Conformations and charge transport characteristics of biphenyldithiol self-assembled-monolayer molecular electronic devices: A multiscale computational study

We report a computational study of conformations and charge transport characteristics of biphenyldithiol (BPDT) monolayers in the (sqrt(3)×sqrt(3))R30° packing ratio sandwiched between Au(111) electrodes. From force-field molecular-dynamics and annealing simulations of BPDT self-assembled monolayers (SAMs) with up to 100 molecules on a Au(111) substrate, we identify an energetically favorable herringbone-type SAM packing configuration and a less-stable parallel packing configuration. Both SAMs are described by the (2sqrt(3)×sqrt(3))R30° unit cell including two molecules. With subsequent density-functional theory calculations of one unit cell of the (i) herringbone SAM with the molecular tilt angle theta[approximate]15°, (ii) herringbone SAM with theta[approximate]30°, and (iii) parallel SAM with theta[approximate]30°, we confirm that the herringbone packing configuration is more stable than the parallel one but find that the energy variation with respect to the molecule tilting within the herringbone packing is very small. Next, by capping these SAMs with the top Au(111) electrode, we prepare three molecular electronic device models and calculate their coherent charge transport properties within the matrix Green's function approach. Current–voltage (I–V) curves are then obtained via the Landauer–Büttiker formula. We find that at low-bias voltages (|V|~0.5 V), the I–V characteristics of the three models show noticeable differences due to different phenyl band structures. We thus conclude that the BPDT SAM I–V characteristics in the low-bias voltage region are mainly determined by the Si–Au interaction within the individual molecule-electrode contact, while both intramolecular conformation and intermolecular interaction can affect the BPDT SAM I–V characteristics in the high-bias voltage region

Planting and harvesting innovation - an analysis of Samsung Electronics

This study explores how firms manage the entire life cycle of innovation projects based on the framework of harvesting and planting innovation. While harvesting innovation seeks new products in the expectation of financial performance in the short term, planting innovation pursues creating value over a long time period. Without proper management of the process of planting and harvesting innovation, firms with limited resources may not be successful in launching innovative new products to seize a momentum in high tech industries. To examine this issue, the case of Samsung Electronics (SE), now an electronics giant originated from a former developing country, is analyzed. SE has shown to effectively utilize co-innovation to maintain numerous planting and harvesting innovation projects. Both researchers and practitioners would be interested in learning about how SE shared risks of innovation investment with external partners at the early stage of innovation cycles

Measuring the Effects of a Land Value Tax on Land Development

The objective of this research is to evaluate a land value tax as a potential policy tool to moderate sprawling development in Nashville, TN, the nation’s most sprawling metropolitan community with a population of one million or more. To achieve this objective, the hypothesis is empirically tested that a land value tax encourages more development closer to preexisting development than farther from preexisting development. Specifically, the marginal effects of a land value tax on the probability of land development is hypothesized to be greater in areas around preexisting development than in areas more distant from preexisting development. The findings show that the marginal effects of a land value tax on the probability of developing parcels that neighbored previously developed parcels was greater than the probability of developing parcels that did not neighbor previously developed parcels. This finding suggests that land value taxation could be used to design compact development strategies that address sprawling development.Land value tax, Land development model, Urban sprawl, Land Economics/Use, Community/Rural/Urban Development,

Negative Externalities on Property Values Resulting from Water Impairment: The Case of the Pigeon River Watershed

The following hypothesis was tested: Willingness to bear a negative water impairment externality differs between those who do and those who do not receive economic benefit from the impairment source, e.g., a paper mill. The hypothesis was tested using a hedonic analysis of ambient water quality in two discrete housing markets in the Pigeon River Watershed, which have been polluted by the operation of a paper mill. The results suggest that North Carolina residents of the subwatersheds with impaired river, who experience economic benefits from the paper mill in addition to harmful effects, do perceive the pollution as a negative externality, whereas they may have a willingness to bear a similar type of negative externality associated with impaired streams. In contrast, the effects of both degraded river and streams on property values is perceived as a negative externality by residents in the Tennessee side, who experience only harmful effects from the pollution. North Carolina residents may hold greater willingness to bear the harmful effects of pollution as a given condition in their decision-making process because they receive economic benefits from the paper mill, while this internalization of the negative externality is weaker for residents in the Tennessee side.negative Externalities, water quality, spatial hedonic model, Environmental Economics and Policy,

Possible performance improvement in [2]catenane molecular electronic switches

Mechanically interlocked bistable supramolecular complexes are promising candidates of molecular electronics. Applying a multiscale computational approach, here we study the coherent charge transport properties of catenane monolayers sandwiched between Cu(111) electrodes. We demonstrate the robust nature of electrical switching behavior with respect to the variations in the monolayer packing density and the type of electrodes, as well as the thermal fluctuations of the molecules. We propose that the asymmetry of molecule-electrode barriers can be utilized to improve the switching ratio

"Choice of Air Cargo Transshipment Airport: An Application to Air Cargo Traffic to/from Northeast Asia"

Based on a unique data set of 760 air cargo transshipment routings to/from the Northeast Asian region in 2000, this paper applies an aggregate form of multinomial logit model to identify the critical factors influencing air cargo transshipment route choice decisions. The analysis focuses on the trade-off between monetary cost and time cost while considering other variables relevant for choice of transshipment airport. The estimation method considers the presence of unobserved attributes, and corrects for resulting endogeneity via a two-stage least squares estimation using instrumental variables. Our empirical results show that choice of air cargo transshipment hub is more sensitive to time cost than the monetary costs such as landing fees and line-haul price. For example, our simulation results suggest that a one-hour reduction in total transport and processing time for a particular O-D air cargo traffic would be more effective than a US$1,000 reduction in airport charges. This suggests that it is important to reduce air cargo connecting time at an airport via adequate investment in capacity and automation even by increasing landing and other airport charges.