3,272 research outputs found
Economics of boar taint prevention without surgical castration in the pork chain
An economic analyses of boar taint prevention without surgical castration is lacking. This paper explores currently feasible alternatives to surgical castration along the pork chain. The considered alternatives include genetic selection (pig breeding stage); altering management strategies (pig growing stage); slaughter at younger age and lower weight (slaughtering stage). Control measures relevant to these alternatives were designed and examined, using costeffectiveness and cost-benefit analysis. Results show that the option of single-sex raising of entire males is more cost-effective compared to the mixed-sex option. The breeding programs combining selection on boar taint and economics are more cost-effective than programs focusing on boar taint only, and also much more cost-effective than slaughtering at a younger age and lower weigh
Transconductance fluctuations as a probe for interaction induced quantum Hall states in graphene
Transport measurements normally provide a macroscopic, averaged view of the
sample, so that disorder prevents the observation of fragile interaction
induced states. Here, we demonstrate that transconductance fluctuations in a
graphene field effect transistor reflect charge localization phenomena on the
nanometer scale due to the formation of a dot network which forms near
incompressible quantum states. These fluctuations give access to fragile
broken-symmetry and fractional quantum Hall states even though these states
remain hidden in conventional magnetotransport quantities.Comment: 6 pages, 3 figure
Radiation induced zero-resistance states in GaAs/AlGaAs heterostructures: Voltage-current characteristics and intensity dependence at the resistance minima
High mobility two-dimensional electron systems exhibit vanishing resistance
over broad magnetic field intervals upon excitation with microwaves, with a
characteristic reduction of the resistance with increasing radiation intensity
at the resistance minima. Here, we report experimental results examining the
voltage - current characteristics, and the resistance at the minima vs. the
microwave power. The findings indicate that a non-linear V-I curve in the
absence of microwave excitation becomes linearized under irradiation, unlike
expectations, and they suggest a similarity between the roles of the radiation
intensity and the inverse temperature.Comment: 3 color figures; publishe
A Mathematical programming Model for Small Scale Family Farms in South Eastern South Dakota
Many farm operators are anxious to use the very latest technological tools in forward planning their farming operations. Among those tools are the computer and mathematical programming models. Small scale family farmers in southeastern South Dakota are as much in need of such technology as any businessman, industrialist, or large farm operator. However, the technical expertise necessary for developing and using a mathematical model has placed a limitation on its practical application. This publication presents a model for small scale family farm operations in southeastern South Dakota along with data input-output procedures that may be used by any person not specially trained in linear programming
Livestock transportation: a model for ex-ante policy analysis
The protection of live animals during transport in the EU is currently regulated under the Council Regulation No. 1/2005. The current legal regime is strongly criticized by the European society. To reform the existing regulation, policy makers need insights into the impact of possible transport restrictions for live animals. In this work, we propose a mathematical programming model to assess the potential impact of a policy reform involving limitations of travelling times and space allowances. This model is implemented for the years 2002 and 2013. A sensitivity analysis is performed on variations of fuel prices and cost of meat transpor
Optically stimulated nanodosimeters with high storage capacity
In this work we report on the thermoluminescence (TL) and optically stimulated luminescence (OSL) properties of beta-Na(Gd,Lu)F-4:Tb3+ nanophosphors prepared via a standard high-temperature coprecipitation route. Irradiating this phosphor with X-rays not only produces radioluminescence but also leads to a bright green afterglow that is detectable up to hours after excitation has stopped. The storage capacity of the phosphor was found to be (2.83 +/- 0.05) x 10(16) photons/gram, which is extraordinarily high for nano-sized particles and comparable to the benchmark bulk phosphor SrAl2O4:Eu2+,Dy3+. By combining TL with OSL, we show that the relatively shallow traps, which dominate the TL glow curves and are responsible for the bright afterglow, can also be emptied optically using 808 or 980 nm infrared light while the deeper traps can only be emptied thermally. This OSL at therapeutically relevant radiation doses is of high interest to the medical dosimetry community, and is demonstrated here in uniform, solution-processable nanocrystals
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