bluuebunny/crossref_metadata_2025_split huggingface dataset:
ChemInform Abstract: Stereoselective Total Synthesis of a Novel Regiomer of Herbarumin I and Its Cytotoxic and Antimicrobial Activities.
Authors: Jangili Paramesh , Kashanna Jajula , Kumar C. Ganesh , Poornachandra Y. , Das Biswanath 
Published: April 2014

AbstractNovel regiomer of herbarumin I (I) exhibits significant cytotoxic activities against five human cancer cell lines, especially against human colon carcinoma and human breast adenocarcinoma.
ChemInform Abstract: A Facile One Pot Strategy for the Synthesis of Well‐Defined Polyacrylates from Acrylic Acid via RAFT Polymerization.
Authors: Li Qianbiao , Wang Taisheng , Dai Jingwen , Ma Chao , Jin Bangkun , Bai Ruke 
Published: April 2014

AbstractA new one‐pot procedure to synthesize linear and hyperbranched polyacrylates is reported.
ChemInform Abstract: Synthesis of Structurally Well‐Defined and Liquid‐Phase‐Processable Graphene Nanoribbons.
Authors: Feng Xinliang , et al. et al. 
Published: April 2014

AbstractLong (<200 nm) liquid‐phase‐processable graphene nanoribbons with a well‐defined structure and a large optical band gap of 1.88 eV are prepared by a bottom‐up solution synthesis through cyclodehydrogenation reactions of polyphenylene precursors with extremely high molecular weight obtained by Diels—Alder polymerization.
ChemInform Abstract: Cross‐Coupling of Heteroarenes by C—H Functionalization: Recent Progress Towards Direct Arylation and Heteroarylation Reactions Involving Heteroarenes Containing One Heteroatom
Authors: Rossi Renzo , Bellina Fabio , Lessi Marco , Manzini Chiara 
Published: April 2014

AbstractReview: results obtained from January 2009 to February 2013 in the area of transition metal‐catalyzed title arylation reactions; 430 refs.
Recyclable Heterogeneous and Low‐Loading Homogeneous Chiral Imidazolidinone Catalysts for α‐Alkylation of Aldehydes
Authors: Salvo Anna Maria Pia , Giacalone Francesco , Noto Renato , Gruttadauria Michelangelo 
Published: April 2014

AbstractTwo polystyrene‐supported and six homogeneous MacMillan imidazolidinone catalysts were prepared and tested for the asymmetric α‐alkylation of propanal with benzodithiolylium tetrafluoroborate. The chiral imidazolidinone was linked to polystyrene through the N‐3 atom or through the phenyl ring and their catalytic activity was compared with that of their unsupported precursors. This comparison has allowed us to find an unsupported catalyst that displays high catalytic activity down to 5 or 2 mol % at room temperature with a high level of enantioselectivity also when used with hexanal and 3‐phenylpropanal. In addition, one of the heterogeneous materials was revealed to be highly recyclable for at least eight cycles with no loss in efficiency working at the same levels of activity and enantioselectivity as the unsupported counterpart.
Generation of Basic Centers in High‐Silica Zeolites and their Application in Gas‐Phase Upgrading of Bio‐Oil
Authors: Keller Tobias C. , Rodrigues Elodie G. , Pérez‐Ramírez Javier 
Published: April 2014

AbstractHigh‐silica zeolites have been reported recently as efficient catalysts for liquid‐ and gas‐phase condensation reactions because of the presence of a complementary source of basicity compared to Al‐rich basic zeolites. Herein, we describe the controlled generation of these active sites on silica‐rich FAU, BEA, and MFI zeolites. Through the application of a mild base treatment in aqueous Na2CO3, alkali‐metal‐coordinating defects are generated within the zeolite whereas the porous properties are fully preserved. The resulting catalysts were applied in the gas‐phase condensation of propanal at 673 K as a model reaction for the catalytic upgrading of pyrolysis oil, for which an up to 20‐fold increased activity compared to the unmodified zeolites was attained. The moderate basicity of these new sites leads to a coke resistance superior to traditional base catalysts such as CsX and MgO, and comparable activity and excellent selectivity is achieved for the condensation pathways. Through strategic acid and base treatments and the use of magic‐angle spinning NMR spectroscopy, the nature of the active sites was investigated, which supports the theory of siloxy sites as basic centers. This contribution represents a key step in the understanding and design of high‐silica base catalysts for the intermediate deoxygenation of crude bio‐oil prior to the hydrotreating step for the production of second‐generation biofuels.
α‐Acryloylamidoalkyl Sulfones in a Synthetic Approach for the Preparation of 6‐Alkyltetrahydropyridin‐2‐ones
Authors: Lucchetti Nicola , Lancianesi Stefano , Petrini Marino 
Published: April 2014

AbstractThe reaction of allylzinc bromides with α‐acryloylamidoalkyl sulfones represents a mild and straightforward entry to the corresponding homoallylamines. These dienyl compounds successfully proceeded in a ring‐closing metathesis reaction by treatment with Grubbs II catalyst to lead to 6‐alkyltetrahydropyridin‐2‐ones. Homoallylamino derivatives that contain a branched terminal alkene moiety preferentially proceeded in cross‐metathesis reaction to give the selective formation of N‐substituted fumaramides.
The normalized topographic method: an automated procedure for gully mapping using GIS
Authors: Castillo Carlos , Taguas Encarnación V. , Zarco‐Tejada Pablo , James Mike R. , Gómez Jose A. 
Published: April 2014

ABSTRACTGully delineation is a critical aspect of accurately determining soil losses but associated methodologies are rarely detailed. Here, we describe a new gully mapping method, the normalized topographic method (NorToM), based on processing digital elevation model (DEM) data, and we assess associated errors when it is applied over a range of geomorphological scales. The NorToM is underpinned by two gully detection variables (normalized slope and elevation) calculated over local windows of prescribed size, and a group of filtering variables. For four study sites, DEMs of gullies were obtained using field and airborne photo‐reconstruction and evaluated using total station and differential global positioning system (dGPS) survey. NorToM provided accurate areal and volume estimates at the individual gully scale but differences increased at the larger gully system and gully network scales. We were able to identify optimal parameters for using the NorToM approach and so confirm that is represents a useful scale‐independent means of gully mapping that is likely to be valid in other environments. Its main limitations are that the normalization process might be time‐consuming at regional scales and the need for a fixed window size when applied to landforms with extreme variations in dimensions. Copyright © 2014 John Wiley & Sons, Ltd.
Biodegradation of Toilet Wastewaters Generated in Aircrafts
Authors: Moreno‐Andrade Iván , Moreno Gloria , Kumar Gopalakrishnan , Buitrón Germán 
Published: April 2014

AbstractWastewater generated in buses and aircrafts are known as blue water due to the addition of blue chemical products to deodorize, sanitize and break down solid waste in tank holdings. The blue water at high concentration presents inhibitory effects on microorganisms making difficult their treatment. This research evaluates the acclimation and degradation of aircraft blue water using discontinuous and continuous bioreactors. Acclimation was conducted in batch mode. In a discontinuous biological process with an initial COD concentration of 1150 mg COD/L, the removal efficiency was higher than 80% as COD, TOC and BOD5. Total Suspended Solids in the effluent were lower than 60 mg/L. In the continuous activated sludge system an initial concentration of 850 mg COD/L of blue wastewater was applied. Here, removal efficiencies up to 72 and 88% as COD and BOD5 were obtained, respectively. For both processes, the application of punctual high concentration of blue water resulted in decrease of removal efficiency (< 40%).
The effect of extraneous elements on spectral line intensity in the cathode‐layer arc
Authors: Scott R. O. 
Published: April 2014

AbstractData are given for the spectral line intensities of various trace elements in the cathode‐layer are when they are incorporated into different bases. The bases considered are alumina, silica, calcium carbonate and phosphate, sodium pyrophosphate, chloride, and carbonate. The effects on the actual line intensities and on the ratios of the line intensities to those of iron as internal standard are considered. Most trace constituents gave their highest line intensities in the alumina base, whilst the more volatile trace constituents like copper, silver, zinc, bismuth, and cadmium tended to be greatly depressed by sodium chloride. Chromium, vanadium, and molybdenum were enhanced by calcium salts and depressed by silica. Constant intensity ratios for cobalt and nickel to iron were obtained in all bases except silica.
Electrometric estimation of chloride in meat products
Authors: Ingram M. , Hawthorne J. R. 
Published: April 2014

AbstractElectrometric titration with silver nitrate in presence of nitric acid using a silver/silver chloride reference electrode has proved a simple and rapid method for the estimation of chloride in meat products. Diluted curing brines may be titrated directly; the chloride in meats cannot be titrated directly but can be almost completely extracted by two extractions merely with water.
Vitamin‐C content of vegetables. Part III. Average figures for raw vegetables
Authors: Lampitt L. H. , Baker L. C. , Parkinson T. L. 
Published: April 2014

AbstractA table summarising 850 results for the concentration of vitamin‐C in raw vegetables is given: an indication of the reliance to be placed on the average figure for any vegetable is obtained by consideration of the number of samples analysed while the degree to which an individual plant may differ from the average is shown by the range of results.
Derivatives of 4‐hydroxybenzoic acid and its methyl and n‐butyl esters. Part I. Derivatives containing substituents in the 3 and 3:5 positions
Authors: Cavill G. W. K. 
Published: April 2014

AbstractThe preparation of 3‐bromo‐, 3:5‐dibromo‐, 3‐nitro‐, 3:5‐dinitro‐, 3‐bromo‐5‐nitro‐, 3‐amino‐, 3‐bromo‐5‐amino‐, and 5‐nitro‐3‐amino‐ substitution products of 4‐hydroxybenzoic acid and of its methyl and n‐butyl esters is described. General methods for the preparation of these compounds are discussed.
The action on certain insects of fabrics impregnated with D.D.T.
Authors: Hayhurst H. 
Published: April 2014

AbstractThe reaction of certain insects to fabrics treated with D.D.T. is the basis of this paper. The results of the investigation show that infestation by insects can be controlled by the use of sacks impregnated with D.D.T. The tests were carried out on Calandra oryzae, Tribolium confusum and Ptinus tectus.
Dried egg. X. The nature of the reactions leading to loss of solubility of dried egg products
Authors: Bate‐Smith E. C. , Hawthorne J. R. 
Published: April 2014

AbstractThe changes which occur during storage in the solubility, concentration of reducing sugar, and free amino nitrogen content of dried egg products have been followed. Data are presented which indicate that the process resulting in loss of solubility takes place in at least two stages, the first involving condensation of the reducing sugar with protein amino groups. This reaction occurs without change in solubility and further reactions must therefore occur. The nature of these reactions and the effect of disaccharides and amino acids in retarding loss of solubility are discussed.
Cholesterol from wool alcohols
Authors: Picard C. W. , Seymour D. E. 
Published: April 2014

AbstractMethods for the isolation of cholesterol from wool alcohols are discussed and a process is described which is based on the formation of a cholesterol‐oxalic acid complex by reaction of the wool alcohols with anhydrous oxalic acid in ethyl acetate or benzene. The sparingly soluble complex is isolated and converted to pure cholesterol or cholesteryl acetate as desired.
Rubber photogelling agents. Part II
Authors: Stevens Henry P. 
Published: April 2014

AbstractA previous paper detailed the evaluation of oxygen and other photogelling agents under insolation. This paper deals similarly with various pro‐ and anti‐oxygens and it is shown that in small proportions all these, act as mild photogelling agents, the effect being rather abruptly reversed when the proportion exceeds the optimum. The relevant factors are discussed.
Manufacture of algal chemicals. III. Laboratory‐scale isolation of laminarin from brown marine algae
Authors: Black W. A. P. , Cornhill W. J. , Dewar E. T. , Woodward F. N. 
Published: April 2014

AbstractMethods for the isolation of laminarin from the common brown algae indigenous to Great Britain have been worked out on the laboratory scale with a view to the ultimate development of a process suitable for large‐scale production. These methods comprise treating the fresh or dried milled weed with hydrochloric acid or sulphuric acid at pH 2·4 and isolating the laminarin from the acid extract.
NDVI and vegetation phenology dynamics under the influence of sunshine duration on the Tibetan plateau
Authors: Wang Hongshuo , Liu Desheng , Lin Hui , Montenegro Alvaro , Zhu Xiaolin 
Published: April 2014

ABSTRACTClimate change has significantly influenced vegetation dynamics on the Tibetan Plateau (TP). Past research mainly focused on vegetation responses to temperature variation and water stress, but the influence of sunshine duration on NDVI and vegetation phenology on the TP is not well understood. In this study, NDVI time series from 1982–2008 were used to retrieve spatiotemporal vegetation dynamics on the TP. Empirical orthogonal function (EOF) analysis was conducted to understand the spatiotemporal variations of NDVI. The Start of Season (SOS) was estimated from NDVI time series with a local threshold method. The first EOF, accounting for 35.1% of NDVI variations on the TP, indicates that NDVI variations are larger in areas with shorter sunshine duration. The needle‐leaved forest and shrub in the southeastern TP are more sensitive to sunshine duration anomalies (p < 0.01) than broad‐leaved forest, steppe, and meadow due to spatial and altitudinal distribution of sunshine duration and vegetation types. The decrease in sunshine duration for the growing season on the TP has resulted in a decreased NDVI trend in some areas of southeastern TP (p ranging from 0.32‐0.05 with threshold ranging from 0.05 to 0.25) in spite of the overall NDVI increase. SOS dynamics in most parts of the TP were mainly related to temperature variability, with precipitation and sunshine duration playing a role in a few regions. This study enhances our understanding of vegetation responses to climatic change on the TP.
Evaluating diatom‐derived Holocene pH reconstructions for Arctic lakes using an expanded 171‐lake training set
Authors: FINKELSTEIN SARAH A. , BUNBURY JOAN , GAJEWSKI KONRAD , WOLFE ALEXANDER P. , ADAMS JENNIFER K. , DEVLIN JANE E. 
Published: April 2014

ABSTRACTInference models from diatoms preserved in lake sediments can be used to reconstruct long‐term pH changes to better understand the process of lake ontogeny. An expanded diatom training set was developed using taxonomically harmonized modern assemblages in surface sediments of 171 lakes spanning a variety of geological and climatic settings across the Canadian Arctic. Lake‐water pH emerged as a significant variable and the most influential in structuring diatom assemblages. The resulting two‐component weighted‐averaging partial least squares pH inference model performs strongly, even after identifying effects of spatial autocorrelation at distances <20 km. The model was then applied to three dated Holocene diatom stratigraphies from Arctic regions of contrasting bedrock geology and buffering capacity, and the significance of the pH reconstructions was assessed. At Lake CF3 in a poorly buffered catchment, a gradual but significant pH decline begins 5000 years after lake inception, coincident with regional Late Holocene cooling. Reconstructions for two well‐buffered, more alkaline sites were not significant, probably due to poor analogues and other factors driving changes in diatom assemblages. Due to sparse soil and vegetation in these and other Arctic basins, bedrock composition is the most important regulator of Holocene pH, and only in poorly buffered lakes does pH primarily represent a climate signal.
Stable microwave generation based on a brillouin fiber laser with saturable absorber
Authors: Peng Zhang , Keyan Dong , Wanzhe Zheng , Qinsong Jia , Xin Liu , Tianshu Wang , Huilin Jiang 
Published: April 2014

ABSTRACTA simple approach to generate stable microwave signals by heterodyning pump light and Stokes lasing light from a dual‐wavelength Brillouin fiber laser is proposed and demonstrated. A 10‐km‐long single mode fiber is used as the Brillouin gain medium, and an ultranarrow linewidth distributed feedback laser is used as Brillouin pump, while a 4‐m‐long unpumped polarization maintaining erbium‐doped fiber and subring cavity suppress unwanted side modes. A 10.7 GHz microwave signal is detected by photodetector and the signal linewidth is about 300 kHz. Signal to noise ratio of the microwave signal is about 50 dB. The power and frequency of microwave signal is highly stable, with almost no fluctuations over the test period. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1513–1516, 2014
Miniaturized designs of circularly polarized slot antenna
Authors: Row Jeen‐Sheen , Lin Yu‐De 
Published: April 2014

ABSTRACTDesigns of reducing the overall antenna size for a circularly polarized slot antenna are studied. The miniaturized design is based on a square‐ring slot antenna fed with an L‐shaped coupling strip, and it is performed by varying the slot shape and simultaneously cutting the ground plane. Two compact prototypes are implemented and measured. For the first one prototype, both the ring slot and ground plane have a narrow rectangular shape, and experimental results demonstrate that it can provide monopole‐like radiation as well as broadband circular polarization operation. As for the second one, its overall antenna dimensions are further reduced to be less than 0.1
, and it has a 3‐dB‐axial‐ratio bandwidth of about 4%. For the two prototypes, processes of the miniaturized designs are shown, and details of the experimental results are given along with the simulated results carried out by HFSS. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1522–1526, 2014
Aperture coupled dual ground back FED s‐slot rectangular microstrip antenna for wide band operation
Authors: Kulkarni N. K. , Mulgi S. N. 
Published: April 2014

ABSTRACTThis article presents an aperture coupled dual ground back fed rectangular microstrip antenna for wideband operation. The bandwidth is enhanced by varying the width of S‐shaped slot placed on the patch and the gap between the feed line on the ground plane of the antenna. The proposed antenna operates between 4 and 16 GHz of frequency range and gives a peak gain of 4.32 dB. The enhancement of bandwidth does not alter the nature of broadside radiation characteristics. The experimental and simulated results are in good agreement with each other. Design concepts of the antenna are given. The experimental results are presented and discussed. The proposed antennas may find applications in WiMax of IEEE802.16d, HIPERLAN/2 and radar communication systems. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1563–1566, 2014
Substrate integrated waveguide dual‐stopband filter
Authors: Esmaeili Mahbubeh , Bornemann Jens 
Published: April 2014

ABSTRACTA dual‐stopband filter in substrate integrated waveguide (SIW) technology is presented. The filter uses a uniform SIW transmission line loaded by three quarter‐wavelength H‐plane stubs spaced by quarter‐wavelength sections. The two stopbands contain three transmission zeros (TZs) each and are located at center frequencies of 10 and 12.2 GHz with corresponding bandwidths of 360 and 500 MHz, respectively. The center frequency and bandwidth of the passband, separating the two stopbands, are 11.03 and 1.26 GHz. A capacitive post is used to improve the return loss of this passband and the location of its reflection zeros (RZs). The filter is prototyped and measured, and good agreement between measured and simulated results is obtained. The measured results confirm the predictions in terms of locations of TZs and RZs as well as passband return loss and stopband attenuation levels. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1561–1563, 2014
Composite right/left‐handed dual‐band metamaterial antenna with improved gain and efficiency
Authors: Bala B. D. , Rahim M. K. A. , Murad N. A. 
Published: April 2014

ABSTRACTIn this article, a duals‐band metamaterial antenna with a new composite right/left‐handed (CRLH) unit cell configuration is proposed. The antenna is a coplanar waveguide (CPW) base which uses quarter wave resonators without via. Both sides of the CPW ground plane are short circuited to the CRLH‐transmission line. The dimension is 31 mm × 22 mm × 1.52 mm, with electrical size of 0.23 λo × 0.17 λo × 0.011 λo at 2.26 GHz, and which is compact in size. Resonance frequency of the negative mode can be altered by controlling the loop currents. Peak gains of 1.74 and 2.69 dBi are obtained at 2.26 and 2.89 GHz. Radiation efficiencies of 64% and 92% are obtained at 2.26 and 2.89 GHz, respectively. The simulated and measured return losses, as well as the radiation patterns, are presented and compared. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1575–1579, 2014
Multilayer phase shifter using aperture and broadside‐coupled microstrip lines
Authors: Ausordin Siti Fatimah , Abdul Rahim Sharul Kamal , Seman Norhudah , Dewan Raimi 
Published: April 2014

ABSTRACTA design of 45° multilayer phase shifter that operates at 2.45 GHz operating frequency is presented in this article. To reduce the size, a technique of introducing multilayer substrate is introduced to the proposed phase shifter. This miniaturization is achieved through the use of suitable radius of aperture and broadside‐coupled ground slot transitions. The result obtained shows that the proposed phase shifter is capable to operate in miniaturized microwave and integrated circuit such as Butler Matrix beam forming network in WLAN application. This multilayer phase shifter was designed with CST Microwave Studio offering a consideration size reduction of 53% compared to conventional ones. Parametric analysis on the radius of aperture and broadside‐coupled microstrip lines of ground slot and patch will be carried out to observe the performance of the multilayer phase shifter. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1590–1593, 2014
Antenna using feed structure for wide impedance bandwidth
Authors: Park Kyoungnam , Lee Jaesuk , Liu Yang , Kim Hyeongdong 
Published: April 2014

ABSTRACTIn this article, an antenna composed of radiator and feed structure for enhancement of impedance bandwidth is proposed. By controlling the coupling between the radiator and feed structure with the length of coupled line, it is possible to achieve a wide impedance bandwidth. Measured result shows that the proposed antenna possesses an impedance bandwidth from 735 to 1100 MHz, which is sufficiently wide to fully cover the long‐term evolution 13, and global system for mobile communication 850 and 900 bands under VSWR 3:1 with a good realized efficiency. Omnidirectional radiation patterns useful for practical application are measured. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1645–1647, 2014