Journal of Spectroscopy http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2015 , Hindawi Publishing Corporation . All rights reserved. Spin-Glass Behavior, Magnetic, and IR Spectroscopy Analysis of Multimetallic Compound Ni0.25Mn1.25[Fe(CN)6]·6.1H2O Tue, 04 Aug 2015 13:16:23 +0000 http://www.hindawi.com/journals/jspec/2015/385215/ Multimetallic Prussian blue compound Ni0.25Mn1.25[Fe(CN)6]·6.1H2O has been prepared by coprecipitation. The temperature-dependent magnetic susceptibilities show the magnet transition for the compound at 8.5 K. According to DC variable-temperature magnetic susceptibility paramagnetic Curie temperature is −9.32 K. The observed value of coercive field (Hc) and the remanent magnetization (Mr) for the compound are 0.32 KOe and 0.36 . According to study of zero-field-cooled (ZFC) and field-cooled (FC) magnetization curves and AC magnetization curves, there exists a spin-glass behaviour in the compound, which exhibits freezing temperature  K, below magnetic transition  K; that glass behavior is termed “reentrant” spin glass. Qing Lin, Xiaofang Liu, Yun He, Haifu Huang, and Xingcan Shen Copyright © 2015 Qing Lin et al. All rights reserved. Development and Characterization of Biocompatible Fullerene [C60]/Amphiphilic Block Copolymer Nanocomposite Tue, 04 Aug 2015 13:05:33 +0000 http://www.hindawi.com/journals/jspec/2015/578160/ We report a supramolecular process for the synthesis of well-defined fullerene (C60)/polymer colloid nanocomposites in an aqueous solution via complex formation. A biocompatible triblock poly(4-vinylpyridine)-b-polyethylene-b-poly(4-vinylpyridine), P4VP8-b-PEO105-b-P4VP8, was synthesized by atom transfer radical polymerization. The block copolymer formed complexes with C60 in toluene and resulted in fullerene assembly in cluster form. Nanocomposite dispersion in an aqueous solution could be obtained using an aged solution of the polymer/C60/toluene solution by a solvent evaporation technique. The UV-Vis and FTIR spectroscopy confirmed the complex formation of fullerene with the polymer which plays a significant role in controlling the PDI and size of polymer/C60 micelles in the toluene solution. The particle size and morphology of P4VP8-b-PEO105-b-P4VP8 and P4VP8-b-PEO105-b-P4VP8/C60 mixture were studied by dynamic light scattering (DLS) and transmission electron microscopy (TEM). In a cytotoxicity test, both pure polymer and the resulting polymer/C60 composite in water showed more than 90% cell viability at 1 mg/mL concentration. Alok Chaurasia, Nando Gopal Sahoo, James T. McLeskey Jr., and Xiao Hu Copyright © 2015 Alok Chaurasia et al. All rights reserved. Raman Spectroscopy for Understanding of Lithium Intercalation into Graphite in Propylene Carbonated-Based Solutions Tue, 04 Aug 2015 12:44:54 +0000 http://www.hindawi.com/journals/jspec/2015/323649/ Electrochemical lithium intercalation within graphite was investigated in propylene carbonate (PC) containing different concentrations, 0.4, 0.9, 1.2, 2.2, 2.8, 3.8, and 4.7 mol dm−3, of lithium perchlorate, LiClO4. Lithium ion was reversibly intercalated into and deintercalated from graphite in 3.8 and 4.7 mol dm−3 solutions despite the use of pure PC as the solvent. However, ceaseless solvent decomposition and intense exfoliation of the graphene layers occurred in other solutions. The results of the Raman spectroscopic analysis indicated that contact ion pairs are present in 3.8 and 4.7 mol dm−3 solutions, which suggested that the presence of contact ion pairs is an important factor that determines the solid electrolyte interphase- (SEI-) forming ability in PC-based electrolytes. Yang-Soo Kim and Soon-Ki Jeong Copyright © 2015 Yang-Soo Kim and Soon-Ki Jeong. All rights reserved. Solar Photocatalytic Degradation of Typical Indoor Air Pollutants Using TiO2 Thin Film Codoped with Iron(III) and Nitrogen Tue, 04 Aug 2015 11:12:24 +0000 http://www.hindawi.com/journals/jspec/2015/259829/ A type of iron and nitrogen codoped titania thin film was prepared by sol-gel method to degrade three typical indoor air pollutants: formaldehyde (HCHO), ammonia (NH3), and benzene (C6H6) under solar light. X-ray diffraction (XRD), UV-Vis spectroscopy, and energy dispersive spectra (EDS) were employed to characterize the photocatalysts. The results showed that the Fe/N codoped TiO2 had a stronger absorption in the visible region than pure, Fe-doped, and N-doped TiO2 and exhibited excellent photocatalytic ability for the degradation of indoor HCHO, NH3, and C6H6. When the three pollutants existed in indoor air at the same time, the removal percentages of HCHO, NH3, or C6H6 after 6 h photocatalytic reaction under solar light reached 48.8%, 50.6%, and 32.0%. The degradation reaction of the three pollutants followed the pseudo-first-order kinetics with the reaction rate constants in the order of 0.110 h−1 for ammonia, 0.109 h−1 for formaldehyde, and 0.060 h−1 for benzene. The reaction rate constant decreased with the increase of initial reactant concentration, which reflected that there was oxidation competition between the substrate and its intermediate during the photocatalytic process. Shuaijie Wang and Xingxing Cheng Copyright © 2015 Shuaijie Wang and Xingxing Cheng. All rights reserved. Effect of Contact Time and Gas Component on Interfacial Tension of CO2/Crude Oil System by Pendant Drop Method Mon, 03 Aug 2015 14:29:11 +0000 http://www.hindawi.com/journals/jspec/2015/285891/ Pendant drop method has been used to measure the equilibrium interfacial tension and dynamic interfacial tension of CO2/crude oil system under the simulated-formation condition, in which the temperature is 355.65 K and pressure ranges from 0 MPa to 30 MPa. The test results indicated that the equilibrium interfacial tension of CO2/crude oil systems decreased with the increase of the systematic pressure. The dynamic interfacial tension of CO2/original oil, CO2/remaining oil, and CO2/produced oil systems is large at the initial contact and decreases gradually after that, and then finally it reaches dynamic balance. In addition, the higher the pressure is, the larger the magnitude of changing of CO2/crude oil interfacial tension with time will reduce. Moreover, by PVT phase experiment, gas-oil ratio, gas composition, and well fluid composition have been got, and different contents of light components in three oil samples under reservoir conditions have also been calculated. The relationship between equilibrium interfacial tensions and pressures of three different components of crude oil and CO2 system was studied, and the higher C1 is, the lower C2–C10 will be, and the equilibrium interfacial tension will get higher. Therefore, the effect of light weight fractions on interfacial tension under formation conditions was studied. Xin Wang, Lifeng Liu, Zengmin Lun, Chengyuan Lv, Rui Wang, Haitao Wang, and Dong Zhang Copyright © 2015 Xin Wang et al. All rights reserved. Preparation and Application of Titanate Nanotubes on Dye Degradation from Aqueous Media by UV Irradiation Mon, 03 Aug 2015 13:25:13 +0000 http://www.hindawi.com/journals/jspec/2015/680183/ Titanate nanotubes were synthesized by a hydrothermal method using commercial TiO2 powder and then used as a photocatalyst. The titanate nanotubes were synthesized by varying the hydrothermal temperature from 110°C to 180°C. The morphological changes and phase transformation of the TiO2 nanotubes were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The particles’ scattering behavior was investigated by Raman studies, and the surface area of the nanotubes was determined by a Brunauer, Emmett, and Teller (BET) analysis. Comparative studies show that the surface area of nanotubes increases with increasing temperature up to 130°C. The catalytic behavior of the synthesized nanotubes was also studied. The as-prepared titanate nanotubes were applied to methylene blue (MB, an organic dye) degradation in aqueous media by UV irradiation. Approximately 99% of the dye was removed from the aqueous media using 2 g/L titanate nanotube when the initial dye concentration was 9 mg/L. The total irradiation time was 2 h. Rui Liu, Wein-Duo Yang, Hui-Ju Chueng, and Bin-Qiao Ren Copyright © 2015 Rui Liu et al. All rights reserved. Effects of Chlorinated Polypropylene on the Conformation of Polypropylene in Polypropylene/Chlorinated Polypropylene/Polyaniline Composites Mon, 03 Aug 2015 12:20:21 +0000 http://www.hindawi.com/journals/jspec/2015/317813/ We investigated the changes in the conformation and crystalline structure of polypropylene (PP) using a combination of Fourier transform infrared spectroscopy (FTIR), wide-angle X-ray diffraction (WAXD), and differential scanning calorimetry (DSC) based on PP/chlorinated PP (CPP)/polyaniline (PANI) composites. The DSC heating thermograms and WAXD patterns of the PP/CPP/PANI composites showed that the β-crystal was affected greatly by the CPP content. Characterization of the specific regularity in the infrared band variation showed that the conformational orders of the helical sequences in PP exhibited major changes that depended on the CPP content. Initially, the intensity ratio of increased with the CPP concentration and reached its maximum level when the CPP content was <13.22% before decreasing as the CPP content increased further. The effect of increased temperature on the conformation of PP was studied by in situ FTIR. Initially, the intensity ratio of decreased slowly with increasing the temperature up to 105°C before decreasing sharply with further increases in temperature and then decreasing slowly again when the temperature was higher than 128°C. Jianjun Chen, Yueyue Jia, Zhiye Zhang, Xinlong Wang, and Lin Yang Copyright © 2015 Jianjun Chen et al. All rights reserved. Laser Raman Spectroscopy with Different Excitation Sources and Extension to Surface Enhanced Raman Spectroscopy Mon, 03 Aug 2015 11:57:25 +0000 http://www.hindawi.com/journals/jspec/2015/895317/ A dispersive Raman spectrometer was used with three different excitation sources (Argon-ion, He-Ne, and Diode lasers operating at 514.5 nm, 633 nm, and 782 nm, resp.). The system was employed to a variety of Raman active compounds. Many of the compounds exhibit very strong fluorescence while being excited with a laser emitting at UV-VIS region, hereby imposing severe limitation to the detection efficiency of the particular Raman system. The Raman system with variable excitation laser sources provided us with a desired flexibility toward the suppression of unwanted fluorescence signal. With this Raman system, we could detect and specify the different vibrational modes of various hazardous organic compounds and some typical dyes (both fluorescent and nonfluorescent). We then compared those results with the ones reported in literature and found the deviation within the range of ±2 cm−1, which indicates reasonable accuracy and usability of the Raman system. Then, the surface enhancement technique of Raman spectrum was employed to the present system. To this end, we used chemically prepared colloidal suspension of silver nanoparticles as substrate and Rhodamine 6G as probe. We could observe significant enhancement of Raman signal from Rhodamine 6G using the colloidal solution of silver nanoparticles the average magnitude of which is estimated to be 103. Md. Wahadoszamen, Arifur Rahaman, Nabil Md. Rakinul Hoque, Aminul I Talukder, Kazi Monowar Abedin, and A. F. M. Yusuf Haider Copyright © 2015 Md. Wahadoszamen et al. All rights reserved. Improving Hyperspectral Image Classification Method for Fine Land Use Assessment Application Using Semisupervised Machine Learning Mon, 03 Aug 2015 11:56:33 +0000 http://www.hindawi.com/journals/jspec/2015/969185/ Study on land use/cover can reflect changing rules of population, economy, agricultural structure adjustment, policy, and traffic and provide better service for the regional economic development and urban evolution. The study on fine land use/cover assessment using hyperspectral image classification is a focal growing area in many fields. Semisupervised learning method which takes a large number of unlabeled samples and minority labeled samples, improving classification and predicting the accuracy effectively, has been a new research direction. In this paper, we proposed improving fine land use/cover assessment based on semisupervised hyperspectral classification method. The test analysis of study area showed that the advantages of semisupervised classification method could improve the high precision overall classification and objective assessment of land use/cover results. Chunyang Wang, Zengzhang Guo, Shuangting Wang, Liping Wang, and Chao Ma Copyright © 2015 Chunyang Wang et al. All rights reserved. Synthesis and Catalytic Performances of a Novel Zn-MOF Catalyst Bearing Nickel Chelating Diimine Carboxylate Ligands for Ethylene Oligomerization Mon, 03 Aug 2015 11:55:33 +0000 http://www.hindawi.com/journals/jspec/2015/310162/ A novel Zn-MOF[Zn3(OH)2L2] was synthesized from dicarboxylate ligands with diimine groups (1,4-bis(4-CO2HC6H4)-2,3-dimethyl-1,4-diazabutadiene). The physicochemical properties of the material were characterized by a series of technologies including XRD, SEM, and ICP. In order to adapt to the ethylene oligomerization process, a catalyst (denoted as Cat.A) possessing active Ni2+ centers was prepared by a postsynthetic treatment method using dichloride nickel as a nickel source in this work. For comparison, α-diimine ligands with/without dicarboxylic acid groups reacted with dichloride nickel to obtain homogenous Cat.B and Cat.C, respectively. The effects of reaction parameters, including n(Al)/n(Ni), temperature, and pressure on the oligomerization activities and oligomers distribution were investigated. The results demonstrated that all of catalysts used with diethylaluminum chloride were active for the ethylene oligomerization. Among them, Cat.A and Cat.B showed higher catalytic activities and higher selectivities to low-carbon α-olefins at atmospheric pressure. The Cat.A exhibited the optimal catalytic activity [6.7 × 105 g/(mol·Ni·h·atm)] for C4 (91.8%) under the conditions of Al/Ni = 1500, P = 1.0 atm, T = 20°C. In addition, Cat.A and Cat.B presented large amount of ethylene polymer, while Cat.C had a higher catalytic activity of ethylene oligomerization at high pressure. Suyan Liu, Ying Zhang, Quan Huo, Sasa He, and Yang Han Copyright © 2015 Suyan Liu et al. All rights reserved. Hydrothermal Synthesis of High Crystalline Silicalite from Rice Husk Ash Mon, 03 Aug 2015 11:28:27 +0000 http://www.hindawi.com/journals/jspec/2015/696513/ The objective of this research work was to evaluate the hydrothermal synthesis of silicalite with high crystallinity within a small particle size. The current study focused on investigating the effects of silica sources such as rice husk ash (RHA) and silica gel (SG), crystallization time, and ratios of NaOH/SiO2, H2O/NaOH, and SiO2/TPABr. The crystallinity, particle size, and morphology were characterized by FT-IR, XRD, particle size analyser, and SEM. The conclusion of the main findings indicated that the XRD patterns of these samples clearly showed a pure phase of MFI structure corresponding to FT-IR spectra with vibration mode at 550 and 1223 cm−1. The highest crystallinity was obtained at reaction time only 6 hours with the mole ratios of NaOH/SiO2, H2O/NaOH and SiO2/TPABr as 0.24, 155, and 30, respectively. When SG was used as a silica source, it was found that the particle size was smaller than that from RHA. The morphologies of all silicalite samples were coffin and cubic-like shape. Chaiwat Kongmanklang and Kunwadee Rangsriwatananon Copyright © 2015 Chaiwat Kongmanklang and Kunwadee Rangsriwatananon. All rights reserved. Evaluation of Temper Embrittlement of 30Cr2MoV Rotor Steels Using Electrochemical Impedance Spectroscopy Technique Mon, 03 Aug 2015 11:28:06 +0000 http://www.hindawi.com/journals/jspec/2015/957868/ Temper embrittlement tends to occur in the turbine rotor after long running, which refers to the decrease in notch toughness of alloy steels in a certain temperature range (e.g., 400°C to 600°C). The severity of temper embrittlement must be monitored timely to avoid further damagement, and the fracture appearance transition temperature (FATT50) is commonly used as an indicator parameter to characterize the temper embrittlement. Compared with conventional destructive methods (e.g., small punch test), nondestructive approaches have drawn significant attention in predicting the material degradation in turbine rotor steels without impairing the integrity of the components. In this paper, laboratory experiments were carried out based on a nondestructive method, electrochemical impedance spectroscopy (EIS), with groups of lab-charged specimens for predicting the temper embrittlement (FATT50) of turbine rotor steel. The results show that there was a linear relationship of interfacial impedance of the specimens and their FATT50 values. The predictive error based on the experiment study is within the range of ±15°C, indicating the predicting model is precise, effective, and reasonable. Zhang Shenghan, Lv Yaling, and Tan Yu Copyright © 2015 Zhang Shenghan et al. All rights reserved. Setting Reaction of Dental Resin-Modified Glass Ionomer Restoratives as a Function of Curing Depth and Postirradiation Time Mon, 03 Aug 2015 09:07:12 +0000 http://www.hindawi.com/journals/jspec/2015/462687/ Specular reflectance Fourier transform infrared (SR-FTIR) spectroscopy was used to study the setting reaction of dental resin-modified glass ionomer (RMGI) restoratives as a function of curing depth and postirradiation time. Two light-cure and one tri-cure RMGI materials were selected and used according to the manufacturers’ instructions. Samples were prepared by filling the mixed materials into custom-made molds and then light-irradiating using a dental curing light. The degree of conversion and the extent of acid-base reaction of the materials at different depths (0, 1, 2, and 4 mm) and postirradiation times (10 min, 1 day, and 7 days) were determined using SR-FTIR spectroscopy in conjunction with the Kramers-Kronig (K-K) transformation. The setting reaction was also investigated using microhardness measurements. The results showed that the depth of cure increased over time by the continuous acid-base reaction rather than photopolymerization or chemical polymerization. Microhardness tests seemed less suitable for studying the setting reaction as a function of postirradiation time, probably due to softening from the humidity. Analysis using specular reflectance in conjunction with the K-K algorithm was an easy and effective method for monitoring the setting reaction of dental RMGI materials. Young Kyung Kim, Kyo-Han Kim, and Tae-Yub Kwon Copyright © 2015 Young Kyung Kim et al. All rights reserved. Synthesis and Characterization of an Iron Nitride Constructed by a Novel Template of Metal Organic Framework Mon, 03 Aug 2015 08:12:49 +0000 http://www.hindawi.com/journals/jspec/2015/362103/ An iron nitride with high surface area was synthesized from an iron-based metal organic framework (Fe-MOF) in this work. During the synthesis process, the Fe-MOF of MIL-53 served as a hard template, a template to impart a certain degree of morphology for iron oxide products and to form porosities for iron nitride products. Moreover, it played the roles of iron sources for the synthesis of the final iron oxides and the iron nitrides. The physicochemical properties of the materials were characterized by a series of technologies including XRD, SEM, and N2-adsorption/desorption. The results showed that the iron nitride synthesized from MIL-53 was α-N. And, the α-N showed the morphology with loosely aggregated particles which favored the formation of rich interparticle porosities. As a result, the surface area of the α-N was larger than those of samples using α-Fe2O3 as precursors and its value was 41 m2/g. In addition, the results agreed that both raw material properties (such as crystallinity and surface areas) and nitriding approaches had significant effects on the surface areas of iron nitrides. Also the results were proved by the iron oxide synthesized with different methods. This new synthetic strategy could be a general approach for the preparation of late transition metal nitrides with peculiar properties. Suyan Liu, Quan Huo, Rongna Chen, Peipei Chen, Yuan Li, and Yang Han Copyright © 2015 Suyan Liu et al. All rights reserved. One-Step Synthesis of High-Quality Water-Soluble CdSe Quantum Dots Capped by N-Acetyl-L-cysteine via Hydrothermal Method and Their Characterization Mon, 03 Aug 2015 07:33:23 +0000 http://www.hindawi.com/journals/jspec/2015/369145/ Novel water-soluble CdSe quantum dots (QDs) have been prepared with N-acetyl-L-cysteine as new stabilizer through a one-step hydrothermal route. The influence of experimental conditions, including reaction time, molar ratio of reactants, and pH value, on the luminescent properties of the obtained CdSe QDs has been systematically investigated. The characterization of as-prepared QDs was carried out through different methods. In particular, we realized qualitative and semiquantitative studies on CdSe QDs through X-ray photoelectron spectroscopy and electron diffraction spectroscopy. The results show that the as-prepared CdSe QDs exhibit a high quantum yield (up to 26.7%), high stability, and monodispersity and might be widely used in biochemical detection and biochemical research. Chunjin Wei, Jinyu Li, Fang Gao, Shuxia Guo, Yongcui Zhou, and Dan Zhao Copyright © 2015 Chunjin Wei et al. All rights reserved. Characterization of the Key Material for Elimination of PM2.5 Particles in the Atmosphere Mon, 03 Aug 2015 07:23:59 +0000 http://www.hindawi.com/journals/jspec/2015/472019/ In recent years, with the gradual deterioration of air quality and with the more and more frequency of haze weather phenomenon, it intrudes into the human body and brings great harm to human health when people are unprepared. The basic theory that anion could purify air and eliminate positive ion explains that anion balata modified bitumen could reduce PM2.5, and the number of anion pavement release relates to the air purification. At the same time, building materials plaza and pavement materials with many functions were designed which can release negative ions, eliminate PM2.5 particles, and decompose harmful components of fuel vehicle exhaust. Bo Qiu, Qingshan Li, Wei Hong, and Guangzhong Xing Copyright © 2015 Bo Qiu et al. All rights reserved. The Drug Metabolism and Pharmacokinetics Investigation about Baicalin Effect and Baicalein on Mice U14 Cervical Cancer Mon, 03 Aug 2015 07:07:08 +0000 http://www.hindawi.com/journals/jspec/2015/632062/ The experiment studies the effect of baicalin and baicalein on mice U14 cervical cancer and its pharmacokinetics in mice. By using different mouse models of cancer treatment program administered and uptake kinetics experiments, tissue distribution experiment, excretion, and metabolism in experimental experiments, we found that baicalin and baicalein can improve immunity and the ability of antioxidation and inhibit the growth of tumor. The absorption of intestinal drug takes place in intestinal tract. Tissue distribution was ideal. Because of the ideal drug distribution, the liver and kidney were protected. Drug was mainly excreted through the feces and bile excretion. Zhanzhao Fu, Ya Di, Liming Gao, Jiandong Wu, Ming Shi, and Fulu Zheng Copyright © 2015 Zhanzhao Fu et al. All rights reserved. Infrared Spectroscopic Characterization of Photoluminescent Polymer Nanocomposites Mon, 03 Aug 2015 07:05:53 +0000 http://www.hindawi.com/journals/jspec/2015/489162/ Organicallycoated inorganic nanoparticles were synthesized to produce photoluminescent nanocomposites based on a polymethyl methacrylate (PMMA) matrix. The nanoparticles comprised organic ligands (acetylsalicylic acid, ASA, and 2-picolinic acid, PA) attached to the lanthanum trifluoride (LaF3) host crystals that were doped with optically active terbium III (Tb3+) and synthesized using solution-based methods. The ligands were employed to functionalize the surface of Tb3+:LaF3 nanocrystals to aid in dispersing the nanoparticles. In order to confirm the presence of the constituents within the inorganic-organic system, the nanoparticles were characterized by infrared spectroscopy and energy-dispersive X-ray spectroscopy. Absorption peaks observed from infrared spectroscopy for all the polymer nanocomposites loaded with organic surface treated nanocrystals exhibited peaks that were not present in undoped PMMA but were characteristic of the dopant and the ligand. Kyle Gipson, Kathryn Stevens, Phil Brown, and John Ballato Copyright © 2015 Kyle Gipson et al. All rights reserved. Raman Spectroscopy and Electrochemical Investigations of Pt Electrocatalyst Supported on Carbon Prepared through Plasma Pyrolysis of Natural Gas Tue, 28 Jul 2015 11:44:47 +0000 http://www.hindawi.com/journals/jspec/2015/329730/ Physicochemical and electrochemical characterisations of Pt-based electrocatalysts supported on carbon (Vulcan carbon, C1, and carbon produced by plasma pyrolysis of natural gas, C2) toward ethanol electrooxidation were investigated. The Pt20/C180 and Pt20/C280 electrocatalysts were prepared by thermal decomposition of polymeric precursors at 350°C. The electrochemical and physicochemical characterisations of the electrocatalysts were performed by means of X-ray diffraction (XRD), transmission electron microscope (TEM), Raman scattering, cyclic voltammetry, and chronoamperometry tests. The XRD results show that the Pt-based electrocatalysts present platinum metallic which is face-centered cubic structure. The results indicate that the Pt20/C180 electrocatalyst has a smaller particle size (10.1–6.9 nm) compared with the Pt20/C280 electrocatalyst; however, the Pt20/C280 particle sizes are similar (12.8–10.4 nm) and almost independent of the reflection planes, which suggests that the Pt crystallites grow with a radial shape. Raman results reveal that both Vulcan carbon and plasma carbon are graphite-like materials consisting mostly of sp2 carbon. Cyclic voltammetry and chronoamperometry data obtained in this study indicate that the deposition of Pt on plasma carbon increases its electrocatalytic activity toward ethanol oxidation reaction. Tereza Cristina Santos Evangelista, Giordano Toscano Paganoto, Marco Cesar Cunegundes Guimarães, and Josimar Ribeiro Copyright © 2015 Tereza Cristina Santos Evangelista et al. All rights reserved. Onset of Intense Surface Enhanced Raman Scattering and Aggregation in the Au@Ag System Tue, 28 Jul 2015 11:15:50 +0000 http://www.hindawi.com/journals/jspec/2015/676748/ Gold core/silver shell (Au@Ag) nanoparticles of ~37 ± 5 nm diameter generate intense SERS ( nm) responses in solution when they interact with the SERS labels rhodamine 6G (R6G), 4-mercaptopyridine (MPY), and 4-mercaptobenzoic acid (MBA). Herein the relationship between SERS intensity, aggregation, and adsorption phenomenon isobserved by titrating Au@Ag with the above labels. As the labels adsorb to the Au@Ag, they drive aggregation as evidenced by the creation of NIR extinction peaks, and the magnitude of this NIR extinction (measured at 830 nm) correlates very closely to magnitude of the intense SERS signals. The label MBA is an exception since it does not trigger aggregation nor does it result in intense SERS; rather intense SERS is recovered only after MBA coated Au@Ag is aggregated with KCl. An “inner filter” model is introduced and applied to compensate for solution extinction when the exciting laser radiation is significantly attenuated. This model permits a summary of the SERS responses in the form of plots of SERS intensity versus the aggregate absorption at 830 nm, which shows the excellent correlation between intense SERS and LSPR bands extinction. Priya Bhatia, Joseph Consiglio, John Diniz, Jia E. Lu, Christopher Hoff, Shelby Ritz-Schubert, and Roger H. Terrill Copyright © 2015 Priya Bhatia et al. All rights reserved. Determination of Anthracycline Drug Residual in Cleaning Validation Swabs of Stainless-Steel Equipment after Production of Cytostatic Injections Using HPLC Analytical Method Sun, 12 Jul 2015 08:00:41 +0000 http://www.hindawi.com/journals/jspec/2015/847349/ Standard cleaning procedures of production line equipment were verified after manufacture of cytostatic injections containing Anthracycline derivate substance. Residual content of Anthracycline drug substance on stainless-steel equipment surface was determined using swab sampling with a specific HPLC-DAD analysis. The acceptance limit was decided as 200.0 μg/100 cm2. Recovery from the stainless-steel surface was 90.1%. Linearity of the method was observed in the concentration range of 0.155–194 μg/mL when estimated using Zorbax TMS (5 μm, 0.25 m × 4.6 mm ID) column at 1.3 mL/min flow rate and 254 nm (DAD 190–600 nm). The mobile phase consisted of lauryl hydrogen sulphate solution (3.7 g/L) : methanol : acetonitrile (54 : 16 : 30, v/v/v) with pH adjusted to 2.5 using phosphoric acid (85%). The LOD and LOQ for Anthracycline derivate were found to be 0.047 and 0.155 μg/mL, respectively. The method validation confirmed the method provides acceptable degree of selectivity, linearity, accuracy, and precision for the intended purposes. Zuzana Slivová and Radka Opatřilová Copyright © 2015 Zuzana Slivová and Radka Opatřilová. All rights reserved. A Review of Spectral Methods for Dispersion Characterization of Carbon Nanotubes in Aqueous Suspensions Sun, 28 Jun 2015 14:38:26 +0000 http://www.hindawi.com/journals/jspec/2015/463156/ Characterization is a crucial step in the study of properties of nanomaterials to evaluate their full potential in applications. Carbon nanotube-based materials have properties that are sensitive to size, shape, concentration, and agglomeration state. It is therefore critical to quantitatively characterize these factors in situ, while the processing takes place. Traditional characterization techniques that rely on microscopy are often time consuming and in most cases provide qualitative results. Spectroscopy has been studied as an alternative tool for identifying, characterizing, and studying these materials in situ and in a quantitative way. In this paper, we provide a critical review of the spectroscopy techniques used to explore the surface properties (e.g., dispersion) characteristics of carbon nanotubes in aqueous suspensions during the sonication process. Jidraph Njuguna, O. Arda Vanli, and Richard Liang Copyright © 2015 Jidraph Njuguna et al. All rights reserved. Identification and Disease Index Inversion of Wheat Stripe Rust and Wheat Leaf Rust Based on Hyperspectral Data at Canopy Level Sun, 28 Jun 2015 14:10:43 +0000 http://www.hindawi.com/journals/jspec/2015/651810/ Stripe rust and leaf rust with similar symptoms are two important wheat diseases. In this study, to investigate a method to identify and assess the two diseases, the canopy hyperspectral data of healthy wheat, wheat in incubation period, and wheat in diseased period of the diseases were collected, respectively. After data preprocessing, three support vector machine (SVM) models for disease identification and six support vector regression (SVR) models for disease index (DI) inversion were built. The results showed that the SVM model based on wavelet packet decomposition coefficients with the overall identification accuracy of the training set equal to 99.67% and that of the testing set equal to 82.00% was better than the other two models. To improve the identification accuracy, it was suggested that a combination model could be constructed with one SVM model and two models built using K-nearest neighbors (KNN) method. Using the DI inversion SVR models, the satisfactory results were obtained for the two diseases. The results demonstrated that identification and DI inversion of stripe rust and leaf rust can be implemented based on hyperspectral data at the canopy level. Hui Wang, Feng Qin, Qi Liu, Liu Ruan, Rui Wang, Zhanhong Ma, Xiaolong Li, Pei Cheng, and Haiguang Wang Copyright © 2015 Hui Wang et al. All rights reserved. Broadband Spectroscopic Thermoacoustic Characterization of Single-Walled Carbon Nanotubes Mon, 15 Jun 2015 06:45:11 +0000 http://www.hindawi.com/journals/jspec/2015/762352/ Carbon nanotubes have attracted interest as contrast agents for biomedical imaging because they strongly absorb electromagnetic radiation in the optical and microwave regions. This study applies thermoacoustic (TA) imaging and spectroscopy to measure the frequency-dependent absorption profile of single-walled carbon nanotubes (SWNT) in the ranges of 2.7–3.1 GHz and 7–9 GHz using two tunable microwave sources. Between 7 and 9 GHz, the peak TA signal for solutions containing semiconducting and metallic SWNTs increased monotonically with a slope of 1.75 AU/GHz () and 2.8 AU/GHz (), respectively, relative to a water baseline. However, after compensating for the background signal from water, it was revealed that the TA signal from metallic SWNTs increased exponentially within this frequency band. Results suggest that TA imaging and spectroscopy could be a powerful tool for quantifying the absorption properties of SWNTs and optimizing their performance as contrast agents for imaging or heat sources for thermal therapy. Daniel R. Bauer, Xiong Wang, Jeff Vollin, Hao Xin, and Russell S. Witte Copyright © 2015 Daniel R. Bauer et al. All rights reserved. Nondestructive Detection of Blackheart in Potato by Visible/Near Infrared Transmittance Spectroscopy Sun, 14 Jun 2015 12:39:08 +0000 http://www.hindawi.com/journals/jspec/2015/786709/ The possibility of using visible/near infrared (Vis/NIR) transmission spectroscopic technique in the 513–850 nm region coupled with partial least squares-linear discriminant analysis (PLS-LDA) and other chemometric methods to classify potatoes with blackheart was investigated. The discrimination performance of different morphological correction methods, including weight correction, height correction, and volume correction, was compared. The results showed that height corrected transmittance has the best performance, with both calibration and validation sets having a success rate of 97.11%. Out of 1800 wavelengths, only six wavelengths (711, 817, 741, 839, 678, and 698 nm) were selected as the optimum wavelengths for the discrimination of blackheart tubers based on principal component analysis (PCA). The data analysis showed that the overall classification rate by PLS-LDA method decreased from 97.11% to 96.82% in calibration set and from 97.11% to 96.53% in validation set, which was acceptable. The importance of these conclusions may be helpful to transfer Vis/NIR transmission technology from laboratory to industrial application in nondestructive, real-time, or portable measurement of potatoes quality. Zhu Zhou, Songwei Zeng, Xiaoyu Li, and Jian Zheng Copyright © 2015 Zhu Zhou et al. All rights reserved. Discriminating the Geographical Origins of Chinese White Lotus Seeds by Near-Infrared Spectroscopy and Chemometrics Wed, 10 Jun 2015 12:40:30 +0000 http://www.hindawi.com/journals/jspec/2015/831246/ The traceability of a Chinese white lotus seed (WLS) with Protected Designation of Origin (PDO) was investigated using near-infrared (NIR) spectroscopy and chemometrics. Three chemometrics methods, discrimination analysis (DA), class modeling, and a newly proposed strategy, the fusion of DA and class modeling, were investigated to compare their capacity to trace the geographical origins of WLS. Least squares support vector machine (LS-SVM) was developed to distinguish the PDO WLS from non-PDO WLS of four main producing areas. A class modeling technique, one-class partial least squares (OCPLS), was developed only using the data of PDO WLS. By the fusion of LS-SVM and OCPLS, the best prediction sensitivity and specificity were 0.900 and 0.973, respectively. The results indicate that fusion of DA and class modeling can enhance the specificity for detection of non-PDO products. The conclusion is that DA and class modeling should be combined for tracing food geographical origins. Lu Xu, Chen-Bo Cai, Yuan-Bin She, and Li-Juan Chen Copyright © 2015 Lu Xu et al. All rights reserved. Spectroscopic Studies of the Behavior of Eu3+ on the Luminescence of Cadmium Tellurite Glasses Sun, 07 Jun 2015 07:40:08 +0000 http://www.hindawi.com/journals/jspec/2015/478329/ The effect of europium doping on the photoluminescence of ZnO-CdO-TeO2 glasses is analyzed. TeO2-based glasses are of high interest as hosts for laser glasses. The Eu-doped oxide glasses were prepared by the conventional melt-quenching method. Five different concentrations of europium nitrate hexahydrate that varied from 0.3 to 1.5 mol% were used. SEM observations revealed the formation of zinc aluminate spinel and disperse droplets of liquid-liquid phase separation in the glasses. X-Ray diffraction reveals the amorphous structure of the fabricated glasses. FT-IR and Raman spectra show the presence of TeO4 and TeO3+1/TeO3 units that conform with the glass matrix. Raman spectra evidenced a band located at 1556 cm−1 that can be related to interstitial molecular oxygen in the glass matrix. Photoluminescence of the glasses showed light emission due to the following europiumtransitions from its , , and levels to its manifolds: (468 nm), (490 nm), (511 nm), (536 nm), (554 nm), (579.5 nm), (592 nm), (613 nm), (652 nm), and (490 nm). The estimated decay time, , was 0.4 ms for all the glasses. I. V. García-Amaya, Ma. E. Zayas, J. Alvarado-Rivera, E. Álvarez, S. A. Gallardo-Heredia, G. A. Limón, R. Lozada-Morales, and J. Ma. Rincón Copyright © 2015 I. V. García-Amaya et al. All rights reserved. Position, Energy, and Transit Time Distributions in a Hemispherical Deflector Analyzer with Position Sensitive Detector Mon, 01 Jun 2015 08:33:21 +0000 http://www.hindawi.com/journals/jspec/2015/153513/ Practical analytic equations, for the ideal field, and numerical results from SIMION simulations, for the fringing field, are presented for the exit radius and transit time of electrons in a hemispherical deflector analyzer (HDA) over a wide range of analyzer parameters. Results are presented for a typically dimensioned HDA with mean radius  mm and interradial separation  mm able to accommodate a 40 mm diameter position sensitive detector (PSD). Results for three different entry positions are compared: (the conventional central entry) and two displaced (paracentric) entries:  mm and  mm. Exit spreads , and base energy resolution are computed for HDA pass energies , 100, 500, and 1000 eV, entry aperture sizes  mm, entry angular spreads °, and an electron beam with relative energy spread . Overall, under realistic conditions, both paracentric entries demonstrate near ideal field behavior and clear superiority over the conventional entry at . The  mm entry has better absolute energy and time spread resolutions, while the  mm has better relative energy resolutions, both offering attractive alternatives for time-of-flight and coincidence applications where both energy and timing resolutions are important. Omer Sise and Theo J. M. Zouros Copyright © 2015 Omer Sise and Theo J. M. Zouros. All rights reserved. Influence of Erbium Ions on the Optical and Structural Properties of Polyvinyl Alcohol Wed, 27 May 2015 10:14:33 +0000 http://www.hindawi.com/journals/jspec/2015/204867/ Polyvinyl alcohol (PVA) films doped with erbium chloride (ErCl3) have been prepared by casting from their aqueous solutions. The structure of the doped samples as well as the interactions between the host PVA and Er+3 was investigated using FTIR spectroscopy. The optical measurement was recorded at room temperature in the range from 200 nm to 2000 nm. FTIR measurements revealed that Er+3 forms complex configuration within the PVA structure. PVA doped with 9 wt% of ErCl3 exhibits energy gap and refractive index of 5.1 eV and 1.72, respectively. The effect of the doping increment of ErCl3 on the optical parameters has been discussed. Taymour A. Hamdalla, Taha A. Hanafy, and Ashraf E. Bekheet Copyright © 2015 Taymour A. Hamdalla et al. All rights reserved. Spectroscopic Evaluations of Interfacial Oxidative Stability of Phosphonic Nanocoatings on Magnesium Mon, 18 May 2015 12:46:15 +0000 http://www.hindawi.com/journals/jspec/2015/350630/ Magnesium (Mg), and its alloys, is being investigated for its potential biomedical applications for its use as a biodegradable metal. However surface modification strategies are needed to modify the surface of the Mg alloy for its applicability in these applications. Self-assembled monolayers (SAMs) have been investigated as a coating strategy on magnesium for biomedical applications. In this report we evaluate the oxidative interfacial stability of phosphonic nanocoatings on magnesium using spectroscopic techniques. Self-assembled mono-/multilayers (SAMs) of octadecylphosphonic acid (ODPA) were formed on the native oxide layer of magnesium alloy using solution deposition technique. The SAMs modified Mg alloy and its oxidative stability were characterized using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). FTIR studies indicated mono-/bidentate bonding of the phosphonic SAMs to the Mg alloy surface. XPS confirmed SAM formation showing presence of “P” peaks while consequently showing decrease in peak intensity of Mg peaks. XPS analysis of the phosphonate peaks showed consistent presence of this peak over a period of 21 days. AFM images showed consistent coverage of the Mg alloy over a period of 21 days. The results collectively confirm that the monolayers are stable under the chosen oxidative study. Anil Mahapatro, Taína D. Matos Negrón, and Alan Nguyen Copyright © 2015 Anil Mahapatro et al. All rights reserved.