The Thermodynamics of Fluid-Phase Benzene via Molecular Simulation

Accurate values for thermodynamic properties throughout the fluid phase are a requirement for the design of separation processes. To date, very few pure substances have been completely characterized because of time and monetary constraints. Low cost computing power now permits complete determination of the thermodynamic properties of pure substances via molecular simulation. Molecular simulation is computational statistical mechanics. Benzene is an important industrial chemical and pharmaceutical precursor. It is the prototypical, symmetric, hexagonal molecule and is an ideal candidate for molecular simulation. The molecular models of three researchers in the field are submitted for Monte Carlo simulation in the virtual laboratories at All claim that their models best represent real benzene. The MC code used for experimentation measures 12 thermodynamic properties with associated errors, and derivatives of the residual Helmholtz energy with respect to density and temperature to order 4. The thermodynamic properties are used to generate a multiparameter fundamental equation of state that represents the model throughout the fluid phase. Thermodynamic properties from the three models are compared to the values from the Goodwin equation of state for benzene. A single model is chosen as the best representative of real benzen

The Thermodynamics of Fluid-Phase Benzene via Molecular Simulation

Accurate values for thermodynamic properties throughout the fluid phase are a requirement for the design of separation processes. To date, very few pure substances have been completely characterized because of time and monetary constraints. Low cost computing power now permits complete determination of the thermodynamic properties of pure substances via molecular simulation. Molecular simulation is computational statistical mechanics. Benzene is an important industrial chemical and pharmaceutical precursor. It is the prototypical, symmetric, hexagonal molecule and is an ideal candidate for molecular simulation. The molecular models of three researchers in the field are submitted for Monte Carlo simulation in the virtual laboratories at All claim that their models best represent real benzene. The MC code used for experimentation measures 12 thermodynamic properties with associated errors, and derivatives of the residual Helmholtz energy with respect to density and temperature to order 4. The thermodynamic properties are used to generate a multiparameter fundamental equation of state that represents the model throughout the fluid phase. Thermodynamic properties from the three models are compared to the values from the Goodwin equation of state for benzene. A single model is chosen as the best representative of real benzen

The production, properties and applications of the zinc imidazolate, ZIF-8.

Venna, Carreon, and Jasinski produced and characterized the first samples of the zinc imidazolate framework ZIF-8 at the University of Louisville in 2010. In this dissertation the production, properties, and applications of this unique metal-organic framework are explored. Previously, only minute laboratory amounts (1/4 gram), of ZIF-8 were produced via time-consuming and expensive processes. Production quantities have been synthesized via both a continuous and a batch process using a spray drying operation to effect separation of the solid product (ZIF-8) from the mother liquor. Approximately 85% of the mother liquor (methanol), can be recovered from the spray dryer resulting in magnitude-of-order savings in time and money. Before any engineering applications could be suggested it was necessary to quantify important physical properties of ZIF-8 not currently available. The density, thermal conductivity, specific heat, and BET surface area were measured via strict ASTM procedures and reported. It was hoped that the massive surface area of ZIF-8 (~ 1300 m2/g), would effect enhanced heat transfer in engineering applications. The Heat Transfer Laboratories at the University of Louisville, served as the testing site for the use of the microparticle ZIF-8 as an agent for enhanced heat transfer when mixed in small vol% in synthetic oil. Unfortunately ZIF-8 delivered no such enhancement

APPLICATIONS OF WEPS AND SWEEP TO NON-AGRICULTURAL LANDS

Soil erosion by wind is a serious problem throughout the United States and the world. Dust from wind erosion obscures visibility and pollutes the air. It fills road ditches where it impacts water quality, causes automobile accidents, fouls machinery, and imperils animal and human health. Dust and specifically particulate matter less than 10 microns (PM10), is regulated by the US-EPA National Ambient Air Quality Standards. The Wind Erosion Prediction System (WEPS) model was developed by the USDA Agricultural Research Service, primarily for the USDA Natural Resources Conservation Service to simulate wind erosion and develop conservation plans on cultivated agricultural lands. WEPS is a process based, daily-time step model that simulates hydrology, plant growth and decomposition, land management, and soil surface erodibility to simulate soil wind erosion loss (total, saltation/creep, suspension, and PM10 sizes) as affected by stochastically simulated local weather. The WEPS erosion sub-model has been developed into a stand-alone companion product that is known as the Single-event Wind Erosion Evaluation Program (SWEEP). SWEEP consists of the stand-alone WEPS Erosion sub-model combined with a user-friendly graphical interface and simulates soil loss and dust emissions from single wind storm events (i.e., one day). In addition to cultivated agricultural lands, wind erosion results in sediment and dust emissions from construction sites, mined and reclaimed land, landfills, and other disturbed lands. Such disturbed lands are often regulated by government agencies. The US-EPA sets limits on pollution levels and establishes permits for pollution release. In addition, state agencies develop State Implementation Plans (SIP’s) and operate permit programs for release of fugitive dust. Although developed for agricultural situations, WEPS and SWEEP are useful tools for simulating erosion by wind for such lands where typical agricultural practices and control methods are not utilized. WEPS is suitable for simulating long term (multiple years) control strategies such as mulching, re-vegetation, and large roughness elements such as burms. SWEEP on the other hand can simulate the potential soil loss for site specific planned surface conditions and control practices for a given date. SWEEP also provides probabilities of dust events given the defined surface conditions for the specified location and date. This paper explores the use of WEPS and SWEEP for developing control strategies for fugitive dust on construction sites and other non-agricultural disturbed lands. Case studies and comparative scenarios with examples of modifying WEPS and SWEEP inputs and management files to simulate common erosion control strategies are presented. Control strategies discussed include the simulation of water and other dust suppressants, wind barriers such as silt and snow fencing and hay bales, anchored and crimped straw mulch, vertical mulches, erosion blankets, re-vegetation, gougers, basin blades, berms, and other roughening practices. For example, dust suppressants are simulated by creating a crusted soil with low loose erodible material on the surface. Example simulations will be demonstrated. The paper describes tools needed to design erosion control plans that are not only cost-effective but also demonstrate regulatory compliance by using a science-based approach to risk assessment

Biodegradation of Congo Red by Phanerochaete chrysosporium

The azo dye Congo Red, was degraded extensively by the wood rotting basidiomycete, Phanerochaete chrysosporium in agitated liquid cultures and in solid malt agar cultures. Upon addition of Congo Red to agitated liquid cultures, the dye was adsorbed to the mycelial pellets in both ligninolytic and non-ligninolytic cultures followed by extensive degradation only in the ligninolytic cultures. This fungus, grown from conidiospores, readily degraded up to 718 μM (500 mg/l) Congo Red in 2.0% malt agar. Decolorization of Congo Red in malt agar plates was suppressed by the addition of supplemental nutrient nitrogen indicating that the lignin degrading system of P. chrysosporium may be important in the biodegradation of this dye. This is supported by the observation that Congo Red is a substrate for purified lignin peroxidase H8. These results are of interest because it had been previously reported that Congo Red was not a substrate for lignin peroxidase nor was it extensively degraded by this fungus

A clarion call for aeolian research to engage with global land degradation and climate change

This editorial represents a clarion call for the aeolian research community to provide increased scientific input to the Intergovernmental Panel on Climate Change (IPCC) and the United Nations Convention to Combat Desertification (UNCCD) and an invitation to apply for ISAR funding to organize a working group to support this engagement

Indicators and Benchmarks for Wind Erosion Monitoring, Assessment and Management

Wind erosion and blowing dust threaten food security, human health and ecosystem services across global drylands. Monitoring wind erosion is needed to inform management, with explicit monitoring objectives being critical for interpreting and translating monitoring information into management actions. Monitoring objectives should establish quantitative guidelines for determining the relationship of wind erosion indicators to management benchmarks that reflect tolerable erosion and dust production levels considering impacts to, for example, ecosystem processes, species, agricultural production systems and human well-being. Here we: 1) critically review indicators of wind erosion and blowing dust that are currently available to practitioners; and 2) describe approaches for establishing benchmarks to support wind erosion assessments and management. We find that while numerous indicators are available for monitoring wind erosion, only a subset have been used routinely and most monitoring efforts have focused on air quality impacts of dust. Indicators need to be related to the causal soil and vegetation controls in eroding areas to directly inform management. There is great potential to use regional standardized soil and vegetation monitoring datasets, remote sensing and models to provide new information on wind erosion across landscapes. We identify best practices for establishing benchmarks for these indicators based on experimental studies, mechanistic and empirical models, and distributions of indicator values obtained from monitoring data at historic or existing reference sites. The approaches to establishing benchmarks described here have enduring utility as monitoring technologies change and enable managers to evaluate co-benefits and potential trade-offs among ecosystem services as affected by wind erosion management

Enhancing wind erosion monitoring and assessment for U.S. rangelands

Wind erosion is a major resource concern for rangeland managers because it can impact soil health, ecosystem structure and function, hydrologic processes, agricultural production, and air quality. Despite its significance, little is known about which landscapes are eroding, by how much, and when. The National Wind Erosion Research Network was established in 2014 to develop tools for monitoring and assessing wind erosion and dust emissions across the United States. The Network, currently consisting of 13 sites, creates opportunities to enhance existing rangeland soil, vegetation, and air quality monitoring programs. Decision-support tools developed by the Network will improve the prediction and management of wind erosion across rangeland ecosystems. © 2017 The Author(s)The Rangelands archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information

Indicators and benchmarks for wind erosion monitoring, assessment and management

Wind erosion and blowing dust threaten food security, human health and ecosystem services across global drylands. Monitoring wind erosion is needed to inform management, with explicit monitoring objectives being critical for interpreting and translating monitoring information into management actions. Monitoring objectives should establish quantitative guidelines for determining the relationship of wind erosion indicators to management benchmarks that reflect tolerable erosion and dust production levels considering impacts to, for example, ecosystem processes, species, agricultural production systems and human well-being. Here we: 1) critically review indicators of wind erosion and blowing dust that are currently available to practitioners; and 2) describe approaches for establishing benchmarks to support wind erosion assessments and management. We find that while numerous indicators are available for monitoring wind erosion, only a subset have been used routinely and most monitoring efforts have focused on air quality impacts of dust. Indicators need to be related to the causal soil and vegetation controls in eroding areas to directly inform management. There is great potential to use regional standardized soil and vegetation monitoring datasets, remote sensing and models to provide new information on wind erosion across landscapes. We identify best practices for establishing benchmarks for these indicators based on experimental studies, mechanistic and empirical models, and distributions of indicator values obtained from monitoring data at historic or existing reference sites. The approaches to establishing benchmarks described here have enduring utility as monitoring technologies change and enable managers to evaluate co-benefits and potential trade-offs among ecosystem services as affected by wind erosion management

U.S. Billion-ton Update: Biomass Supply for a Bioenergy and Bioproducts Industry

The Report, Biomass as Feedstock for a Bioenergy and Bioproducts Industry: The Technical Feasibility of a Billion-Ton Annual Supply (generally referred to as the Billion-Ton Study or 2005 BTS), was an estimate of “potential” biomass within the contiguous United States based on numerous assumptions about current and future inventory and production capacity, availability, and technology. In the 2005 BTS, a strategic analysis was undertaken to determine if U.S. agriculture and forest resources have the capability to potentially produce at least one billion dry tons of biomass annually, in a sustainable manner—enough to displace approximately 30% of the country’s present petroleum consumption. To ensure reasonable confidence in the study results, an effort was made to use relatively conservative assumptions. However, for both agriculture and forestry, the resource potential was not restricted by price. That is, all identified biomass was potentially available, even though some potential feedstock would more than likely be too expensive to actually be economically available. In addition to updating the 2005 study, this report attempts to address a number of its shortcoming