High Quality Al-Ga-In-N Heterostructures Fabricated by MOVPE Growth in Multiwafer Reactors

We present results on the growth of Al-Ga-In-N films in multiwafer reactors with 7×2″ wafer capacity. The design of these reactors allows the combination of high efficiency (TMGa efficiency for GaN around 30%) and excellent uniformity. Results on the growth of all materials from the Al-Ga-In-Nitride family are presented in detail. GaN is grown with an excellent optical quality and very good thickness uniformity below 2% across 2″ wafers. The material quality is shown by electron mobility of more than 500 cm2/Vs at an intentional Si-doping of approximately 1×1017 cm−3. Controlled acceptor doping with Mg yields carrier concentrations between 5×1016 and 1018 cm−3. The layer thickness uniformity of the films are better than 2% over a 2″ wafer area. GaInN is grown with PL emission wavelengths in the visible blue region showing a uniformity better than 1.5 nm standard deviation. The film thickness uniformity represents the same figures as obtained for the binary. The compositional uniformity of AlGaN is in the sub 1% range corresponding to a wavelength variation below 1 nm.The fabrication of heterostructures from these binary and ternary materials is described as well as results from the characterization of these structures. The results show that reliable and efficient production of Al-Ga-In-Nitride based optoelectronic devices can be performed in multiwafer reactors.

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Printability of papers recycled from toner and inkjet-printed papers after deinking and recycling processes

Journal of Applied Biomaterials & Functional Materials ◽

10.5301/jabfm.5000386 ◽

2017 ◽

Vol 16 (2) ◽

pp. 76-82

Author(s):

Arif Karademir ◽

Cem Aydemir ◽

Dogan Tutak ◽

Raja Aravamuthan

Keyword(s):

High Efficiency ◽

Color Change ◽

Paper Industry ◽

Optical Quality ◽

Recycled Paper ◽

High Optical Quality ◽

Contemporary World ◽

Before And After ◽

Better Than

Background: In our contemporary world, while part of the fibers used in the paper industry is obtained from primary fibers such as wood and agricultural plants, the rest is obtained from secondary fibers from waste papers. To manufacture paper with high optical quality from fibers of recycled waste papers, these papers require deinking and bleaching of fibers at desired levels. High efficiency in removal of ink from paper mass during recycling, and hence deinkability, are especially crucial for the optical and printability quality of the ultimate manufactured paper. Methods: In the present study, deinkability and printability performance of digitally printed paper with toner or inkjet ink were compared for the postrecycling product. To that end, opaque 80 g/m2 office paper was digitally printed under standard printing conditions with laser toner or inkjet ink; then these sheets of paper were deinked by a deinking process based on the INGEDE method 11 p. After the deinking operation, the optical properties of the obtained recycled handsheets were compared with unprinted (reference) paper. Then the recycled paper was printed on once again under the same conditions as before with inkjet and laser printers, to monitor and measure printing color change before and after recycling, and differences in color universe. Results: Recycling and printing performances of water-based inkjet and toner-based laser printed paper were obtained. The outcomes for laser-printed recycled paper were better than those for inkjet-printed recycled paper. Conclusions: Compared for luminosity Y, brightness, CIE a* and CIE b* values, paper recycled from laser-printed paper exhibited higher value than paper recycled from inkjet-printed paper.

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Characterization of Rh/Si multilayer structure by HREM and HAADF

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100121016 ◽

1992 ◽

Vol 50 (1) ◽

pp. 122-123

Author(s):

Y. Cheng ◽

J. Liu ◽

M.B. Stearns ◽

D.G. Steams

Keyword(s):

Normal Incidence ◽

High Resolution Electron Microscopy ◽

X Rays ◽

Beam Direction ◽

Cross Sectional ◽

Optical Elements ◽

Resolution Electron ◽

Point To Point ◽

Better Than

The Rh/Si multilayer (ML) thin films are promising optical elements for soft x-rays since they have a calculated normal incidence reflectivity of ∼60% at a x-ray wavelength of ∼13 nm. However, a reflectivity of only 28% has been attained to date for ML fabricated by dc magnetron sputtering. In order to determine the cause of this degraded reflectivity the microstructure of this ML was examined on cross-sectional specimens with two high-resolution electron microscopy (HREM and HAADF) techniques.Cross-sectional specimens were made from an as-prepared ML sample and from the same ML annealed at 298 °C for 1 and 100 hours. The specimens were imaged using a JEM-4000EX TEM operating at 400 kV with a point-to-point resolution of better than 0.17 nm. The specimens were viewed along Si [110] projection of the substrate, with the (001) Si surface plane parallel to the beam direction.

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Synthesis and characterization of flame-retardant-wrapped carbon nanotubes and its flame retardancy in epoxy nanocomposites

Polymers and Polymer Composites ◽

10.1177/09673911211024582 ◽

2021 ◽

pp. 096739112110245

Author(s):

Jiangbo Wang

Keyword(s):

Carbon Nanotubes ◽

Heat Release ◽

Flame Retardant ◽

Flame Retardancy ◽

Total Heat Release ◽

Pristine Cnts ◽

Peak Heat Release Rate ◽

Ep Matrix ◽

Better Than

A novel phosphorus-silicon containing flame-retardant DOPO-V-PA was used to wrap carbon nanotubes (CNTs). The results of FTIR, XPS, TEM and TGA measurements exhibited that DOPO-V-PA has been successfully grafted onto the surfaces of CNTs, and the CNTs-DOPO-V-PA was obtained. The CNTs-DOPO-V-PA was subsequently incorporated into epoxy resin (EP) for improving the flame retardancy and dispersion. Compared with pure EP, the addition of 2 wt% CNTs-DOPO-V-PA into the EP matrix could achieve better flame retardancy of EP nanocomposites, such as a 30.5% reduction in peak heat release rate (PHRR) and 8.1% reduction in total heat release (THR). Furthermore, DMTA results clearly indicated that the dispersion for CNTs-DOPO-V-PA in EP matrix was better than pristine CNTs.

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Optically transparent vertical silicon nanowire arrays for live-cell imaging

Journal of Nanobiotechnology ◽

10.1186/s12951-021-00795-7 ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Roey Elnathan ◽

Andrew W. Holle ◽

Jennifer Young ◽

Marina A. George ◽

Omri Heifler ◽

...

Keyword(s):

High Efficiency ◽

Silicon Nanowire ◽

Live Cell ◽

Si Nanowires ◽

Contrast Imaging ◽

Silicon Nanowire Arrays ◽

Transparent Substrate ◽

Optically Transparent ◽

Vertically Aligned

AbstractProgrammable nano-bio interfaces driven by tuneable vertically configured nanostructures have recently emerged as a powerful tool for cellular manipulations and interrogations. Such interfaces have strong potential for ground-breaking advances, particularly in cellular nanobiotechnology and mechanobiology. However, the opaque nature of many nanostructured surfaces makes non-destructive, live-cell characterization of cellular behavior on vertically aligned nanostructures challenging to observe. Here, a new nanofabrication route is proposed that enables harvesting of vertically aligned silicon (Si) nanowires and their subsequent transfer onto an optically transparent substrate, with high efficiency and without artefacts. We demonstrate the potential of this route for efficient live-cell phase contrast imaging and subsequent characterization of cells growing on vertically aligned Si nanowires. This approach provides the first opportunity to understand dynamic cellular responses to a cell-nanowire interface, and thus has the potential to inform the design of future nanoscale cellular manipulation technologies.

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Isolation and characterization of pathogenic Escherichia coli bacteriophages from chicken and beef offal

BMC Research Notes ◽

10.1186/s13104-019-4859-y ◽

2020 ◽

Vol 13 (1) ◽

Author(s):

Celosia Lukman ◽

Christopher Yonathan ◽

Stella Magdalena ◽

Diana Elizabeth Waturangi

Keyword(s):

Escherichia Coli ◽

Foodborne Pathogens ◽

High Efficiency ◽

Multiplicity Of Infection ◽

Isolation And Characterization ◽

Transmission Electron ◽

Pathogenic Escherichia Coli ◽

Family Based

Abstract Objective This study was conducted to isolate and characterize lytic bacteriophages for pathogenic Escherichia coli from chicken and beef offal, and analyze their capability as biocontrol for several foodborne pathogens. Methods done in this research are bacteriophage isolation, purification, titer determination, application, determination of host range and minimum multiplicity of infection (miMOI), and bacteriophage morphology. Results Six bacteriophages successfully isolated from chicken and beef offal using EPEC and EHEC as host strain. Bacteriophage titers observed between 109 and 1010 PFU mL−1. CS EPEC and BL EHEC bacteriophage showed high efficiency in reduction of EPEC or EHEC contamination in meat about 99.20% and 99.04%. The lowest miMOI was 0.01 showed by CS EPEC bacteriophage. CI EPEC and BL EPEC bacteriophage suspected as Myoviridae family based on its micrograph from Transmission Electron Microscopy (TEM). Refers to their activity, bacteriophages isolated in this study have a great potential to be used as biocontrol against several foodborne pathogens.

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Preparation and Characterization of Talc Filled Thermoplastic Polyurethane/Polypropylene Blends

Journal of Polymers ◽

10.1155/2014/289283 ◽

2014 ◽

Vol 2014 ◽

pp. 1-8 ◽

Cited By ~ 7

Author(s):

Emi Govorčin Bajsić ◽

Vesna Rek ◽

Ivana Ćosić

Keyword(s):

Thermal Properties ◽

Thermoplastic Polyurethane ◽

Mechanical Analysis ◽

Degree Of Crystallinity ◽

Scanning Calorimetry ◽

Polypropylene Blends ◽

Pp Blends ◽

The Degree Of Crystallinity ◽

Better Than

The effect of the addition of talc on the morphology and thermal properties of blends of thermoplastic polyurethane (TPU) and polypropylene (PP) was investigated. The blends of TPU and PP are incompatible because of large differences in polarities between the nonpolar crystalline PP and polar TPU and high interfacial tensions. The interaction between TPU and PP can be improved by using talc as reinforcing filler. The morphology was observed by means of scanning electron microscopy (SEM). The thermal properties of the neat polymers and unfilled and talc filled TPU/PP blends were studied by using dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The addition of talc in TPU/PP blends improved miscibility in all investigated TPU/T/PP blends. The DSC results for talc filled TPU/PP blends show that the degree of crystallinity increased, which is due to the nucleating effect induced by talc particles. The reason for the increased storage modulus of blends with the incorporation of talc is due to the improved interface between polymers and filler. According to TGA results, the addition of talc enhanced thermal stability. The homogeneity of the talc filled TPU/PP blends is better than unfilled TPU/PP blends.

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Aerodynamic Characterization of Transonic Turbine Vanes Optimized to Attenuate Rotor Forcing

Volume 7: Turbomachinery, Parts A, B, and C ◽

10.1115/gt2011-46553 ◽

2011 ◽

Author(s):

R. Puente ◽

G. Paniagua ◽

T. Verstraete

Keyword(s):

High Efficiency ◽

Prediction Method ◽

Optimization Procedure ◽

3D Design ◽

Turbine Vanes ◽

Turbine Vane ◽

Loss Prediction ◽

Transonic Turbine ◽

Characteristic Features

A multi-objective optimization procedure is applied to the 3D design of a transonic turbine vane row, considering efficiency and stator outlet pressure distortion, which is directly related to induced rotor forcing. The characteristic features that define different individuals along the Pareto Front are described, analyzing the differences between high efficiency airfoils and low interaction. Pressure distortion is assessed by means of a model that requires only of the computation the steady flow field in the domain of the stator. The reduction of aerodynamic rotor forcing is checked via unsteady multistage aerodynamic computations. A well known loss prediction method is used to drive the efficiency of one optimization run, while CFD analysis is used for another, in order to assess the reliability of both methods. In both cases, the decomposition of total losses is performed to quantify the influence on efficiency of reducing rotor forcing. Results show that when striving for efficiency, the rotor is affected by few, but intense shocks. On the other hand, when the objective is the minimization of distortion, multiple shocks will appear.

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Insights into the Functionality of the Putative Residues Involved in Enterocin AS-48 Maturation

Applied and Environmental Microbiology ◽

10.1128/aem.01154-10 ◽

2010 ◽

Vol 76 (21) ◽

pp. 7268-7276 ◽

Cited By ~ 19

Author(s):

Rubén Cebrián ◽

Mercedes Maqueda ◽

José Luis Neira ◽

Eva Valdivia ◽

Manuel Martínez-Bueno ◽

...

Keyword(s):

Posttranslational Modifications ◽

High Efficiency ◽

Specific Protein ◽

Culture Conditions ◽

Site Directed Mutagenesis ◽

Circular Structure ◽

Cleavage Enzyme ◽

Site Recognition ◽

Biosynthetic Machinery

ABSTRACT AS-48 is a 70-residue, α-helical, cationic bacteriocin produced by Enterococcus faecalis and is very singular in its circular structure and its broad antibacterial spectrum. The AS-48 preprotein consists of an N-terminal signal peptide (SP) (35 residues) followed by a proprotein moiety that undergoes posttranslational modifications to yield the mature and active circular protein. For the study of the specificity of the region of AS-48 that is responsible for maturation, three single mutants have been generated by site-directed mutagenesis in the as-48A structural gene. The substitutions were made just in the residues that are thought to constitute a recognition site for the SP cleavage enzyme (His-1, Met1) and in those involved in circularization (Met1, Trp70). Each derivative was expressed in the enterococcal JH2-2 strain containing the necessary native biosynthetic machinery for enterocin production. The importance of these derivatives in AS-48 processing has been evaluated on the basis of the production and structural characterization of the corresponding derivatives. Notably, only two of them (Trp70Ala and Met1Ala derivatives) could be purified in different forms and amounts and are characterized for their bactericidal activity and secondary structure. We could not detect any production of AS-48 in JH2-2(pAM401-81 His-1Ile ) by using the conventional chromatographic techniques, despite the high efficiency of the culture conditions applied to produce this enterocin. Our results underline the different important roles of the mutated residues in (i) the elimination of the SP, (ii) the production levels and antibacterial activity of the mature proteins, and (iii) protein circularization. Moreover, our findings suggest that His-1 is critically involved in cleavage site recognition, its substitution being responsible for the blockage of processing, thereby hampering the production of the specific protein in the cellular culture supernatant.

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