bluuebunny/crossref_metadata_2025 huggingface dataset:
Rapid fabrication of paper-based microfluidic analytical devices with desktop stereolithography 3D printer
Authors: He Yong , Wu Wen-bin , Fu Jian-zhong
Published: December 2014

In this study, we developed a novel and facile method for fabricating paper-based microfluidic analytical devices (μPADs) with dynamic mask photo curing (DMPC), generated by a desktop stereolithography (SL) three-dimensional printer (3DP).
Ultrafine β-AgVO3 nanoribbons derived from α-AgVO3 nanorods by water evaporation method and its application for lithium ion batteries
Authors: Zeng Hui , Wang Qiang , Rao Yuanyuan
Published: December 2014

Monoclinic β-AgVO3 nanoribbons with thickness of 10–20 nm, width of 80–100 nm and length of several hundred micrometers have been successfully prepared by a water evaporation method without using any template and organic surfactant.
A simple and effective fluorescent probe based on rhodamine B for determining Pd2+ions in aqueous solution
Authors: Cui Jie , Li Dong-Peng , Shen Shi-Li , Liu Jin-Ting , Zhao Bao-Xiang
Published: December 2014

It is demonstrated that the mechanism of the probe to Pd2+and images under a UV lamp.
The impact of 1,2,3-triazoles in the design of functional coatings
Authors: Kantheti Sasidhar , Narayan Ramanuj , Raju K. V. S. N.
Published: December 2014

This review article presents an overview of the application of 1,2,3-triazoles in the design of various high performance organic coatings with properties like anti-corrosive, anti-microbial, self-healing, hybrid nanocomposite, bio degradableetc.
Fluorescent diphenylfluorene-pyrenyl copolymer with dibenzothiophene-S,S-dioxide and adamantane units for explosive vapor detection
Authors: Wang Yuerong , Gao Yixun , Chen Lei , Fu Yanyan , Zhu Defeng , He Qingguo , Cao Huimin , Cheng Jiangong , Zhang Runsheng , Zheng Shuiqing , Yan Songmao
Published: December 2014

This proposed strategy of incorporating SO units can be used as a promising approach to the development of fluorescent conjugated sensing materials.
Bismuth oxide nanoparticles as a nanoscale guide to form a silver–polydopamine hybrid electrocatalyst with enhanced activity and stability for the oxygen reduction reaction
Authors: Murali Settu , Chang Jen-Lin , Zen Jyh-Myng
Published: December 2014

High dispersion Ag nanoparticles were successfully synthesized on functionalized polydopamine@Bi2O3NPs for use as electrocatalyst. Synergetic effect was found to enhance the catalytic ability for direct 4e−transfer in oxygen reduction reaction.
Neogenkwanines A–H: daphnane-type diterpenes containing 4,7 or 4,6-ether groups from the flower bud of Daphne genkwa
Authors: Li Ling-Zhi , Song Shao-Jiang , Gao Pin-Yi , Li Fei-Fei , Wang Li-Hui , Liu Qing-Bo , Huang Xiao-Xiao , Li Dan-Qi , Sun Yu
Published: December 2014

Neogenkwanines A–H (1–8), eight daphnane-type diterpenes possessing new skeletons with 4,7- or 4,6-ether groups, along with seven known ones (10–16), were isolated from Daphne genkwa.
Stereoselective synthesis of trans-THF rings using an oxidative cyclisation-radical deoxygenation sequence: application to the formal synthesis of trans-(2R,5R)-linalool oxide
Authors: Sheikh Nadeem S.
Published: December 2014

Permanganate-mediated oxidative cyclisation-Barton–McCombie radical deoxygenation sequence is applied to 1,5-dienes to achieve stereoselective synthesis of trans-2,5-disubstituted THF rings.
Preparation and characterization of porous polyelectrolyte complex membranes for nanofiltration
Authors: Yang Yanqin , Zhang Qifeng , Li Shenghai , Zhang Suobo
Published: December 2014

Flexible and freestanding PEC membranes for nanofiltration are prepared through a combination of blend film casting and ammonia soaking procedure.
Three dimensional (3D) flexible graphene foam/polypyrrole composite: towards highly efficient supercapacitors
Authors: Chabi Sakineh , Peng Chuang , Yang Zhuxian , Xia Yongde , Zhu Yanqiu
Published: December 2014

Polypyrrole (PPY) functionalized 3 dimensional (3D) graphene foam (GF) with remarkable electrochemical performance has been synthesized in this work.
Glucose-assisted synthesis of the hierarchical TiO2 nanowire@MoS2 nanosheet nanocomposite and its synergistic lithium storage performance
Authors: Li Xiaodan , Li Wei , Li Meicheng , Cui Peng , Chen Dehong , Gengenbach Thomas , Chu Lihua , Liu Huiyuan , Song Guangsheng
Published: December 2014

A hierarchical TiO2 nanowire@MoS2 nanosheet nanocomposite is synthesized by a facile glucose-assisted hydrothermal approach and exhibits synergistic lithium storage properties with improved electrochemical performance.
Impact of K‐factor and active current reduction during fault‐ride‐through of generating units connected via voltage‐sourced converters on power system stability
Authors: Weise Bernd
Published: December 2014

This study investigates the impact of the injection of additional reactive current and of active current reduction during fault‐ride‐through (FRT) of generating units connected to the grid via fully rated voltage‐sourced converter (VSC generating units) on the behaviour and stability of the power system. The primary focus is on voltage support, transient stability and frequency stability. The investigation is carried out via computer simulations using a fictitious transmission system, based on German grid code requirements. The K‐factor of the dependence of additional reactive current with voltage deviation, the method of active current limitation during FRT and the rate of active power recovery after fault clearance are varied. Results and influences are illustrated and discussed. They show that with an increasing number of converter‐connected generating units in power systems, a careful selection of the parameters becomes very important. Insufficient grid code requirements may increase the risk of system instability. Conclusions are drawn and recommendations for optimal settings with respect to future development of grid codes are provided. The mechanism of loss of synchronism of VSC generating units because of inadequate current injection (current angle instability) is explained.
Pseudo‐Zernike‐based multi‐pass automatic target recognition from multi‐channel synthetic aperture radar
Authors: Clemente Carmine , Pallotta Luca , Proudler Ian , De Maio Antonio , Soraghan John J. , Farina Alfonso
Published: December 2014

The capability to exploit multiple sources of information is of fundamental importance in a battlefield scenario. Information obtained from different sources, and separated in space and time, provides the opportunity to exploit diversities to mitigate uncertainty. In this study, the authors address the problem of automatic target recognition (ATR) from synthetic aperture radar platforms. The author's approach exploits both channel (e.g. polarisation) and spatial diversity to obtain suitable information for such a critical task. In particular they use the pseudo‐Zernike moments (pZm) to extract features representing commercial vehicles to perform target identification. The proposed approach exploits diversities and invariant properties of pZm leading to high confidence ATR, with limited computational complexity and data transfer requirements. The effectiveness of the proposed method is demonstrated using real data from the Gotcha dataset, in different operational configurations and data source availability.
On the multi‐hop performance of receiver based MAC protocol in routing protocol for low‐power and lossy networks‐based low power and lossy wireless sensor networks
Authors: Akhavan Mohammad Reza , Aijaz Adnan , Choobkar Sabrieh , Aghvami Abdol‐Hamid
Published: December 2014

In this study, the authors focus on utilising receiver‐based MAC protocol (RB‐MAC) and adaptive RB‐MAC in routing protocol for low power and lossy wireless sensor networks routing protocol in low‐power and lossy wireless channel. This results in a cross‐layer approach in which routing decisions can be made based on MAC‐layer functionalities. The authors study the effects of multiple receiver nodes, size of preamble and variable duty‐cycle in number of retransmissions. Retransmissions increase energy consumptions and delay. Analytical and numerical results confirm that the RB‐MAC and adaptive RB‐MAC outperform the existing state‐of‐the art sender‐based MAC protocols in terms of end‐to‐end energy‐efficiency, reliability and delay. Simulation result demonstrates that using receiver‐based MAC protocols in RPL‐based lossy channel imply less retransmissions than sender‐based MAC.
Analysis of sensor impulse response effects on Cramèr–Rao lower bounds for signal parameter estimators
Authors: Gower Ephraim S. , Hawksford Malcom O.J.
Published: December 2014

In this study, a generic analysis of sensor impulse response effects on linearly filtered channel noise is presented to illustrate the resulting variations to the Cramèr–Rao lower bounds (CRLBs) of signal parameter estimators in signal processing and communication applications. The authors start by deriving the density function of a filtered signal, which is shown to be a mixture density, and hence the exact expressions for the mean and variance. Simulation results are used to confirm the derivations, which are then used to investigate the effects of impulse response length and variance, as well as channel noise length and variance effects on the resulting CRLBs. Results indicate that for non‐zero‐mean channel noise and impulse responses, the resulting mean of filtered noise can be relatively large causing adverse deviations to parameter estimations. The filtered noise variance is shown to be proportional to the impulse response energy, where for long duration of signal capture the CRLB is significantly increased.
Preparation and electrochemical behaviour study of layered Bi2SrTa2O9 with a cationic manganese porphyrin
Authors: Tao Tiantian , Zhang Xiaobo , Liu Lin , Ma Juanjuan , Zhang Dongen , Pan Binbin , Tong Zhiwei
Published: December 2014

Layered Bi2SrTa2O9 was achieved by solid‐phase synthesis and then cationic metalloporphyrin 5,10,15,20‐tetrakis(N‐methylpyridinium‐4‐yl) porphyrinato manganese (MnTMPyP), was intercalated into layered material Bi2SrTa2O9 by a guest‐exchange method using n ‐PrNH3+‐SrTa2O7 as a precursor. The new intercalation multicomposite MnTMPyP‐SrTa2O7 was characterised using X‐ray diffraction, infrared and scanning electron micrograph images. Moreover, the MnTMPyP‐SrTa2O7 nanocomposite exhibited fine electrocatalytic activity towards oxygen reduction.
A Ka-band TM02 mode relativistic backward wave oscillator with cascaded resonators
Authors: Teng Yan , Cao Yinbin , Song Zhimin , Ye Hu , Shi Yanchao , Chen Changhua , Sun Jun
Published: December 2014

By combining the Cerenkov-type generator with the cascaded resonators, this paper proposes a Ka-band relativistic backward wave oscillator operating under the guide magnetic field 1.0 T with high power handling capability and high conversion efficiency. It is found that TM02 can be selected as the operation mode in order to increase the power handling capability and provide sufficient coupling with the electron beam. In slow wave structure (SWS), ripples composed of semicircle on top of the rectangle enhance the wave-beam interaction and decrease the intensity of the electric field on the metallic surface. Taking advantage of the resonator cascades, the output power and the conversion efficiency are promoted greatly. The front cascaded resonators efficiently prevent the power generated in SWS from leaking into the diode region, and quicken the startup of the oscillation due to the premodulation of the beam. However, the post cascade slightly postpones the startup because of the further energy extraction from the electron beam. The numerical simulation shows that generation with power 514 MW and efficiency 41% is obtained under the diode voltage 520 kV and current 2.4 kA. And the microwave with the pure frequency spectrum of 29.35 GHz radiates in the pure TM01 mode.
Study of beam loading and its compensation in the Compact Ultrafast Terahertz Free-Electron Laser injector linac
Authors: Lal Shankar , Pant K. K.
Published: December 2014

The RF properties of an accelerating structure, and the pulse structure and charge per bunch in the electron beam propagating through it are important parameters that determine the impact of beam loading in the structure. The injector linac of the Compact Ultrafast Terahertz Free-Electron Laser (CUTE-FEL) has been operated with two different pulse structures during initial commissioning experiments and the effect of beam loading on the accelerated electron beam parameters has been studied analytically for these two pulse structures. This paper discusses the analytical study of beam loading in a Standing Wave, Plane Wave Transformer linac employed in the CUTE-FEL setup, and a possible technique for its compensation for the electron beam parameters of the CUTE-FEL. A parametric study has been performed to study beam loading for different beam currents and to optimize injection time of the electron beam to compensate beam loading. Results from the parametric study have also been used to explain previously observed results from acceleration experiments in the CUTE-FEL setup.
Angle-resolved effective potentials for disk-shaped molecules
Authors: Heinemann Thomas , Palczynski Karol , Dzubiella Joachim , Klapp Sabine H. L.
Published: December 2014

We present an approach for calculating coarse-grained angle-resolved effective pair potentials for uniaxial molecules. For integrating out the intramolecular degrees of freedom we apply umbrella sampling and steered dynamics techniques in atomistically-resolved molecular dynamics (MD) computer simulations. Throughout this study we focus on disk-like molecules such as coronene. To develop the methods we focus on integrating out the van der Waals and intramolecular interactions, while electrostatic charge contributions are neglected. The resulting coarse-grained pair potential reveals a strong temperature and angle dependence. In the next step we fit the numerical data with various Gay-Berne-like potentials to be used in more efficient simulations on larger scales. The quality of the resulting coarse-grained results is evaluated by comparing their pair and many-body structure as well as some thermodynamic quantities self-consistently to the outcome of atomistic MD simulations of many-particle systems. We find that angle-resolved potentials are essential not only to accurately describe crystal structures but also for fluid systems where simple isotropic potentials start to fail already for low to moderate packing fractions. Further, in describing these states it is crucial to take into account the pronounced temperature dependence arising in selected pair configurations due to bending fluctuations.
Lithium solvation in dimethyl sulfoxide-acetonitrile mixtures
Authors: Semino Rocío , Zaldívar Gervasio , Calvo Ernesto J. , Laria Daniel
Published: December 2014

We present molecular dynamics simulation results pertaining to the solvation of Li+ in dimethyl sulfoxide-acetonitrile binary mixtures. The results are potentially relevant in the design of Li-air batteries that rely on aprotic mixtures as solvent media. To analyze effects derived from differences in ionic size and charge sign, the solvation of Li+ is compared to the ones observed for infinitely diluted K+ and Cl− species, in similar solutions. At all compositions, the cations are preferentially solvated by dimethyl sulfoxide. Contrasting, the first solvation shell of Cl− shows a gradual modification in its composition, which varies linearly with the global concentrations of the two solvents in the mixtures. Moreover, the energetics of the solvation, described in terms of the corresponding solute-solvent coupling, presents a clear non-ideal concentration dependence. Similar nonlinear trends were found for the stabilization of different ionic species in solution, compared to the ones exhibited by their electrically neutral counterparts. These tendencies account for the characteristics of the free energy associated to the stabilization of Li+Cl−, contact-ion-pairs in these solutions. Ionic transport is also analyzed. Dynamical results show concentration trends similar to those recently obtained from direct experimental measurements.
Ab initio non-relativistic spin dynamics
Authors: Ding Feizhi , Goings Joshua J. , Frisch Michael J. , Li Xiaosong
Published: December 2014

Many magnetic materials do not conform to the (anti-)ferromagnetic paradigm where all electronic spins are aligned to a global magnetization axis. Unfortunately, most electronic structure methods cannot describe such materials with noncollinear electron spin on account of formally requiring spin alignment. To overcome this limitation, it is necessary to generalize electronic structure methods and allow each electron spin to rotate freely. Here, we report the development of an ab initio time-dependent non-relativistic two-component spinor (TDN2C), which is a generalization of the time-dependent Hartree-Fock equations. Propagating the TDN2C equations in the time domain allows for the first-principles description of spin dynamics. A numerical tool based on the Hirshfeld partitioning scheme is developed to analyze the time-dependent spin magnetization. In this work, we also introduce the coupling between electron spin and a homogenous magnetic field into the TDN2C framework to simulate the response of the electronic spin degrees of freedom to an external magnetic field. This is illustrated for several model systems, including the spin-frustrated Li3 molecule. Exact agreement is found between numerical and analytic results for Larmor precession of hydrogen and lithium atoms. The TDN2C method paves the way for the ab initio description of molecular spin transport and spintronics in the time domain.
A high stability and repeatability electrochemical scanning tunneling microscope
Authors: Xia Zhigang , Wang Jihao , Hou Yubin , Lu Qingyou
Published: December 2014

We present a home built electrochemical scanning tunneling microscope (ECSTM) with very high stability and repeatability. Its coarse approach is driven by a closely stacked piezo motor of GeckoDrive type with four rigid clamping points, which enhances the rigidity, compactness, and stability greatly. It can give high clarity atomic resolution images without sound and vibration isolations. Its drifting rates in XY and Z directions in solution are as low as 84 pm/min and 59 pm/min, respectively. In addition, repeatable coarse approaches in solution within 2 mm travel distance show a lateral deviation less than 50 nm. The gas environment can be well controlled to lower the evaporation rate of the cell, thus reducing the contamination and elongating the measurement time. Atomically resolved SO42− image on Au (111) work electrode is demonstrated to show the performance of the ECSTM.
Atomic simulation of mechanical behavior of Mg in a super-lattice of nanocrystalline Mg and amorphous Mg-Al alloy
Authors: Song H. Y. , An M. R. , Li Y. L. , Deng Q.
Published: December 2014

The mechanical properties of a super-lattice architecture composed of nanocrystalline Mg and Mg-Al amorphous alloy are investigated using molecular dynamics simulation. The results indicate that deformation mechanism of nanocrystalline Mg is obviously affected by the amorphous boundary spacing and temperature. The strength of the material increases with the decrease of amorphous boundary spacing, presenting a Hall-Petch effect at both 10 K and 300 K. A stress platform and following stiffness softening, as well as a linear strengthening in the plastic stage, are observed when the amorphous boundary spacing below 8.792 nm at 10 K. The implying reason may be that the amorphous boundary acts as the dislocations emission and absorption source. However, the second stress peak is not observed for the models at 300 K. Instead, the flow stress in plastic stage is a nearly constant value. The simulation demonstrates the emergence of the new grain, accompanied by the deformation twins and stacking faults associated with the plastic behaviors at 300 K. The general conclusions derived from this work may provide a guideline for the design of high-performance hexagonal close-packed metals.
A dynamic Monte Carlo study of anomalous current voltage behaviour in organic solar cells
Authors: Feron K. , Zhou X. , Belcher W. J. , Fell C. J. , Dastoor P. C.
Published: December 2014

We present a dynamic Monte Carlo (DMC) study of s-shaped current-voltage (I-V) behaviour in organic solar cells. This anomalous behaviour causes a substantial decrease in fill factor and thus power conversion efficiency. We show that this s-shaped behaviour is induced by charge traps that are located at the electrode interface rather than in the bulk of the active layer, and that the anomaly becomes more pronounced with increasing trap depth or density. Furthermore, the s-shape anomaly is correlated with interface recombination, but not bulk recombination, thus highlighting the importance of controlling the electrode interface. While thermal annealing is known to remove the s-shape anomaly, the reason has been not clear, since these treatments induce multiple simultaneous changes to the organic solar cell structure. The DMC modelling indicates that it is the removal of aluminium clusters at the electrode, which act as charge traps, that removes the anomalous I-V behaviour. Finally, this work shows that the s-shape becomes less pronounced with increasing electron-hole recombination rate; suggesting that efficient organic photovoltaic material systems are more susceptible to these electrode interface effects.
Electron heating in low pressure capacitive discharges revisited
Authors: Kawamura E. , Lieberman M. A. , Lichtenberg A. J.
Published: December 2014

The electrons in capacitively coupled plasmas (CCPs) absorb energy via ohmic heating due to electron-neutral collisions and stochastic heating due to momentum transfer from high voltage moving sheaths. We use Particle-in-Cell (PIC) simulations to explore these heating mechanisms and to compare the PIC results with available theories on ohmic and stochastic heating. The PIC results for ohmic heating show good agreement with the ohmic heating calculation of Lafleur et al. [Phys. Plasmas 20, 124503 (2013)]. The PIC results for stochastic heating in low pressure CCPs with collisionless sheaths show good agreement with the stochastic heating model of Kaganovich et al. [IEEE Trans. Plasma Sci. 34, 696 (2006)], which revises the hard wall asymptotic model of Lieberman [IEEE Trans. Plasma Sci. 16, 638 (1988)] by taking current continuity and bulk oscillation into account.
Charge state, angular distribution, and kinetic energy of ions from multicomponent-cathodes in vacuum arc devices
Authors: Nikolaev A. G. , Oks E. M. , Savkin K. P. , Yushkov G. Yu. , Frolova V. P. , Barengolts S. A.
Published: December 2014

We present research results on vacuum arc plasma produced with multicomponent cathode made of several different elements. The ion mass-to-charge-state spectra of the plasmas were studied by time-of-flight spectrometry. The angular distributions of different ion species were measured, and the kinetic energy of their directed (streaming) motion was determined. It is shown that the fractional composition of ions of different cathode components in the plasma flow from the cathode spot closely matches the fractional content of these components in the composite cathode. The charge states of ions of the various cathode components are determined by the average electron temperature in the cathode spot plasma. The angular distribution of lower mass ions in the plasma from a multicomponent cathode is less isotropic and broader than for the plasma from a single-component cathode of the same light element. The directed kinetic energies of the ions of the different components for plasma from a multicomponent cathode are lower for lighter elements and greater for heavier elements compared to the ion directed energy for plasmas from single-component cathodes made of the same materials. The physical processes responsible for these changes in the ion charge states in multicomponent-cathode vacuum arc plasma are discussed.
Energy deposition dynamics of femtosecond pulses in water
Authors: Minardi Stefano , Milián Carles , Majus Donatas , Gopal Amrutha , Tamošauskas Gintaras , Couairon Arnaud , Pertsch Thomas , Dubietis Audrius
Published: December 2014

We exploit inverse Raman scattering and solvated electron absorption to perform a quantitative characterization of the energy loss and ionization dynamics in water with tightly focused near-infrared femtosecond pulses. A comparison between experimental data and numerical simulations suggests that the ionization energy of water is 8 eV, rather than the commonly used value of 6.5 eV. We also introduce an equation for the Raman gain valid for ultra-short pulses that validates our experimental procedure.
Large exchange bias and magnetocaloric effect in TbMn2Si2
Authors: Maji Bibekananda , Ray Mayukh K. , Suresh K. G. , Banerjee S.
Published: December 2014

We report multiple first order magnetic transitions in TbMn2Si2 as evidenced by the thermal hysteresis in the M-T data and the Arrott plots. Metamagnetic transitions are observed at various temperatures as a result of the antiferromagnetic to ferromagnetic transition of the Mn sublattice. Very interestingly, the compound shows significant exchange bias field of about 600 Oe at 5 K, which is attributed to the formation of small domains or regions with ferromagnetic and antiferromagnetic interactions. Furthermore, a large magnetocaloric effect has been found at relatively low fields at both the transition regions. Maximum magnetic entropy changes (−ΔSM) of 7.2 and 5.4 J kg−1 K−1 have been observed at 68 K and at 48 K, respectively, at 20 kOe.
Effect of feeding a balanced ration on milk production, microbial nitrogen supply and methane emissions in field animals
Authors: Garg M. R. , Sherasia P. L. , Phondba B. T. , Hossain S. A.
Published: December 2014

Dairy animals in developing countries produce more methane (CH4), primarily on account of feed rations imbalanced in nutrients. A field study on early lactating cows (n = 80) and buffaloes (n = 82) was conducted to evaluate the effect of feeding a balanced ration on milk production, microbial nitrogen (N) supply and CH4 emissions in different agroclimatic regions of India. CH4 emissions was measured using the sulfur hexafluoride tracer technique, before and after feeding a balanced ration. Feeding practices revealed that intake of protein was adequate in the ration of experimental animals in most of the regions, except for the buffaloes of the western region. Metabolisable energy (MJ/cow.day) intake was higher by 7.6% and 13.6% in cows of western and northern regions, respectively. In buffaloes, energy intake (MJ metabolisable energy/buffalo.day) was higher by 11.5% in the western region but lower by 17.7% in the central region. Average calcium intake was deficient by 23.5% and 35.1%, whereas phosphorus intake was deficient by 33.2% and 56.2% in cows and buffaloes, respectively. Feeding a balanced ration increased (P < 0.05) average daily milk production by 6.7% and 7.6%, whereas cost of production decreased by 13.7% and 9.9% in cows and buffaloes, respectively. Fat-corrected milk increased from 9.1 to 9.8 kg/cow.day and from 6.9 to 7.7 kg/buffalo.day. Intestinal flow of microbial N improved significantly by 25.5% and 26.7% in cows and buffaloes, respectively. Balanced feeding reduced CH4 emissions (g/kg milk yield) by 17.3% (P < 0.05) in cows and 19.5% (P < 0.01) in buffaloes. The present study indicates that feeding a balanced ration improves milk production and microbial N supply, and reduces CH4 emissions in field animals.
Identification of bioactive grassland plants for reducing enteric methane production and rumen proteolysis using an in vitro screening assay
Authors: Niderkorn V. , Macheboeuf D.
Published: December 2014

The aim of this study was to conduct in vitro rumen fermentation assays on a large number of grassland plants to discriminate them on the basis of their potential to combine high nutritive value for ruminants and a reduced impact on the environment. In total, 156 plant species collected from diversified grasslands in the French Massif Central were screened by measuring several parameters, including in vitro true organic matter digestibility (IVTOMD), methane (CH4) production and ammonia nitrogen (N-NH3) in the incubation medium as an indicator of dietary protein degradation in the rumen. The results were expressed relative to perennial ryegrass (PRG) values used as a reference. We observed that the fermentation of 13 plants produced 50% less CH4 per unit of OM truly digested than did fermentation of PRG. Among these plants, two (Bidens tripartita subsp. Tripartite and Scrophularia nodosa) reduced CH4 by more than 80%. In terms of protein degradation, the fermentation of 37 plants halved the ratio between N-NH3 and plant N content compared with PRG, of which six had values below the detection level of the assay. Interestingly, 16 plants showed simultaneously a reduction of more than 80% in N-NH3 production and 30% in CH4 production, including three plants (Sedum telephium subsp. maximum, Oenothera biennis and Geranium sylvaticum) with an IVTOMD higher than 80%. This study has provided more knowledge about the use of lesser-known plants as whole plant forage by ruminants, and has identified candidate plants for potential use as additives in the form of plant extracts.
A pilot study into the use of global navigation satellite system technology to quantify the behavioural responses of sheep during simulated dog predation events
Authors: Manning Jaime K. , Fogarty Eloise S. , Trotter Mark G. , Schneider Derek A. , Thomson Peter C. , Bush Russell D. , Cronin Greg M.
Published: December 2014

The predation of sheep (Ovis aries) by wild and domestic dogs (Canis lupis) is a major issue in Australia, causing serious welfare issues to inflicted animals. The estimated cost of sheep and cattle production losses caused by wild dogs when combined with an extensive range of control measures, costs the Australian economy AU$66 million annually. Spatio-temporal data derived from global navigation satellite system (GNSS) devices were used to quantify the behavioural responses of two flocks of 15 Merino ewes ranging from 2 to 8 years old (average 4.5 years) during simulated dog predation events. Each sheep was fitted with a GNSS collar, and the behavioural responses of the sheep were video recorded during six trials (three per flock). The behavioural data collated from video recordings were then compared with the movement metrics derived from the GNSS collars. Derived metrics include the spatial distribution of flock members, speed of animal movement and specific behavioural changes including centripetal rotation (circling behaviour of the flock, with individual sheep seeking the centre). While the spatial distribution data did not appear to be specific enough to enable identification of a predation event, the velocity of sheep was higher (P < 0.001) during compared with before and after a simulated dog predation event. Centripetal rotation occurred in 80% of the simulated predation events during this study, and may provide a means for identifying predation. The spatio-temporal data from GNSS devices have potential as a research tool to assist in understanding sheep movement patterns during a dog attack. While further research and mathematical modelling of predation events is clearly required, the application of remote sensing technology has the potential to improve future livestock monitoring.
Bioactive forage legumes as a strategy to improve silage quality and minimise nitrogenous losses
Authors: Copani G. , Ginane C. , Le Morvan A. , Niderkorn V.
Published: December 2014

The use of forage legumes as a source of protein for ruminants is a sustainable strategy to reduce the use of inorganic-nitrogen fertiliser. In addition, some legumes species contain naturally bioactive secondary compounds, which could improve silage quality and digestive processes in ruminants. The aim of this study is to investigate the effects of bioactive legumes containing condensed tannins or polyphenol oxidase, ensiled alone or in mixture with a grass, on silage quality and conservation characteristics. Six mini-silos were prepared in triplicate as follows: 100% red clover (RC), 100% sainfoin (SF), 100% Timothy (T, control without bioactive compounds), binary mixtures 50% T + 50% RC, 50% T + 50% SF and ternary mixture 50% T + 25% RC + 25% SF. Condensed tannins remain unaltered during the silage-making process in terms of quantity and chemical structures, while polyphenol oxidase is activated during this process. All the silages that contained bioactive legumes were better conserved than the pure grass silo. In addition bioactive legumes were able to preserve protein from their degradation during the silage process. Inclusion of bioactive legumes can improve silage quality, and polyphenol oxidase may be more efficient than condensed tannins to improve the nitrogen value of silage.
Effect of type and inclusion level of cold-pressed oilseed cakes on in vitro rumen fermentation
Authors: Benhissi H. , García-Rodríguez A. , Beltrán de Heredia I.
Published: December 2014

The current study was conducted to explore the impact of inclusion of different types and levels of cold-pressed oilseed cakes on in vitro rumen fermentation and gas production parameters. Two batch fermentation trials (24 and 96 h) were conducted using the in vitro gas production technique. In each trial, three types of lipid sources [palm fat (PF), cold-pressed rapeseed cake (CPRC) and cold-pressed sunflower cake (CPSC)] × two levels of total fat (30 and 60 g/kg DM) were evaluated. Incubated substrates were made from iso-energetic and isoproteic basal mixtures of barley straw and concentrate (ratio 10 : 90). During the 24-h incubation trial, samples were collected 24 h post-incubation to measure volatile fatty acids (VFA) and methane production. The 96-h incubation was used to assess the rate and extent of in vitro gas production. CPSC showed lower total VFA (P < 0.001) and methane (P < 0.001) production, compared with PF and CPRC. High fat level decreased total VFA (P < 0.001) and methane (P < 0.001) production compared with low level of inclusion. Molar proportions of individual VFA and acetate to propionate ratio were not affected by lipid supplementation. CPSC reduced (P = 0.006) asymptotic gas production at high fat level, compared with PF and CPRC. Neither supplementation level nor type of lipid affected the fractional gas production rate or lag time. In conclusion, there was no difference in ruminal fermentation when either CPRC or PF were added but CPSC altered microbial fermentation in vitro at a total fat level of 60 g/kg DM.
Factors influencing the occurrence of high ultimate pH in three muscles of lamb carcasses in Australia
Authors: McPhail N. G. , Stark J. L. , Ball A. J. , Warner R. D.
Published: December 2014

Chilled lamb meat exported from Australia has, on occasions, been rejected by importing countries due to greening, after only 6 weeks of storage time. Greening is known to be more prevalent in high ultimate pH (pHu) beef meat (>5.9). There are few data available for lamb carcasses in Australia on the occurrence of high pHu meat, which may have an impact on the understanding and control of quality and greening during storage. The aim of this project was to determine the prevalence of, and influencing factors for, high pHu meat in a range of muscle types in lamb carcasses in Australia. Muscle pHu data were collected from a total of 1614 carcasses from 78 lots at four lamb processing plants in Victoria and New South Wales in autumn and spring of 2013. The pHu of the knuckle (rectus femoris), rack (longissimus) and blade (infraspinatus) was measured and data on carcass and lot characteristics were recorded. Data were subjected to restricted maximum likelihood and generalised linear mixed model analysis. The mean pHu of the knuckle, rack and shoulder were 6.06, 5.79 and 6.12 respectively, and the main factors influencing muscle pHu and occurrence of dark-cutting were breed, season, electrical stimulation and carcass weight. Merino lambs had a higher pHu in the blade and knuckle than did other breeds (P < 0.05, P < 0.01 respectively). Lambs processed in autumn had a higher predicted pHu in the blade and knuckle and a higher percentage dark-cutting (DC; pHu >6.0) for those muscles, than did those processed in spring (P < 0.05). Carcasses that had been electrically stimulated had a higher %DC and a higher pHu in all three muscles (P < 0.05). Carcass weight had a significant effect on the pHu of all three muscles (P < 0.001), with heavier carcasses having a lower pHu and lower %DC. The pHu of the rack was not a reliable predictor for the pHu in other muscles of the lamb carcass. In conclusion, the high occurrence of DC in the muscles, particularly the blade and knuckle, suggests that these muscles may be at risk for producing greening in the vacuum bag during storage.
Use of nitrate and Propionibacterium acidipropionici to reduce methane emissions and increase wool growth of Merino sheep
Authors: de Raphélis-Soissan V. , Li L. , Godwin I. R. , Barnett M. C. , Perdok H. B. , Hegarty R. S.
Published: December 2014

The effects of dietary nitrate and of Propionibacterium acidipropionici (PA) on methane and nitrous oxide emissions, methaemoglobinaemia, volatile fatty acid (VFA) concentration and productivity of sheep were studied. It was hypothesised that PA supplementation would increase the rate of nitrite reduction to ammonia in the rumen and therefore reduce risks of methaemoglobinaemia. Fine-wool Merino wethers (n = 28; 31.8 ± 3.7 kg; 11 months of age) were acclimated to four isonitrogenous and isoenergetic diets based on oaten chaff (1.0 kg/day) supplemented with either urea (1.1% of DM; T1 and T2) or a nitrate source (2.0% of DM; T3 and T4) while T2 and T4 were also supplemented with PA (11.5 × 1010 CFU/day). Replacing urea with nitrate lowered methane production (g/day) by 19% and methane yield (g/kg DMI) by 15%, improved clean wool growth by 12% (P < 0.001) and tended to increase skin temperature (P < 0.1). Nitrate increased ruminal acetate to propionate ratio by 27%, increased plasma nitrite and nitrate concentrations and blood methaemoglobin (MetHb) level up to 45% of total haemoglobin. Nitrous oxide emission from sheep confined in respiration chambers was higher (P < 0.001) when nitrate was fed, lowering the net benefit of methane mitigation on global warming potential (CO2 equivalents/kg DMI) by 18%. In contrast, PA had little effect, decreasing total VFA concentration (P < 0.05), increasing rumen pH (P < 0.05) and clean wool growth (P < 0.05) of urea-fed sheep. This study confirmed the beneficial effects of nitrate on net greenhouse gas reduction and wool growth, but showed that methaemoglobinaemia risks may be higher when diets are fed at a restricted level and contain only low levels of readily fermented carbohydrate. PA supplementation was not effective in reducing methaemoglobinaemia, but did increase clean wool growth of urea-fed sheep.
Effects of including olive cake in the diet on performance and rumen function of beef cattle
Authors: Estaún J. , Dosil J. , Al Alami A. , Gimeno A. , de Vega A.
Published: December 2014

Beef meat in many Mediterranean countries is produced by feeding the animals with high proportions of concentrates and barley straw. In these conditions, feeding costs are high and compromise the profitability of feedlots. Mediterranean countries are also major producers of olive oil, and the processing of this product generates a large quantity of co-products with a high environmental impact. No data appear available in the literature about the effects of including olive by-products in the diet of beef cattle on animal performance. A pen-feeding study was carried out during two growing phases: from 100 to 250 kg (12 weeks), and from 250 to 450 kg (18 weeks). During the first phase 120 steers (mostly Friesian, with an average age of 129 ± 1.1 days) were distributed in six groups of 20 animals each. Two groups were assigned to one of each of the following treatments: a control compound feed based on barley, control with 10% dry matter (DM) substituted by second-extraction pitted and dehydrated olive cake, and control with 20% DM substituted by olive cake. Compound feeds of this first phase were formulated to contain 16–17% crude protein, and were offered ad libitum to the animals. Barley straw was offered as a roughage source. Animals were weighed every 3 weeks, and a digestibility trial was carried out in the middle of the period with four animals per treatment. During the second phase, compound feeds were formulated to contain 14.5–15% crude protein. Rumen fermentation was studied using six steers and the feeds employed in the second growing phase, following a crossover design with two periods. Concentrates were offered once daily allowing at least 10% refusals. Barley straw was also offered as a source of roughage. For each period of the crossover, 15 days were allowed for adaptation to the experimental diets. Samples of rumen liquid were taken at 0 (just before), 4 and 8 h after feeding. The pH, and concentrations of ammonia and volatile fatty acids were determined. Inclusion of up to 20% second-extraction pitted and dehydrated olive cake (DM basis) in the diet did not affect performance of beef steers for the whole growth period. Inclusion of those ingredients in the diet of these animals might be advisable depending on their market price.
Meal pattern analysis for effects of compound feed formulation in mid to late lactating dairy cows fed hay and compound feed both ad libitum
Authors: Leen F. , Navarro-Villa A. , Fowers R. , Martín-Tereso J. , Pellikaan W. F.
Published: December 2014

The Kempen System is a dairy feeding system allowing ad libitum access to pelleted compound feed (CF) and hay. This system allows high DM intake (DMI) up to 30 kg DM (80% CF), but small and frequent CF meals are essential to reduce negative ruminal pH fluctuations. Little is known about feed intake patterns of cows on ad libitum and separated access to CF and hay. Meal pattern analysis was performed to evaluate feed intake behaviour of two different isoenergetic and isonitrogenous CF (starch vs fibre), contrasting in neutral detergent fibre, acid detergent fibre and starch content. Twenty primi- and multiparous Holstein-Friesian cows (203 ± 35.4 days in milk) received grass hay ad libitum with one of the two CF also offered ad libitum. Meal criteria, the shortest non-feeding interval between feeding events separating two consecutive meals, were used to cluster feeding events into separate meals. The meal criteria were determined per cow by fitting the log10-transformed feeding intervals to Gaussian–Gaussian probability density functions. The DMI of CF fibre (18.8 ± 0.54 kg) tended to be greater (P = 0.09) than starch (18.1 ± 0.54 kg/day), while that of grass hay (4.8 ± 0.29 kg) was unaffected (P = 0.23). The CF meal size did not differ (P = 0.26) between treatments (starch 2.9 vs fibre 3.0 ± 0.11 kg/meal), but number of meals per day (6.36 ± 0.229, P = 0.87) and meal durations (64 ± 3.5 min, P = 0.87) did not differ between treatments. The differences in CF formulation were insufficient to create detectable differences in feed intake nor intake behaviour patterns.
Effect of glucagon-like peptide-1 and ghrelin on liver metabolites in steers
Authors: El-Sabagh M. , Taniguchi D. , Sugino T. , Obitsu T. , Taniguchi K.
Published: December 2014

Glucagon-like peptide 1 (GLP-1) and ghrelin have opposite regulatory effects on glucose metabolism in non-ruminants. However, mechanisms by which GLP-1 and ghrelin regulate nutrient partitioning, particularly in the liver, have been much less demonstrated in ruminants. A novel metabolomic method based on capillary electrophoresis time-of-flight mass spectrometry (CE-TOFMS) combined with multivariate statistical analysis was applied to address the GLP-1 and ghrelin-induced metabolic changes in the liver of steers. Three Holstein steers (400 ± 5.0 kg LW) fed a maintenance diet according to Japanese feeding standards were randomly assigned to three treatments (GLP-1, ghrelin and saline) in a 3 × 3 Latin square design with one week apart. Liver biopsies were taken 30 min after a single injection (1.0 μg/kg LW) of GLP-1 or ghrelin, and analysed for metabolites by Agilent CE-TOFMS system. Also, blood samples were collected for plasma hormones analysis. Results indicated that 20 and 10 liver metabolites were altered (P < 0.05) by GLP-1 and ghrelin, respectively. Pathway analysis showed that GLP-1 is involved in biochemical pathways related to glycolysis/gluconeogenesis, lipogenesis and lipid export from the liver, oxidative stress defence and protein turnover. Ghrelin was shown to be involved in pathways related to glycolysis, protein anabolism and phospholipid biosynthesis. However, plasma concentrations of insulin, growth hormone and glucagon did not differ between treatments. These results imply that GLP-1 and ghrelin are involved in multibiochemical pathways that go beyond simply regulating glucose metabolism. In addition, the effects of GLP-1 and ghrelin may potentially be independent of insulin and growth hormone, respectively.
Influence of supplementation of tropical plant feed additives on in vitro rumen fermentation and methanogenesis
Authors: Chatterjee P. N. , Kamra D. N. , Agarwal N. , Patra A. K.
Published: December 2014

Tropical plants rich in secondary metabolites have the potential to modulate rumen fermentation for more efficient food production with reduced environmental impact. In the present study after extensive screening, three tropical tree leaves (Bahunia variegata, Psidium guajava and Cannabis indica) and three herbs (Cinnamomum zeylanicum, Trachyspermum ammi and Cinnamomum tamala) were selected to evaluate their effect on buffalo rumen fermentation. Total gas production, substrate degradability, volatile fatty acid pattern and enzyme activities were not affected by any of the plants tested in this study. However, methane production was lowered (P ≤ 0.05) due to inclusion of P. guajava leaves. Anti-methanogenic/anti-protozoal metabolites present in tropical plants seem to be better extracted by ethanol solvent and accordingly the best performing plant i.e. different levels of P. guajava extract was used for further evaluation. Both the methane inhibition and defaunating action of ethanol extract of P. guajava were found to be dose dependent. In conclusion, leaves of P. guajava appear to be a promising plant feed additive for decreasing methane production without affecting feed degradability in the rumen.