosis (MS) is a demyelinating disease which usually manifests as clinically isolated syndrome (CIS). Approximately 70% of patients with CIS progress to MS. Therefore, there is a pressing need to identify the most accurate predictive factors of CIS developing into MS, some of which could be a clear clinical phenotype of early MS as well as lesions in magnetic resonance imaging (MRI), pathological findings in cerebrospinal fluid (CSF) and evoked potentials (EP) tests. The problem is of outstanding importance since early MS diagnosis and treatment prevents long-term disability. The aim of our study is to analyze the factors that could influence the progression of CIS to MS. Materials and Methods: This study is a retrospective data analysis which included patients with their primary CIS diagnosis between 1st January 2015 and 1st January 2020. The prevalence and predictive value of clinical symptoms, MRI lesions, pathological CSF and EP findings were evaluated in accordance with the final diagnosis and compared between the sexes and age groups. Results: Out of 138 CIS patients, 49 (35.5%) patients progressed to MS. MS patients were more likely to have a diminished sense of vibration and proprioception (χ2 = 9.033, p = 0.003) as well as spinal cord MRI lesions (χ2 = 7.209, p = 0.007) in comparison with the non-MS group. Positive oligoclonal bands (OCBs) in CSF (χ2 = 34.859, p ≤ 0.001) and pathological brainstem auditory evoked potential (BAEP) test findings (χ2 = 10.924, p ≤ 0.001) were more prevalent in the MS group. Diminished sense of vibration and proprioception increased the risk for developing MS by 13 times (p = 0.028), whereas positive OCBs in CSF increased the risk by 100 times (p < 0.001). MS patients that were older than 50 years were more likely to exhibit positive Babinski’s reflex (χ2 = 6.993, p = 0.03), decreased muscle strength (χ2 = 13.481, p = 0.001), ataxia (χ2 = 8.135, p = 0.017), and diminished sense of vibration and proprioception (χ2 = 7.918, p = 0.019) in comparison with both younger age groups. Conclusions: Diminished sense of vibration and proprioception, spinal cord MRI lesions, positive OCBs and pathological BAEP test findings were more common among patients that developed MS. Diminished sense of vibration and proprioception along with positive CSF OCBs are predictors of CIS progressing to MS. Older patients that develop MS have more symptoms in general, such as positive Babinski’s reflex, decreased muscle strength, ataxia, and diminished sense of vibration and proprioception.
Initial Data and a Clinical Diagnosis Transition for the Aiginition Longitudinal Biomarker Investigation of Neurodegeneration (ALBION) Study
Authors: Scarmeas Nikolaos , Daskalaki Argyro , Kalligerou Faidra , Ntanasi Eva , Mamalaki Eirini , Gargalionis Antonios N. , Patas Kostas , Chatzipanagiotou Stylianos , Yannakoulia Mary , Constantinides Vasilios C.
Published: August 2022

Background and Objectives: This article presents data from the ongoing Aiginition Longitudinal Biomarker Investigation of Neurodegeneration study (ALBION) regarding baseline clinical characterizations and CSF biomarker profiles, as well as preliminary longitudinal data on clinical progression. Materials and Methods: As of March 2022, 138 participants who either were cognitively normal (CN, n = 99) or had a diagnosis of mild cognitive impairment (MCI, n = 39) had been recruited at the specialist cognitive disorders outpatient clinic at Aiginition Hospital. Clinical characteristics at baseline were provided. These patients were followed annually to determine progression from CN to MCI or even dementia. CSF biomarker data (amyloid β1-42, phosphorylated tau at threonine 181, and total tau) collected using automated Elecsys® assays (Roche Diagnostics) were available for 74 patients. These patients were further sorted based on the AT(N) classification model, as determined by CSF Aβ42 (A), CSF pTau (T), and CSF tTau (N). Results: Of the 49 CN patients with CSF biomarker data, 21 (43%) were classified as exhibiting “Alzheimer’s pathologic change” (A+Τ– (Ν)−) and 6 (12%) as having “Alzheimer’s disease” (A+T–(N)+, A+T+(N)–, or A+T+(N)+). Of the 25 MCI patients, 8 (32%) displayed “Alzheimer’s pathologic change”, and 6 (24%) had “Alzheimer’s disease”. A total of 66 individuals had a mean follow-up of 2.1 years (SD = 0.9, min = 0.8, max = 3.9), and 15 of those individuals (22%) showed a clinical progression (defined as a worsening clinical classification, i.e., from CN to MCI or dementia or from MCI to dementia). Overall, participants with the “AD continuum” AT(N) biomarker profile (i.e., A+T–(N)–, A+T–(N)+, A+T+(N)–, and A+T+(N)+) were more likely to clinically progress (p = 0.04). Conclusions: A CSF “AD continuum” AT(N) biomarker profile is associated with an increased risk of future clinical decline in CN or MCI subjects.
Association of Parathyroid and Differentiated Thyroid Carcinomas: A Narrative Up-To-Date Review of the Literature
Authors: Simescu Razvan , Pop Miana , Piciu Andra , Muntean Valentin , Piciu Doina
Published: August 2022

Aim: Parathyroid carcinoma (PC) is a rare endocrine malignancy that represents 0.005% of all malignant tumors. Associated PC and differentiated thyroid carcinoma (DTC) is an exceptionally rare condition, and the preoperative diagnostics and proper treatment are challenging. Almost all PCs and the majority of DTCs are diagnosed postoperatively, making correct surgical treatment questionable. Specific guidelines for parathyroid and thyroid carcinomas association treatment are lacking. The purposes of our study were to identify the association between parathyroid and thyroid carcinomas, to analyze the available published data, and to evaluate the possible relationship between preoperative diagnostic and surgical decision-making, and outcome-related issues. Material and methods: We performed a literature review of several databases from the earliest records to March 2022, using controlled vocabulary and keywords to search for records on the topic of PC and WDTC pathological association. The reference lists from the initially identified articles were analyzed to obtain more references. Results: We identified 25 cases of PC and DTC association, 14 more than the latest review from 2021. The mean age of patients was 55, with a female to male ratio of about 3:1. Exposure to external radiation was identified in only one patient, although it is considered a risk factor the development of both PC and DTC. The preoperative suspicion of PC was stated by the authors in only 25% of cases, but suspicion based on clinical, laboratory, ultrasound (US), and fine needle aspiration (FNA) criteria could have been justified in more than 50% of them. With neck ultrasound, 40% of patients presented suspicious features both for PC and thyroid carcinoma. Intra-operatory descriptions of the lesions revealed the highest suspicion (83.3%) of PC, but en bloc resection was recommended and probably performed in only about 50% of the cases. Histopathological examinations of the thyroid revealed different forms of papillary thyroid carcinoma (PTC) in most cases. Postoperative normocalcemia was achieved in 72% of patients, but follow-up data was missing in about 25% of cases. Conclusion: Associated PC and DTC is an exceptionally rare condition, and the preoperative diagnostic and treatment of the patients is a challenge. However, in most cases pre- and intraoperative suspicious features are present for identification by a highly specialized multidisciplinary endocrine team, who can thus perform the optimal treatment to achieve curability.
Ultra-Selective CMSMs Derived from Resorcinol-Formaldehyde Resin for CO2 Separation
Authors: Rahimalimamaghani Arash , Pacheco Tanaka David Alfredo , Llosa Tanco Margot A. , Neira D’Angelo Maria Fernanda , Gallucci Fausto
Published: August 2022

A resorcinol-formaldehyde precursor was synthesized to fabricate the CO2 selective Carbon Molecular Sieve Membranes (CMSMs) developed in this study. The degree of polymerization (DP) was analyzed via Gel Permeation Chromatography (GPC) and its effect on the CO2/N2 perm-selectivity and CO2 permeance was investigated. The membrane that was polymerized at 80 °C (named R80) was selected as the best performing CMSM after a preliminary test. The post treatment with oxidative atmosphere was performed to increase the CO2 permeance and CO2/N2 perm-selectivity on membrane R80. The gas permeation results and Pore Size Distribution (PSD) measurements via perm-porometry resulted in selecting the membrane with an 80 °C polymerization temperature, 100 min of post treatment in 6 bar pressure and 120 °C with an oxygen concentration of 10% (named R80T100) as the optimum for enhancing the performance of CMSMs. The 3D laser confocal microscopy results confirmed the reduction in the surface roughness in post treatment on CMSMs and the optimum timing of 100 min in the treatment. CMSM R80T100 exhibiting CO2/N2 ideal selectivity of 194 at 100 °C with a CO2 permeability of 4718 barrier was performed higher than Robeson’s upper bound limit for polymeric membranes and also the other CMSMs fabricated in this work.
Optimization of CO2/H2 Separation over Ba-SAPO-34 Zeolite Membrane Synthesized by Microwave Heating
Authors: Ng Tiffany Yit Siew , Viriya Vinosha , Chew Thiam Leng , Yeong Yin Fong , Ahmad Abdul Latif , Ho Chii-Dong , Jawad Zeinab Abbas
Published: August 2022

CO2/H2 separation using membrane technology is an important research area in order to obtain high purity hydrogen as one source of clean energy. Finding a suitable inorganic membrane is one of the critical issues, which needs to be explored for CO2/H2 separation. In the present study, Ba-SAPO-34 zeolite membrane was synthesized and followed by a modification process. CO2/H2 separation of the membrane was investigated by varying the independent process variables (CO2 % in the feed, pressure difference across the membrane and temperature). Modeling and optimization for the responses (CO2/H2 separation selectivity and CO2 permeance) was performed by applying response surface methodology and central composite design, which is available in Design Expert software. The accuracy of the models in predicting the response was tested by comparing with the experimental value of response and the two values were in good agreement. The optimization of the models gave CO2 permeance of 19.23 × 10−7 mol/m2 s Pa and CO2/H2 separation selectivity of 11.6 at 5% CO2 in the feed, a pressure difference of 100 kPa, and temperature of 30 °C for Ba-SAPO-34 zeolite membrane.
Online Detection of Keyhole Status in a Laser-MIG Hybrid Welding Process
Authors: Fan Xi’an , Gao Xiangdong , Huang Yuhui , Zhang Yanxi
Published: August 2022

During laser-metal inert gas (MIG) hybrid welding, a large amount of welding status information is generated in droplet transfer, keyhole and molten pool. In this paper, austenitic stainless steel was adopted as an experimental object, with a dual high-speed camera system used to obtain real-time images of droplet transfer, keyhole and molten pool in a laser-MIG hybrid welding process. The changing regulation of a keyhole in three different penetration states (i.e., non-penetration, partial penetration and normal penetration) was analyzed by extracting the morphological characteristics of a keyhole shape, and combining the droplet transition information and the shape of the weld pool. Experimental results show that the proposed method could effectively reflect the variation characteristics of the keyhole, and the correlation among the keyhole characteristics, the droplet transfer information, the weld pool shape and the welding status, and provide a new perspective for online detection of the laser-MIG welding quality.
Suitability of Eroded Particles from Die-Sink Electro Discharge Machining for Additive Manufacturing—Review, Characterization and Processing
Authors: Voigt Oliver , Peuker Urs Alexander
Published: August 2022

In this bipartite study, waste products of die-sink electro discharge machining (die-sink EDM) are investigated. EDM is based on an erosive character of discharges leading to material removal and molten material congeals in the dielectric. The aim is to show a theoretical suitability of these particles for a further usage as a secondary, recycled material in additive manufacturing (AM). Due to the energy- and cost-intensive process of gas atomization for AM powders, there is a need for alternative concepts for particle generation. The first part deals with an intensive review of references from the literature regarding particle size and circularity using image analysis. Secondly, real waste streams were investigated after washing and cleaning processes for oil removal via laser diffraction, dynamic image analysis, SEM with energy dispersive X-ray spectroscopy (EDX) as well as optical emission spectroscopy (ICP OES), categorized within the literature and compared to commercial AM powders. In general, it could be shown that, in principle, recycled particles fulfill main requirements for an AM usage regarding size and shape. Reference powders show median particle sizes of 30 µm to 34 µm and circularities of 0.90 to 0.93, whereas eroded particles exhibit an x50 value of 27 µm and circularity of 0.90, too. However, chemical purity, mainly caused by carbon contamination (5.4 wt% in eroded powder compared to 0.4 wt% in reference powder), must be improved before printing via AM machines. Additionally, several separation techniques have to be applied to remove undesired elements (alumina).
Effect of Solution Heat Treatment by Induction on UNS S31803 Duplex Stainless Steel Joints Welded with the Autogenous TIG Process
Authors: Ferreira Paula Munier , Pereira Elaine Cristina , Pinheiro Flávia Wagner , Monteiro Sergio Neves , Azevedo Afonso R. G.
Published: August 2022

In the oil and gas industry, the manufacture of equipment using materials that resist aggressive media is one of the greatest challenges. UNS S31803 duplex stainless steel is widely used for this purpose owing to its good combination of mechanical and corrosion resistance. The objective of this work was to evaluate the effect of induction solution heat treatment using autogenous TIG welding on UNS S31803 DSS sheets. Sheet samples were subjected to two different treatment parameters for a duration of 10 s and at temperatures of 1050 and 1150 °C. The results obtained with the treatments were compared with those of the as-welded condition, which was the reference condition. Quantitative and qualitative analyses of the samples were carried out, in addition to microstructural characterization using confocal microscopy and a corrosion resistance study as per ASTM G48 standard. We observed that the best results were obtained with a treatment of 10 s at 1150 °C, which was able to eliminate chromium nitrides and re-establish the proper balance of the ferrite and austenite phases. In addition, the treatment was able to reduce hardness and provide welds free of cracks and discontinuities, also presenting a low corrosion rate.
Microstructure, Mechanical Properties and Fire Resistance of High Strength Mg-Gd-Y-Zr Alloys
Authors: Qian Yafeng , Zhao Yanhui , Dong Xiaorui , Yu Wei , Feng Jianhang , Yu Hui
Published: August 2022

With the lightest green structural material for 21st century, a significant weight reduction effect was expected to solve the lightweight problem in aerospace and other fields. However, the material’s poor mechanical properties and flammability limited its widely application in such fields. In this paper, the GWK series alloys (Mg-5.3Gd-4.11Y-0.13Zr, Mg-5.5Gd-4.22Y-0.19Zr, and Mg-5.46Gd-4.02Y-0.20Zr, in wt.%) were designed, and we explored the effect of alloy composition and process on the microstructure and properties of GWK series alloys subject to casting, homogenization, extrusion, ageing and ignition. The result show that Mg-5.3Gd-4.11Y-0.13Zr alloy after T4 treatment at 500 °C/6 h obtains an excellent solid solution effect. In addition, the aged alloy shows a good balance of mechanical properties, a tensile strength of 405 MPa, yield strength of 275 MPa, as well as elongation of 8.12%, and excellent non-flammability.
Microbiologically Influenced Corrosion Mechanism of Ferrous Alloys in Marine Environment
Authors: Khan M. Saleem , Liang Tao , Liu Yuzhi , Shi Yunzhu , Zhang Huanhuan , Li Hongyu , Guo Shifeng , Pan Haobo , Yang Ke , Zhao Ying
Published: August 2022

In marine environments, microbial attacks on metallic materials result in microbiologically influenced corrosion (MIC), which could cause severe safety accidents and high economic losses. To date, MIC of a number of metallic materials ranging from common steels to corrosion-resistant ferrous alloys has been reported. The MIC process has been explained based on (1) bio-catalyzed oxygen reduction; (2) kinetics alternation of the corrosion process by increasing the mass transport of the reactants and products; (3) production of corrosive substances; and (4) generation of auxiliary cathodic reactants. However, it is difficult to have a clear understanding of the MIC mechanism of ferrous alloys due to the interdisciplinary nature of MIC and lack of deep knowledge about the interfacial reaction between the biofilm and ferrous alloys. In order to better understand the effect of the MIC process on ferrous alloys, here we comprehensively summarized the process of biofilm formation and MIC mechanisms of ferrous alloys.
Impact of Processing on the Creep Properties of High Performance Ferritic (HiperFer) Steels
Authors: Kuhn Bernd , Talik Michal
Published: August 2022

High performance ferritic (HiperFer) stainless steels constitute a new class of low-cost, heat resistant, hardenable materials which combine high creep and fatigue strength with increased steam oxidation and wet corrosion resistance. The fundamental relationships regarding the alloy composition, microstructure, and resulting mechanical properties are largely known and already published, while relevant commercialization issues, such as the effect of processing on the microstructure, have not yet been addressed. The current paper outlines the impact of the forming parameters on the resulting microstructure and the achievable creep properties. Thermomechanical treatment is demonstrated as an effective method for increasing the creep strength for a given chemical composition. This may constitute a key enabler for cost savings in component production, e.g., for the simple machining of “drop-in” turbine blades or bolts from forged bar stock material.
Machine Learning Algorithm to Predict Obstructive Coronary Artery Disease: Insights from the CorLipid Trial
Authors: Panteris Eleftherios , Deda Olga , Papazoglou Andreas S. , Karagiannidis Efstratios , Liapikos Theodoros , Begou Olga , Meikopoulos Thomas , Mouskeftara Thomai , Sofidis Georgios , Sianos Georgios , Theodoridis Georgios , Gika Helen
Published: August 2022

Developing risk assessment tools for CAD prediction remains challenging nowadays. We developed an ML predictive algorithm based on metabolic and clinical data for determining the severity of CAD, as assessed via the SYNTAX score. Analytical methods were developed to determine serum blood levels of specific ceramides, acyl-carnitines, fatty acids, and proteins such as galectin-3, adiponectin, and APOB/APOA1 ratio. Patients were grouped into: obstructive CAD (SS > 0) and non-obstructive CAD (SS = 0). A risk prediction algorithm (boosted ensemble algorithm XGBoost) was developed by combining clinical characteristics with established and novel biomarkers to identify patients at high risk for complex CAD. The study population comprised 958 patients (CorLipid trial (NCT04580173)), with no prior CAD, who underwent coronary angiography. Of them, 533 (55.6%) suffered ACS, 170 (17.7%) presented with NSTEMI, 222 (23.2%) with STEMI, and 141 (14.7%) with unstable angina. Of the total sample, 681 (71%) had obstructive CAD. The algorithm dataset was 73 biochemical parameters and metabolic biomarkers as well as anthropometric and medical history variables. The performance of the XGBoost algorithm had an AUC value of 0.725 (95% CI: 0.691–0.759). Thus, a ML model incorporating clinical features in addition to certain metabolic features can estimate the pre-test likelihood of obstructive CAD.
Research on Metal Corrosion Resistant Bioinspired Special Wetting Surface Based on Laser Texturing Technology: A Review
Authors: Zhang Li , Tan Zheng , Zhang Chong , Tang Jingrong , Yao Chi , You Xiangyu , Hao Bo
Published: August 2022

Metal substrates are widely used in engineering production. However, material life reduction and economic loss due to chemical and electrochemical corrosion are a major problem facing people. Electrochemical corrosion is the main corrosion mode of metals, such as seawater corrosion. It is found that the superhydrophobic surface treated by laser texturing plays an important role in the corrosion resistance of the substrate, with the laser texturing process and post-treatment affecting the corrosion resistance. The corrosion resistance is positively correlated with the superhydrophobic property of the surface. For the mechanism of corrosion resistance, this paper summarizes the effect of micro-nano structure, surface-modified coating, oxidation layer or new product layer, surface inhomogeneity, crystal structure, and slippery surface on corrosion resistance. Superhydrophobic surface and slippery surface are two common types of bioinspired, special wetting surfaces. In order to prepare better superhydrophobic and corrosion-resistant surfaces, this paper summarizes the selection and optimization of laser parameters, surface structure, processing media, and post-treatment from the point of view of mechanism and law. In addition, after summarizing the corrosion resistance mechanism, this paper introduces a series of characterization experiments that can measure the corrosion resistance, providing a reference for preparation and evaluation of the surface.
Investigation of the Combined Effect of Total Ionizing Dose and Time-Dependent Dielectric Breakdown on PDSOI Devices
Authors: Yang Jianye , Liu Hongxia , Yang Kun
Published: August 2022

The combined effect of total ionization dose (TID) and time-dependent dielectric breakdown (TDDB) of partially depleted silicon-on-insulator (PDSOI) NMOSFET is investigated. First, the effect of TDDB on the parameter degradation of the devices was investigated by accelerated stress tests. It is found that TDDB stress leads to a decrease in off-state current, a positive drift in threshold voltage, and a reduction of maximum transconductance. Next, the degradation patterns of TID effect on the devices are obtained. The results show that the parameter degradation due to gamma radiation is opposite to the TDDB stress. Finally, the combined effect of TID and TDDB is investigated. It is found that the drift of the devices’ sensitive parameters due to TDDB stress decreases in a total dose of gamma radiation environment. The TDDB lifetime is shortened, but the pattern of gate current change remains unchanged. The failure mechanism of the gate oxide layer under TDDB stress is not changed after irradiation.
Lysinibacillus sp. GG242 from Cattle Slurries Degrades 17β-Estradiol and Possible 2 Transformation Routes
Authors: Wu Sicheng , Hao Peng , Gou Changlong , Zhang Xiqing , Wang Lixia , Basang Wangdui , Zhu Yanbin , Gao Yunhang
Published: August 2022

Environmental estrogen pollution has long been a concern due to adverse effects on organisms and ecosystems. Biodegradation is a vital way to remove estrogen, a strain of Lysinibacillus sp. was isolated, numbered strain GG242. The degradation rate of 100 mg·L−1 17β-estradiol (E2)) > 95% in one week, and compared with extracellular enzymes, intracellular enzymes have stronger degradation ability. Strain GG242 can maintain a stable E2 degradation ability under different conditions (20–35 °C, pH 5–11, salinity 0–40 g·L−1). Under appropriate conditions (30 °C, pH 8, 1 g·L−1 NaCl), the degradation rate increased by 32.32% in one week. Based on the analysis of transformation products, inferred E2 was converted via two distinct routes. Together, this research indicates the degradation potential of strain GG242 and provides new insights into the biotransformation of E2.
Genetic Relationship between Granite and Fluorite Mineralization in the Shuanghuajiang Fluorite Deposit, Northern Guangxi, South China: Evidence from Geochronology, REE, and Fluid Geochemistry
Authors: Li Gen , Fang Guicong , Feng Zuohai , Xu Cheng , Huang Zhennan , Wang Chunzeng
Published: August 2022

Hydrothermal vein-type fluorite deposits are the most important metallogenic type of fluorite deposits in South China, most of which are closely related to granitoid in space; however, the genetic relationship between granitoid and fluorite mineralization remains controversial. The Shuanghuajiang fluorite deposit in northern Guangxi of South China is a typical vein-type fluorite deposit hosted in a granite pluton, with the orebodies occurring within brittle faults. Zircon U-Pb dating of the hosting Xiangcaoping granite yields an emplacement age of 228.04 ± 0.76 Ma (MSWD = 0.072). Fluorite Sm-Nd dating yields an isochron age of 185 ± 18 Ma. The new age data indicate that the fluorite deposit was precipitated significantly later than the emplacement of the hosting Xiangcaoping granite pluton. The fluorite and granite exhibit similar rare earth element (REE) patterns with negative Eu anomalies, suggesting that fluorine (F) was derived from the granite. The fluorite fluid inclusions show a homogeneous temperature mainly ranging between 165 °C and 180 °C. Salinity is typically less than 1% NaCl eqv, while the δ18OV-SMOW and δDV-SMOW values are between −5.2‰–−6.1‰ and −17.35‰–−23.9‰, respectively. These indicate that the ore-forming fluids were a NaCl-H2O system with medium-low temperature and low salinity, which is typical for meteoric water. Given the combined evidence of geochronology, REE, and fluid geochemistry, the mineralization of the Shuanghuajiang fluorite deposit is unrelated to magmatic-hydrothermal activity but achieved via hydrothermal circulation and leaching mechanisms. Our study presents a genetic relationship between the fluorite deposit and granitoids based on an example of northern Guangxi, providing a better understanding of the genesis of hydrothermal vein-type fluorite deposits in granitoids outcropping areas.
The Migration of Cd in Granitic Residual Soil and Marine Clay: Batch and Column Studies
Authors: Zarime Nur Aishah , Solemon Badariah , Wan Yaacob Wan Zuhairi , Che Omar Rohayu
Published: August 2022

Due to the world’s population growth, excessive solid waste generation is a serious environmental issue. The landfill leachate infiltrates the soils, pollutes the groundwater, and puts all living things at risk. This study investigates the geotechnical properties of the soils (marine clay and granitic residual soil) and the migration of cadmium (Cd) using a high-speed centrifuge column test. All soil samples were subjected to physicochemical, morphology and mineralogy properties analyses, including the determination of their particle size distribution, Atterberg limits, specific gravity, compaction, permeability, pH, organic content, cation exchange capacity (CEC) and specific surface area (SSA). They were also subjected to analyses by X-ray diffraction (XRD) and scanning electron microscope (SEM). This research utilizes two types of adsorption tests: batch tests and column infiltration tests. For the Batch test, the elimination percentage of Cd in marine clay was up to 86% (SBMC2) to 98% (SBMC1) at an initial value of 75 mg/L. While the granitic residual soil showed the maximum removal percentages of Cd were 39% (KGR) to 47% (BGR). For the column infiltration test, the soils were subjected to different g-force, (i.e., 10× g and 20× g) and two different soil weights (i.e., 10 and 20 g of soils). The study revealed that marine clay (partition coefficient, Kd = 10–23 L/Kg) has better adsorption on Cd compared to granitic residual soils (Kd = 0.6 to 0.9 L/Kg). The study also concludes that marine clay (SBMC) is one of the natural clay-based energy materials which can effectively use as an engineered clay liner.
Effects of NaOH Content on the Reduction Kinetics of Hematite by Using Suspension Magnetization Roasting Technology
Authors: Yuan Shuai , Li Xinyu , Wang Xun , Zhang Hao , Li Yanjun
Published: August 2022

Red mud is a potential iron resource that needs to be urgently exploited and utilized. However, due to the properties of high alkalinity, fine particle size and complex mineral composition, the utilization of red mud is difficult. Focusing on red mud’s prominent feature of high alkalinity, this paper studies the influence of NaOH content on the reduction kinetics of hematite, which is the main component of red mud. The results show that the conversion degree of hematite was strongly inhibited by NaOH, and the magnetization and specific magnetic susceptibility of reduction products was significantly decreased with the increase in NaOH content. Meanwhile, the results of the calculation of kinetics parameters demonstrate that the addition of NaOH did not affect the control step of the reduction of hematite, while it dramatically decreased the reduction rate of hematite. Moreover, thermodynamic analysis and SEM-EDS detection were conducted to uncover the inhibited mechanism of NaOH on the reduction of hematite, which indicated that sodium ferrite could be produced spontaneously under the experimental conditions and that it is hard for it to be further reduced by CO. Furthermore, the produced sodium ferrite formed a dense film, which covered the surface of the hematite particles, inhibiting the diffusion of CO and thereby hindering the reduction of the interior hematite.
The Molecular Weaponry Produced by the Bacterium Hafnia alvei in Foods
Authors: Ramos-Vivas José , Tapia Olga , Elexpuru-Zabaleta María , Pifarre Kilian Tutusaus , Armas Diaz Yasmany , Battino Maurizio , Giampieri Francesca
Published: August 2022

Hafnia alvei is receiving increasing attention from both a medical and veterinary point of view, but the diversity of molecules it produces has made the interest in this bacterium extend to the field of probiotics, the microbiota, and above all, to its presence and action on consumer foods. The production of Acyl Homoserine Lactones (AHLs), a type of quorum-sensing (QS) signaling molecule, is the most often-studied chemical signaling molecule in Gram-negative bacteria. H. alvei can use this communication mechanism to promote the expression of certain enzymatic activities in fermented foods, where this bacterium is frequently present. H. alvei also produces a series of molecules involved in the modification of the organoleptic properties of different products, especially cheeses, where it shares space with other microorganisms. Although some strains of this species are implicated in infections in humans, many produce antibacterial compounds, such as bacteriocins, that inhibit the growth of true pathogens, so the characterization of these molecules could be very interesting from the point of view of clinical medicine and the food industry. Lastly, in some cases, H. alvei is responsible for the production of biogenic amines or other compounds of special interest in food health. In this article, we will review the most interesting molecules that produce the H. alvei strains and will discuss some of their properties, both from the point of view of their biological activity on other microorganisms and the properties of different food matrices in which this bacterium usually thrives.
Effects of Supplemental Light Spectra on the Composition, Production and Antimicrobial Activity of Ocimum basilicum L. Essential Oil
Authors: Chu Ha Thi Thu , Vu Thi Nghiem , Dinh Thuy Thi Thu , Do Phat Tien , Chu Ha Hoang , Tien Tran Quoc , Tong Quang Cong , Nguyen Manh Hieu , Ha Quyen Thi , Setzer William N.
Published: August 2022

This study was performed to investigate the effects of different supplemental light spectra and doses (duration and illuminance) on the essential oil of basil (Ocimum basilicum L.) cultivated in the net-house in Vietnam during four months. Ten samples of basil aerial parts were hydrodistilled to obtain essential oils which had the average yields from 0.88 to 1.30% (v/w, dry). The oils analyzed using GC-FID and GC-MS showed that the main component was methyl chavicol (87.4–90.6%) with the highest values found in the oils of basil under lighting conditions of 6 h/day and 150–200 µmol·m−2·s−1. Additional lighting conditions caused the significant differences (p < 0.001) in basil biomass and oil production with the highest values found in the oils of basil under two conditions of (1) 71% Red: 20% Blue: 9.0% UVA in at 120 μmol·m−2·s−1 in 6 h/day and (2) 43.5% Red: 43.5% Blue: 8.0% Green: 5.0% Far-Red at 100 μmol·m−2·s−1 in 6 h/day. The oils of basil in some formulas showed weak inhibitory effects on only the Bacillus subtilis strain. Different light spectra affect the biomass and essential oil production of basil, as well as the concentrations of the major components in the oil.
A Highly Selective and Sensitive Fluorescent Sensor Based on Molecularly Imprinted Polymer-Functionalized Mn-Doped ZnS Quantum Dots for Detection of Roxarsone in Feeds
Authors: Li Fei , Gao Jie , Wu Haocheng , Li Yijun , He Xiwen , Chen Langxing
Published: August 2022

Roxarsone (ROX) as an organoarsenic feed additive has been widely used in livestock breeding and poultry industry, but ROX can degrade into highly toxic inorganic arsenic species in natural environments to threaten to the environment and human health. Therefore, there is a considerable interest in developing convenient, selective and sensitive methods for the detection of ROX in livestock breeding and poultry industry. In this work, a fluorescent molecularly imprinted polymer (MIPs) probe based on amino-modified Mn-ZnS quantum dots (QDs) has been developed by sol–gel polymerization for specific recognition of ROX. The synthesized MIPs-coated Mn-ZnS QDs (MIPs@Mn-ZnS QDs) have highly selective recognition sites to ROX because there are multi-interactions among the template ROX, functional monomer phenyltrimethoxysilane and the amino-functionalized QDs such as the π–π conjugating effect, hydrogen bonds. Under the optimal conditions, an obvious fluorescence quenching was observed when ROX was added to the solution, and the quenching mechanism could be explained as the photo-induced electron transfer. The MIPs@Mn-ZnS QDs sensor exhibited sensitive response to ROX in the linear range from 3.75 × 10−8 M to 6.25 × 10−7 M (R2 = 0.9985) and the limit of detection down to 4.34 nM. Moreover, the fluorescence probe has been applied to the quantitative detection of ROX in feed samples, and the recovery was in the range of 91.9% to 108.0%. The work demonstrated that the prepared MIPs@Mn-ZnS QDs probe has a good potential for rapid and sensitive determination of ROX in complicated samples.
Chlorophyll Detection by Localized Surface Plasmon Resonance Using Functionalized Carbon Quantum Dots Triangle Ag Nanoparticles
Authors: Nazri Nur Afifah Ahmad , Azeman Nur Hidayah , Bakar Mohd Hafiz Abu , Mobarak Nadhratun Naiim , Aziz Tg Hasnan Tg Abd , Zain Ahmad Rifqi Md , Arsad Norhana , Luo Yunhan , Bakar Ahmad Ashrif A.
Published: August 2022

An optical sensor-based localized surface plasmon resonance (LSPR) sensor was demonstrated for sensitive and selective chlorophyll detection through the integration of amino-functionalized carbon quantum dots (NCQD) and triangle silver nanoparticles (AgNPs). The additions of amino groups to the CQD enhance the detection of chlorophyll through electrostatic interactions. AgNPs-NCQD composite was fabricated on the surface of the silanized glass slide using the self-assembly technique. The experimental results showed that the AgNPs-NCQD film-based LSPR sensor detects better than AgNPs and AgNPs-CQD films with a good correlation coefficient (R2 = 0.9835). AgNPs-NCQD showed a high sensitivity response of 2.23 nm ppm−1. The detection and quantification limits of AgNPs-NCQD are 1.03 ppm and 3.40 ppm, respectively, in the range of 0.05 to 6 ppm. Throughout this study, no significant interference was observed among the other ionic species (NO2−, PO4−, NH4+, and Fe3+). This study demonstrates the applicability of the proposed sensor (AgNPs-NCQD) as a sensing material for chlorophyll detection in oceans.
Improved Ferroelectric Properties in Hf0.5Zr0.5O2 Thin Films by Microwave Annealing
Authors: Zhao Biyao , Yan Yunting , Bi Jinshun , Xu Gaobo , Xu Yannan , Yang Xueqin , Fan Linjie , Liu Mengxin
Published: August 2022

In the doped hafnia(HfO2)-based films, crystallization annealing is indispensable in forming ferroelectric phases. In this paper, we investigate the annealing effects of TiN/Hf0.5Zr0.5O2/TiN metal-ferroelectric-metal (MFM) capacitors by comparing microwave annealing (MWA) and rapid thermal annealing (RTA) at the same wafer temperature of 500 °C. The twofold remanent polarization (2Pr) of the MWA device is 63 µC/cm2, surpassing that of the RTA device (40 µC/cm2). Furthermore, the wake-up effect is substantially inhibited in the MWA device. The orthorhombic crystalline phase is observed in the annealed HZO films in the MWA and RTA devices, with a reduced TiN and HZO interdiffusion in MWA devices. Moreover, the MFM capacitors subjected to MWA treatment exhibit a lower leakage current, indicating a decreased defect density. This investigation shows the potential of MWA for application in ferroelectric technology due to the improvement in remanent polarization, wake-up effect, and leakage current.