FAPRI 2005 Outlook for Missouri Agriculture

Agricultural and Food Policy,

Stochastic model for the 3D microstructure of pristine and cyclically aged cathodes in Li-ion batteries

It is well-known that the microstructure of electrodes in lithium-ion batteries strongly affects their performance. Vice versa, the microstructure can exhibit strong changes during the usage of the battery due to aging effects. For a better understanding of these effects, mathematical analysis and modeling has turned out to be of great help. In particular, stochastic 3D microstructure models have proven to be a powerful and very flexible tool to generate various kinds of particle-based structures. Recently, such models have been proposed for the microstructure of anodes in lithium-ion energy and power cells. In the present paper, we describe a stochastic modeling approach for the 3D microstructure of cathodes in a lithium-ion energy cell, which differs significantly from the one observed in anodes. The model for the cathode data enhances the ideas of the anode models, which have been developed so far. It is calibrated using 3D tomographic image data from pristine as well as two aged cathodes. A validation based on morphological image characteristics shows that the model is able to realistically describe both, the microstructure of pristine and aged cathodes. Thus, we conclude that the model is suitable to generate virtual, but realistic microstructures of lithium-ion cathodes

Experimental study of low-frequency oscillations and large-scale circulations in turbulent mixed convection

The formation and dynamics of large-scale circulations in forced and mixed convection has been studied at ambient and elevated fluid pressure by means of particle image velocimetry and temperature measurements. The study has been conducted in two rectangular containers of the same shape and aspect ratios of Cxz = 1 and Cyz = 5. For the measurements at high fluid pressure the dimensions of the cell have been scaled down by a factor of 5. Air with Pr = 0.7 has been used as fluid in both configurations. Forced convection has been investigated at Re = 1.01 x 104 and mixed convection has been studied at Ar = 3.3, Re = 1.01 x 10 up4 and Ra = 2.4 x 10 up8. In this configuration low-frequency oscillations in the heat transfer between the inlet and outlet have been found for mixed convection. Instantaneous velocity vector fields obtained from particle image velocimetry have been analysed using proper orthogonal decomposition and an algorithm to detect the core and the core centre position of large-scale circulations

A State-Level Agricultural Sector Policy Model: Baseline and Implications of the Dunkel Text on Agriculture for Iowa

A better understanding of the relationship between a state\u27s agricultural sector and the national agricultural economy increases the ability of agricultural interest groups to anticipate and understand policy developments. This paper develops and documents a state-level model of the Iowa agricultural sector. The model is used to evaluate the future performance of the Iowa agricultural economy, given a specific set of assumptions about the general economy, agricultural policies, the weather, and technological change. When the model is used to analyze the implications of the Dunkel text on agriculture, the increase in Iowa net farm income is found to be proportionally higher than the increase in U.S. net farm income, because Iowa\u27s agricultural economy is concentrated in commodities that benefit from the Dunkel text

A State-Level Agricultural Sector Policy Model: Baseline and Implications of the Dunkel Text on Agriculture for Iowa

A better understanding of the relationship between a state\u27s agricultural sector and the national agricultural economy increases the ability of agricultural interest groups to anticipate and understand policy developments. This paper develops and documents a state-level model of the Iowa agricultural sector. The model is used to evaluate the future performance of the Iowa agricultural economy, given a specific set of assumptions about the general economy, agricultural policies, the weather, and technology change. When the model is used to analyze the implications of the Dunkel text on agriculture, the increase in Iowa net farm income is found to be proportionally higher then the increase in U.S. net farm income, because Iowa\u27s agricultural economy is concentrated in commodities that benefit from the Dunkel text

Experimentelle Untersuchung zum thermischen Komfort im Grenzbereich des Luftzugempfindens in einer generischen Fahrzeugkabine

Ob auf dem Weg zur Arbeit oder in den Urlaub – in den heutigen Industriestaaten verbringt der Mensch einen nicht unwesentlichen Teil seiner Zeit im Fahrzeug. Nicht zuletzt deswegen und aufgrund des gesteigerten Wettbewerbs ist der thermische Komfort im Fahrzeug ein mitentscheidendes Argument für die Profilierung im Wettbewerb der Fahrzeughersteller. Für die Auslegung einer Klimatisierung im PKW ist es das Ziel thermische Bedingungen herzustellen, die von möglichst allen Passagieren als behaglich wahrgenommen werden. In diesem Zusammenhang stellt sich die Frage, wie man den thermischen Komfort in einem Fahrzeug vergleichbar bewerten kann. Hierzu gibt es eine Vielzahl von Methoden und Normen zur Charakterisierung und Bewertung des thermischen Komforts in PKW. Jedoch zeigen Untersuchungen, dass die Normen den thermischen Komfort im Grenzbereich des Zugluftempfindens nur unvollständig beschreiben. Das Ziel dieses Forschungsvorhabens ist daher die Untersuchung der Auswirkung von Zugluft auf den thermischen Komfort in Abhängigkeit der folgenden Einflussgrößen: Lufttemperatur, Strahlung, Luftmassenstrom, Luftgeschwindigkeit und Turbulenzgrad. Hierzu wurden die objektiven Komfortparameter in einer generischen Fahrzeugkabine mithilfe eines thermischen Menschmodells bestimmt und basierend auf der Methode der Äquivalenttemperatur nach EN ISO14505-2 bewertet. Die Ergebnisse der Untersuchung sollen mit den aktuellen Normen verglichen werden. Im Zuge dessen soll außerdem geprüft werden, inwieweit eine Anpassung bestehender Normen unter Berücksichtigung des Luftzugempfindens möglich und sinnvoll ist. Auf der Fachtagung werden wir die Ergebnisse einer Teilstudie zur Untersuchung des thermischen Komforts im Grenzbereich des Zugluftempfindens als Funktion der Anströmgeschwindigkeit und des Turbulenzgrads präsentieren

Study on the Influence of Turbulence on Thermal Comfort for Draft Air

Today you can find various standards to assess thermal comfort. However, it lacks on standards for the assessment of thermal comfort in car cabins, particularly in case of high momentum air-flow or draft. Thermal comfort is often perceived differently in cars compared to e.g. in buildings or coaches. With the objective to overcome this problem, an experimental study of the impact of the draft on thermal comfort is carried out. In this paper, we present results of an investigation focusing on the influence of turbulence intensity on thermal comfort. Draft is simulated in a generic car cabin in the following parameter ranges: temperature T=17 ∘C–29 ∘C, velocity U=0.25 m/s–2.5 m/s and turbulence intensity ILT=16% and IHT=32%. The thermal comfort is determined by means of a thermal manikin and infrared thermography to evaluate the thresholds of thermal comfort based on the German Industrial Norms

Electrofused giant protoplasts of Saccharomyces cerevisiae as a novel system for electrophysiological studies on membrane proteins

AbstractGiant protoplasts of Saccharomyces cerevisiae of 10–35 µm in diameter were generated by multi-cell electrofusion. Thereby two different preparation strategies were evaluated with a focus on size distribution and “patchability” of electrofused protoplasts. In general, parental protoplasts were suitable for electrofusion 1–12 h after isolation. The electrophysiological properties of electrofused giant protoplasts could be analyzed by the whole-cell patch clamp technique. The area-specific membrane capacitance (0.66±0.07 µF/cm2) and conductance (23–44 µS/cm2) of giant protoplasts were consistent with the corresponding data for parental protoplasts. Measurements with fluorescein-filled patch pipettes allowed to exclude any internal compartmentalisation of giant protoplasts by plasma membranes, since uniform (diffusion-controlled) dye uptake was only observed in the whole-cell configuration, but not in the cell-attached formation. The homogeneous structure of giant protoplasts was further confirmed by the observation that no plasma membrane associated fluorescence was seen in the interior of giant cells after electrofusion of protoplasts expressing the light-activated cation channel Channelrhodopsin-2 (ChR2) linked to yellow fluorescent protein (YFP). Patch clamp analysis of the heterologously expressed ChR2-YFP showed typical blue light dependent, inwardly-directed currents for both electrofused giant and parental protoplasts. Most importantly, neither channel characteristics nor channel expression density was altered by electric field treatment. Summarising, multi-cell electrofusion increases considerably the absolute number of membrane proteins accessible in patch clamp experiments, thus presumably providing a convenient tool for the biophysical investigation of low-signal transporters and channels

Low-cost Thermal Manikin - A Competitive Instrument to Simulate Thermal Loads and to Determine Thermal Passenger Comfort

A low-cost and practicable measurement instrument which allows the simulation of the heat loads and the obstruction of a human passenger, while simultaneously determining the thermal comfort, is highly desirable. At the DLR, a TM was developed which meets these requirements. The TM reveals a simplified, however, realistic shape and heat load of a human body. Furthermore, we defined a process chain to calibrate the TM in order to use it as an instrument for evaluating the thermal passenger comfort. However, the TM is continuously being developed further. Current projects address the topics of dimensionless characterization of the TM with the objective to identify the physical quantities which determine thermal comfort