bluuebunny/crossref_metadata_2025 huggingface dataset:
Prevalence, frequency, onset, desistance and criminal career duration in self‐reports compared with official records
Authors: Farrington David P. , Ttofi Maria M. , Crago Rebecca V. , Coid Jeremy W.
Published: October 2014

Aim

The main aim of this article is to compare prevalence and frequency, ages of onset and desistance, and criminal career duration, according to self‐reports and convictions.

Method

In the Cambridge Study in Delinquent Development, 411 London males have been followed up from age 8 to age 48, in interviews and criminal records.

Results

Virtually all males admitted at least one of eight offences, compared with about one third who were convicted. In self‐reports, the number of offences was over 30 times greater, the age of onset was earlier and the career duration was longer, compared with convictions. However, the age of desistance was generally later according to convictions.

Conclusions

Self‐reported ages of desistance may be affected by increasing concealment with age. The gap between the first self‐reported offence and the first conviction provides an opportunity for early intervention. Copyright © 2014 John Wiley & Sons, Ltd.
Supercritical CO2 Extraction of 1‐Butanol and Acetone from Aqueous Solutions Using a Hollow‐Fiber Membrane Contactor
Authors: Moreno Teresa , Tallon Stephen J. , Catchpole Owen J.
Published: October 2014

Porocritical extraction was applied to the separation of 1‐butanol and acetone from aqueous solutions modeling a typical acetone‐butanol‐ethanol (ABE) fermentation broth. The efficiency of two lab‐scale hollow‐fiber membrane contactors of different was studied under various flow rates, solvent‐to‐feed ratios, and pressure conditions. Global and individual, i.e., tube side, membrane, and shell side mass transfer coefficients were determined. The main contribution to mass transfer resistance was found in the shell side in all cases, and experimentally determined shell side mass transfer coefficients were compared to values predicted by existing correlations.
Chiral Resolution of Racemic Cyclopropanecarboxylic Acids in Supercritical Carbon Dioxide
Authors: Varga Dániel , Bánsághi György , Pérez Jorge Agustín Martínez , Miskolczi Sándor , Hegedűs László , Simándi Béla , Székely Edit
Published: October 2014

The chiral resolution of two racemic cyclopropanecarboxylic acids with the resolving agents (S)‐2‐(N‐benzylamino)butan‐1‐ol and (R)‐1‐phenylethanamine was investigated. The resolutions were based on diastereomer salt crystallization in supercritical carbon dioxide. Unreacted compounds were removed by an extraction step. Experiments were performed in a continuously stirred tank reactor and good enantioselectivities were obtained in a single step. Pressure, temperature, and density were found to strongly affect both the optical purity and the selectivity of the resolutions. The crystal structures of the formed diastereomer salts were also studied via X‐ray diffraction.
Influence of scCO2, Ultrasound, and Quaternary Ammonium Salt on Gelation Time and Structural Characteristics of Silica
Authors: Hanu Alina‐Mihaela , Kareth Sabine , Puls Angela , Ivanova Mihaela , Mallick Bert , Mudring Anja‐Verena , Petermann Marcus
Published: October 2014

In situ synthesis of silica gels via a one‐step sol‐gel process at ambient pressure or in supercritical CO2 was investigated. The influence of compressed gas, ultrasound irradiation, and quaternary ammonium salt (choline chloride) on the gelation time was determined. The obtained samples were characterized by N2 adsorption/desorption measurements, scanning electron microscopy in combination with energy dispersive X‐ray spectroscopy (SEM/EDX), and Fourier transform infrared‐attenuated total reflection spectroscopy (FTIR‐ATR). The retention capacity of the corresponding silica aerogels for Rhodamine B was evaluated as a model for organic water pollutants. The obtained results proved that scCO2 has a beneficial effect, leading to a reduction of the gelation time. The obtained aerogels exhibit a higher surface area and larger pore diameter as well as a well‐defined cylindrical pore structure.
Oiling‐Out and Crystallization of Vanillin from Aqueous Solutions
Authors: Sorensen Thore J.
Published: October 2014

Dynamic light scattering experiments performed on precrystalline liquid solutions that shows oiling‐out at higher vanillin concentration resulted in scattering from assumed precrystalline clusters. The structures appear during crash‐cooling into the supersaturated area and grow to µm size. They decrease in size and number at the appearance of visible crystals and might be unstable amorphous phases or or precrystalline structures that fit into the classical theory of crystallization. The data presented explains as to why the temperature‐time history influences the behavior of crystallization and shows that structures can coexist with the oiling‐out phenomena, but not as a direct part of it.
Mathematical Modeling of Hydrogen Production via Methanol‐Steam Reforming with Heat‐Coupled and Membrane‐Assisted Reactors
Authors: Chein Rei‐Yu , Chen Yen‐Cho , Chung Jacob Nan‐Chu
Published: October 2014

Hydrogen production and purification via methanol‐steam reforming was studied in a membrane reactor coupled with a catalytic combustor heat supply, applying 1D non‐isothermal mathematical models. Both mass and heat transfer behaviors were evaluated simultaneously in three reactor components. Based on data of methanol conversion, hydrogen recovery, and carbon monoxide selectivity, the membrane reactor performance was found to be controlled by the methanol‐air flow rate in the combustor, reformer operating pressure, and sweep gas flow rate. Higher hydrogen permeation driving force leads to high reformer operating pressure and sweep gas flow rate. Methanol conversion is enhanced compared with a conventional reactor under the same operation conditions with increased hydrogen removal from the reformer.
Nutrient Management in Processing of Steam‐Exploded Lignocellulose Phytomass
Authors: Maroušek Josef , Hašková Simona , Zeman Robert , Váchal Jan , Vaníčková Radka
Published: October 2014

Energy production from phytomass residues such as harvest leftovers is generally accepted as a sustainable way. Excellent results may be reviewed in papers based on laboratory observations. However, trials performed on a commercial scale show that without proper disintegration long retention times, huge fermenters, or various chemicals are required. The results obtained in a commercial scale suggest that intensive disintegration makes subsequent processes less manageable. Two conventional methods of nutrient management and the recently proposed method, which takes into account the availability of nutrients, have been robustly tested. The data from all three methods and the technological and cost assessment that followed demonstrated that the application of the newly proposed method opens up the potential for further optimization, which may lead up to significant reductions in energy price.
Influence of Cyclopentadienyl Ring‐Tilt on Electron‐Transfer Reactions: Redox‐Induced Reactivity of Strained [2] and [3]Ruthenocenophanes
Authors: Russell Andrew D. , Gilroy Joe B. , Lam Kevin , Haddow Mairi F. , Harvey Jeremy N. , Geiger William E. , Manners Ian
Published: October 2014

In contrast to ruthenocene [Ru(η5‐C5H5)2] and dimethylruthenocene [Ru(η5‐C5H4Me)2] (7), chemical oxidation of highly strained, ring‐tilted [2]ruthenocenophane [Ru(η5‐C5H4)2(CH2)2] (5) and slightly strained [3]ruthenocenophane [Ru(η5‐C5H4)2(CH2)3] (6) with cationic oxidants containing the non‐coordinating [B(C6F5)4]− anion was found to afford stable and isolable metalmetal bonded dicationic dimer salts [Ru(η5‐C5H4)2(CH2)2]2[B(C6F5)4]2 (8) and [Ru(η5‐C5H4)2(CH2)3]2[B(C6F5)4]2 (17), respectively. Cyclic voltammetry and DFT studies indicated that the oxidation potential, propensity for dimerization, and strength of the resulting RuRu bond is strongly dependent on the degree of tilt present in 5 and 6 and thereby degree of exposure of the Ru center. Cleavage of the RuRu bond in 8 was achieved through reaction with the radical source [(CH3)2NC(S)SSC(S)N(CH3)2] (thiram), affording unusual dimer [(CH3)2NCS2Ru(η5‐C5H4)(η3‐C5H4)C2H4]2[B(C6F5)4]2 (9) through a haptotropic η5–η3 ring‐slippage followed by an apparent [2+2] cyclodimerization of the cyclopentadienyl ligand. Analogs of possible intermediates in the reaction pathway [C6H5ERu(η5‐C5H4)2C2H4][B(C6F5)4] [E=S (15) or Se (16)] were synthesized through reaction of 8 with C6H5EEC6H5 (E=S or Se).
Selective Host–Guest Interaction between Metal Ions and Metal–Organic Frameworks Using Dynamic Nuclear Polarization Enhanced Solid‐State NMR Spectroscopy
Authors: Guo Zhiyong , Kobayashi Takeshi , Wang Lin‐Lin , Goh Tian Wei , Xiao Chaoxian , Caporini Marc A. , Rosay Melanie , Johnson Duane D. , Pruski Marek , Huang Wenyu
Published: October 2014

The host–guest interaction between metal ions (Pt2+ and Cu2+) and a zirconium metal–organic framework (UiO‐66‐NH2) was explored using dynamic nuclear polarization‐enhanced 15N{1H} CPMAS NMR spectroscopy supported by X‐ray absorption spectroscopy and density functional calculations. The combined experimental results conclude that each Pt2+ coordinates with two NH2 groups from the MOF and two Cl− from the metal precursor, whereas Cu2+ do not form chemical bonds with the NH2 groups of the MOF framework. Density functional calculations reveal that Pt2+ prefers a square‐planar structure with the four ligands and resides in the octahedral cage of the MOF in either cis or trans configurations.
Dendrimer‐Type Peptoid‐Decorated Hexaphenylxylenes and Tetraphenylmethanes: Synthesis and Structure in Solution and in the Gas Phase
Authors: Peschko Katharina , Schade Alexandra , Vollrath Sidonie B. L. , Schwarz Ulrike , Luy Burkhard , Muhle‐Goll Claudia , Weis Patrick , Bräse Stefan
Published: October 2014

Branched organic nanostructures are useful scaffolds that find multiple applications in a variety of fields. Here, we present a novel approach to dendrimer‐like structures. Our design contains a rigid hydrocarbon‐based core (hexaphenylxylylene/tetraethynylphenylmethane) combined with a library of N‐substituted oligoglycines (so‐called peptoids) providing a flexible shell. The use of click chemistry allows rapid assembly of the nanostructures. The possibility of tuning the size and the solubility of this new type of nanostructure will be advantageous for future applications such as heterogeneous catalysis.
Six‐Coordinate Lanthanide Complexes: Slow Relaxation of Magnetization in the Dysprosium(III) Complex
Authors: Na Bo , Zhang Xue‐Jing , Shi Wei , Zhang Yi‐Quan , Wang Bing‐Wu , Gao Chen , Gao Song , Cheng Peng
Published: October 2014

A series of six‐coordinate lanthanide complexes {(H3O)[Ln(NA)2]⋅H2O}n (H2NA=5‐hydroxynicotinic acid; Ln=GdIII (1⋅Gd); TbIII (2⋅Tb); DyIII (3⋅Dy); HoIII (4⋅Ho)) have been synthesized from aqueous solution and fully characterized. Slow relaxation of the magnetization was observed in 3⋅Dy. To suppress the quantum tunneling of the magnetization, 3⋅Dy diluted by diamagnetic YIII ions was also synthesized and magnetically studied. Interesting butterfly‐like hysteresis loops and an enhanced energy barrier for the slow relaxation of magnetization were observed in diluted 3⋅Dy. The energy barrier (Δτ) and pre‐exponential factor (τ0) of the diluted 3⋅Dy are 75 K and 4.21×10−5 s, respectively. This work illustrates a successful way to obtain low‐coordination‐number lanthanide complexes by a framework approach to show single‐ion‐magnet‐like behavior.
Effect of solution pH and influence of water hardness on caffeine adsorption onto activated carbons
Authors: Couto Osorio Moreira , Matos Inês , da Fonseca Isabel Maria , Arroyo Pedro Augusto , da Silva Edson Antônio , de Barros Maria Angélica Simões Dornellas
Published: October 2014

There has been little research into the effects of the water hardness and pH of surface waters on the adsorption of caffeine on activated carbons. The aim of this study was to determine the influence of these water characteristics on different activated carbons. Caffeine adsorption from the aqueous phase was studied using biomass derived activated carbons (DD: dende coco and BB: babassu coco) and a commercially available activate carbon (NO: Norit® GAC 1240 plus). The functionalized carbons in an inert atmosphere was also studied and were denominated DI, BI, NI. Results highlight the importance of pH in caffeine adsorption: the highest removals were obtained for pH 3.0 and decrease for higher pH. The adsorption isotherms obtained were fitted to the Freundlich and Langmuir models. Calcium and magnesium ions were adsorbed to a varied extent on the activated carbons. The hardness in solution decreased their adsorption due to a competition effect. KF and qm from the Freundlich equation linearly decreased with water hardness due to salt‐screened electrostatic repulsions between charged molecules. The amount adsorbed from deionized water was largest because there was no competition between inorganic ions and molecules.
Elevated Stratopause Events During 2003–2011 Revealed by SABER/TIMED Temperature Observations
Authors: Jing SHUAI , Chun‐Ming HUANG , Shao‐Dong ZHANG , Fan YI , Kai‐Ming HUANG , Quan GAN , Yun GONG
Published: October 2014

The elevated stratopause (ES) events in the winter (January–March) of 2006, 2009 and 2010 at 70°N are studied based on the SABER/TIMED temperature measurements in the period from 2003 to 2011. In each of these three winters, there suddenly appeared the maximum atmospheric temperature around 80 km between 25 and 85 km in late January–early February, which meant that the stratopause jumped from the normal location (∼50 km) with temperature ∼260 K up to the higher location (∼80 km) with temperature ∼230 K, and this phenomenon was identified as the ES event. As time went on, the ES height decreased gradually and returned to its normal level. Meanwhile the ES temperature increased from ∼230 K to ∼260 K. It is noteworthy that the applied data set indicates that although stratospheric warming occurred in every boreal winter, only after the major sudden stratospheric warming (SSWs) accompanying with the polar vortex splitting, the ES events could occur. Furthermore, in the ES events winter, gravity wave (GW) activity enhancement could be observed at ∼80 km between late January and early February, corresponding to the ES occurrence height and time. After February GW activity became weaker above 75 km and stronger below 75 km when the ES decreased with time. The correlation analyses between GW activity and the ES event indicate the possible contribution of GW activity to the formation of the ES event.
Generalization of the Expression of Cementation Radius in Contact Cement Theory and Its Application
Authors: Xue‐Hui HAN , Jun‐Xin GUO , Feng‐Bi LI , Long YANG
Published: October 2014

The general expressions of cementation radius in the loose sandstone are proposed on the basis of the geometry relationship between the grain and cement with the assumption that the contact thickness is not zero. The expressions of cementation radius of Contact Cement Theory (CCT) proposed by Dvorkin et al. (1996) don't consider the effect of contact thickness, which makes it only applicable for the pore cemented loose sandstone. To solve this problem, the general expressions of cementation radius are proposed, in which the effect of contact thickness on the velocity of loose sandstone is analyzed. And its application in the prediction of the compressional and shear wave velocity of basally cemented loose sandstone is discussed. The results show that when the contact thickness increases, the compressional and shear wave velocities decrease. Such trend is more obvious when the porosity increases or the content of cement decreases. The ratio of compressional wave velocity to the velocity of shear wave (Vp/Vs) increases with the contact thickness if the porosity or cement content keeps stable. Vp/Vs changes with porosity in different ways for different contact thicknesses. When the thickness is small, the ratio decreases a little with the increase of porosity, but when the thickness becomes large, it changes in the other way. For the basally cemented loose sandstone, the modified model using the general expression of cementation radius predicts both the compressional and the shear wave velocities better than the original CCT. The study also shows that the change of the rigidity of the basally cemented loose sandstone caused by porosity or cement content change cannot be predicted by Vp/Vs, but it can predict that caused by the change of contact thickness.
In Situ Measurements and Comprehensive Research on the Present Crustal Stress of Northern South China Sea
Authors: Qun‐Ce CHEN , Tao‐Yuan FAN , Xu‐Shen LI , Sheng‐Lin HE , Chong‐Yuan ZHANG , Wen MENG
Published: October 2014

It is necessary for developing of ocean resources, safety evaluation of geological environment and engineering to understand the status and distribution of present crustal stress in the northern South China Sea. The nature conditions restrict the research on the crustal stress of the whole South China Sea, whose characters and controlling factors are not clear. In situ stress measurement is a useful way to get the stress magnitude and direction. The stress direction can be got through the logging FMI data in ocean oil field. The numerical modeling can extrapolate the stress status and distribution in the interested area under the constraint of the in situ measured stress, FMI deduced stress and the plate tectonic environment. The west bound of northern South China Sea is Red River Fault‐Eastern Vietnam strike slip large Fault which is controlled by the collision of India plate and Euro‐Asia plate and the uplift of Tibet. The east bound of northern South China Sea is Manila trench, which have three different tectonic stress sections, plate collision near Taiwan and near Luzon, and extension between Taiwan and Luzon induced by South China Sea subduction under the Philippines plate. The authors measured in situ the magnitude and direction of stress in Ledong county, Hainan province through hydraulic fracturing, where the exposed rock body is intact and the landform is gentle. The measured rock in well is intact and the curve of measured pressure is fit to the standard, which shows that the measured stress is reliable. The optimal direction of measured maximum stress is NW‐NWW. According to the Byerlee criteria, the measured stress cannot induce the active fault to be reactivated recently. The logging FMI interpretation of marginal oil basin in the northern South China Sea shows that the optimal direction of maximum principal stress is NW‐NNW in Yinggehai basin, and NNW in Qiongdongnan basin. Constrained by the in situ measured stress and the focal mechanism the numerical modeling shows that the crustal stress in northern South China Sea is characterized by the different stress status in different zone due to India plate, Euro‐Asia plate and Philippine plate playing different role. In the area near Taiwan the crustal stress is dominated by the collision of Philippe plate and Euro‐Asia plate, and the direction of maximum principal stress is E‐W. Along marginal northern South China Sea the crustal stress is influenced by extension induced by the Euro‐Asia plate subduction under the Philippine plate at the Manila trench, and the maximum principal stress gradually turns to S‐N and NW.
An Inversion Technique for the Mechanisms of Local and Regional Earthquakes: Generalized Polarity and Amplitude Technique (I)—Principle and Numerical Tests
Authors: Chuan YAN , Li‐Sheng XU
Published: October 2014

An inversion technique for focal mechanisms of local and regional earthquakes, named Generalized Polarity and Amplitude Technique (GPAT), is proposed based on the progress already made over decades, and its feasibility and capability of resisting disturbance are tested by a series of numerical experiments. At first, an inversion equation system is constructed with the vectors consisting of the polarities of the P‐wave first‐motion and the maximal amplitudes of generalized phases on a basis of the concept of wave field, and a technique for solving the equation system is specified. Then, a series of experiments are conducted for testing the effect of various factors on inversion results, including distribution of observation stations, number of the stations, random noises, errors in epicenter location, errors in focal depth and errors in velocity model. Finally, a special experiment is designed to test the comprehensive effect of all the factors. The experiments suggest that the GPAT is feasible, and has a rather good capability of resisting disturbance. It must be stressed that the errors in velocity model have the strongest effect on inversion results compared with other factors.
Comparison of Inversion Method of Wide Angle Ocean Bottom Seismometer Profile: A Case Study of Profile OBS973‐2 Across Liyue Bank in the South China Sea
Authors: Xiong‐Wei NIU , Xiao‐Dong WEI , Ai‐Guo RUAN , Zhen‐Li WU
Published: October 2014

Deep crust structure of the wide angle seismic profile OBS973‐2, which crosses the central sea basin and Liyue bank in the southern of South China Sea (SCS), represents one of the direct evidences for conjugate spreading and evolution of SCS. For this reason, we remodeled the data by using both forward and inversion methods for a detailed crustal velocity structure, and also compared results with depth profile of multi‐channel seismic (MCS) close to OBS973‐2 for more reliable crust thickness. Comparing to former works, and according to the new velocity models, we divided the profile to three parts of continental crust (0∼200 km in the profile), continent and ocean transition (COT, 200∼280 km in the profile) and ocean crust (280∼370 km in the profile). And their crust structures are obviously different. Sediment layer in the continental crust shows a feature of horizontal variations in both thickness and velocity, and total crust thickness in continental part is thick (about 20 km). In the COT, both thickness and velocity are horizontally smooth, and the total thickness of crust is thinner (about 8 km). And in the ocean crust, the crust thickness thins to 6 km. There are two main conclusions, (1) the method of using data collected by wide angle seismic and multi‐channel seismic and using both forward and inversion software in modeling will obtain more reliable information of crust structure, (2) the new insights on the crust structure are as follows. (a) We get the seaward thinning of Moho and its depth of about 12∼18 km below the sea level in COT from both wide angle and multi‐channel seismic profiles. (b) No high velocity layer was found beneath COT, which represents non volcanic passive continental margin and its conjugate spreading point is Zhongsha massif. (c) Heavy extension occurred in upper crust of continental part, which shows horizontal velocity anomalies and low velocity zone in the velocity model and a large number of normal faults in the multi‐channel seismic profile.
Ring Opening of N‐Sulfonyl Aziridines by Amines in Silica‐Water
Authors: Li Tiantian , Ma Xiaosi , Qi Junmei , Sun Feifei , Ma Ning
Published: October 2014

Ring opening reactions of N‐sulfonyl aziridines by primary and secondary amines in silica gel (SG)‐water system were achieved, which provided a mild, practical and environmentally benign method to synthesize mono‐ and bis‐sulfonyl substituted amines. When primary and secondary amines were used in excess, they reacted with N‐sulfonyl aziridines smoothly at room temperature, mainly affording 1:1 ring opening products. Reactions of primary amines with 2 equiv. of aziridines produced 2:1 ring opening products. Some 1:1 products can be cyclized with CS2 to synthesize N‐sulfonyl cyclothioureas also in water.
Synthesis and Surface Activity Study of a Novel Branched Fluorinated Anion Surfactant with CF3CF2CF2C(CF3)2 Group
Authors: Sha Min , Pan Renming , Zhan Lewu , Xing Ping , Jiang Biao
Published: October 2014

A novel branched fluorinated anion surfactant 4‐(3,3,4,4,5,5,5‐heptafluoro‐2,2‐bis‐tri‐fluoromethyl‐pentyl)benzene lithium phosphonate was successfully synthesized via a four‐step route using perfluoro‐2‐methyl‐2‐pentene as starting material. The surface activity was investigated. The result showed that the cmc value of the surfactant in water is about 1.5×10−2 mol/L at 298 K and the surface tension of the aqueous solution is 19.2 mN/m at the cmc.
Ni(II) Ternary Complex Based on Antimicrobial Drug Enoxacin: Synthesis and Biological Properties
Authors: Huang Wanyun , Kong Shilin , Wang Zhongchang , Pan Chengxue , Zhu Hailiang
Published: October 2014

First Ni(II) ternary complex using the quinolone antibacterial agent enoxacin (HEn) as ligand and 1,10‐phenanthroline as co‐ligand has been synthesized and characterized. It is a mononuclear structure, in which enoxacin acts as a bidentate ligand bound to the metal through the ketone oxygen and a carboxylate oxygen atom. The complex exhibited good binding propensity to human and bovine serum albumin proteins having relatively high binding constants (6.40×104 and 7.12×104, respectively). The investigation of the interaction of the complex with calf‐thymus (CT) DNA has been performed with UV and circular dichroism (CD) spectroscopies, indicating that they bind to CT DNA probably by the intercalative binding mode. The binding constant (Kb) of the complex with CT DNA calculated with UV is 2.03×105, which is higher than that of free enoxacin drug (2.09×104) and even higher than that of typical intercalation indicator (1.23×105) of ethidium bromide (EB). Fluorescence competitive studies with EB have revealed that the complex exhibited the ability to displace the DNA‐bound EB using the intercalative binding site. In addition, the antimicrobial activity showed that the complex exhibited a little bit good inhibition (MIC=1.843 (g·mL−1) against B. subtilis than free HEn.
Diastereoselective Nitroaldol Reaction Catalyzed by Binuclear Copper(II) Complexes in Aqueous Medium
Authors: Arunachalam Rajendran , Aswathi Chirayil S. , Das Anjan , Kureshy Rukhsana I. , Subramanian Palani S.
Published: October 2014

Polydentate ligands 1 and 2, which incorporate a terminal pyridyl moiety and an oxygen‐rich oxalate dihydrizide/malonic dihydrizide spacer moiety, as well as their binuclear metal complexes [Cu212] and [Cu222], which adopt a 1:1 metal/ligand ratio, were synthesized and characterized. Both complexes were screened for their catalytic activity in the nitroaldol reaction, in which [Cu212] worked efficiently as catalyst for both substituted benzaldehyde and pyridinecarboxaldehyde, whereas [Cu222] is highly substrate specific and showed activity towards nitro‐substituted aldehydes and pyridinecarboxaldehyde. Furthermore, as helicates are intrinsically chiral, the stereochemical architecture in the binuclear double‐stranded Cu2 helicates as catalyst favored the diastereoselective syn product with nitroethane and nitropropane and their respective diastereoselectivities were determined by using 1H NMR spectroscopy.
Multiple output differential OTA with linearizing bulk‐driven active‐error feedback loop for continuous‐time filter applications
Authors: Szczepanski Stanislaw , Pankiewicz Bogdan , Koziel Slawomir , Wojcikowski Marek
Published: October 2014

A CMOS circuit realization of a highly linear multiple‐output differential operational transconductance amplifier (OTA) has been proposed. The presented approach exploits a differential pair as an input stage with both the gate and the bulk terminals as signal ports. For the proposed OTA, improved linearity is obtained by means of the active‐error feedback loop operating at the bulk terminals of the input stage. SPICE simulations of the OTA show that, for 0.35 µm AMS process, total harmonic distortion at 1.36Vpp is less than 1% with dynamic range equal to 60.1 dB at power consumption of 276 μW from 3.3 V supply. As an example, both single output and dual differential OTAs are used to design third‐order elliptic low‐pass filters. The cut‐off frequency of the filters is 1 MHz. The power consumption of the OTA‐C filter utilizing the dual output differential OTA is reduced to 1.24 mW in comparison to 2.2 mW consumed by the single output differential OTA‐C filter counterpart. Copyright © 2014 John Wiley & Sons, Ltd.
A synthetic stimulant never tested in humans, 1,3‐dimethylbutylamine (DMBA), is identified in multiple dietary supplements
Authors: Cohen Pieter A. , Travis John C. , Venhuis Bastiaan J.
Published: October 2014

A synthetic stimulant never before studied in humans, 1,3‐dimethylbutylamine (DMBA), was suspected of being present in dietary supplements. DMBA is an analogue of the pharmaceutical stimulant, 1,3‐dimethylamylamine (DMAA), which was recently banned by the US Food and Drug Administration. We obtained all dietary supplements sold by US distributors that listed an ingredient on the label, such as AMP Citrate, that might be a marketing name for DMBA. Supplements were analyzed for the presence and quantity of DMBA. Fourteen supplements met our inclusion criteria and were analyzed by two separate laboratories using ultra high performance liquid chromatography (UHPLC) ‐ mass spectrometry and a reference standard. The identity of DMBA was confirmed in 12 supplements in the range of 13 to 120 mg DMBA per serving. Following recommendations on the supplement label for maximum daily intake, customers would consume from 26 to 320 mg of DMBA per day. Supplements containing DMBA were marketed to improve athletic performance, increase weight loss and enhance brain function. DMBA has never before been detected in supplements. The stimulant has never been studied in humans; its efficacy and safety are entirely unknown. Regulatory agencies should act expeditiously to warn consumers and remove DMBA from all dietary supplements. Copyright © 2014 John Wiley & Sons, Ltd.
A metagenomics‐based approach to the top‐down effect on the detritivore food web: a salamanders influence on fungal communities within a deciduous forest
Authors: Walker Donald M. , Lawrence Brandy R. , Esterline Dakota , Graham Sean P. , Edelbrock Michael A. , Wooten Jessica A.
Published: October 2014

The flow of energy within an ecosystem can be considered either top‐down, where predators influence consumers, or bottom‐up, where producers influence consumers. Plethodon cinereus (Red‐backed Salamander) is a terrestrial keystone predator who feeds on invertebrates within the ecosystem. We investigated the impact of the removal of P. cinereus on the detritivore food web in an upland deciduous forest in northwest Ohio, U.S.A. A total of eight aluminum enclosures, each containing a single P. cinereus under a small log, were constructed in the deciduous forest. On Day 1 of the experiment, four salamanders were evicted from four of the eight enclosures. Organic matter and soil were collected from the center of each enclosure at Day 1 and Day 21. From each sample, DNA was extracted, fungal‐specific amplification performed, and 454 pyrosequencing was used to sequence the nuclear ribosomal internal transcribed spacer (ITS2) region and partial ribosomal large subunit (LSU). Changes in overall fungal community composition or species diversity were not statistically significant between treatments. Statistically significant shifts in the most abundant taxonomic groups of fungi were documented in presence but not absence enclosures. We concluded that P. cinereus does not affect the overall composition or diversity of fungal communities, but does have an impact on specific groups of fungi. This study used a metagenomics‐based approach to investigate a missing link among a keystone predator, P. cinereus, invertebrates, and fungal communities, all of which are critical in the detritivore food web.
Effects of Ultrasonic Agitation on the Structural and Magnetic Properties of CoFe2O4 Nanocrystals
Authors: Almeida Silva Anielle Christine , Gratens Xavier , Chitta Valmir Antonio , Franco Sinésio Domingues , Souza da Silva Ricardo , Condeles José Fernando , Dantas Noelio Oliveira
Published: October 2014

Cobalt ferrite nanocrystals (CoFe2O4) were synthesized by means of ultrasonic agitation and afterward subjected to different annealing temperatures. The structural and morphological properties of the nanocrystals were investigated by means of X‐ray diffraction and scanning electron microscopy. The results showed that the samples were composed of CoFe2O4 monophase nanocrystals. The particle size increased with increasing annealing temperatures. Infrared spectroscopy and magnetization showed that the samples exhibited the usual features of CoFe2O4 nanocrystals. Superparamagnetism was not observed at room temperature. However, the results indicated that the samples could be considered single‐domain particles with blocking temperatures greater than 300 K. Both infrared and magnetic results indicated possible diffusion of cobalt ions from tetrahedral to octahedral sites as a function of the annealing temperature.
β‐Tetrasubstituted meso‐Tetra(4′‐n‐butylphenyl)porphyrins and Their Metal Complexes: Synthesis and Structural Properties
Authors: Bhyrappa Puttaiah , Sarangi Ujwal K. , Velkannan Veerapandian , Ramkumar Venkatachalam
Published: October 2014

A new family of ‐tetrasubstituted porphyrins, 2,3,12,13‐tetra[phenylethynyl (PE)/4‐methoxyphenyl (4″‐CH3OPh)/4‐carboxy methylesterphenyl (4″‐CH3CO2Ph)]‐5,10,15,20‐tetrakis(4′‐n‐butylphenyl)porphyrin, H2T(4′‐BuPh)P(R)4 and their metal (CoII, CuII and ZnII) complexes were synthesized using H2T(4′‐BuPh)PBr4 as the precursor. These porphyrins show red‐shifted absorption bands and follow the nature of the β‐pyrrole substituent, R: PE > Br > 4″‐CO2CH3Ph ≈ 4″‐OCH3Ph. Crystal structures of MT(4′‐BuPh)P(PE)4 (M = 2H, CoII, CuII and ZnII) derivatives were determined by single‐crystal XRD and they are isomorphous. The normal coordinate structure decomposition analysis of these structures reveal a slight wave‐type of distortion of the macrocycle. Electrochemical redox properties of these derivatives show an anodic shift in potentials relative to their metallotetraphenylporphyrins (MTPPs), and this has been ascribed mainly to the electronic effect of the substituents.
A Mononuclear Manganese Complex of a Tetradentate Nitrogen Ligand – Synthesis, Characterizations, and Application in the Asymmetric Epoxidation of Olefins
Authors: Shen Duyi , Miao Chengxia , Wang Shoufeng , Xia Chungu , Sun Wei
Published: October 2014

A new chiral manganese complex (C1) bearing a tetradentate nitrogen ligand containing chiral bipyrrolidine and benzimidazole moieties was prepared. The structure of C1 was confirmed by ESI‐MS and crystallography. This manganese complex is an active catalyst for the asymmetric epoxidation of various olefins with excellent conversion (up to 99 %) and high enantiomeric excess (up to 96 % ee) with hydrogen peroxide as the oxidant in the presence of 2‐ethylhexanoic acid or acetic acid. Compared with previous structurally similar manganese complexes with different diamine backbones (C2, cyclohexanediamine; C3, diamine from L‐proline), C1 showed improved asymmetric induction, especially for simple olefins such as styrene derivatives and substituted chromene. The possible reasons for the improvement of the ee values are discussed in the text on the basis of the crystal structures of the manganese complexes.
Copper(II) Clusters of Two Pairs of 2,3‐Dihydroxybutanedioyl Dihydrazones: Synthesis, Structure, and Magnetic Properties
Authors: Chen Zilu , Zhou Suping , Shen Yanling , Zou Huahong , Liu Dongcheng , Liang Fupei
Published: October 2014

Condensation reactions of (2R,3R)‐ and (2S,3S)‐2,3‐dihydroxybutanedihydrazide with salicylaldehyde and 3‐methoxysalicylaldehyde gave two enantiomeric pairs, (2R,3R)/(2S,3S)‐2,3‐dihydroxybutanedioylbis(salicylaldehydehydrazone) [(2R,3R)‐BSH and (2S,3S)‐BSH] and (2R,3R)/(2S,3S)‐2,3‐dihydroxybutanedioyl bis(3‐methoxysalicylaldehydehydrazone) [(2R,3R)‐MBSH and (2S,3S)‐MBSH]. Their reactions with CuII salts provided two chiral hexanuclear clusters [Cu6L2(C5H5N)10]2[C5H6N]3(ClO4)7·(CH3OH)·(C5H5N) [L = (2R,3R)‐BSH; (2S,3S)‐BSH] and four chiral tridecanuclear clusters [Cu13L3(OH)2(CH3COO)6(C5H5N)6(DMF)3]·6DMF·3H2O [L = (2R,3R)‐BSH; (2S,3S)‐BSH] and [Cu13X3(OH)2(CH3COO)6(C5H5N)2(DMF)8]·6H2O [X = (2R,3R)‐MBSH, (2S,3S)‐MBSH]. Their structures were determined by single‐crystal X‐ray diffraction analysis. All six compounds are enantiomers of each other. The two hexanuclear clusters exhibit two orthogonal linear trinuclear units. The two pairs of tridecanuclear clusters display esthetic structures with different symmetries; they feature rare heptanuclear vertex‐sharing dicubane cores and their six unshared CuII vertexes are linked to another six CuII ions. These represent the first examples of chiral clusters bearing dicubane cores. Magnetic studies revealed the presence of overall antiferromagnetic interactions in these compounds.
Microbial oils: A customizable feedstock through metabolic engineering
Authors: Ledesma‐Amaro Rodrigo
Published: October 2014

In addition to animal fats and vegetable oils, microbial oils are gaining importance as a renewable feedstock for the chemical industry. One of the main advantages in the use of microorganisms to produce oils is the versatility and malleability of the microbial metabolism, which make it more easily manipulated. Thereby, the composition and properties of microbial oils can be designed through metabolic engineering. Consequently, the required chemical steps to synthesize a market product may be significantly reduced, together with the production costs. Accordingly, microorganisms have been engineered to: i) accumulate a high amount of lipids; ii) tune lipid composition; and iii) facilitate lipid extraction. Finally, microbial oils can be used as feedstock by the chemical industry to produce a huge variety of commodities, such as lubricants, polymers, fuels, coatings or surfactants.

Microbial oils are considered promising alternatives to fossil fuels as feedstock for the chemical industry. Additionally they present advantages over vegetable oils and animal fats since microorganisms can be easily engineered: i) to accumulate high amount of lipids; ii) to be enriched in a desired kind of lipid; and iii) to facilitate the extraction of the oil from the cells. This short article is intended to present the concept of microbial oils to the general reader, taking into special consideration the malleability of microbial oils by metabolic engineering.
A high drying temperature causes degradation of sterols and tocopherols in yellow‐seeded Brassica napus oils
Authors: Gawrysiak‐Witulska Marzena , Rudzińska Magdalena , Siger Aleksander , Bartkowiak‐Broda Iwona
Published: October 2014

The aim of the conducted investigations was to determine the effect of drying temperature on the changes in free fatty acid, phytosterol and tocopherol (T) contents in yellow‐seeded Brassica napus oils. Seeds were dried in a thin layer at 40, 60, 80, 100 and 120°C. Changes in phytosterols were assessed using GC‐MS, while tocopherols were assessed by HPLC. Degradation of phytosterols and tocopherols and an increased content of free fatty acids followed the applied drying temperature. During drying at 40 and 60°C, changes were statistically non‐significant, while at 120°C, losses of phytosterols reached 29% and tocopherols 23%.

Practical applications: Drying of rapeseeds is an important stage of its production. However, we need to remember that these seeds are biological material highly sensitive to thermal treatment. Thus we need to search for the most advantageous conditions for their drying, with special emphasis on the preservation of bioactive components affecting human health. The analyses conducted compared the range of losses of bioactive components—phytosterols, tocopherols and plastochromanol‐8 during drying.

Yellow‐seeded Brassica napus were dried in a thin layer at 40, 60, 80, 100 and 120°C. The effect of drying temperature on the free fatty acid, phytosterol and tocopherol content changes in oils was determined. Degradation of phytosterols, tocopherols and the increase in free fatty acid content were related to the applied drying temperature.
Mass propagation of Helianthus annuus suspension cells in orbitally shaken bioreactors: Improved growth rate in single‐use bag bioreactors
Authors: Werner Sören , Greulich Judith , Geipel Katja , Steingroewer Juliane , Bley Thomas , Eibl Dieter
Published: October 2014

Stirred tank‐bioreactors made of glass or steel, wave‐mixed, and orbitally shaken bag bioreactors have all proven to be suitable for the rapid development and commercial production of bioactive compounds with plant cell suspensions. Although these bag bioreactors are characterized by reduced foam formation and less flotation in comparison to stirred systems, their power input is limited. Engineering parameters such as mixing time, oxygen transfer, and power input are dependent on the viscosity of the liquid and thus, investigations with plant cell suspensions are necessary. However, to save time and achieve better controllability, sodium carboxymethyl cellulose (Na‐CMC) solutions in concentrations ranging from 1 to 20 g L−1, with viscosities of between 0.005 and 0.4 Pa·s, were identified as appropriate model systems for mimicking plant cell suspensions with packed cell volumes of between 30 and 70 % and similar viscosities. The current study has shown that it is possible to transfer a Helianthus annuus cell suspension process from an orbitally shaken CultiBag RM 1 L to a CultiBag RM with a 10 L working volume by adjusting the operating parameters to achieve a constant kLa value. A maximum specific growth rate μmax of around 0.25 d−1 was achieved, which corresponds to optimized data for shake flasks and even exceeds the growth rate for stirred glass bioreactors.
Comparing simple and advanced tools for structural fire safety engineering
Authors: Henneton Nicolas , Renaud Christophe , Zhao Bin
Published: October 2014

The present paper gives an overview of the actual tools available for the estimation of the fire development and of the resulting thermal actions on structural members. A case study is developed on the basis of the Fire Safety Engineering methodology, respectively with two different approaches, one based on ‘advanced’ tools and another one based on ‘simplified’ tools. Indeed, three categories of fire models are used in this study, each of which corresponding to a different level of precision and complexity: hand calculations, zone models, and computational fluid dynamics (CFD) models. The case study is relative to the calculation of the heating of a portal frame in a gymnasium, under localised real fire conditions. It is shown through comparisons that, in this case, predictions of analytical methods are, to certain extent, in good agreement with predictions of the CFD model. In particular, it is demonstrated the relevance of using a simplified method of EN 1991‐1‐2 to predict thermal actions to vertical members. The obtained results also highlight the need to develop more relevant analytical methods in order to predict the temperature field during a fire in a large volume. Copyright © 2014 John Wiley & Sons, Ltd.
Forecast of Performance Parameters of Automotive Fuel Cell Systems – Delphi Study Results
Authors: Thoennes M. , Busse A. , Eckstein L.
Published: October 2014

Fuel cells are a promising propulsion technology option in sustainable and zero‐emission drivetrain strategies as they offer a high potential to significantly reduce well‐to‐wheel greenhouse gas emissions and the dependency on fossil energy resources. At the same time, the current technological performance of automotive fuel cell systems is not yet sufficient to meet market demands. Therefore, the technical development of fuel cells is a critical factor for a successful market introduction of fuel cell electric vehicles (FCEV). This paper describes the methodology and results of a two‐round Delphi Survey conducted by the Institut für Kraftfahrzeuge of RWTH Aachen University to assess the technological potential of polymer electrolyte membrane fuel cell (PEMFC) systems in automotive applications by 2030. The analysis of the current and future performance level of key performance indicators (KPI) of automotive fuel cell systems helps to identify critical performance parameters and to prioritize research and development demands. KPI analyzed in the Delphi Survey as forecast parameters include system efficiency, durability, power density, and specific power.
Achieving 360 NL h−1 Hydrogen Production Rate Through 30‐Cell Solid Oxide Electrolysis Stack with LSCF–GDC Composite Oxygen Electrode
Authors: Zheng Y. , Chen T. , Li Q. , Wu W. , Miao H. , Xu C. , Wang W. G.
Published: October 2014

A 30‐cell solid oxide electrolysis (SOE) stack consisting of 30‐cell planar Ni–YSZ hydrogen electrode‐supported single cell with La0.6Sr0.4Co0.2Fe0.8O3–δ–Ce0.9Gd0.1O1.95 (LSCF–GDC) composite oxygen electrodes, interconnects, and sealing materials was tested at 750 °C in steam electrolysis mode for hydrogen production. The direction of gas flow in the stack was a cross‐flow configuration, and the stack configuration was designed to open gas flow channels at the air outlet. The electrolysis efficiency of the stack was higher than 100% at 90/10H2O/H2 ratio under <0.5 A cm−2 current density. During hydrogen production, the stack was operated at 750 °C under 0.5 A cm−2 constant current density for more than 500 h with 4.06% k h−1 degradation rate. Up to 73% steam conversion rate and 91.6% current efficiency were obtained; the net hydrogen production rate reached as high as 361.4 NL h−1. Our results suggested that the SOE stack that was designed with LSCF–GDC composite oxygen electrode could be used to conduct large‐scale hydrogen production.
A Novel Membraneless Direct Hydrazine/Air Fuel Cell
Authors: Yi Q. , Chu H. , Tang M. , Zhang Y. , Liu X. , Zhou Z. , Nie H.
Published: October 2014

In this paper multi‐walled carbon nanotubes (MWCNTs) supported binary AgNi nanoparticles are prepared by chemical reduction of Ag and Ni precursors with NaBH4. Fe/PANI catalyst is obtained by direct pyrolysis of Fe‐doped polyaniline in N2 atmosphere at high temperature. Results show that the Fe/PANI catalyst presents high electroactivity for oxygen reduction reaction (ORR) in alkaline media. The onset potential for ORR is 0.01 V(vs Hg/HgO) and the ORR current density is 3.4 mA cm−2@2000rpm at –0.4 V(vs HgO/Hg). A gas diffusion electrode is fabricated by using the Fe/PANI as the electrocatalyst of ORR. In alkaline media the AgNi/MWCNT catalyst displays efficient electroactivity for hydrazine oxidation. A lower onset potential of –0.5 V(vs Hg/HgO) and high current density for hydrazine oxidation are observed. A novel membrane‐less direct hydrazine/air fuel cell is designed by using the AgNi/MWCNT catalyst as the anode and the gas diffusion electrode as the cathode. The as‐fabricated fuel cell works properly and presents higher power density and current density.