APS LABS (Advanced Power Systems Research Center)

Our mission is to promote & facilitate education and research in clean, efficient, and sustainable power and powertrain systems. The center was established in 2007 and in 2014 the 55,000 sq ft APSRC building located near the airport was denoted as a MTU core facility. Our new research contracts in FY2016 were over 2.5M. Our partners include automotive OEMs: GM, Ford, FCA, Toyota, Honda; Commercial OEMs: Cummins, Deere, Detroit, Isuzu, MHI; Suppliers: Delphi, Denso, Borg Warner, Hitachi; and DOE Labs: ANL, ORNL, PNNL, SNL, & INL. We have seven staff to assist in educational and R&D programs and facilities to support research at the fundamental to applied scale. The Mobile Lab provides outreach, education, and demonstration platform. We were recently awarded a 3.5M DOE ARPA-e program with GM to advance mobility and efficiency through connected an automated vehicle technologies. View more online at http://apslabs.me.mtu.edu.https://digitalcommons.mtu.edu/techtalks/1016/thumbnail.jp

DOE APRA-E NEXTCAR program on connected and automated vehicles in collaboration with GM

Within the $3.5M ARPA-e NEXTCAR program, Michigan Tech in collaboration with GM will development and demonstrate on a fleet of eight 2017 Chevrolet Volts and a mobile connected cloud computing center, a Vehicle Dynamics and Powertrain (VD&PT) model-based predictive controller (MPC) encompassing a real-time VD&PT dynamic model leveraging vehicle conductivity (V2X) with real-time traffic modeling and predictive speed horizons and eco-routing. The objective is to achieve a minimum of 20% reduction in energy consumption (electric + fuel) through the first ever real-time implementation and connection of route planning, powertrain energy management MPC algorithms. Connectivity data from vehicles, infrastructure, GPS, traffic and desired route planning combined with a dynamic model of the powertrain-vehicle system allows prediction of the vehicle’s future speed profile and enables forward looking optimization of powertrain mode selection, energy utilization from the battery and fuel source, and distribution of propulsive torque from the electric motors and/or internal combustion engine. Development and testing will be done at MCity and within a complete integrated vehicle and traffic simulation model.https://digitalcommons.mtu.edu/techtalks/1033/thumbnail.jp

Combustion knock detection and control through statistical characterization of knock levels

A method of statistically characterizing combustion knock events includes receiving signals from a sensing device such as an accelerometer, estimating at least one parameter of a probability distribution function based on the received signals, and calculating a value indicative of an r/h percentile based on the parameter to predict upcoming combustion knock events.https://digitalcommons.mtu.edu/patents/1030/thumbnail.jp

Review of sensing methodologies for estimation of combustion metrics

For reduction of engine-out emissions and improvement of fuel economy, closed-loop control of the combustion process has been explored and documented by many researchers. In the closed-loop control, the engine control parameters are optimized according to the estimated instantaneous combustion metrics provided by the combustion sensing process. Combustion sensing process is primarily composed of two aspects: combustion response signal acquisition and response signal processing. As a number of different signals have been employed as the response signal and the signal processing techniques can be different, this paper did a review work concerning the two aspects: combustion response signals and signal processing techniques. In-cylinder pressure signal was not investigated as one of the response signals in this paper since it has been studied and documented in many publications and also due to its high cost and inconvenience in the application

Molecular aspects of herbicide binding in chloroplasts = [Molekulaire aspekten van herbicide binding in chloroplasten]

Many weed-controlling agents act by inhibiting the process of photosynthesis. Their mode of action is a displacement of the secondary quinone electron acceptor of photosystem II from its proteinaceous binding environment. This results in a blocking of the electron transport. Consequently plants are no longer able to produce ATP and to reduce NADP +, which eventually leads to starvation and death.In this thesis an attempt is made to characterize the interactions of herbicides with their binding environment. Several herbicides were used to measure binding kinetics in a wildtype and a triazine -resistant biotype of Common Lambsquarters, Chenopodium album L.In Chapter 1 a general introduction is given on photosynthesis, chloroplast structure and function, the chloroplast genome, and herbicide action and resistances.Chapter 2 describes the methods used to isolate chloroplasts and to measure oxygen production. Also the fluorescence induction measurements are described, which can be used as a rapid method to discriminate between herbicide-sensitive and -resistant plants. Procedures for the simultaneous isolation of total plant nucleic acids, for the separation of DNA and RNA and for the respective sequence analyses are outlined.In Chapter 3 a model is described which can be used to simulate flash- induced oxygen production by isolated thylakoids. In the literature a model was described before, which explains the observed 4-step oscillation in flash-induced oxygen evolution by assuming the existence of 4 different S-states of the oxygen evolving complex. This model is refined here by assuming the values of the miss parameters αto be dependent on both the redox state of the quinone acceptor complex (Q A .Fe.Q B ) of photosystem II and on the S-state transition involved. The best fit between theoretical and experimental oxygen evolution patterns is obtained when 4 different miss parameters are distinguished, corresponding with the 4 S-state transitions of the oxygen evolving complex. The values of two of these αparameters, notably those for the 2 ndand 4 thflash, are found to approach 0, while the other two have values of about 0.2 and 0.4. The value for the double hit parameter βis found to be about 0.06. The oxygen evolving complexes of thoroughly dark adapted chloroplasts are found to be for almost 100 % in the most stable single oxidized state S 1 . A fraction of 30 % of the reaction centers is assumed to be connected to a oneelectron donor D, which is able to reduce the S 2 - or S 3 -state of the oxygen evolving complex with a half time of 2-3 seconds.In Chapter 4 the derived model is used to determine the exchange ,parameters of herbicides with the secondary acceptor Q B . These exchanges, which influence the oxygen evolution patterns, can be determined by comparing experimental and theoretical patterns for various herbicide concentrations and flash frequencies. The I 50 -values derived from the measurements are in agreement with values measured with other methods. The resistance to triazine compounds proved to be caused by an increase in the herbicide release rather than by a lower binding rate. Configuration around a chiral carbon atom, present in two pairs of isomers of cyanoacrylate inhibitors, has a strong influence on inhibition properties. The differences are largely due to alterations in the release kinetics. This observation suggests that herbicide binding is determined mainly by physical properties, like e.g. hydrophobicity. A stationary binding, resulting in a significant electron transport inhibition, requires a strict molecular shape.In Chapter 5 partial sequence analyses from DNA and mRNA isolated from a Chenopodium album wildtype and a triazine -resistant biotype are presented. The only difference found was an adenine to guanine point mutation resulting in a serine to glycine alteration at position 264 in the D1 (herbicide binding) protein.The thesis is concluded with Chapter 6, the general discussion, in which an alternative explanation for redox reactions at the photosystem II acceptor side is presented. In this model the non-heme iron, located between the primary and the secondary acceptor of photosystem II, is proposed to play an active role in in vivo electron transport

The chromatin remodeller ACF acts as a dimeric motor to space nucleosomes.

Evenly spaced nucleosomes directly correlate with condensed chromatin and gene silencing. The ATP-dependent chromatin assembly factor (ACF) forms such structures in vitro and is required for silencing in vivo. ACF generates and maintains nucleosome spacing by constantly moving a nucleosome towards the longer flanking DNA faster than the shorter flanking DNA. How the enzyme rapidly moves back and forth between both sides of a nucleosome to accomplish bidirectional movement is unknown. Here we show that nucleosome movement depends cooperatively on two ACF molecules, indicating that ACF functions as a dimer of ATPases. Further, the nucleotide state determines whether the dimer closely engages one or both sides of the nucleosome. Three-dimensional reconstruction by single-particle electron microscopy of the ATPase-nucleosome complex in an activated ATP state reveals a dimer architecture in which the two ATPases face each other. Our results indicate a model in which the two ATPases work in a coordinated manner, taking turns to engage either side of a nucleosome, thereby allowing processive bidirectional movement. This novel dimeric motor mechanism differs from that of dimeric motors such as kinesin and dimeric helicases that processively translocate unidirectionally and reflects the unique challenges faced by motors that move nucleosomes

Sharp estimates on the first eigenvalue of the p-Laplacian with negative Ricci lower bound

We complete the picture of sharp eigenvalue estimates for the p-Laplacian on a compact manifold by providing sharp estimates on the first nonzero eigenvalue of the nonlinear operator $\Delta_p$ when the Ricci curvature is bounded from below by a negative constant. We assume that the boundary of the manifold is convex, and put Neumann boundary conditions on it. The proof is based on a refined gradient comparison technique and a careful analysis of the underlying model spaces.Comment: Sign mistake fixed in the proof of the gradient comparison theorem (theorem 5.1 pag 10), and some minor improvements aroun

Polar distortions in hydrogen bonded organic ferroelectrics

Although ferroelectric compounds containing hydrogen bonds were among the first to be discovered, organic ferroelectrics are relatively rare. The discovery of high polarization at room temperature in croconic acid [Nature \textbf{463}, 789 (2010)] has led to a renewed interest in organic ferroelectrics. We present an ab-initio study of two ferroelectric organic molecular crystals, 1-cyclobutene-1,2-dicarboxylic acid (CBDC) and 2-phenylmalondialdehyde (PhMDA). By using a distortion-mode analysis we shed light on the microscopic mechanisms contributing to the polarization, which we find to be as large as 14.3 and 7.0\,$\mu$C/cm$^{2}$ for CBDC and PhMDA respectively. These results suggest that it may be fruitful to search among known but poorly characterized organic compounds for organic ferroelectrics with enhanced polar properties suitable for device applications.Comment: Submitte

Controlling Stray Electric Fields on an Atom Chip for Rydberg Experiments

Experiments handling Rydberg atoms near surfaces must necessarily deal with the high sensitivity of Rydberg atoms to (stray) electric fields that typically emanate from adsorbates on the surface. We demonstrate a method to modify and reduce the stray electric field by changing the adsorbates distribution. We use one of the Rydberg excitation lasers to locally affect the adsorbed dipole distribution. By adjusting the averaged exposure time we change the strength (with the minimal value less than $0.2\,\textrm{V/cm}$ at $78\,\mu\textrm{m}$ from the chip) and even the sign of the perpendicular field component. This technique is a useful tool for experiments handling Ryberg atoms near surfaces, including atom chips