Linear-response theory of spin Seebeck effect in ferromagnetic insulators

We formulate a linear response theory of the spin Seebeck effect, i.e., a spin voltage generation from heat current flowing in a ferromagnet. Our approach focuses on the collective magnetic excitation of spins, i.e., magnons. We show that the linear-response formulation provides us with a qualitative as well as quantitative understanding of the spin Seebeck effect observed in a prototypical magnet, yttrium iron garnet.Comment: 6 pages, 3 figures. Added references and revised argument on the length scales at the end of Sec.

5.11 A research about different residues in pollen and honey samples

Within the cooperative project “Reference system for a healthy honey bee colony – FIT BEE” the subproject “Multifactorial influences on honey bee colonies and establishment of a GIS-based expert information system” was conducted by LAVES Institute for Apidology Celle. The project lasted for four years and was funded by BLE / BMELV. In addition to research about influences of different habitats (city and country sites) on honey bee colonies, residues from Plant Protection Products (PPPs), Heavy Metals and Polycyclic Aromatic Hydrocarbons (PAHs) were analysed in pollen and honey samples.During the project a total of 62 different residues from PPPs were analysed (11 insecticides, 18 herbicides and 33 fungicides) as well as one synergist. Thiacloprid was found in every fourth pollen sample on average with a maximum concentration of 0.16 mg / kg (bee bread). In the country site group and the travel group over 80 % of the pollen samples had PPP-residues, in the city site group 25 % (n = 80 / group, 2012 + 2013). In the country site group 15 active ingredients (a.i.) were parallel in one pollen sample, in the travel group 11 and in the city group 3 with maximum concentrations > 10 mg / kg in pollen samples from the country site. From the 15 pooled honey samples 7 had PPP-residues, especially the spring samples (oil seed rape honey). In all honey samples analysed, four a.i`s were found in the honey samples in total (Thiacloprid (max. 0.05 mg / kg)), Boscalid (0.005 mg / kg), Dimoxystrobin (0.005 mg / kg) and Carbendazim (max. 0.04 mg / kg)). The PPP-data were comparable to the PAH- and the Heavy Metal data: In the pollen samples were more residues and in higher concentration than in the honey samples. Honey is a lipophobic matrix and pollen a lipophilic matrix. Most of the residues solve better in a lipophilic matrix and the bees act as a filter for the nectar / honey.Within the cooperative project “Reference system for a healthy honey bee colony – FIT BEE” the subproject “Multifactorial influences on honey bee colonies and establishment of a GIS-based expert information system” was conducted by LAVES Institute for Apidology Celle. The project lasted for four years and was funded by BLE / BMELV. In addition to research about influences of different habitats (city and country sites) on honey bee colonies, residues from Plant Protection Products (PPPs), Heavy Metals and Polycyclic Aromatic Hydrocarbons (PAHs) were analysed in pollen and honey samples.During the project a total of 62 different residues from PPPs were analysed (11 insecticides, 18 herbicides and 33 fungicides) as well as one synergist. Thiacloprid was found in every fourth pollen sample on average with a maximum concentration of 0.16 mg / kg (bee bread). In the country site group and the travel group over 80 % of the pollen samples had PPP-residues, in the city site group 25 % (n = 80 / group, 2012 + 2013). In the country site group 15 active ingredients (a.i.) were parallel in one pollen sample, in the travel group 11 and in the city group 3 with maximum concentrations > 10 mg / kg in pollen samples from the country site. From the 15 pooled honey samples 7 had PPP-residues, especially the spring samples (oil seed rape honey). In all honey samples analysed, four a.i`s were found in the honey samples in total (Thiacloprid (max. 0.05 mg / kg)), Boscalid (0.005 mg / kg), Dimoxystrobin (0.005 mg / kg) and Carbendazim (max. 0.04 mg / kg)). The PPP-data were comparable to the PAH- and the Heavy Metal data: In the pollen samples were more residues and in higher concentration than in the honey samples. Honey is a lipophobic matrix and pollen a lipophilic matrix. Most of the residues solve better in a lipophilic matrix and the bees act as a filter for the nectar / honey

Establishing the ratio of rock salts and organic compounds to reduce the number of Chloride and Sodium ions in the soil when de-icing roads

The research analyzes the amount of salt being dumped onto roads and its effect on trees, specifically the Red Maple and Eastern Hemlock. The goal is to find an alternative to rock salt without completely eliminating its use. The experiment involves using three different alternatives-volcanic mineral, beet juice, cheese brine-and constructing a ratio between a baseline amount of salt and alternative. The result of this is to find the smallest amount of salt needed to efficiently melt ice and cause least damage to trees. Analyzing leaf water content will show which alternative works best

Mesoscopic Stern-Gerlach spin filter by nonuniform spin-orbit interaction

A novel spin filtering in two-dimensional electron system with nonuniform spin-orbit interactions (SOI) is theoretically studied. The strength of SOI is modulated perpendicular to the charge current. A spatial gradient of effective magnetic field due to the nonuniform SOI causes the Stern-Gerlach type spin separation. The direction of the polarization is perpendicular to the current and parallel to the spatial gradient. Almost 100 % spin polarization can be realized even without applying any external magnetic fields and without attaching ferromagnetic contacts. The spin polarization persists even in the presence of randomness.Comment: 6 pages, 5 figures (2 color figures), to appear in Phys. Rev. B, Rapid Commu

Conductance fluctuations in the presence of spin scattering

Electron transport through disordered systems that include spin scatterers is studied numerically. We consider three kinds of magnetic impurities: the Ising, the XY and the Heisenberg. By extending the transfer matrix method to include the spin degree of freedom, the two terminal conductance is calculated. The variance of conductance is halved as the number of spin components of the magnetic impurities increases. Application of the Zeeman field in the lead causes a further halving of the variance under certain conditions.Comment: to be published in Phys. Rev.

Examination of silver-graphite lithographically printed resistive strain sensors

This paper reports the design and manufacture of three differing types of resistive strain sensitive structures fabricated using the Conductive Lithographic Film (CLF) printing process. The structures, utilising two inks prepared with silver and graphite particulates as the conductive phase, have been analysed to determine electrical and mechanical properties with respect to strain, temperature and humidity when deposited on four alternative substrate materials (GlossArt, PolyArt, Teslin and Melinex)