bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of phosphorus on the characteristics of starch in winter wheat
Authors: Li Chun Y. , Li Cheng , Zhang Run Q. , Liang Wei
Published: October 2014

The effect of different phosphorus levels (P0: P2O5 0 kg/hm2; LP: P2O5 105 kg/hm2; HP: P2O5 210 kg/hm2) on the characteristics of starch in Xindong 20 and Xindong 23 winter wheat varieties was studied. The phosphorus‐induced changes in starch characteristics were variety‐dependent. Wheat starch granules of two cultivars showed bimodal size distributions under different phosphorus conditions. B‐granule proportion increased in response to phosphorus in Xindong 20. XRD analysis of starches showed that A‐type polymorphic structure and peak positions does not change under different phosphorus level. Small differences were observed in intensities of all fingerprint peaks (15°, 17°, 18°, 20°, and 23° 2θ). Xindong 20 flour under condition of HP showed significantly higher trough viscosity, final viscosity, and setback than that under P0 condition. In response to HP, Xindong 20 and Xindong 23 starches showed significantly higher water‐binding capacity.
Molecular structure of starch in grains is not affected by common dwarfing genes in rice (sd1) and sorghum (dw3)
Authors: Gilbert Robert G. , Besnard David J. Y. , Reeve Ashton J. , Lambrides Christopher J. , Hasjim Jovin
Published: October 2014

Dwarf cereal crops are widely grown world‐wide because they offer productivity advantages to farmers, but the question of whether dwarfing genes change starch structure has not been examined. Starch properties, including digestion rate and mechanical properties of starch‐containing biomaterials, are influenced by its structure, and thus significant changes might have health implications. Starch molecular structures of the grains from a semi‐dwarf sd1 rice (Oryza sativa L.) mutant (Calrose 76) and its near‐isogenic wild‐type (Calrose) counterpart as well as of those from three dwarf sorghum (Sorghum bicolor L.) mutants and their near‐isogenic tall revertants (due to the spontaneous reverse mutation of dw3 gene) were analyzed to understand the pleiotropic effects of dwarfing genes on starch biosynthesis in the grains. The structures of (fully branched) whole starch molecules and branch‐chain length (from enzymatically debranched starch) were characterized using size‐exclusion chromatography. The weight–average MW and radius of gyration of whole starch molecules were characterized using multiple‐angle laser light scattering. There were no significant structural differences between each dwarf variety and its near‐isogenic wild‐type or tall revertant counterpart. Hence plant height reduction in rice and sorghum, controlled by the sd1 and dw3 genes, respectively, does not affect the biosynthesis of starch molecules in grains and is expected to have no significant impacts on starch crystalline and granular structures as well as starch functional properties, including its nutritional values.
Comparative study on the blends of PBS/thermoplastic starch prepared from waxy and normal corn starches
Authors: Li Jiwei , Luo Xuegang , Lin Xiaoyan , Zhou Ye
Published: October 2014

In this study, waxy (0% amylose) and normal (26% amylose) corn starches were used to prepare thermoplastic starch (WTPS and NTPS, respectively). Furthermore, comparative blends of poly (butylene succinate) (PBS) and WTPS and NTPS were prepared for investigating the effect of starch type and PBS content on the properties of PBS/TPS blends. Morphology, processability, mechanical properties, water resistance, and thermal stability of the blends were evaluated. The results showed that the plasticization and processing of waxy corn starch were more easily performed than normal corn starch. The melt flow index, tensile properties, water resistance, and thermo stability of the PBS/TPS blends increased significantly with increasing PBS content. In addition, compared with the PBS/NTPS blends, the combination of PBS and WTPS could gain some excellent performances such as good processability, superior mechanical properties, and higher water resistance.
Production, purification, and characterization of thermostable α‐amylase from thermophilic Geobacillus stearothermophilus
Authors: Fincan Sema Agüloğlu , Enez Barış
Published: October 2014

The α‐amylase (α‐1‐4‐D‐glucan glucanohydrolase; EC 3.2.1.1) secreted by Geobacillus stearotermophilus was purified and characterized. Maximum enzyme production was achieved after 24 h cultivation at pH 7.0 and 55°C. The enzyme was active in a broad temperature range, between 50 and 80°C, with an optimum at 70°C; and maximum activity was at pH 7.0. The enzyme was purified using 80% ammonium sulfate precipitation, dialysis, Sephadex G‐100 gel filtration, and DEAE‐cellulose column chromatography, with a 46‐fold and 65% recovery and showed a MW of 63 kDa by SDS‐PAGE. It was determined that the purified enzyme was stable at 50 and 60°C, and pH 7.0. It was determined that the purified enzyme was stable at 50 and 60°C at the end of 2 h. The enzyme retained 100% activity pH 7.0 at the end of 3 h. The enzyme was activated by Ca2+, Mn2+, and Triton X‐100, but strongly inhibited by Cu2+, Zn2+, Fe2+, and Hg2+. The enzyme follows Michaelis–Menten kinetics with Km and Vmax values of 0.051 mM and 1.424 μmol/min, respectively.
Predictability of the consistency of porridges using different methods to measure flour swelling
Authors: de Carvalho Irene Stuart Torrie , Granfeldt Yvonne , Eliasson Ann‐Charlotte , Dejmek Petr
Published: October 2014

The consistency of porridge made from sweet potato, cowpea, soybean, sorghum, and maize flours was measured in a texture analysis method using back extrusion. The consistency measured was correlated to the swelling volume of the flours, and determined by centrifugation, gravity sedimentation, and least gelation concentration. The reference level of maximum acceptable consistency was estimated from measurements on two ready‐to‐use child porridges. In general, porridge consistency could not be predicted accurately from swelling volume measured using any of the methods. However, gravity sedimentation, which is the simplest, gave the most consistent results. This method could be used in the field to provide a conservative approximate maximum flour concentration for porridge of acceptable consistency.
Preparation of water‐soluble oxidized starch with high carbonyl content by sodium hypochlorite
Authors: Yi Xianjun , Zhang Shufen , Ju Benzhi
Published: October 2014

Water‐soluble oxidized starch with high carbonyl content (DOCO = 0.40) was prepared using a one‐step method with sodium hypochlorite (NaClO) as the primary oxidant and under the mediation of sodium bromide (NaBr) and hydroxylamine hydrochloride (NH2OH · HCl). The influences of pH, initial starch concentration, and the amount of NaBr and NH2OH · HCl on the carbonyl and carboxyl content were discussed. The molar ratio of carbonyl to carboxyl groups can be adjusted from 0.8 to 2.2 by controlling the dropping speed of NaClO. The formation of carbonyl and carboxyl groups on the oxidized starch was confirmed by Fourier‐transform infrared (FT‐IR) and 13C NMR spectroscopy. The molecular weight of the oxidized starch determined by SEC revealed modest degradation. Besides, a good solubility of the oxidized starch in cold water was also proved based on the study of its solubility and swelling properties.
Nanoprecipitation of native pea starches treated in alkaline media at various temperatures employing a dedicated microwave reactor
Authors: Juna Shazia , Hayden Stephan , Damm Markus , Kappe C. Oliver , Huber Anton
Published: October 2014

Starch dispersions/solutions were prepared by heating native pea starch in 1 M NaOH(aq) at various temperatures (50–100°C) using a dedicated microwave reactor. The influence of temperature upon the apparent molecular and hydrodynamic characteristics was investigated employing asymmetrical flow field flow‐fractionation coupled with multi‐angle light scattering and a RI detector (AF4/MALS/RI). Apparent molar masses, apparent radii of gyration and hydrodynamic radii decreased as a function of increasing processing temperature. Treated starch solutions were precipitated in either ethanol or methanol and the resultant precipitates were dried on either glass or Teflon surfaces. The shapes and sizes of the starch nanoprecipitates (evaluated from SEM images) were influenced by a number of factors including, temperature employed for preparing aqueous starch dispersion/solutions, solvent employed during the precipitation phase, and the nature of drying surfaces.
The influence of oxidation, extrusion and oxidation/extrusion on physico‐chemical properties of potato starch
Authors: Gumul Dorota , Krystyjan Magdalena , Buksa Krzysztof , Ziobro Rafał , Zięba Tomasz
Published: October 2014

The aim of the research was to compare several physico‐chemical parameters of potato starch modified using oxidation, extrusion, and combination of both, including content of amylose and non‐polysaccharide components, amount of carboxyl groups, molecular mass distribution of polymers, pasting ability, and rheological properties. It was observed that oxidation, extrusion, and combined oxidation/extrusion of starch resulted in an increase of ash in potato starch, and the oxidized starch contained the lowest amount of non‐carbohydrate compounds. Oxidation resulted in a decrease of phosphorus, while its content after extrusion increased. It was found that the level of apparent amylose dropped after all applied types of modification. Water binding capacity and solubility of oxidized starch differed slightly from the values measured for native starch, while a huge change in these characteristics was caused by extrusion. The highest change of molecular mass was observed after combined modification and the lowest in case of extruded starch. Modification of starch affected its rheological properties, which exhibited low viscosity and was more susceptible to shearing forces.
Towards meso–meso‐Linked Porphyrin Arrays and meso‐Aryl Expanded Porphyrins
Authors: Osuka Atsuhiro
Published: October 2014

meso–meso‐Linked porphyrin arrays and meso‐aryl‐substituted expanded porphyrins have continuously fueled my imagination for many years. In this account, my expertise in chemical research is retrospectively summarized with a particular focus on how these two novel categories of porphyrinoids were found by our group. As part of our photosynthetic model studies in collaboration with Prof. N. Mataga, the energy‐gap dependence of intramolecular charge separation was examined by exploring the photoexcited dynamics of 1,4‐phenylene‐bridged hybrid porphyrin dimers. This study required electron‐deficient porphyrins in the dimers that could serve as an electron‐accepting unit towards an octaalkyl‐substituted Zn(II) porphyrin donor. To this end, we employed meso‐nitrated porphyrins and meso‐pentafluorophenyl porphyrins. Efforts to prepare these electron‐deficient porphyrins allowed us to serendipitously find both a meso–meso‐linked porphyrin dimer and a series of meso‐pentafluorophenyl‐substituted expanded porphyrins. The meso–meso‐linked Zn(II) porphyrin dimer was found as a byproduct in the nitration of 5,10‐diaryl Zn(II) porphyrin with AgNO2 but became a major product in the reaction with AgPF6. This finding opened up a new path to directly linked porphyrin oligomers. The series of meso‐pentafluorophenyl‐substituted expanded porphyrins were prepared via BF3·OEt2‐catalyzed condensation of pyrrole and pentafluorobenzaldehyde when the reaction was run at tenfold‐higher substrate concentrations, as compared to the optimal conditions for the synthesis of 5,10,15,20‐tetrakis(pentafluorophenyl)porphyrin. These expanded porphyrins have been shown to have attractive attributes such as flexible structures, versatile electronic states, multi‐metal coordination, anion sensing, and large nonlinear optical properties. While these studies were mostly curiosity‐driven, some of our work covers rather more general interests: how linearly connected molecules can be rationally synthesized and isolated in a pure and discrete form, how large π‐conjugation can be realized to allow for very low energy electronic transitions, and how easily Möbius aromatic and antiaromatic molecules can be prepared.
Mosaics, Quilts, Science and Crystal Structures – Which one Inspires the Other?
Authors: Férey Gérard
Published: October 2014

This paper gives some examples of the strange relations between mosaics and crystal structures, their respective contributions to the representation and a possible way to create new solid matter.
One-dimensional GaN nanomaterials transformed from one-dimensional Ga2O3 and Ga nanomaterials
Authors: Han X. Y. , Gao Y. H. , Zhang X. H.
Published: October 2014

One-dimensional (1D) GaN nanomaterials exhibiting various morphologies and atomic structures were prepared via ammoniation of either Ga2O3 nanoribbons, Ga2O3 nanorods or Ga nanowires filled into carbon nanotubes (CNTs). The 1D GaN nanomaterials transformed from Ga2O3 nanoribbons consisted of numerous GaN nanoplatelets having the close-packed plane, i.e. (0002)2H or (111)3C parallel to the axes of starting nanoribbons. The 1D GaN nanomaterials converted from Ga2O3 nanorods were polycrystalline rods covered with GaN nanoparticles along the axes. The 1D GaN nanomaterials prepared from Ga nanowires filled into CNTs displayed two dominant morphologies: (i) single crystalline GaN nanocolumns coated by CNTs, and (ii) pure single crystalline GaN nanowires. The cross-sectional shape of GaN nanowires were analyzed through the transmission electron microscopy (TEM) images. Formation mechanism of all-mentioned 1D GaN nanomaterials is then thoroughly discussed.
A vacuum nano-casting route to magnetite cores/mesoporous silica shell composites
Authors: Guo L. M. , Shi J. L.
Published: October 2014

Hollow mesoporous silica spheres with magnetite cores (HMSMC) have been fabricated by Vacuum Nano-casting Route. The amount of magnetite cores and saturation magnetization value can be easily adjusted by changing the concentration of iron nitrate solution used in the synthesis procedure. Furthermore, the as-prepared HMSMCs still maintain narrow mesopore distribution, high surface area and large pore volume after the hollow cores of hollow mesoporous silica spheres were filled with magnetite particles. Specially, when the saturation magnetization value of as-prepared HMSMCs reaches 22.0 emu/g, the surface area and pore volume of corresponding HMSMCs are 149 m2/g and 0.19 cm3/g, respectively, and the pore size is 2.30 nm. The corresponding samples are characterized by X-ray diffraction, N2 sorption isotherms, transmission electron microscopy and vibrating-sample magnetometer.
Schottky photodiode using submicron thick diamond epilayer for flame sensing
Authors: Koide Y. , Liao M. Y. , Alvarez J. , Imura M. , Sueishi K. , Yoshifusa F.
Published: October 2014

The sensing of a flame can be performed by using wide-bandgap semiconductors, which offer a high signal-to-noise ratio since they only response the ultraviolet emission in the flame. Diamond is a robust semiconductor with a wide-bandgap of 5.5 eV, exhibiting an intrinsic solar-blindness for deep-ultraviolet (DUV) detection. In this work, by using a submicron thick boron-doped diamond epilayer grown on a type-Ib diamond substrate, a Schottky photodiode device structure- based flame sensor is demonstrated. The photodiode exhibits extremely low dark current in both forward and reverse modes due to the holes depletion in the epilayer. The photodiode has a photoconductivity gain larger than 100 and a threshold wavelength of 330 nm in the forward bias mode. CO and OH emission bands with wavelengths shorter than 330 nm in a flame light are detected at a forward voltage of −10 V. An alcohol lamp flame in the distance of 250 mm is directly detected without a focusing lens of flame light.
Ballistic current induced effective force on magnetic domain wall
Authors: Wang C. , Xia K.
Published: October 2014

The collective dynamics of magnetic domain wall under electric current is studied in the form of spin transfer torque (STT). The out-of-plane STT induced effective force is obtained based on the Landau-Lifshitz-Gilbert (LLG) equation including microscopic STT terms. The relation between microscopic calculations and collective description of the domain wall motion is established. With our numerical calculations based on tight binding free electron model, we find that the non adiabatic out-of-plane torque components have considerable non-local properties. It turns out that the calculated effective forces decay significantly with increasing domain wall widths.
Colloidal silicon nanocrystallites for low-cost solar cell development
Authors: Švrček V.
Published: October 2014

In this letter a formation of solution based of bulk-heterojunction based on freestanding silicon nanocrystals (Si-ncs) and conjugated ((poly(3-hexylthiophene) (P3HT) polymer is demonstrated. Surfactant free Si-ncs prepared by low-cost electrochemical etching are applied for fabrication of bulk-heterojunction and photo-conductive blends. We show that the optimum blend performance is at 40 wt% nanocrystallites concentration within the P3HT polymer matrix. Furthermore, we illustrate that solar cell transport properties can be improved by nanosecond laser fragmentation of the nanocrystallites micrograins in ethanol. It argues that the Si-ncs/polymer blend with refine nanocrystaline structure may impact the development of low-cost solar cells by environmental- friendly mean.
Highly ordered TiO2 nano-pore arrays fabricated from a novel polymethylmethacrylate/polydimethylsiloxane soft template
Authors: Zhong P. , Que W. X.
Published: October 2014

A novel soft polymer template containing a double-layer structure, which includes a thin layer of polymethylmethacrylate (PMMA) used as a pattern layer and a thicker layer of polydimethylsiloxane (PDMS) used as a back layer, was fabricated from a replica molding process. Anodic aluminum oxide (AAO) template was used as the replica mold to be replicated to the polymethylmethacrylate layer by a thermal infiltration process under a vacuum condition. Results indicate that PMMA/PDMS soft templates with different sizes could be easily fabricated from the as-prepared AAO replica mold. The PMMA/PDMS soft templates were then employed to imprint a TiO2 gel for achieving TiO2 nano-pore arrays. After the imprinting process, the PDMS layer was firstly peeled off and the PMMA layer was then removed into acetonitrile, which can avoid any demolding problems like damages or distortions. The TiO2 nano-pore arrays with the crystalline of anatase could be obtained at a heat treatment temperature of 450°C.
Fabrication of anatase titanium dioxide nanotubes by electroless deposition using polycarbonate for separate casting method
Authors: Boehme M. , Fu G. , Ionescu E. , Ensinger W.
Published: October 2014

Titanium dioxide nanotubes (TNTs) were prepared by electroless deposition using ion track etched polycarbonate templates. The ion tracks were prepared to the desired diameter of the TNTs outer diameter. Titanium dioxide nanotubes with a diameter of minimum 80 nm having a wall thickness of minimum 10 nm can be fabricated using this method. To achieve nanotubes with thin walls and small surface roughness the tubes were generated by a several steps procedure under aqueous conditions at nearly room temperature. The presented approach will process open end nanotubes with well defined outer diameter and wall thickness. Using this method TNT arrays up to 109 tubes per cm2 having a tube length up to 30 μm can be produced, single tubes are also possible. The structural properties of the grown TNTs were investigated by using various analytical techniques, i.e. scanning electron microscopy (SEM), energy dispersive X-ray fluoresence spectrometer (EDX), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Raman spectroscopy and Photoluminescence.
Novel micro-ring structured ZnO photoelectrode for dye-sensitized solar cell
Authors: Hossain M. F. , Zhang Z. H. , Takahashi T.
Published: October 2014

The micro-ring like structured zinc oxide (ZnO) film was deposited on SnO2: F coated glass substrate by sol-gel dip-coating technique with 1.0 g polyethylene glycol (PEG) content. The surface morphology of micro-ring structured ZnO film has been confirmed by the scanning electron microscope. This ZnO film is used to fabricate the solar cell with the help of ruthenium based dye and carbon counter electrode. The photoelectric and incident photon-to-current conversion efficiency was 1.17% and 48.4%, respectively. The DSC results have been compared with ZnO films prepared without PEG contents.
Reactive wetting behaviors of Sn/Cu systems: A molecular dynamics study
Authors: Hsieh J. Y. , Chen J. L. , Chen C. , Lin H. C. , Yang S. S. , Hwang C. C.
Published: October 2014

Influences of temperature and Sn-Cu droplet’s composition on reactive wettings of Cu(100), Cu(110), and Cu(111) surfaces were analyzed, by using molecular dynamics (MD) calculations. As a result, the spreading on Cu(110)(Cu(100)) has the fastest (slowest) wetting kinetics. A higher temperature or a diluter Cu content in the Sn-Cu alloy droplet results in a higher wettability. Moreover, this work has addressed a theory for positioning the interface separating the liquidus and solidus alloys in the spreading film to confirm the hypothesis that the reactive wetting will come to the end when the interface saturates with the temperature-dependent solidus weight fraction of Cu.
Effects of source-drain underlaps on the performance of silicon nanowire on insulator transistors
Authors: Bhowmick Sishir , Alam Khairul
Published: October 2014

The effects of source-drain underlaps on the performance of a top gate silicon nanowire on insulator transistor are studied using a three dimensional (3D) self-consistent Poisson-Schrodinger quantum simulation. Voltage-controlled tunnel barrier is the device transport physics. The off current, the on/off current ratio, and the inverse subthreshold slope are improved while the on current is degraded with underlap. The physics behind this behavior is the modulation of a tunnel barrier with underlap. The underlap primarily affects the tunneling component of drain current. About 50% contribution to the gate capacitance comes from the fringing electric fields emanating from the gate metal to the source and drain. The gate capacitance reduces with underlap, which should reduce the intrinsic switching delay and increase the intrinsic cut-off frequency. However, both the on current and the transconductance reduce with underlap, and the consequence is the increase of delay and the reduction of cut-off frequency.
Rigid polyurethane foam reinforced with cellulose whiskers: Synthesis and characterization
Authors: Li Yang , Ren Hongfeng , Ragauskas Arthur J.
Published: October 2014

A novel nanocomposite of rigid polyurethane foam was prepared by the polymerization of a sucrose-based polyol, a glycerol-based polyol and polymeric methylene diphenyl diisocyanate in the presence of cellulose whiskers. The cell morphology of the resulting foams was examined by scanning electron microscopy which showed both the pure foam and the nanocomposite foam had homogeneous cell dispersion and uniform cell size of approximately 200 μm. Analysis of the foams by Fourier transform infrared (FT-IR) spectroscopy indicated that both samples exhibited signals attributed to the polyurethane including the NH stretching and bending vibrations at 3320 cm−1 and 1530 cm−1, the OC=O vibration at 1730 cm−1 and the CO-NH vibration at 1600 cm−1. FT-IR analysis of the nanocomposite indicated that cellulose whiskers were crosslinked with the polyurethane matrix as the signal intensity of the OH stretch at 3500 cm−1 was significantly reduced in comparison to the spectral data acquired for a control sample prepared from the pure polyurethane foam mixed with cellulose whiskers. According to ASTM standard testing procedures, the tensile modulus, tensile strength and yield strength of the nanocomposite foam were found to be improved by 36.8%, 13.8% and 15.2%, and the compressive modulus and strength were enhanced by 179.9% and 143.4%, respectively. Dynamic mechanical analysis results testified the improvements of mechanical properties and showed a better thermal stability of the nanocomposite foam.
Fabrication of multi-level 3-dimension microstructures by phase inversion process
Authors: Song Y.
Published: October 2014

One process based on phase inversion of fillers in microstructures for the fabrication of multi-level three-dimensional (3-D) microstructures is described using SU-8, a kind of epoxy photoresist, as the model constructing materials. This process is depicted by use of the routine photolithography technique to construct the top layer of 3-D microstructures on the bottom layer of 3-D microstructures layer by layer. This process makes it possible to fabricate multi-level 3-D microstructures with connectors at desired locations, and to seal long span microstructures (e.g. very shallow channels with depth less than 50 μm and width more than 300 μm) without blockage. In addition, this process can provide a sealing layer by the solidification of a liquid polymer layer, which can be as strong as the bulk constructing materials for microstructures due to a complete contact and cross-linking between the sealing layer and the patterned layers. The hydrodynamic testing indicates that this kind of sealing and interconnection can endure a static pressure of more than 10 MPa overnight and a hydrodynamic pressure drop of about 5.3 MPa for more than 8 hours by pumping the tetrahydrofuran solution through a 60 μm wide micro-channels.
Synthesis, characterizations and hydrophobicity of micro/nano scaled heptadecafluorononanoic acid decorated copper nanoparticle
Authors: Chen Hung-Hsia , Anbarasan R. , Kuo Long-Sheng , Tsai Meng-Yu , Chen Ping-Hei , Chiang Kuei-Feng
Published: October 2014

Copper nanoparticle was synthesized in the presence of heptadecafluorononanoic acid by the conventional solution immersion method at room temperature from the copper plate, as a resource material. The bulk etching rate was calculated by the weight loss method. The pale green colored Cu-HDFN was characterized by Fourier transform infrared spectroscopy, UV-Visible spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy and contact angle measurements and the results are critically analyzed.
Extracellular synthesis of silver nanoparticles using dried leaves of pongamia pinnata (L) pierre
Authors: Raut Rajesh W. , Kolekar Niranjan S. , Lakkakula Jaya R. , Mendhulkar Vijay D. , Kashid Sahebrao B.
Published: October 2014

Extract of oven dried leaves of Pongamia pinnata (L) Pierre was used for the synthesis of silver nanoparticles. Stable and crystalline silver nanoparticles were formed by the treatment of aqueous solution of AgNO3 (1mM) with dried leaf extract of Pongamia pinnata (L) Pierre. UV-visible spectroscopy studies were carried out to quantify the formation of silver nanoparticles. Transmission electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopy were used to characterize the silver nanoparticles. TEM image divulges that silver nanoparticles are quite polydispersed, the size ranging from 20 nm to 50 nm with an average of 38 nm. Water soluble heterocyclic compounds such as flavones were mainly responsible for the reduction and stabilization of the nanoparticles. Silver nanoparticles were effective against Escherichia coli (ATCC 8739), Staphylococcus aureus (ATCC 6538p), Pseudomonas aeruginosa (ATCC 9027) and Klebsiella pneumoniae (clinical isolate). The move towards extracellular synthesis using dried biomass appears to be cost effective, eco-friendly to the conventional methods of nanoparticles synthesis.
A low-voltage and energy-efficient full adder cell based on carbon nanotube technology
Authors: Navi Keivan , Rad Rabe’e Sharifi , Moaiyeri Mohammad Hossein , Momeni Amir
Published: October 2014

Scaling problems and limitations of conventional silicon transistors have led the designers to exploit novel nano-technologies. One of the most promising and feasible nano-technologies is CNT (Carbon Nanotube) based transistors. In this paper, a high-speed and energy-efficient CNFET (Carbon Nanotube Field Effect Transistor) based Full Adder cell is proposed for nanotechnology. This design is simulated in various supply voltages, frequencies and load capacitors using HSPICE circuit simulator. Significant improvement is achieved in terms of speed and PDP (Power-Delay-Product) in comparison with other classical and state-of-the-art CMOS and CNFET-based designs, existing in the literature. The proposed Full Adder can also drive large load capacitance and works properly in low supply voltages.
Low-energy electronic states of carbon nanocones in an electric field
Authors: Chen Jun-Liang , Su Ming-Horng , Hwang Chi-Chuan , Lu Jian-Ming , Tsai Chia-Chang
Published: October 2014

The low-energy electronic states and energy gaps of carbon nanocones in an electric field are studied using a single-π-band tight-binding model. The analysis considers five perfect carbon nanocones with disclination angles of 60°, 120°, 180°, 240° and 300°, respectively. The numerical results reveal that the low-energy electronic states and energy gaps of a carbon nanocones are highly sensitive to its geometric shape (i.e. the disclination angle and height), and to the direction and magnitude of an electric field. The electric field causes a strong modulation of the state energies and energy gaps of the nanocones, changes their Fermi levels, and induces zero-gap transitions. The energy-gap modulation effect becomes particularly pronounced at higher strength of the applied electric field, and is strongly related to the geometric structure of the nanocone.
Performance comparison of zero-Schottky-barrier and doped contacts carbon nanotube transistors with strain applied
Authors: Wahab Md. Abdul , Alam Khairul
Published: October 2014

Atomistic quantum simulation is performed to compare the performance of zero-Schottky-barrier and doped source-drain contacts carbon nanotube field effect transistors (CNTFETs) with strain applied. The doped source-drain contact CNTFETs outperform the Schottky contact devices with and without strain applied. The off-state current in both types of contact is similar with and without strain applied. This is because both types of contact offer very similar potential barrier in off-state. However, the on-state current in doped contact devices is much higher due to better modulation of on-state potential profile, and its variation with strain is sensitive to the device contact type. The on/off current ratio and the inverse subthreshold slope are better with doped source-drain contact, and their variations with strain are relatively less sensitive to the device contact type. The channel transconductance and device switching performance are much better with doped source-drain contact, and their variations with strain are sensitive to device contact type.
Preparation and growth mechanism of nickel nanowires under applied magnetic field
Authors: Wang J. , Zhang L. Y. , Liu P. , Lan T. M. , Zhang J. , Wei L. M. , Kong Eric Siu-Wai , Jiang C. H. , Zhang Y. F.
Published: October 2014

Nickel nanowires with large aspect ratio of up to 300 have been prepared by a hydrazine hydrate reduction method under applied magnetic field. The diameter of nickel nanowires is about 200 nm and length up to 60 μm. The role of magnetic field on the growth of magnetic nanowires is discussed and a magnetic nanowire growth mechanism has been proposed. Nickel ions are firstly reduced to nickel atoms by hydrazine hydrates in a strong alkaline solution and grow into tiny spherical nanoparticles. Then, these magnetic particles will align under a magnetic force and form linear chains. Furthermore, the as-formed chains can enhance the local magnetic field and attract other magnetic particles nearby, resulting finally as linear nanowires. The formation and the size of nanowires depend strongly on the magnitude of applied magnetic field.
Optical absorption and photoelectron collection properties of silicon wafers with conical quantum nanocrystals structure
Authors: Vashpanov Yuriy , Jeong Jae-Il
Published: October 2014

A conical form of nano-sized quantum cluster was formed on the surface of p-type crystalline silicon [111] wafer by anode electrochemical etching in HF-based solution. The conical surface is highly effective in absorbing sunlight and transporting photoelectrons to semiconductor material. These are because each cone has a graded band gap with the energy level in the range from 1.1 to 3 eV which can be considered as consisting of quantum dots in different sizes. Since the boron concentration on the surface of each cone gradually decreases from top to bottom, a continuously varying electrical field is created along the cone height. This electric field is forcing photoelectrons generated in the cone to move rapidly to the direction perpendicular to wafer surface. Hence the drift time of photoelectrons can be less than their recombination time within the thin layer close to the bottom of the cone.
Reducing SU-8 hygroscopic swelling by ultrasonic treatment
Authors: Liqun Du , Benzhuang Zhang , Yaping Liu
Published: October 2014

The volume expansion of SU-8 resist brings serious dimensional errors to electroformed structures. Two approaches have been proposed to reduce resist distortions during electroforming: electroforming at room temperature and adding auxiliary features for mask patterns. However, the former method induces higher internal stresses in the electroformed metal layers. And the latter method makes it difficult to predict the expansion behaviors of the resists. In the paper, the thermal expansion of the SU-8 mould is calculated by ANSYS firstly, and the lower thermal expansion value indicates that hygroscopic swelling plays a leading role in SU-8 mould distortions. An original technique is presented to reduce SU-8 hygroscopic swelling by ultrasonic treatment. The dimensional errors of the electroformed structure fabricated on the ultrasonic treatment mould are 50% lower than the one without ultrasonic treatment. Simulation of hygroscopic swelling is conducted by finite element analysis, and the results indicate that the hygroscopic strain ε of SU-8 after electroforming is declined from 6.8% to 3.1% because of ultrasonic. The measurements show that ultrasonic treatment increased the water contact angle of cured SU-8 from 70.8° to 74.9°. Based on these results, the mechanism of ultrasonic effect on hygroscopic swelling is proposed from the view of ultrasonic vibration decreasing the number of hydroxyl groups in SU-8. The research presents a novel method to improve the precisions of electroformed structures. It has no influence on the internal stresses of final structures and does not increase the complexities of mask layouts.
Controlling Diffusion by Varying Width of Layers in Nano Channel
Authors: Goyal Ishu , Srivastava Sunita , Tankeshwar K.
Published: October 2014

Diffusive dynamics of fluid forming layers of high and low density regions in a nanochannel has been investigated. Diffusion coefficient in direction parallel and perpendicular to the confining wall has been found to show behaviour which is not observed in micro channel or bulk systems. The behaviour of diffusion is found to be controlled by the width of layers formed in nanochannel due to wall and particle interactions. This is an important result as width of layers and hence flow of fluid inside nano pores/tube can be controlled by an external source.
Five New MVL Current Mode Differential Absolute Value Circuits Based on Carbon Nano-tube Field Effect Transistors (CNTFETs)
Authors: Jamalizadeh Mojtaba , Sharifi Fazel , Moaiyeri Mohammad Hossein , Navi Keivan , Hashemipour Omid
Published: October 2014

Carbon Nano-Tube Field Effect Transistors (CNTFETs) are being widely studied as possible successors to silicon MOSFETs. Using current mode has many advantages such as performing sum operation by means of a simple wired connection. Also, direction of the current can be used to exhibit the sign of digits. It is expected that the advantages of current mode approaches will become even more important with increased speed requirements and decreased supply voltage. In this paper, we present five new circuit designs for differential absolute value in current mode logic which have been simulated by CNTFET model. The considered base current for this model is 2 µA and supply voltage is 0.9 V. In all of our designs we used N-type CNTFET current mirrors which operate as truncated difference circuits. The operation of Differential Absolute Value circuit calculates the difference between two input currents and our circuit designs are operate in 8 logic levels.
High Oxygen Nanocomposite Barrier Films Based on Xylan and Nanocrystalline Cellulose
Authors: Saxena Amit , Elder Thomas J. , Kenvin Jeffrey , Ragauskas Arthur J.
Published: October 2014

The goal of this work is to produce nanocomposite film with low oxygen permeability by casting an aqueous solution containing xylan, sorbitol and nanocrystalline cellulose. The morphology of the resulting nanocomposite films was examined by scanning electron microscopy and atomic force microscopy which showed that control films containing xylan and sorbitol had a more open structure as compared to xylan-sorbitol films containing sulfonated nanocrystalline cellulose. The average pore diameter, bulk density, porosity and tortuosity factor measurements of control xylan films and nanocomposite xylan films were examined by mercury intrusion porosimetry techniques. Xylan films reinforced with nanocrystalline cellulose were denser and exhibited higher tortuosity factor than the control xylan films. Control xylan films had average pore diameter, bulk density, porosity and tortuosity factor of 0.1730 µm, 0.6165 g/ml, 53.0161% and 1.258, respectively as compared to xylan films reinforced with 50% nanocrystalline cellulose with average pore diameter of 0.0581 µm, bulk density of 1.1513 g/ml, porosity of 22.8906% and tortuosity factor of 2.005. Oxygen transmission rate tests demonstrated that films prepared with xylan, sorbitol and 5%, 10%, 25% and 50% sulfonated nanocrystalline cellulose exhibited a significantly reduced oxygen permeability of 1.1387, 1.0933, 0.8986 and 0.1799 cm3·µm/m2·d·kPa respectively with respect to films prepared solely from xylan and sorbitol with a oxygen permeability of 189.1665 cm3·µm/m2·d·kPa. These properties suggested these nanocomposite films have promising barrier properties.
Optimised NSAIDs-loaded Biocompatible Nanoparticles
Authors: Roullin V. Gaëlle , Callewaert Maïté , Molinari Michaël , Delavoie Franck , Seconde Aurélie , Andry Marie-Christine
Published: October 2014

In this formulation study, biocompatible non steroidal anti-inflammatory (NSAIDs)-loaded nanoparticles were designed as models to be further integrated in a prosthesis surface functionalization. A modified spontaneous emulsion-solvent diffusion methodology was used to produce drug-loaded PLGA nanoparticles without any purification or solvent evaporation requirements. Formulation parameters, such as lactide/glycolide ratio, polymer concentration, solvent/non solvent ratio and non solvent phase, as well as the non ionic tensioactive P188 co-precipitation composition were systematically explored. The optimized formulation (mean size: 145 nm, surface charge: −13 mV) was employed to encapsulate various amounts of NSAIDs in a simple and scalable manner. The drug release was characterized in vitro by a complete release for 48 h. These results encourage upcoming preliminary steps for in vivo experiments of prosthesis surface functionalization.
Structural and Optical Characteristics of Silica Nanotubes Using CNTs as Template
Authors: Malekfar Rasoul , Rajabi M. Hassan , Majless Ara M. Hossein
Published: October 2014

Silica coated multi-wall carbon nanotubes (MWCNTs), silica@MWCNTs and nanocomposites were synthesized by a sol-gel method. By using the synthesized nanocomposites and also CNTs as templates, silica nanotubes (silica-NTs) were prepared. The optical properties of fabricated nanocomposites and nanotubes were characterized by back-scattering micro Raman, UV/Vis/NIR and FT-IR spectra, which show the presence of CNTs structure in the nanocomposites. UV/Vis/NIR and FT-IR spectra also show the presence of silica compounds. The recorded spectra from UV/Vis/NIR and FT-IR also confirm the presence of silica compounds in the nanotubes. The results of FE-SEM imaging data indicate that the synthesized samples are MWCNTs coated uniformly by silica molecules, which act as the template to synthesize silica-NTs.
Fabrication of a Highly Sensitive Hydrazine Electrochemical Sensor Based on Bimetallic Au-Pt Hybrid Nanocomposite onto Modified Electrode
Authors: Azadbakht Azadeh , Abbasi Amir Reza
Published: October 2014

In this research a novel nickel complex was used as electrocatalyst for electrooxidation of hydrazine. A nano-structured nickel-complex was electrodeposited on a bimetallic Au-Pt inorganic-organic hybrid nanocomposite modified electrode. The electrode possesses a three-dimensional (3D) porous network nanoarchitecture, in which the bimetallic Au-Pt NPs serving as metal nanoparticle based microelectrode ensembles are distributed in the matrix of interlaced 3, 3′, 5, 5′-Tetramethylbenzidine (TMB) organic nanofibers (NFs). Surface structure and composition of the sensor was characterized by scanning electron microscopy. Electrocatalytic oxidation of hydrazine on the surface of modified electrode was investigated with cyclic voltammetry method. The results showed that the nickel-complex films displayed excellent electrochemical catalytic activities towards hydrazine oxidation. The hydrodynamic amperometry at rotating modified electrode at constant potential versus reference electrode was used for detection of hydrazine. Under optimized conditions the calibration plots were linear in the concentration range of 0.2–85 μM and detection limit was found to be 0.1 μM. The modified electrode exhibited reproducible behavior and a high level stability during the electrochemical experiments, making it particularly suitable for the analytical purposes.
Global Public Health Impact of Recovered Supplies from Operating Rooms: A Critical Analysis with National Implications
Authors: Wan Eric L. , Xie Li , Barrett Miceile , Baltodano Pablo A. , Rivadeneira Andres F. , Noboa Jonathan , Silver Maya , Zhou Richard , Cho Suzy , Tam Tammie , Yurter Alp , Gentry Carol , Palacios Jorge , Rosson Gedge D. , Redett Richard J.
Published: October 2014

Background

In modern operating rooms, clean and unused medical supplies are routinely discarded and can be effectively recovered and redistributed abroad to alleviate the environmental burden of donor hospitals and to generate substantial health benefits at resource‐poor recipient institutions.

Methods

We established a recovery and donation program to collect clean and unused supplies for healthcare institutions in developing nations. We analyzed items donated over a 3‐year period (September 2010–November 2013) by quantity and weight, and estimated the projected value of the program under potential nationwide participation. To capture the health benefits attributable to the donated supplies at recipient institutions, we partnered with two tertiary‐care centers in Guayaquil, Ecuador and conducted a pilot study on the utility of the donated supplies at the recipient institutions (October 2013). We determined the disability‐adjusted life years (DALY) averted for all patients undergoing procedures involving donated items and estimated the annual attributable DALY as well as the cost per DALY averted both by supply and by procedure.

Results

Approximately, 2 million lbs (907,185 kg) per year of medical supplies are recoverable from large non‐rural US academic medical centers. Of these supplies, 19 common categories represent a potential for donation worth US $15 million per year, at a cost‐utility of US $2.14 per DALY averted.

Conclusions

Hospital operating rooms continue to represent a large source of recoverable surgical supplies that have demonstrable health benefits in the recipient communities. Cost‐effective recovery and need‐based donation programs can significantly alleviate the global burden of surgical diseases.
Separation of Enantiomeric Triacylglycerols by Chiral‐Phase HPLC
Authors: Řezanka Tomáš , Sigler Karel
Published: October 2014

Liquid chromatography–atmospheric pressure chemical ionization mass spectrometry (LC–MS/APCI) with a chiral phase was used for separation of triacylglycerols (TAG) obtained either by organic synthesis or isolated from different algal species. We present chromatographic characteristics and tandem mass spectra of enantiomers and positional isomers (regioisomers) of C16, C18 and C20 polyunsaturated fatty acids. The retention time was found to depend on the structure of the given TAG, increasing with increasing number of double bonds and decreasing with increasing number of the carbons in TAG, with the exception of dieicosapentaenoyl‐palmitoyl‐glycerols.
Production of Lipase from Geotrichum candidum Using Corn Steep Liquor in Different Bioreactors
Authors: Maldonado Rafael Resende , Aguiar‐Oliveira Elizama , Pozza Eduardo Luiz , Costa Fátima Aparecida Almeida , Filho Francisco Maugeri , Rodrigues Maria Isabel
Published: October 2014

The production of an extracellular lipase using corn steep liquor (CSL) as the nitrogen source in the cultivation of Geotrichum candidum NRRLY‐552 was evaluated. The optimized conditions in shake flasks were CSL, 8.0 % w/v, soybean oil, 0.6 % w/v, pH 7.0, 30 °C, 250 rpm, and 48 h, resulting in a maximum lipase productivity of 0.438 U mL−1 h−1(U = the amount of enzyme required to liberate 1 μmol of fatty acid per minute). Scale‐up was evaluated with airlift and stirred tank reactors; the best conditions, respectively, were 1 vvm(volume of gas per volume of medium per minute) of aeration which resulted in 0.535 U mL−1 h−1 (32 h) and 1 vvm and 300 rpm resulting in 0.563 U mL−1 h−1 (16 h). To facilitate downstream processes, lipase production was also evaluated using CSL previously clarified with activated charcoal resulting in 0.275 U mL−1 h−1 (24 h) using 12 % (w/v) of clarified CSL in shake flasks. The obtained results showed that CSL leads to similar productivity compared to peptone using the same microorganism under similar conditions. In addition the cost of fermentation medium using CSL is much lower because it is a very inexpensive by‐product from corn processing.
Synthesis and Diameter-dependent Thermal Conductivity of InAs Nanowires
Authors: Ren Pinyun , Zhu Xiaoli , Han Jinyun , Xu Jinyou , Ma Liang , Li Honglai , Zhuang Xiujuan , Zhou Hong , Zhang Qinglin , Xia Minggang , Pan Anlian
Published: October 2014

In this work, we synthesized high-quality InAs nanowires by a convenient chemical vapor deposition method, and developed a simple laser heating method to measure the thermal conductivity of a single InAs nanowire in air. During the measurement, a focused laser was used to heat one end of a freely suspended nanowire, with its other end embedded into a carbon conductive adhesive. In order to obtain the thermal conductivity of InAs nanowires, the heat loss in the heat transfer process was estimated, which includes the heat loss through air conduction, the heat convection, and the radiation loss. The absorption ratio of the laser power in the InAs nanowire was calculated. The result shows that the thermal conductivity of InAs nanowires monotonically increases from 6.4 W m−1 K−1 to 10.5 W m−1 K−1 with diameters increasing from 100 nm to 190 nm, which is ascribed to the enhanced phonon-boundary scattering.