Formulation and optimization of the energy-based blended quasicontinuum method

We formulate an energy-based atomistic-to-continuum coupling method based on blending the quasicontinuum method for the simulation of crystal defects. We utilize theoretical results from Ortner and Van Koten (manuscript) to derive optimal choices of approximation parameters (blending function and finite element grid) for microcrack and di-vacancy test problems and confirm our analytical predictions in numerical tests

Use of shallow samples to estimate the total carbon storage in pastoral soils

Using data from pastoral soils sampled by horizon at 56 locations across New Zealand, we conducted a meta-analysis. On average, the total depth sampled was 0.93 ± 0.026 m (± SEM), and on a volumetric basis, the total C storage averaged 26.9 ± 1.8, 13.9 ± 0.6 and 9.2 ± 1.4 kg C m⁻² for allophanic (n=12), non-allophanic (n=40) and pumice soils (n=4), respectively. We estimated the total C storage, and quantified the uncertainty, using the data for samples taken from the uppermost A-horizon whose depth averaged 0.1 ± 0.003 m. For A-horizon samples of the allophanic soils, the mean C content was 108 ± 6 g C kg⁻¹ and the bulk density was 772 ± 29 kg m⁻³, for non-allophanic soils they were 51 ± 4 g C kg⁻¹ and 1055 ± 29 kg m⁻³, and for pumice soils they were 68 ± 9 g C kg⁻¹ and 715 ± 45 kg m⁻³. The C density —a product of the C content and bulk density —of the A-horizon samples was proportional to their air-dried water content, a proxy measure for the mineral surface area. By linear regression with C density of the A-horizon, the total C storage could be estimated with a standard error of 3.1 kg C m⁻², 19% of the overall mean

A novel heteroditopic terpyridine-pincer ligand as building block for mono- and heterometallic Pd(II) and Ru(II) complexes

A palladium-catalyzed Stille coupling reaction was employed as a versatile method for the synthesis of a novel terpyridine-pincer (3, TPBr) bridging ligand, 4'-{4-BrC6H2(CH2NMe2)(2)-3,5}-2,2':6',2 ''-terpyridine. Mononuclear species [PdX(TP)] (X = Br, Cl), [Ru(TPBr)(tpy)](PF6)(2), and [Ru(TPBr)(2)](PF6)(2), synthesized by selective metalation of the NCNBr-pincer moiety or complexation of the terpyridine of the bifunctional ligand TPBr, were used as building blocks for the preparation of heterodi- and trimetallic complexes [Ru(TPPdCl)(tpy)](PF6)(2) (7) and [Ru(TPPdCl)(2)]-(PF6)(2) (8). The molecular structures in the solid state of [PdBr(TP)] (4a) and [Ru(TPBr)(2)](PF6)(2) (6) have been determined by single-crystal X-ray analysis. Electrochemical behavior and photophysical properties of the mono-and heterometallic complexes are described. All the above di- and trimetallic Ru complexes exhibit absorption bands attributable to (MLCT)-M-1 (Ru -> tpy) transitions. For the heteroleptic complexes, the transitions involving the unsubstituted tpy ligand are at a lower energy than the tpy moiety of the TPBr ligand. The absorption bands observed in the electronic spectra for TPBr and [PdCl(TP)] have been assigned with the aid of TD-DFT calculations. All complexes display weak emission both at room temperature and in a butyronitrile glass at 77 K. The considerable red shift of the emission maxima relative to the signal of the reference compound [Ru(tpy)(2)](2+) indicates stabilization of the luminescent (MLCT)-M-3 state. For the mono- and heterometallic complexes, electrochemical and spectroscopic studies (electronic absorption and emission spectra and luminescence lifetimes recorded at room temperature and 77 K in nitrile solvents), together with the information gained from IR spectroelectrochemical studies of the dimetallic complex [Ru(TPPdSCN)(tpy)](PF6)(2), are indicative of charge redistribution through the bridging ligand TPBr. The results are in line with a weak coupling between the {Ru(tpy)(2)} chromophoric unit and the (non)metalated NCN-pincer moiety

Pengaruh Variasi Tegangan Dan Waktu Terhadap Kekerasan Lapisan Nikel Dengan Metode Electroplating Pada Coran Aluminium Scrap

Aluminum is widely used in the industry for its light weight, corrosion resistance and good heat conductivity and high electrical. Violence is not so high and a less attractive appearance needs to be fixed, one of which with a coat of aluminum with a Nickel electroplating process. This research aims to know the influence of voltage and time of Nickel plating on aluminum scrap casting. The specimen made from castings of optional with a size of 30 x 30 x 10 mm. Nickel coated aluminum with electroplating process with a voltage of 3, 4.5 and 6 volt. With the variation of time coating 5, 10 and 15 minutes. Once coated, micro hardness testing done by the method of testing the Vickers with a load of 10 gr and detained 10 s. test results indicate the presence of nickel plating hardness values increase with increasing voltage and time. Electric voltage 3 volts of 10.4%-15.9%, 4.5 volt voltage of 14.3%-4.62%, and 6-volt voltage of 24.8%-84.2

In situ measurements of plasma properties during gas-condensation of Cu nanoparticles

Since the mean, standard deviation, and modality of nanoparticle size distributions can vary greatly between similar input conditions (e.g., power and gas flow rate), plasma diagnostics were carried out in situ using a double-sided, planar Langmuir probe to determine the effect the plasma has on the heating of clusters and their final size distributions. The formation of Cu nanoparticles was analyzed using cluster-plasma physics, which relates the processes of condensation and evaporation to internal plasma properties (e.g., electron temperature and density). Monitoring these plasma properties while depositing Cu nanoparticles with different size distributions revealed a negative correlation between average particle size and electron temperature. Furthermore, the modality of the size distributions also correlated with the modality of the electron energy distributions. It was found that the maximum cluster temperature reached during plasma heating and the material’s evaporation point regulates the growth process inside the plasma. In the case of Cu, size distributions with average sizes of 8.2, 17.3, and 24.9 nm in diameter were monitored with the Langmuir probe, and from the measurements made, the cluster temperatures for each deposition were calculated to be 1028, 1009, and 863 K. These values are then compared with the onset evaporation temperature of particles of this size, which was estimated to be 1059, 1068, and 1071 K. Thus, when the cluster temperature is too close to the evaporation temperature, less particle growth occurs, resulting in the formation of smaller particles

Pertumbuhan dan Produksi Hijauan Arbila (Phaseolus Lunatus) sebagai Pakan Ternak Akibat Dosis Bokashi Gulma Pastura yang Berbeda di Lahan Kering

Penelitian bertujuan untuk mengevaluasi pertumbuhan dan produksi hijauan arbila (Phaseolus lunatusL.) sebagai dampak dari penambahan bokashi gulma pasture seperti Chromolaenadan kotoran sapi pada level yang berbeda,  telah  dilaksanakan selama 8 bulan di kebun pakan ternak Desa Noelbaki - Kupang Tengah dan Laboratorium Teknologi  Pakan Ternak, dirancang berdasarkan Rancangan Acak Lengkap (RAL) dengan 5 perlakuan dan 4 ulangan = 20 unit percobaanyaitu B0: tanpa bokashi (kontrol), B10:  penambahan bokashi 10 ton/ha, B20 :bokashi 20 ton/ha, B30:  bokashi 30 ton/ha, dan  B40:  bokashi 40 ton/ha.  Variabel yang diamati adalah persentasi bintil akar efektif (%), Serapan nitrogen (g/polybag), panjang tanaman, jumlah tunas pertanaman (buah), produksi bahan segar hijauan (g/polybag), dan  produksi bahan kering hijauan (g/polybag).Data yang di peroleh di analisis  varians berdasarkan RAL dan  dilanjutkan dengan uji Duncan), Gomes dan Gomez (2010). Hasil penelitian menunjukkan bahwa dosis bokashi Cromolaena berpengaruh nyata (P<0,05)  terhadap persentasi bintil akar efektif, serapan nitrogen, dan berpengaruh sangat nyata (P<0,01) produksi bahan segar dan produksi bahan kering hijauan. Akan tetapi tidak berbeda terhadap panjang tanaman dan  jumlah tunas. Uji Duncan menunjukkan bahwa perlakuan B40 menunjukkan hasil tertinggi dan yang terendah adalah pada perlakuan B0. Disimpulkan bahwa produkstivitas arbila dipengaruhi oleh dosis bokashi cromolaena dengan dosis terbaik adalah 40 ton/ha.Penelitian bertujuan untuk mengevaluasi pertumbuhan dan produksi hijauan arbila (Phaseolus lunatusL.) sebagai dampak dari penambahan bokashi gulma pasture seperti Chromolaenadan kotoran sapi pada level yang berbeda,  telah  dilaksanakan selama 8 bulan di kebun pakan ternak Desa Noelbaki - Kupang Tengah dan Laboratorium Teknologi  Pakan Ternak, dirancang berdasarkan Rancangan Acak Lengkap (RAL) dengan 5 perlakuan dan 4 ulangan = 20 unit percobaanyaitu B0: tanpa bokashi (kontrol), B10:  penambahan bokashi 10 ton/ha, B20 :bokashi 20 ton/ha, B30:  bokashi 30 ton/ha, dan  B40:  bokashi 40 ton/ha.  Variabel yang diamati adalah persentasi bintil akar efektif (%), Serapan nitrogen (g/polybag), panjang tanaman, jumlah tunas pertanaman (buah), produksi bahan segar hijauan (g/polybag), dan  produksi bahan kering hijauan (g/polybag).Data yang di peroleh di analisis  varians berdasarkan RAL dan  dilanjutkan dengan uji Duncan), Gomes dan Gomez (2010). Hasil penelitian menunjukkan bahwa dosis bokashi Cromolaena berpengaruh nyata (P<0,05)  terhadap persentasi bintil akar efektif, serapan nitrogen, dan berpengaruh sangat nyata (P<0,01) produksi bahan segar dan produksi bahan kering hijauan. Akan tetapi tidak berbeda terhadap panjang tanaman dan  jumlah tunas. Uji Duncan menunjukkan bahwa perlakuan B40 menunjukkan hasil tertinggi dan yang terendah adalah pada perlakuan B0. Disimpulkan bahwa produkstivitas arbila dipengaruhi oleh dosis bokashi cromolaena dengan dosis terbaik adalah 40 ton/ha

Development of an Optimization-Based Atomistic-to-Continuum Coupling Method

Atomistic-to-Continuum (AtC) coupling methods are a novel means of computing the properties of a discrete crystal structure, such as those containing defects, that combine the accuracy of an atomistic (fully discrete) model with the efficiency of a continuum model. In this note we extend the optimization-based AtC, formulated in arXiv:1304.4976 for linear, one-dimensional problems to multi-dimensional settings and arbitrary interatomic potentials. We conjecture optimal error estimates for the multidimensional AtC, outline an implementation procedure, and provide numerical results to corroborate the conjecture for a 1D Lennard-Jones system with next-nearest neighbor interactions.Comment: 12 pages, 3 figure

Experimental study of the vidicon system for information recording using the wide-gap spark chamber of gamma - telescope gamma-I

The development of the gamma ray telescope is investigated. The wide gap spark chambers, used to identify the gamma quanta and to determine the directions of their arrival, are examined. Two systems of information recording with the spark chambers photographic and vidicon system are compared

Does White Clover (Trifolium repens) Abundance in Temperate Pastures Determine Sitona obsoletus (Coleoptera: Curculionidae) Larval Populations?

To determine if host plant abundance determined the size of clover root weevil (CRW) Sitona obsoletus larval populations, a study was conducted over four years in plots sown in ryegrass (Lolium perenne) (cv. Nui) sown at either 6 or 30 kg/ha and white clover (Trifolium repens) sown at a uniform rate of 8 kg/ha. This provided a range of % white clover content to investigate CRW population establishment and impacts on white clover survival. Larval sampling was carried out in spring (October) when larval densities are near their spring peak at Lincoln (Canterbury, New Zealand) with % clover measured in autumn (April) and spring (September) of each year. Overall, mean larval densities measured in spring 2012, 2013, 2014 and 2015 were 310, 38, 59 and 31 larvae m-2, respectively. There was a significant decline in larval populations between 2012 and 2013, but spring populations were relatively uniform thereafter. The mean % white clover measured in autumns of 2012 to 2015 was 17, 10, 3 and 11%, respectively. In comparison, mean spring % white clover from 2012 to 2015, averaged c. 5% each year. Analysis relating spring (October) larval populations to % white clover measured in each plot in autumn (April) found the 2012 larval population to be statistically significantly larger in the ryegrass 6 kg/ha plots than 30 kg/ha plots. Thereafter, sowing rate had no significant effect on larval populations. From 2013 to 2015, spring larval populations had a negative relationship with the previous autumn % white clover with the relationship highly significant for the 2014 data. When CRW larval populations in spring 2013 to 2015 were predicted from the 2013 to 2015 autumn % white clover, respectively, based on their positive relationship in 2012, the predicted densities were substantially larger than those observed. Conversely, when 2015 spring larval data and % clover was regressed against 2012-2014 larval populations, observed densities tended to be higher than predicted, but the numbers came closer to predicted for the 2013 and 2014 populations. These differences are attributed to a CRW population decline that was not accounted by % white clover changes, the CR

Effect of Strain on Ferroelectric Field Effect in Strongly Correlated Oxide Sm0.5Nd0.5NiO3

We report the effect of epitaxial strain on the magnitude and retention of the ferroelectric field effect in high quality PbZr0.3Ti0.7O3 (PZT)/3.8-4.3 nm Sm0.5Nd0.5NiO3 (SNNO) heterostructures grown on (001) LaAlO3 (LAO) and SrTiO3 (STO) substrates. For SNNO on LAO, which exhibits a first-order metal-insulator transition (MIT), switching the polarization of PZT induces a 10 K shift in the transition temperature TMI, with a maximum resistance change between the on and off states of Δ/on ~75%. In sharp contrast, only up to 5% resistance change has been induced in SNNO on STO, where the MIT is second-order, with the modulation of TMI negligibly small. We also observe thermally activated retention of the off state resistance Roff in both systems, with the activation energy of 22 meV (28 meV) for devices on LAO (STO). The time dynamics and thermal response of the field effect instability points to phonon-assisted interfacial trapping of charged mobile defects, which are attributed to strain induced oxygen vacancies. At room temperature, Roff stabilizes at ~55% and ~19% of the initial switching levels for SNNO on LAO and STO, respectively, reflecting the significantly different oxygen vacancy densities in these two systems. Our results reveal the critical role of strain in engineering and modeling the complex oxide composite structures for nanoelectronic and spintronic applications