Spatial Pricing Patterns of Cellulosic Biomass under Oligopsony – A Multi-agent Simulation Model

Agribusiness, Industrial Organization, Research Methods/ Statistical Methods, Resource /Energy Economics and Policy,

Choice of optimum feedstock portfolio for a cellulosic ethanol plant – A dynamic linear programming solution

When the lignocellulosic biofuels industry reaches maturity and many types of biomass sources become economically viable, management of multiple feedstock supplies – that vary in their yields, density (tons per unit area), harvest window, storage and seasonal costs, storage losses, transport distance to the production plant – will become increasingly important for the success of individual enterprises. The manager’s feedstock procurement problem is modeled as a multi-period sequence problem to account for dynamic management over time. The case is illustrated with a hypothetical 53 million annual US gallon cellulosic ethanol plant located in south west Kansas that requires approximately 700,000 metric dry tons of biomass. The problem is framed over 40 quarters (10 years), where the production manager minimizes cumulative costs by choosing the land acreage that has to be contracted with for corn stover collection, or dedicated energy production and the amount of biomass stored for off-season. The sensitivity of feedstock costs to changes in yield patterns, harvesting and transport costs, seasonal costs and the extent of area available for feedstock procurement are studied. The outputs of the model include expected feedstock cost and optimal mix of feedstocks used by the cellulosic ethanol plant every year. The problem is coded and solved using GAMS software. The analysis demonstrates how the feedstock choice affects the resulting raw material cost for cellulosic ethanol production, and how the optimal combination varies with two types of feedstocks (annual and perennial).Cellulosic ethanol, feedstock, switchgrass, miscanthus, corn stover, optimization, biofuels, biomass, energy, renewable, Agribusiness,

Testing for Speculative Behavior in US Corn Ethanol Investments

Crude oil price speculation during 2000s could have increased installed capacity in corn ethanol plants beyond what was warranted by the market factors. We use Muth’s commodity pricing model and Flood and Garber’s tests to test for speculative investment in US corn ethanol industry. The ethanol price expectations are derived using a system of supply-demand-inventory describing US ethanol markets under rational expectations (perfect foresight). These price expectations can help differentiate the installed capacity into two: capacity supported by the market fundamentals and the probable capacity that is installed based on speculation. Econometric estimation procedures and functional form approximations are discussed.ethanol, speculation, commodity prices, investment, Agricultural Finance, Financial Economics, Q14, Q41, D8, L71,

Asymmetric emission of high energy electrons in the two-dimensional hydrodynamic expansion of large xenon clusters irradiated by intense laser fields

Energy spectra and angular distributions have been measured of electrons that are emitted upon disassembly of $Xe_{150000}$ following irradiation by intense (10$^{15}-10^{16}$ W cm$^{-2}$) laser pulses whose durations are varied over the 100-2200 fs range. The cluster explosion dynamics occur in the hydrodynamic regime. Electron emission is found to be unexpectedly asymmetric and exhibits a resonance when the laser pulse duration is $\sim$1 ps. These results are rationalized by extending the hydrodynamic model to also take into account the force that the light field exerts on the polarization charge that is induced on surface of the cluster. We show that the magnitude of this electrostrictive force is comparable to those of Coulombic and the hydrodynamic forces, and it exhibits resonance behavior. Contrary to earlier understanding, we find that low-energy electrons are connected to the resonance in energy absorption by the cluster. The high-energy electrons seem to be produced by a mechanism that is not so strongly influenced by the resonance.Comment: 1 Revtex file, 8 figs. in eps forma

Explosions of water clusters in intense laser fields

Energetic, highly-charged oxygen ions, $O^{q+}$ ($q\leq 6$), are copiously produced upon laser field-induced disassembly of highly-charged water clusters, $(H_2O)_n$ and $(D_2O)_n$, $n\sim$ 60, that are formed by seeding high-pressure helium or argon with water vapor. $Ar_n$ clusters (n$\sim$40000) formed under similar experimental conditions are found undergo disassembly in the Coulomb explosion regime, with the energies of $Ar^{q+}$ ions showing a $q^2$ dependence. Water clusters, which are argued to be considerably smaller in size, should also disassemble in the same regime, but the energies of fragment O$^{q+}$ ions are found to depend linearly on $q$ which, according to prevailing wisdom, ought to be a signature of hydrodynamic expansion that is expected of much larger clusters. The implication of these observations on our understanding of the two cluster explosion regimes, Coulomb explosion and hydrodynamic expansion, is discussed. Our results indicate that charge state dependences of ion energy do not constitute an unambiguous experimental signature of cluster explosion regime.Comment: Submitted to Phys. Rev.

Topical nano-delivery of 5-fluorouracil: Preparation and characterization of water-in-oil nanoemulsion

Purpose: To prepare and characterize a water-in-oil nanoemulsion of 5-fluorouracil (5FU) for enhanced skin penetration.Methods: Nanoemulsions of 5FU were prepared using Capyrol (propylene glycol monocaprylate). Transcutol (highly purified diethylene glycol monoethyl ether) and polyethylene glycol (PEG) 400 as oil, surfactant and co-surfactant, respectively. The optimized formulations were subjected to heating - cooling cycling, centrifugation and freeze - thaw cycling to assess their stability. Particle size distribution and zeta potential of the nanoemulsions were evaluated. Furthermore, in vitro and in vivo skin permeation studies were carried out on the formulations in a rat model. Skin irritation studies were also performed on rats to assess the irritation potential of the formulations. The 1 % w/v of Carbopol 934 gel loaded with 1 % 5FU was used as control (FU gel).Results: The results showed that the mean droplet size of the nanoemulsions was ~100 nm with a zeta potential of ± 15. Significant increase in permeability was also observed for the nanoemulsion formulations compared with control. The steady-state flux (Jss), enhancement ratio and permeability coefficient (Kp) for optimized nanoemulsion formulation were significantly (p < 0.05) higher than those of the conventional gel (control). Both in vitro and in vivo skin retention results indicate higher drug release from the nanoemulsion (292.45 μg/cm2) than for control (121.42 μg/cm2). Mean irritation index for the nanoemulsion was significantly lower than for control.Conclusion: The results suggest that a water-in-oil nanoemulsion is safe and can potentially be used to promote skin penetration of 5FU following topical application on the skin for the treatment of some skin diseases.Keywords: Nanoemulsion, Controlled release, 5-Fluorouracil, Skin penetration, Skin irritatio

Divisor graphs with four triangles

In this paper, we investigate divisor graphs with four triangles and establish a forbidden subgraph characterization for all divisor graphs containing four triangles.Publisher's Versio

Antitumor activity of polyphenolic extract of Ichnocarpus frutescens

Aim: Phytochemical and dietary antioxidants are known to decrease the risk of many diseases such as cancer and cardiovascular diseases. In this study polyphenolic extract (PPE) of leaves of Ichnocarpus frutescens was evaluated for antitumor activity in vivo. Materials and Methods: Murine Ehrlich ascites carcinoma (EAC) model was used to assess PPE antitumor activity in vivo. PPE cytotoxicity was determined in vitro in U-937 monocytoid leukemia and K-562 erythroleukemia cell lines. PPE also have been assessed for the free radical scavenging activity against superoxide and nitric oxide radicals. Acute oral toxicity was performed by acute toxic classic method. The total phenolics content was quantified by the Folin-Ciocalteu method. Results: Results of in vivo study showed a significant decrease in tumor volume, viable tumor cell count and a significant increase of life span in the PPE treated group compared to untreated one: the life span of PPE treated animals increased by 53.41% (50 mg PPE/kg) and 73.95% (100 mg PPE/kg). PPE (5, 10 and 20 µg/mL) effectively inhibits in vitro proliferation of U-937 and K-562 cell lines. PPE exhibited pronounced radical scavenging activity with an inhibitory concentration (IC50) value of 167.46 µg/mL and 158.52 µg/mL against superoxide and nitric oxide radicals, respectively. Conclusion: PPE of Ichnocarpus frutescens possesses strong free radical scavenging activity and anti-tumor activity in vitro and in vivo.Цель: исследовать противоопухолевую активность экстракта полифенолов (РРЕ) из листьев Ichnocarpus frutescens на модели in vivo. Материалы и методы: для анализа противопухолевой активности РРЕ in vivo использовали модель асцитной карциномы Эрлиха мыши. Цитотоксичность PPE in vitro изучали на клетках моноцитоидной лейкемии линии U-937 и эритроидной лейкемии линии K Также была проанализирована способность PPE к элиминации свободных радикалов. Острую токсичность препарата проверяли классическим методом. Общее содержание фенолов определяли методом Фолина — Чикалто. Результаты: результаты исследования in vivo продемонстрировали значительное уменьшение объема опухоли, количества живых опухолевых клеток и значительное увеличение продолжительности жизни у животных, получавших лечение PPE: продолжительность жизни в группах, получавших 50 и 100 мг РРЕ/кг, повысилась на 53,41% и 73,95% соответственно. PPE в концентрациях 5, 10 и 20 µ/мл инибировал in vitro пролиферацию клеток линий U-937 и K-562. PPE проявил высокую активность к элиминации свободных радикалов с величиной 50 167,46 µг/мл и 158,52 µг/мл по отношению к супероксид-аниону и оксиду азота. Выводы: PPE из Ichnocarpus frutescens обладает высокой противоопухолевой активностью in vitro и in vivo