bluuebunny/crossref_metadata_2025_split huggingface dataset:
Click‐Conjugation of Nanogold‐Functionalized PAMAM Dendrimer: Toward a Novel Electrochemical Detection Platform
Authors: Tang Ying , Zhang Jin , Tang Dianyon , Teng Liumei , Lv Jing , Tang Dianping 
Published: June 2015

AbstractThis work reports a new electrochemical monitoring platform for sensitive detection of Cu2+ coupling click chemistry with nanogold‐functionalized PAMAM dendrimer (AuNP‐PAMAM). The system involved an alkyne‐modified carbon electrode and an azide‐functionalized AuNP‐PAMAM. Initially, the added Cu2+ was reduced to Cu+ by the ascorbate, and then the azide‐modified AuNP‐PAMAM was covalently conjugated to the electrode via Cu+‐catalyzed azide‐alkyne click reaction. The carried AuNPs accompanying PAMAM dendrimer could be directly monitored by stripping voltammetry after acidic pretreatment. By introduction of high‐loading PAMAM dendrimer with gold nanoparticles, as low as 2.8 pM Cu2+ (ppt) could be detected, which was 125‐fold lower than that of gold nanoparticle‐based labeling strategy. The method exhibited high specificity toward target Cu2+ against other potentially interfering ions, and was applicable for monitoring Cu2+ in drinking water with satisfactory results.
Potentiostatic Electrochemical Preparation of Bismuth Nanoribbons and its Application in Biologically Poisoning Lead and Cadmium Heavy Metal Ions Detection
Authors: Devasenathipathy Rajkumar , Karthik Raj , Chen Shen‐Ming , Mani Veerappan , Vasantha V. S. , Ali M. Ajmal , Elshikh Mohamed S. , Lou Bih‐Show , Al‐Hemaid Fahad M. A. 
Published: June 2015

AbstractA simple and elegant electrochemical potentiostatic method has been described for the preparation of highly stable and electrocatalytically active bismuth nanoribbons (BiNRs). The average length and width of the BiNRs were of 100±50 nm and 10±5 µm, respectively. Here, disodium ethylene diamine tetraacetate was employed as a scaffold for the growth of BiNRs. The formation of BiNRs was confirmed by surface morphological, elemental and cyclic voltammetric analyses. The BiNRs exhibited excellent electrocatalytic ability in detecting biologically poisoning heavy metal ions such as lead and cadmium. The described BiNRs based sensor presents good linear dependence on lead and cadmium ions in the concentration range of 1–50 µg/L for both metal ions with a detection limit of 0.104 µg/L for lead and 0.145 µg/L for cadmium.
Experimental Study on Anode and Cathode Pressure Difference Control and Effects in a Proton Exchange Membrane Fuel Cell System
Authors: Li Yankun , Zhao Xingqiang , Tao Shiyong , Li Qi , Chen Weirong 
Published: June 2015

AbstractIn a proton exchange membrane fuel cell (PEMFC) system, controlling the pressure balance between the anode and the cathode reactants is very important, especially for transient processes involving big load changes. Unreasonable pressure following the control may lead to pressure imbalance, which may result in damage to the thin membranes inside the fuel cell stack. A pressure difference control method for maintaining the pressure difference on both sides of the membrane within a reasonable scope is proposed in this paper. This method is also applied in an actual PEMFC system for pressure‐balance control. In the experiments involving a 14.4 kW PEMFC system with 100 A current jumps, the pressure difference between the anode hydrogen and cathode air could be controlled within allowable values. The results reveal that the proposed method can be used to control the anode inlet pressure more simply and rapidly following the cathode pressure changes, which could be more effective for membrane protection.
A Tale of Two Mounts: The History of Chemistry at the Hebrew University of Jerusalem
Authors: Shaik Sason 
Published: June 2015

AbstractThis is the story of the establishment of the Hebrew University (HU), and within it, the sub‐story of the first school of chemistry in the Land of Israel, from 1923. It spans more than 100 years, from the publication of the pamphlet, Eine Jüdische Hochschule, in 1902, all the way to 2015. The story starts with a dream, almost in the realm of science fiction, the audacious vision of building a university in a stateless and impoverished region, and all the way to an Institute of Chemistry of HU that has served as the mother of chemistry in the State of Israel.
The effect of an alginate carrier on bone formation in a hydroxyapatite scaffold
Authors: Coathup Melanie J. , Edwards Thomas C. , Samizadeh Sorousheh , Lo Wei‐Jen , Blunn Gordon W. 
Published: June 2015

AbstractThis study investigated the osteoconductive properties of a porous hydroxyapatite (HA) scaffold manufactured using a novel technique similar to the bread‐making process, alone and in combination with an alginate polysaccharide fiber gel (HA/APFG putty) and autologous bone marrow aspirate (BMA). The hypothesis was that the HA/APFG putty would be as osteoconductive as granular HA and that the presence of BMA would further enhance bone formation in an ovine femoral condyle critical defect model. Thirty‐six defects were created and either (1) porous HA granules, (2) HA/APFG putty, or (3) HA/APFG putty + BMA were implanted. After retrieval at 6 and 12 weeks, image analysis techniques were used to quantify bone apposition rates, new bone area, bone–HA scaffold contact, and implant resorption. At 6 weeks postsurgery, significantly lower bone apposition rates were observed in the HA/APFG putty group when compared to the HA (p = 0.014) and HA/APFG putty + BMA (p = 0.014) groups. At 12 weeks, significantly increased amounts of new bone formation were measured within the HA scaffold (33.56 ± 3.53%) when compared to both the HA/APFG putty (16.69 ± 2.7%;p = 0.043) and the defects containing HA/APFG putty + BMA (19.31 ± 3.8%;p = 0.043). The use of an APFG gel as a carrier for injectable CaP bone substitute materials delayed bone formation in this model compared to HA granules alone which enhanced bone formation especially within the interconnected smaller pores. Our results also showed that the addition of autologous BMA did not further enhance its osteoconductive properties. Further study is required to optimize the degradation rate of this APFG binding agent before using as a directly injectable material for repair of bone defect. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1328–1335, 2016.
Accumulation of γ‐aminobutyric acid in soybean by hypoxia germination and freeze–thawing incubation
Authors: Yang Runqiang , Feng Li , Wang Shufang , Yu Nanjing , Gu Zhenxin 
Published: June 2015

AbstractBACKGROUNDγ‐Aminobutyric acid (GABA) can be synthesised by the GABA shunt and polyamine degradation pathway in plants under hypoxia stress and lower temperature. The hypoxia germination freeze–thawing incubation was used as a new technique for accumulating more GABA in soybean.RESULTSResults showed that glutamate decarboxylase (GAD) and diamine oxidase (DAO) activity as well as GABA content increased during germination within 24 h under hypoxia. However, the contents of dry matters and protein decreased. When the hypoxia‐treated sprouts were frozen at −18 °C for 12 h and thawed at 25 °C for 6 h, GABA content increased drastically to 7.21‐fold of the non‐frozen sprouts. Subsequently, the freeze–thawing sprouts were ground into homogenates and incubated. GABA content was 14.20‐fold of the only‐soaked seeds when homogenates was incubated at 45 °C for 80 min within 400 µmol L−1 pyridoxine (VB6) (pH 6.5).CONCLUSIONThe hypoxia germination freeze–thawing incubation was an effective method for accumulating GABA in soybean. During incubation, DAO was more important for GABA formation in homogenate of germinated soybean compared with GAD. © 2015 Society of Chemical Industry
Comparative analysis of the antioxidant and anticancer activities of chestnut inner shell extracts prepared with various solvents
Authors: Jung Byeong Su , Lee Na‐Kyoung , Na Da Som , Yu Hwan Hee , Paik Hyun‐Dong 
Published: June 2015

AbstractBACKGROUNDThe chestnut inner shell (CIS) has long been used as a medicinal herb for strengthening the antioxidant in the cosmetic industry. However, little is known about the antioxidant and anticancer effects of the CIS.RESULTSThe antioxidant and anticancer effects of CIS extracts (CISEs) were investigated by the use of various methods and cancer cell lines, respectively. The total polyphenol content of CISEs using ethanol, methanol, butanol, ethyl acetate and water were 53.30, 43.98, 32.16, 26.79 and 11.53 mg gallic acid equivalents g−1, respectively. The CISEs using ethanol and methanol exhibited high antioxidant activities in the 1,1‐diphenyl‐2‐picrylhydrazyl radical scavenging activity, β‐carotene bleaching and ferric reducing ability of plasma assays; the effects were equivalent to those of butylated hydroxytoluene. All CISEs at 2.5 mg mL−1 were shown to have a cytotoxic effect over 50%, and the CISE using ethyl acetate at 0.6 mg mL−1 was proved to have 90% cytotoxic effect against the tested cancer cells.CONCLUSIONThe ethanol and methanol CISEs had potent antioxidant effects, and the ethyl acetate CISE had the highest cytotoxicity. These results suggest that CISEs could be used as functional ingredients for antioxidant and anticancer effects in foods as extraction solvents. © 2015 Society of Chemical Industry
Composite Beads Based on Chitosan and a Synthetic Polycation with Sorption Properties Modulated by the Cross‐Linking Strategy
Authors: Dragan Ecaterina Stela , Cocarta Ana Irina 
Published: June 2015

SummaryA comparative study on the relation between the cross‐linking strategy and binding capacity of Cu2+, and Ni2+, of some novel composite beads based on chitosan (CS) and poly(vinylamine) (PVAm), is presented in the paper. The equilibrium sorption capacity of the metal ions onto the CS/PVAm composite beads was strongly depending on the cross‐linking strategy, and on the metal ion. Thus, the maximum sorption capacity values obtained by fitting the Langmuir isotherm on the data at 25 °C were 192.57 mg Cu2+/g, and 175.05 mg Ni2+/g, for the in‐situ cross‐linked beads, and 166.55 mg Cu2+/g, and 130.97 mg Ni2+/g, for the post‐cross‐linked beads.
Crosslinking Copolymerization of Vinyl Monomers Using Non‐Vinyl Crosslinker: Morpholine Substituted Poly (vinyl methyl ketone)
Authors: Ince Ahmet , Bicak Niyazi 
Published: June 2015

SummaryMorpholine substituted poly(vinyl methyl ketone) (MSP) is presented as non‐vinyl crosslinker forming insoluble polymers in polymerization of vinyl monomers. In this process, crosslinking occurs via double bonds in situ formed by thermal de‐amination of MSP above 70 °C as demonstrated in polymerization of methylmethacrylate (MMA), styrene and 4‐vinyl pyridine (4‐VP) monomers.
Polymerization of Aniline in Microemulsion by Catalytic Air Oxidation
Authors: Kumru Baris , Bicak Niyazi 
Published: June 2015

SummaryA copper catalyzed air oxidation process is presented for polymerization of aniline in a microemulsion constituting with cetyltrimethylammonium chloride (CTAC) and n‐butanol. The process was demonstrated to give stable and pitch‐dark emulsions of Emeraldine base in molecular weights of 33800 Da, as inferred from the capillary viscometer. A fairly linear viscosity‐conversion relation was noted in each case up to 95.0% of conversion. Differential light scattering (DLS) measurements showed 70 nm of average particle size for the polyaniline (PANI) in the emulsion. Conductivities measured by four‐ point probe technique indicated conductivities 8.3×10−8 and 9.8 Scm−1 for un‐doped and doped PANI.
The Synthesis of Bio‐Based Flame‐Retarded Epoxy‐Precursors
Authors: Keglevich György , Bagi Péter , Rapi Zsolt , Bakó Péter , Drahos László , Szolnoki Beáta , Marosi György 
Published: June 2015

SummaryThe synthesis of phosphorylated di‐ and triallyl glucopyranosides was elaborated that may be regarded as precursors of bio‐based monomers having potential flame‐retardant properties. In a separate series of experiments, the phosphorylation of methyl‐α‐d‐glucopyranoside was also investigated.
Preparation of the Poly(styrene) Based Imidazole Containing Quaternary Chloroacetamide Modified Sorbent for Removal of Phenol
Authors: Bildik Fatih , Yavuz Erdem , Sismanoglu Tuba , Filiz Senkal Bahire 
Published: June 2015

SummaryCrosslinked copolymer beads were prepared by suspension polymerization of 4‐vinylbenzyl chloride (VBC) and ethyleneglycole dimethacrylate (EGDMA) mixtures. The resulting copolymer beads with quaternary amide functions were prepared in two steps: (1) modification of imidazole with PVBC and (2) quaternization of imidazole modified beads with chloroacetamide. The resulting polymer resin, which had a chloroacetamide content of 4.50 mmol/g, was effective in extracting phenol from aqueous solutions. The phenol sorption capacity was around 0.208 g phenol/g resin in non‐buffered conditions. The adsorption conditions (initial phenol concentration and pH) were varied to evaluate the mechanism of adsorption of phenol on the prepared resin. This resin is also able to remove phenol completely even from highly diluted aqueous phenol solutions.
Semicontinuous Emulsion Copolymerization of Vinyl acetate and Butyl acrylate with Nonionic Surfactants (Triton X Series)
Authors: Karacetin Gülsüm , Sarac Ayfer 
Published: June 2015

SummaryIn this study, the copolymerization of vinyl acetate (VAc) and butyl acrylate (BuA) in water semicontinuous emulsions made with the nonionic surfactants, Triton Xs, was studied as a function number of ethylene oxide (EO, X) and their concentrations. The copolymerization of VAc and BuA was initiated by peroxide at proper temperature in order to improve the efficiency of droplet nucleation and maintain the stability of the emulsion. The effects of EO's in the surfactant structure and surfactant concentration on latex colloidal and physicochemical properties were investigated.
A new biopolymer substrate‐based compact monopole antenna covering RFID, WiMAX, and C/X‐band
Authors: Ahsan Md Rezwanul , Islam Mohammad Tariqul , Ullah Mohammad Habib 
Published: June 2015

ABSTRACTA simple design, compact size, multiband monopole antenna comprises of wide arcs and square slots on its radiating element is proposed in this article. After successful completion of the numerical simulation, the proposed antenna has been fabricated with its optimum parameters on 1.0 mm thick 24 × 17 mm2 custom‐made biopolymer substrate with relative dielectric constant εr = 10.0 and loss tangent 0.002. The experimental results obtained from the antenna prototype have been validated with numerical results and they are well matched. The measured data confirms the bandwidth for S11 <−10 dB are of 712 MHz (90.3%), 1.38 GHz (41.3%), 2.46 GHz (30.7%) at 0.788, 3.34, and 8.01 GHz band, respectively. The antenna prototype shows almost symmetrical radiation patterns with maximum measured gain of 1.37, 2.8, and 3.56 dBi for lower, middle, and highest frequency band, respectively. Based on the excellent matching, wide bandwidth, stable radiation, and acceptable gain performance, the compact size monopole antenna finds its potential application in RFID, WiMAX, and C/X‐band applications. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2002–2005, 2015
Bandwidth enhancement in compact dual open‐loop antenna for UHF near‐field RFID reader
Authors: Chen Hua‐Ming , Lin Yi‐Fang , Chen Chien‐Hung , Hsu Jui‐Chan 
Published: June 2015

ABSTRACTA compact dual open‐loop antenna is proposed to provide enhanced bandwidth in near‐field applications in the ultra‐high frequency band. The antenna generates a strong and uniform magnetic field in a near‐field zone of the smaller open‐loop antenna. For increased bandwidth, two open loops with individual half‐wavelength perimeters are etched on each side of an FR4 printed circuit board. The antenna was fabricated in a compact overall size (dimensions, 60 × 60 × 0.8 mm3) and achieves an interrogation zone of 50 × 50 mm2 with good impedance matching and uniform magnetic field distribution in a 888–932 MHz band. Performance tests indicate that the proposed antenna has a reading distance of up to 130 mm for near‐field applications and is suitable for radio frequency identification reader applications. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2008–2012, 2015
Rectangular waveguide fed DRA using tapered waveguide section
Authors: Jasmine P. M. , Abdulla P. , Raphika P. M. 
Published: June 2015

ABSTRACTA novel technique for coupling enhancement of rectangular waveguide fed hemispherical dielectric resonator antenna (DRA) is presented in this article. Waveguide with tapered section at the end is terminated by a thick ground plane and a slot is cut at the center of the ground plane for exciting the DRA. Introduction of tapering at the end of the waveguide provides substantial improvement in matching between the waveguide and DRA. The effects of different antenna parameters on return loss characteristics are studied. The experimental results show reasonable agreement with simulated results. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2025–2028, 2015
The effect of the gate‐drain distance on high frequency and noise performance for AlGaN/GaN HEMT
Authors: Shen Li , Chen Bo , Sun Ling , Gao Jianjun 
Published: June 2015

ABSTRACTThe influence of the gate‐drain distance on high frequency and noise performance of AlGaN/GaN high electron mobility transistors (HEMT) is investigated in this article. AlGaN/GaN HEMTs with three different gate‐drain separation structures are fabricated using 0.25 μm gatelength process, and a detailed comparative study on their device performances is performed. Small signal model parameters are determined from S‐parameter on‐wafer measurement up to 40 GHz, and the noise parameters are determined up to 18 GHz based on 50 Ω noise figure on‐wafer measurement system. The variation of intrinsic small signal model parameters and noise model parameters with different gate‐drain separation is studied. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2020–2023, 2015
High efficiency power amplifier with frequency band selective matching networks
Authors: Jeong Junhyung , Kim Phirun , Jeong Yongchae 
Published: June 2015

ABSTRACTIn this article, a high efficiency power amplifier (PA) with frequency selective matching networks (MNs) that can provide passband impedance matching as well as suppression of out‐of‐band signals simultaneously is proposed. The proposed frequency selective MN consists of a λ/4 length coupled line, a λ/2 length open step‐impedance resonator stub, and a λ/6 length bias line terminated with a bypass capacitor. For experimental validation, the PA with input and output frequency selective MNs is designed and fabricated for the US PCS band (1.93–1.99 GHz). The measurement results show that the output power and power add efficiency are 43 dBm and 70.3%, respectively, at the center frequency of 1.96 GHz, and the out‐of‐band suppression is higher than 32 dB. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2031–2034, 2015
Design of a high‐sensitivity ground radiation antenna for wireless headsets
Authors: Zhang Rui , Liu Yang , Kim Hyunghoon , Kim Hyeongdong 
Published: June 2015

ABSTRACTA slot‐type ground radiation antenna and a high‐speed digital circuit are modeled within a Bluetooth headset to demonstrate a useful method to reduce high‐speed digital noise. The method of noise reduction is based on the theory of characteristic modes. Modifying the structure of the antenna and thereby changing the characteristic mode excited by the antenna leads to decoupling between the antenna and the circuit, achieving the high‐sensitivity property of the antenna. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2104–2108, 2015
Compact triple band‐notched printed antenna with multislots for UWB applications
Authors: Tang Zhi‐jun , Zhan Jie , Wu Xiao‐feng 
Published: June 2015

ABSTRACTA novel compact planar printed antenna is designed and analyzed for ultrawideband wireless applications. The proposed antenna is constructed by a circular patch with a circular split‐ring slot gradually varying the width, a U‐shaped slot, a small strip slot, and a segmental ground plane with three slits. To broaden the bandwidth and produce notches, three different type slots are incorporated in the antenna radiating patch, and multiple slits are embedded onto the defected ground plane. The simulated and measured results show that the antenna yields a wider bandwidth ranging from 2.9 to 13.0 GHz (the return loss less than −10 dB) with the three notched bands of 3.30–3.70 GHz (WiMAX band), 4.50–4.83 GHz (Receiving frequency for INSAT/Super‐Extended C‐band), and 6.67–7.15 GHz (Transmitting frequency for INSAT/Super‐Extended C‐band). Furthermore, the proposed antenna has achieved average peak gain of 5.50 dBi and stable quasi‐omnidirectional radiation patterns. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2056–2060, 2015
Two axis direction finding antenna system using sum–difference patterns in X band
Authors: Shaikh Sarmad Ahmed , Tekin Ibrahim 
Published: June 2015

ABSTRACTThis work proposes the direction finding antenna system in two axis (θ1, θ2) in X band using sum (Σ) and difference (Δ) patterns of received signal. Direction finding system is constructed by implementing the microstrip patch antenna array and 180° hybrid rat race ring coupler which generates Σ and Δ patterns of received RF signal. Initially, direction of arrival (DOA) is obtained in one axis, (θ1), vertical direction, using the Σ–Δ patterns of antenna array of two elements. Using the equations of Σ and Δ of two input signals, radiation patterns at different θ values have been observed in simulation and compared with measured pattern values of constructed circuit. By taking the ratio of Δ to Σ patterns, DOA has been estimated of designed circuit. Another circuit similar to first circuit, oriented at 90° (horizontal direction) has been implemented to estimate the DOA (θ2) in other axis. By taking the 3D radiation patterns of each circuit in anechoic chamber, both circuits are measured for performance; and from 0 to ±40°, DOA has been observed with rms error of less than 5° in both axis. At 10 GHz operating frequency, experimental results, using material RT Duroid 5880, show that satisfactory performance can be achieved with proposed setup. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2085–2092, 2015
Dual‐band Wilkinson power divider constructed using I‐shaped lines
Authors: Chin Kuo‐Sheng , Lin Tzu‐Chiang , Chang Chih‐Chun , Wang Yu‐Chung , Kuo Hao‐Che , Hu Jyun‐Yi 
Published: June 2015

ABSTRACTDual‐band Wilkinson power dividers were constructed using I‐shaped lines. Inserting a stepped‐impedance stub in the middle of the lines could induce a shunt susceptance to achieve dual‐band 90° operation. The proposed circuit structure and synthesis equation had two degrees of freedom which could be exploited to reduce the impedance and length of the lines. An experimental 2.4/5.2 GHz Wilkinson power divider was demonstrated. The measurement shows S21 = −3.24 dB and S31 = −3.21 dB at 2.4 GHz and S21 = −3.26 dB and S31 = −3.37 dB at 5.2 GHz. The measured isolation level was 35.95 dB (2.4 GHz) and 36.57 dB (5.2 GHz). © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2034–2037, 2015
Predicting the return loss performance of a hexa‐band PIFA using ANFIS
Authors: Gehani Aarti , Pujara Dhaval A. 
Published: June 2015

ABSTRACTThis letter presents the application of Adaptive Neuro Fuzzy Inference System (ANFIS) for predicting the return loss performance of a hexa‐band Planar Inverted‐F Antenna (PIFA). The PIFA physical parameters were given as inputs to the model, while the antenna return loss characteristics was obtained as the output. The return loss thus obtained was compared with the measured return loss and it was found in close agreement. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2072–2075, 2015