bluuebunny/crossref_metadata_2025 huggingface dataset:
Practical Aspects of Multiwavelength Analytical Ultracentrifugation
Authors: Pearson Joseph , Cölfen Helmut
Published: March 2019

Open-source Multiwavelength Analytical Ultracentrifugation (MWL-AUC) detection systems have been evolving for over a decade. Continual advances emerging out of several research groups have brought the instrumentation technology to increasingly higher levels of performance. The capabilities of MWL-AUC have been documented in many publications, demonstrating the applicability of broad spectrum absorbance acquisitions in analytical ultracentrifugation to a wide array of scientific fields. Despite numerous examples of the usefulness and unique advantages of MWL-AUC, the adoption of the technology by more research groups has been slow. The complexity of the hardware, integration within an ultracentrifuge platform and lack of practical construction and operational information is the likely source of reluctance. Here, we clearly describe the challenges facing a researcher considering adopting MWL-AUC technology in their own laboratories, and provide the information necessary to implement and operate a MWL-AUC system. The discussion includes details of detector assembly, optical alignment, and acquisition parameter settings necessary to achieve high quality experimental results.
Autologous Matrix-Induced Chondrogenesis (AMIC) and AMIC Enhanced by Autologous Concentrated Bone Marrow Aspirate (BMAC) Allow for Stable Clinical and Functional Improvements at up to 9 Years Follow-Up: Results from a Randomized Controlled Study
Authors: de Girolamo Laura , Schönhuber Herbert , Viganò Marco , Bait Corrado , Quaglia Alessandro , Thiebat Gabriele , Volpi Piero
Published: March 2019

The aims of the study were to evaluate long-term outcomes after autologous matrix-induced chondrogenesis (AMIC) in the treatment of focal chondral lesions and to assess the possible improvements given by the combination of this technique with bone marrow aspirate concentrate (BMAC). Twenty-four patients (age range 18–55 years) affected by focal knee chondral lesions were treated with standard AMIC or AMIC enhanced by BMAC (AMIC+). Pain (Visual Analogue Scale (VAS)) and functional scores (Lysholm, International Knee Documentation Committee (IKDC), Tegner, Knee injury and Osteoarthritis Outcome Score (KOOS)) were collected pre-operatively and then at 6, 12, 24, 60, and 100 months after treatment. Magnetic resonance imaging (MRI) evaluation was performed pre-operatively and at 6, 12, and 24 months follow-ups. Patients treated with AMIC+ showed higher Lysholm scores (p = 0.015) and lower VAS (p = 0.011) in comparison with patients in the standard AMIC group at the 12 months follow-up. Both treatments allowed for functional and pain improvements with respect to pre-operative levels lasting up to 100 months. MRI revealed consistent cartilage repair at 24 months in both groups. This study shows that AMIC and AMIC+ are effective treatments for focal chondral lesions with beneficial effect lasting up to 9 years. AMIC+ allows for faster recovery from injury, and is thus more indicated for patients requiring a prompt return to activity. Level of evidence: II, randomized controlled trial in an explorative cohort.
Long-Term Effects of Initiating Continuous Subcutaneous Insulin Infusion (CSII) and Continuous Glucose Monitoring (CGM) in People with Type 1 Diabetes and Unsatisfactory Diabetes Control
Authors: Senn Jon-Duri , Fischli Stefan , Slahor Lea , Schelbert Susanne , Henzen Christoph
Published: March 2019

Background: We aimed to assess the long-term effects of the introduction of continuous subcutaneous insulin infusion (CSII) and continuous glucose monitoring (CGM) in people with type 1 diabetes (T1D). Methods: A prospective single-centre cohort study including participants with T1D and HbA1c > 7.5%. After completing a course in flexible intensified insulin treatment (FIT), participants were offered treatment change to CSII/CGM. FIT participants with HbA1c ≤ 7.5% who remained on multiple daily injections (MDI) and without CGM were monitored as a separate cohort to compare the cumulative incidence of diabetic complications. Results: The study cohort included 41 participants with T1D (21 male/20 female). The mean age (±SD) at inclusion was 24.2 ± 10.9 years, the mean follow-up was 8.9 ± 2.8 years, and the mean diabetes duration at the end of the study was 15.9 ± 10.1 years. The mean HbA1c level before the introduction of CSII was 8.8 ± 1.3% (73 ± 8 mmol/mol), and decreased significantly thereafter to 8.0 ± 1.1% (63 ± 7 mmol/mol) (p = 0.0001), and further to 7.6 ± 1.1% (59 ± 11 mmol/mol) after the initiation of CGM (p = 0.051). In the MDI group the HbA1c levels did not change significantly during a mean follow-up of 6.8 ± 3.2 years. The frequency of severe hypoglycaemia after the introduction of CSII/CGM declined significantly (from 9.7 to 2.2 per 100 patient-years, p = 0.03), and the cumulative incidence of newly diagnosed diabetic microvascular complications were comparable between the study group and the observational cohort. Conclusion: In people with T1D and unsatisfactory diabetes control the introduction of CSII and CGM results in a substantial and long-term improvement.
Morphodynamic Acceleration Techniques for Multi-Timescale Predictions of Complex Sandy Interventions
Authors: Luijendijk Arjen P. , de Schipper Matthieu A. , Ranasinghe Roshanka
Published: March 2019

Thirty one percent (31%) of the world’s coastline consists of sandy beaches and dunes that form a natural defense protecting the hinterland from flooding. A common measure to mitigate erosion along sandy beaches is the implementation of sand nourishments. The design and acceptance of such a mitigating measure require information on the expected evolution at time scales from storms to decades. Process-based morphodynamic models are increasingly applied, together with morphodynamic acceleration techniques, to obtain detailed information on this wide scale of ranges. This study shows that techniques for the acceleration of the morphological evolution can have a significant impact on the simulated evolution and dispersion of sandy interventions. A calibrated Delft3D model of the Sand Engine mega-nourishment is applied to compare different acceleration techniques, focusing on accuracy and computational times. Results show that acceleration techniques using representative (schematized) wave conditions are not capable of accurately reproducing the morphological response in the first two years. The best reproduction of the morphological behavior of the first five years is obtained by the brute force simulations. Applying input filtering and a compression factor provides similar accuracy yet with a factor five gain in computational cost. An attractive method for the medium to long time scales, which further reduces computational costs, is a method that uses representative wave conditions based on gross longshore transports, while showing similar results as the benchmark simulation. Erosional behavior is captured well in all considered techniques with variations in volumes of about 1 million m 3 after three decades. The spatio-temporal variability of the predicted alongshore and cross-shore distribution of the morphological evolution however have a strong dependency on the selected acceleration technique. A new technique, called ’brute force merged’, which incorporates the full variability of the wave climate, provides the optimal combination of phenomenological accuracy and computational efficiency (a factor of 20 faster than the benchmark brute force technique) at both the short and medium to long time scales. This approach, which combines realistic time series and the mormerge technique, provides an attractive and flexible method to efficiently predict the evolution of complex sandy interventions at time scales from hours to decades.
Molecular Strategies to Diagnose Mucormycosis
Authors: Millon Laurence , Scherer Emeline , Rocchi Steffi , Bellanger Anne-Pauline
Published: March 2019

Molecular techniques have provided a new understanding of the epidemiology of mucormycosis and improved the diagnosis and therapeutic management of this life-threatening disease. PCR amplification and sequencing were first applied to better identify isolates that were grown from cultures of biopsies or bronchalveolar lavage samples that were collected in patients with Mucorales infection. Subsequently, molecular techniques were used to identify the fungus directly from the infected tissues or from bronchalveolar lavage, and they helped to accurately identify Mucorales fungi in tissue samples when the cultures were negative. However, these tools require invasive sampling (biospsy, bronchalveolar lavage), which is not feasible in patients in poor condition in Hematology or Intensive Care units. Very recently, PCR-based procedures to detect Mucorales DNA in non-invasive samples, such as plasma or serum, have proved successful in diagnosing mucormycosis early in all patients, whatever the clinical status, and these procedures are becoming essential to improving patient outcome.
Global Epidemiology of Mucormycosis
Authors: Prakash Hariprasath , Chakrabarti Arunaloke
Published: March 2019

Mucormycosis is an angio-invasive fungal infection, associated with high morbidity and mortality. A change in the epidemiology of mucormycosis has been observed in recent years with the rise in incidence, new causative agents and susceptible population. The rise has been perceived globally, but it is very high in the Asian continent. Though diabetes mellitus overshadow all other risk factors in Asia, post-tuberculosis and chronic renal failure have emerged as new risk groups. The rhino-cerebral form of mucormycosis is most commonly seen in patients with diabetes mellitus, whereas, pulmonary mucormycosis in patients with haematological malignancy and transplant recipients. In immunocompetent hosts, cutaneous mucormycosis is commonly seen following trauma. The intriguing clinical entity, isolated renal mucormycosis in immunocompetent patients is only reported from China and India. A new clinical entity, indolent mucormycosis in nasal sinuses, is recently recognized. The causative agents of mucormycosis vary across different geographic locations. Though Rhizopus arrhizus is the most common agent isolated worldwide, Apophysomyces variabilis is predominant in Asia and Lichtheimia species in Europe. The new causative agents, Rhizopus homothallicus, Mucor irregularis, and Thamnostylum lucknowense are reported from Asia. In conclusion, with the change in epidemiology of mucormycosis country-wise studies are warranted to estimate disease burden in different risk groups, analyse the clinical disease pattern and identify the new etiological agents.
3,6-Dibromopyridazine-4,5-diamine
Authors: Chmovzh Timofey , Knyazeva Ekaterina , Ustimenko Olga , Rakitin Oleg
Published: March 2019

Dihalogenated derivatives of 1,2,5-chalcogenadiazoles fused with benzene or heterocyclic rings are of interest as starting compounds for photovoltaic materials. The 1,2,5-chalcogenadiazole ring in these heterocycles was most commonly prepared from the corresponding ortho-diamine moiety. In this communication, 3,6-dibromopyridazine-4,5-diamine was prepared via the reaction of 4,7-dibromo[1,2,5]thiadiazolo[3,4-d]pyridazine with sodium methoxide in THF by heating at reflux for four hours. The structure of the newly synthesized compound was established by means of high resolution mass-spectrometry, 1H, 13C-NMR and IR spectroscopy, and mass-spectrometry.
Tribological Characterization of Micron-/Nano-Sized WC-9%Co Cemented Carbides Prepared by Spark Plasma Sintering at Elevated Temperatures
Authors: Wohaibi Saleh Al , Mohammed Abdul Samad , Laoui Tahar , Hakeem Abbas Saeed , Adesina Akeem Yusuf , Patel Faheemuddin
Published: March 2019

The present study investigates the high temperature tribological performance of spark plasma sintered, nano- and micron-sized tungsten carbide (WC) bonded by 9 wt.% cobalt (Co). The composites were fabricated using a two-step procedure of mixing followed by spark plasma sintering (SPS). Ball-on-disc wear tests were conducted at a normal load of 30 N, linear speed of 0.1 m/s under dry conditions and at three different temperatures (room temperature, 300 °C and 600 °C). Field emission scanning electron microscopy (FESEM), optical profilometry and energy dispersive X-ray (EDS) spectroscopy were used to analyze the surface morphology and the wear track area. At room temperature, it was observed that the nano-sized WC composites exhibited better wear resistance than the micron-sized WC composites. The wear resistance of the nano-sized samples declined significantly relative to that of the micron-sized samples with an increase in temperature. This decline in performance was attributed to the higher surface area of nano-sized WC particles, which underwent rapid oxidation at elevated temperatures, resulting in poor wear resistance. The wear rate observed at 600 °C for the micron-sized WC composites was 75% lower than that of the nano-sized cemented carbide. Oxidative wear was observed to be the predominant wear mechanism for both cemented carbide samples at elevated temperatures.
Fast Removal of Propranolol from Water by Attapulgite/Graphene Oxide Magnetic Ternary Composites
Authors: Deng Yuehua , Li Yani , Nie Wenjie , Gao Xiang , Zhang Lei , Yang Pengli , Tan Xiaochun
Published: March 2019

In this work, a novel adsorbent attapulgite/graphene oxide magnetic composite (ATP/Fe3O4/GO) was synthesized for removing propranolol (PRO) from aqueous water. The factors affecting the PRO adsorption process onto ATP/Fe3O4/GO including pH, ionic strength, sorbent dosage, and humic acid were systematically investigated by batch experiments. Meanwhile, magnetic attapulgite (ATP/Fe3O4) and magnetic graphene oxide (GO/Fe3O4) were prepared for the comparison of the adsorption performance for PRO. The structural and surface characteristics of the resulting materials were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, zeta potential measurements, and scanning electron microscope. The results showed that the adsorption rate of PRO onto ATP/Fe3O4/GO was up to 99%, faster and higher than that of other adsorbents involved at neutral pH. Moreover, the adsorption kinetics were better fitted with pseudo-first-order kinetic model than the second-order kinetic model. The adsorption data were fitted well with the Freundlich isotherm equations, implying that the adsorption process was heterogeneous. The adsorption reaction was endothermic and spontaneous according to the thermodynamic parameters. All results indicated that ATP/Fe3O4/GO was a promising adsorbent for removing PRO from water.
Removal of Hazardous Oxyanions from the Environment Using Metal-Oxide-Based Materials
Authors: Weidner Ewelina , Ciesielczyk Filip
Published: March 2019

Scientific development has increased the awareness of water pollutant forms and has reawakened the need for its effective purification. Oxyanions are created by a variety of redox-sensitive metals and metalloids. These species are harmful to living matter due to their toxicity, nondegradibility, and mobility in aquatic environments. Among a variety of water treatment techniques, adsorption is one of the simplest, cheapest, and most effective. Since metal-oxide-based adsorbents poses a variety of functional groups onto their surface, they were widely applied in ions sorption. In this paper adsorption of harmful oxyanions by metal oxide-based materials according to literature survey was studied. Characteristic of oxyanions originating from As, V, B, W and Mo, their probable adsorption mechanisms and comparison of their sorption affinity for metal-oxide-based materials such as iron oxides, aluminum oxides, titanium dioxide, manganium dioxide, and various oxide minerals and their combinations are presented in this paper.
Magnetic Field Patterning of Nickel Nanowire Film Realized by Printed Precursor Inks
Authors: Mahajan Chaitanya G. , Alfadhel Ahmed , Irving Mark , Kahn Bruce E. , Borkholder David A. , Williams Scott A. , Cormier Denis
Published: March 2019

This paper demonstrates an easily prepared novel material and approach to producing aligned nickel (Ni) nanowires having unique and customizable structures on a variety of substrates for electronic and magnetic applications. This is a new approach to producing printed metallic Ni structures from precursor materials, and it provides a novel technique for nanowire formation during reduction. This homogeneous solution can be printed in ambient conditions, and it forms aligned elemental Ni nanowires over large areas upon heating in the presence of a magnetic field. The use of templates or subsequent purification are not required. This technique is very flexible, and allows the preparation of unique patterns of nanowires which provides opportunities to produce structures with enhanced anisotropic electrical and magnetic properties. An example of this is the unique fabrication of aligned nanowire grids by overlaying layers of nanowires oriented at different angles with respect to each other. The resistivity of printed and cured films was found to be as low as 560 µΩ∙cm. The saturation magnetization was measured to be 30 emu∙g−1, which is comparable to bulk Ni. Magnetic anisotropy was induced with an axis along the direction of the applied magnetic field, giving soft magnetic properties.
Highly Selective CMOS-Compatible Mid-Infrared Thermal Emitter/Detector Slab Design Using Optical Tamm-States
Authors: Pühringer Gerald , Jakoby Bernhard
Published: March 2019

In this work, we propose and evaluate a concept for a selective thermal emitter based on Tamm plasmons suitable for monolithic on-chip integration and fabrication by conventional complementary metal oxide semiconductor (CMOS)-compatible processes. The original design of Tamm plasmon structures features a purely one-dimensional array of layers including a Bragg mirror and a metal. The resonant field enhancement next to the metal interface corresponding to optical Tamm states leads to resonant emission at the target wavelength, which depends on the lateral dimensions of the bandgap structure. We demonstrate the application of this concept to a silicon slab structure instead of deploying extended one dimensional layers thus enabling coupling into slab waveguides. Here we focus on the mid-infrared region for absorption sensing applications, particularly on the CO2 absorption line at 4.26 µm as an example. The proposed genetic-algorithm optimization process utilizing the finite-element method and the transfer-matrix method reveals resonant absorption in case of incident modes guided by the slab and, by Kirchhoff’s law, corresponds to emittance up to 90% depending on different choices of the silicon slab height when the structure is used as a thermal emitter. Although we focus on the application as an emitter in the present work, the structure can also be operated as an absorber providing adjusted lateral dimensions and/or exchanged materials (e.g., a different choice for metal).
Effect of Process Parameters and High-Temperature Preheating on Residual Stress and Relative Density of Ti6Al4V Processed by Selective Laser Melting
Authors: Malý Martin , Höller Christian , Skalon Mateusz , Meier Benjamin , Koutný Daniel , Pichler Rudolf , Sommitsch Christof , Paloušek David
Published: March 2019

The aim of this study is to observe the effect of process parameters on residual stresses and relative density of Ti6Al4V samples produced by Selective Laser Melting. The investigated parameters were hatch laser power, hatch laser velocity, border laser velocity, high-temperature preheating and time delay. Residual stresses were evaluated by the bridge curvature method and relative density by the optical method. The effect of the observed process parameters was estimated by the design of experiment and surface response methods. It was found that for an effective residual stress reduction, the high preheating temperature was the most significant parameter. High preheating temperature also increased the relative density but caused changes in the chemical composition of Ti6Al4V unmelted powder. Chemical analysis proved that after one build job with high preheating temperature, oxygen and hydrogen content exceeded the ASTM B348 limits for Grade 5 titanium.
Reactivity and Hydration Property of Synthetic Air Quenched Slag with Different Chemical Compositions
Authors: Wang Hui , Wang Yali , Cui Suping , Wang Jianfeng
Published: March 2019

Air quenched slag is processed by a fast air cooling method which is developed with the advantages of recovering heat from molten slag and water conservation compared to the water quenching method. Air quenched slags with different chemical compositions are synthesized in the lab by designing three chemical composition ratios: (CaO + MgO)/(SiO2 + Al2O3), CaO/MgO and SiO2/Al2O3, which are donated as CM/SA, C/M and S/A, respectively. The effect of different chemical compositions on the phase compositions of synthetic air quenched slag, the strength and hydration properties of slag blends were investigated by using various characterization techniques. The results show that the amorphous content of air quenched slag decreased with the increasing basicity CM/SA of slag. The S/A ratio of slag was the dominant factor for the compressive strength of slag blends at 28 days and negatively correlated with strength. Decreasing the S/A ratio of slag increased the reactivity of slag and its reaction degree indicated by higher hydration heat release, lower CH content, greater chemical combined water amount and denser microstructure. Moreover, thermodynamic modelling revealed that a higher S/A of slag leads to the increase of C-(A)-S-H and AFt contents, whilst decreasing the amounts of Ht, AFm-SO4 phases and the total volume of hydrates.
Luminescent Mesoporous Silica Nanohybrid Based on Drug Derivative Terbium Complex
Authors: Maturi Fernando E. , Sábio Rafael M. , Silva Robson R. , Lahoud Marcelo G. , Meneguin Andréia B. , Valente Gustavo T. , Caface Raphael A. , Leite Ilaiáli S. , Inada Natalia M. , Ribeiro Sidney J. L.
Published: March 2019

Mesoporous silica nanoparticles prepared by organic template-driven synthesis have been successfully explored as carriers of the drug-derivate green luminescent complex of terbium (III) with the nonsteroidal anti-inflammatory drug ketoprofen. The terbium (III) complex was synthesized by reacting ketoprofen sodium salt with terbium (III) chloride, which was further adsorbed onto the surface of mesoporous nanoparticles with a mean particle size of 47 ± 4 nm and pore size of 11 nm. The incorporation of the complex into mesoporous silica nanoparticles was tracked by the decrease in the surface area and pore size of the nanoparticles, and successfully demonstrated by substantial changes in the adsorption isotherms and thermal and vibrational spectroscopy results. The cytotoxicity assay and confocal microscopy have shown that the novel luminescent nanohybrid presents high cell viability and the characteristic terbium (III) emission can be assessed through two-photon excitation, which paves the way for bioimaging applications in nanomedicine.
Rapid Fabrication of High-Performance CaO-Based Integral Ceramic Mould by Stereolithography and Non-Aqueous Gelcasting
Authors: Yang Qiang , Zhu Weijun , Lu Zhongliang , Li Dichen , Wang Zhongrui , Wang Fu
Published: March 2019

A high-performance CaO-based integral ceramic mould was fabricated for investment casting by stereolithography (SLA) and non-aqueous gelcasting. The rheology of tert-butyl alcohol (TBA)-based CaO slurries and the effect of gelation parameters on the gelation time and strength of the green body were investigated to obtain a high-quality green body of the CaO-based integral ceramic mould. Then the pre-sintering and sintering processes were optimized to avoid cracks, reduce the sintering shrinkage, and improve the strength of CaO-based ceramic mould. The results showed that the CaO-based slurry with 56 vol % solid loading and 3 wt % dispersant content exhibited high stability and good flowability. The optimized gelation parameters were determined to be a monomer content of 20 wt %, a ratio of crosslinker to monomer of 0.06, an initiator content of 1 wt % and a gelation temperature of 40 °C. A reasonable sintering regime was identified to avoid cracks and guarantee a low shrinkage of 0.6%, a room temperature bending strength of 14.12 MPa and a high temperature (1200 °C) strength of 8.22 MPa. The CaO-based integral ceramic mould fabricated in this study has many advantages including excellent thermal stability, reaction-resistance to molten active alloys, ease of dissolution, and enhanced efficiency and economy in comparison to SiO2 or Al2O3 ceramic moulds.
Enhancing Damage-Sensing Capacity of Strain-Hardening Macro-Steel Fiber-Reinforced Concrete by Adding Low Amount of Discrete Carbons
Authors: Nguyen Duy-Liem , Kim Dong-Joo , Thai Duc-Kien
Published: March 2019

The effects of adding micro-carbon fibers on the electro-mechanical response of macro-steel fiber-reinforced concretes (MSFRCs) under tension were investigated. Two MSFRCs were investigated and they had identical mortar matrix but different fiber contents: MSFRC1 and MSFRC2 contained 1.0 and 1.5 vol.% fibers, respectively. The volume contents of added micro-carbon fibers were 0 to 1.5 vol.% in MSFRC1 and 0 to 0.75 vol.% in MSFRC2, respectively. The addition of 0.5 vol.% micro-carbon fibers, in both MSFRC1 and MSFRC2, produced significantly enhanced damage-sensing capability and still retained their strain-hardening performance together with multiple micro cracks. However, when the content of carbon fibers was more than 0.5 vol.%, the MSFRCs generated tensile strain-softening behavior and reduced damage-sensing capability. Furthermore, the effects of temperature and humidity on the electrical resistivity of MSFRCs were investigated, as were the effects of adding multi-walled carbon nanotubes on the damage-sensing capability of MSFRCs.
Model Based on an Effective Material-Removal Rate to Evaluate Specific Energy Consumption in Grinding
Authors: Nápoles Alberro Amelia , González Rojas Hernán A. , Sánchez Egea Antonio J. , Hameed Saqib , Peña Aguilar Reyna M.
Published: March 2019

Grinding energy efficiency depends on the appropriate selection of cutting conditions, grinding wheel, and workpiece material. Additionally, the estimation of specific energy consumption is a good indicator to control the consumed energy during the grinding process. Consequently, this study develops a model of material-removal rate to estimate specific energy consumption based on the measurement of active power consumed in a plane surface grinding of C45K with different thermal treatments and AISI 304. This model identifies and evaluates the dissipated power by sliding, ploughing, and chip formation in an industrial-scale grinding process. Furthermore, the instantaneous positions of abrasive grains during cutting are described to study the material-removal rate. The estimation of specific chip-formation energy is similar to that described by other authors on a laboratory scale, which allows to validate the model and experiments. Finally, the results show that the energy consumed by sliding is the main mechanism of energy dissipation in an industrial-scale grinding process, where it is denoted that sliding energy by volume unity decreases as the depth of cut and the speed of the workpiece increase.
Corrosion Initiation and Propagation on Carburized Martensitic Stainless Steel Surfaces Studied via Advanced Scanning Probe Microscopy
Authors: Kvryan Armen , Efaw Corey M. , Higginbotham Kari A. , Maryon Olivia O. , Davis Paul H. , Graugnard Elton , Trivedi Hitesh K. , Hurley Michael F.
Published: March 2019

Historically, high carbon steels have been used in mechanical applications because their high surface hardness contributes to excellent wear performance. However, in aggressive environments, current bearing steels exhibit insufficient corrosion resistance. Martensitic stainless steels are attractive for bearing applications due to their high corrosion resistance and ability to be surface hardened via carburizing heat treatments. Here three different carburizing heat treatments were applied to UNS S42670: a high-temperature temper (HTT), a low-temperature temper (LTT), and carbo-nitriding (CN). Magnetic force microscopy showed differences in magnetic domains between the matrix and carbides, while scanning Kelvin probe force microscopy (SKPFM) revealed a 90–200 mV Volta potential difference between the two phases. Corrosion progression was monitored on the nanoscale via SKPFM and in situ atomic force microscopy (AFM), revealing different corrosion modes among heat treatments that predicted bulk corrosion behavior in electrochemical testing. HTT outperforms LTT and CN in wear testing and thus is recommended for non-corrosive aerospace applications, whereas CN is recommended for corrosion-prone applications as it exhibits exceptional corrosion resistance. The results reported here support the use of scanning probe microscopy for predicting bulk corrosion behavior by measuring nanoscale surface differences in properties between carbides and the surrounding matrix.
Fabrication of Carboxymethylcellulose/Metal-Organic Framework Beads for Removal of Pb(II) from Aqueous Solution
Authors: Jin Huo-Xi , Xu Hong Ping , Wang Nan , Yang Li-Ye , Wang Yang-Guang , Yu Di , Ouyang Xiao-Kun
Published: March 2019

The ability to remove toxic heavy metals, such as Pb(II), from the environment is an important objective from both human-health and ecological perspectives. Herein, we describe the fabrication of a novel carboxymethylcellulose-coated metal organic material (MOF-5–CMC) adsorbent that removed lead ions from aqueous solutions. The adsorption material was characterized by Fourier-transform infrared spectroscopy, X-ray diffractometry, scanning electron microscopy, and X-ray photoelectron spectroscopy. We studied the functions of the contact time, pH, the original concentration of the Pb(II) solution, and adsorption temperature on adsorption capacity. MOF-5–CMC beads exhibit good adsorption performance; the maximum adsorption capacity obtained from the Langmuir isotherm-model is 322.58 mg/g, and the adsorption equilibrium was reached in 120 min at a concentration of 300 mg/L. The adsorption kinetics is well described by pseudo-second-order kinetics, and the adsorption equilibrium data are well fitted to the Langmuir isotherm model (R2 = 0.988). Thermodynamics experiments indicate that the adsorption process is both spontaneous and endothermic. In addition, the adsorbent is reusable. We conclude that MOF-5–CMC is a good adsorbent that can be used to remove Pb(II) from aqueous solutions.
Microstructural Characterization of Porous Clay-Based Ceramic Composites
Authors: Freitas Dutra Lorena , Freitas Monica E. , Grillet Anne-Cécile , Mendes Nathan , Woloszyn Monika
Published: March 2019

Clay-based materials are the most traditional components of buildings. To improve their performance in a sustainable way, agents can be mixed to fired clay acting as a pore-forming factor. However, firing temperatures highly influence their microstructure which is closely linked to a material’s final performance as a ceramic block. To highlight the influence of the firing temperature on microstructure, and more specifically on the pore size distribution of clay-based materials, three innovative porous materials were manufactured. These materials were produced by mixing clay and pore-forming agents. They were characterized by optical and scanning electronic microscopy, x-ray diffraction, mercury intrusion and nitrogen adsorption. These techniques allow the phase identification of materials, show sample microstructure and quantify the pore size distribution at different scales. Furthermore, geometric parameters of sample microstructure such as grain diameter and roundness are estimated by using computer software. To conclude, results provide an enlightenment about the influence of material microstructure on the pore size distribution at two firing temperatures. These results can be useful to allow the tune of porous characteristics and, therefore, contribute to the production of more sustainable construction materials.
Optical Coherence Tomography Investigations and Modeling of the Sintering of Ceramic Crowns
Authors: Duma Virgil-Florin , Sinescu Cosmin , Bradu Adrian , Podoleanu Adrian
Published: March 2019

Dental prostheses are sintered in ovens that sometimes suffer from a loss of calibration. This can lead to variations of the sintering temperature outside the range recommended by the manufacturer. Stress and even fractures in dental ceramics may occur, and this leads to the necessity to rebuild the dental construct. The aim of this work is to monitor the quality of sintering processes using an established biomedical imaging technique—optical coherence tomography (OCT). Conventional current procedures imply the fabrication of supplemental samples that add to the expenses and are only evaluated visually. To our knowledge, we were the first to propose the use of OCT, a non-destructive method that brings objectivity for such assessments, focusing, in a previous study, on metal ceramic dental prostheses. Here, a different material, pressed ceramics, is considered, while we propose a quantitative assessment of the results—using reflectivity profiles of en-face (i.e., constant-depth) OCT images of sintered samples. The results for both the pressed ceramics and metal ceramics prostheses are discussed by obtaining the analytic functions of their reflectivity profiles. A multi-parametric analysis demonstrates the best parameter to characterize the loss of calibration of dental ovens. Rules-of-thumb are extracted; producing dental prostheses with defects can thus be avoided.
Coupling Effect of Porosity and Cell Size on the Deformation Behavior of Al Alloy Foam under Quasi-Static Compression
Authors: Yang Donghui , Wang Hui , Guo Sensen , Chen Jianqing , Xu Yongmin , Lei Dong , Sun Jiapeng , Wang Lei , Jiang Jinghua , Ma Aibin
Published: March 2019

Closed-cell AlCu5Mn alloy foam with porosity range of ~45–90% were fabricated by the melt-foaming route. The pore structure of the fabricated Al alloy foam was analyzed and the coupling effect of porosity and cell size on the quasi-static compression behavior of the foam was investigated. The results show that the cell size of the foam decreases with the porosity decline from the view of the contribution rate to the porosity and the hierarchical pore structure characteristics becomes obvious when the foam porosity is low; the compression stress–strain curves of the foams with high porosity (>74%) are serrated due to the large cell size being easy to deform and more strain needed to let the stress recover. Meanwhile, the compression curve of the foams with low porosity (<74%) are smooth without serration, which is attributed to the hierarchical pore structure and less strain needed to let the stress recovery.
Graphene Nanomaterials-Based Radio-Frequency/Microwave Biosensors for Biomaterials Detection
Authors: Lee Hee-Jo , Yook Jong-Gwan
Published: March 2019

In this paper, the advances in radio-frequency (RF)/microwave biosensors based on graphene nanomaterials including graphene, graphene oxide (GO), and reduced graphene oxide (rGO) are reviewed. From a few frontier studies, recently developed graphene nanomaterials-based RF/microwave biosensors are examined in-depth and discussed. Finally, the prospects and challenges of the next-generation RF/microwave biosensors for wireless biomedical applications are proposed.
Brevenal, a Marine Natural Product, is Anti-Inflammatory and an Immunomodulator of Macrophage and Lung Epithelial Cells
Authors: Keeler Devon M. , Grandal Meghan K. , McCall Jennifer R.
Published: March 2019

Chronic respiratory diseases, including chronic obstructive pulmonary disease (COPD), cystic fibrosis, and asthma, are some of the leading causes of illness and fatalities worldwide. The search for novel treatments led to the exploration of marine natural products as drug candidates to combat the debilitating effects of mucus accumulation and chronic inflammation. Previous research showed that an alga-derived compound, brevenal, could attenuate the effects of inflammatory agents, but the mechanisms by which it exerted its effects remained unclear. We investigated the effects of brevenal on lipopolysaccharide (LPS) induced cytokine/chemokine production from murine macrophages and human lung epithelial cells. It was found that brevenal reduces proinflammatory mediator secretion while preserving anti-inflammatory secretion from these cells. Furthermore, we found that brevenal does not alter cell surface Toll-like receptor 4 (TLR4) expression, thereby maintaining the cells’ ability to respond to bacterial infection. However, brevenal does alter macrophage activation states, as demonstrated by reduced expression of both M1 and M2 phenotype markers, indicating this putative anti-inflammatory drug shifts innate immune cells to a less active state. Such a mechanism of action would be ideal for reducing inflammation in the lung, especially with patients suffering from chronic respiratory diseases, where inflammation can be lethal.
Study on Intensification Behavior of Bismuth Ions on Gold Cyanide Leaching
Authors: Yang Yongbin , Lai Meixiang , Zhong Qiang , Li Qian , Xu Bin , Jiang Tao
Published: March 2019

Gold cyanide leaching is inefficient with conventional cyanidation. Bismuth ions can improve the efficiency of gold cyanidation by intensifying gold dissolution. The electrochemical behavior, structure information, and surface product of gold anodic dissolution were studied during the intensification of bismuth ions on gold cyanide leaching. The electrochemical analysis showed that the bismuth ions can not only improve anode current density, but also make gold dissolve at a lower potential, increase the corrosion current and intensify gold anodic dissolution. The microstructure analysis showed that bismuth ions intensified the cyanide corrosion of the gold surface, causing a large number of loose honeycombs, gullies, pits, and large holes on the gold surface. The XPS, FT-IR, and Raman analysis showed that there is weak information of C≡N in the spectrum of Bi intensification contrasting to that of conventional cyanidation. Cyanide compounds may be the insoluble AuCNads, which does not deposit on the surface of gold plate after Bi intensification cyanidation. The insoluble intermediate AuCNads is likely to react promptly with CN- to form soluble Au(CN ) 2 − , making less insoluble AuCNads deposits on the gold surface. Therefore, bismuth ions can promote the dissolution of insoluble AuCNads, prevents its passivation film to cover around the gold plate, keeps cyanide good contact with gold, and finally accelerates the cyanide dissolution of gold.
Comparison of Energy Consumption and CO2 Emission for Three Steel Production Routes—Integrated Steel Plant Equipped with Blast Furnace, Oxygen Blast Furnace or COREX
Authors: Song Jiayuan , Jiang Zeyi , Bao Cheng , Xu Anjun
Published: March 2019

High CO2 emissions and energy consumption have greatly restricted the development of China’s iron and steel industry. Two alternative ironmaking processes, top gas recycling-oxygen blast furnace (TGR-OBF) and COREX®, can reduce CO2 emissions and coking coal consumption in the steel industry when compared with a conventional blast furnace (BF). To obtain parameters on the material flow of these processes, two static process models for TGR-OBF and COREX were established. Combining the operating data from the Jingtang steel plant with established static process models, this research presents a detailed analysis of the material flows, metallurgical gas generation and consumption, electricity consumption and generation, comprehensive energy consumption, and CO2 emissions of three integrated steel plants (ISP) equipped with the BF, TGR-OBF, and COREX, respectively. The results indicated that the energy consumption of an ISP with the TGR-OBF was 16% and 16.5% lower than that of a conventional ISP and an ISP with the COREX. Compared with a conventional ISP, the coking coal consumption in an ISP with the TGR-OBF and an ISP with the COREX were reduced by 39.7% and 100% respectively. With the International Energy Agency factor, the ISP with the TGR-OBF had the lowest net CO2 emissions, which were 10.8% and 35.0% lower than that of a conventional ISP and an ISP with the COREX. With the China Grid factor, the conventional ISP had the lowest net CO2 emissions—2.8% and 24.1% lower than that of an ISP with the TGR-OBF and an ISP with the COREX, respectively.
Strain Hardening, Damage and Fracture Behavior of Al-Added High Mn TWIP Steels
Authors: Madivala Manjunatha , Schwedt Alexander , Prahl Ulrich , Bleck Wolfgang
Published: March 2019

The strain hardening and damage behavior of Al-added twinning induced plasticity (TWIP) steels were investigated. The study was focused on comparing two different alloying concepts by varying C and Mn contents with stacking fault energy (SFE) values of 24 mJ/m 2 and 29 mJ/m 2 . The evolution of microstructure, deformation mechanisms and micro-cracks development with increasing deformation was analyzed. Al-addition has led to the decrease of C diffusivity and reduction in tendency for Mn-C short-range ordering resulting in the suppression of serrated flow caused due to dynamic strain aging (DSA) in an alloy with 0.3 wt.% C at room temperature and quasi-static testing, while DSA was delayed in an alloy with 0.6 wt.% C. However, an alloy with 0.6 wt.% C showing DSA effect exhibited enhanced strain hardening and ductility compared to an alloy with 0.3 wt.% C without DSA effect. Twinning was identified as the most predominant deformation mode in both the alloys, which occurred along with dislocation glide. Al-addition has increased SFE thereby delaying the nucleation of deformation twins and prolonged saturation of twinning, which resulted in micro-cracks initiation only just prior to necking or failure. The increased stress concentration caused by the interception of deformation twins or slip bands at grain boundaries (GB) has led to the development of micro-cracks mainly at GB and triple junctions. Deformation twins and slip bands played a vital role in assisting inter-granular crack initiation and propagation. Micro-cracks that developed at manganese sulfide and aluminum nitride inclusions showed no tendency for growth even after large deformation indicating the minimal detrimental effect on the tensile properties.
Flavan-3-ols Content in Red Raspberry Leaves Increases under Blue Led-Light Irradiation
Authors: Kobori Ryo , Hashimoto Seiya , Koshimizu Hayato , Yakami Shuich , Hirai Mizuki , Noro Kenta , Kawasaki Takashi , Saito Akiko
Published: March 2019

Berry fruits are well known to contain large amounts of polyphenol compounds. Among them, flavan-3-ol derivatives are a group of secondary metabolism compounds currently attracting a great deal of attention owing to their health benefits. Not only the fruits, but also the leaves of raspberry plants, are highly esteemed for tea making around the world and are largely used for food. In this report, we discuss the results of our study on the effect of light and temperature on polyphenol accumulation in raspberry leaves. When raspberry was cultivated in a plant factory unit and light intensity, wavelength, and temperature were varied, the amount of total polyphenol increased under blue light. Quantitative determination of (+)-catechin, (–)-epicatechin, procyanidin B4, flavan-3-ol trimer, which are flavan-3-ol derivatives, was carried out using HPLC, whereby we confirmed their increase under blue light. Semi-quantitative RT-PCR showed correlation between chalcone synthase (CHS) gene expression and the amounts of the compounds measured in the leaves.
Single-Sided Near-Field Wireless Power Transfer by A Three-Dimensional Coil Array
Authors: Hajiaghajani Amirhossein , Ahn Seungyoung
Published: March 2019

Wirelessly powered medical microrobots are often driven or localized by magnetic resonance imaging coils, whose signal-to-noise ratio is easily affected by the power transmitter coils that supply the microrobot. A controlled single-sided wireless power transmitter can enhance the imaging quality and suppress the radiation leakage. This paper presents a new form of electromagnet which automatically cancels the magnetic field to the back lobes by replacing the traditional circular coils with a three-dimensional (3D) coil scheme inspired by a generalized form of Halbach arrays. It is shown that, along with the miniaturization of the transmitter system, it allows for improved magnetic field intensity in the target side. Measurement of the produced magnetic patterns verifies that the power transfer to the back lobe is 15-fold smaller compared to the corresponding distance on the main lobe side, whilst maintaining a powering efficiency similar to that of conventional planar coils. To show the application of the proposed array, a wireless charging pad with an effective powering area of 144 cm2 is fabricated on 3D-assembled printed circuit boards. This 3D structure obviates the need for traditional magnetic shield materials that place limitations on the working frequency and suffer from non-linearity and hysteresis effects.
Field Based Assessment of Capsicum annuum Performance with Inoculation of Rhizobacterial Consortia
Authors: Kaushal Manoj , Mandyal Priyanka , Kaushal Rajesh
Published: March 2019

Plant growth promoting rhizobacteria (PGPR) are associated with plant roots and augment plant productivity and immunity by reducing fertilizer application rates and nutrient runoff. Studies were conducted to evaluate bell pepper transplants amended with formulation of consortium of two indigenous PGPR isolates (Bacillus subtilis and Bacillus pumilus) in terms of increase in yield and disease resistance under field conditions. Transplants were planted into plots treated by NPK (nitrogen, phosphorus and potassium), fungicides, soil solarization, MeBr fumigation, PGPR and untreated soil. Treatments were assessed for incidence of soil-borne phytopathogens viz. Phytophthora capsici and Colletotrichum sp. Highly significant increases in bell pepper transplant growth occurred in response to formulations of PGPR isolates. Transplant vigor and survival in the field were also improved by PGPR treatments. Consortium of Bacillus subtilis and Bacillus pumilus reduced disease incidence of damping off by 1.81% and anthracnose by 1.75%. Numbers of colony forming units of Phytophthora capsici and Colletotrichum sp. were significantly higher in all plots than those treated with PGPR consortium. Incidence of seed rot and seedling blight on bell pepper was significantly lower in PGPR-treated plots and highest in untreated plots. Total fruit yield of bell pepper increased by 379.36% with PGPR consortium (Bacillus subtilis and Bacillus pumilus).