Literature review of physical and chemical pretreatment processes for lignocellulosic biomass

Different pretreatment technologies published in public literature are described in terms of the mechanisms involved, advantages and disadvantages, and economic assessment. Pretreatment technologies for lignocellulosic biomass include biological, mechanical, chemical methods and various combinations thereof. The choice of the optimum pretreatment process depends very much on the objective of the biomass pretreatment, its economic assessment and environmental impact. Only a small number of pretreatment methods has been reported as being potentially cost-effective thus far. These include steam explosion, liquid hot water, concentrated acid hydrolysis and dilute acid pretreatments

Conditional Spectrum Computation Incorporating Multiple Causal Earthquakes and Ground‐Motion Prediction Models

The Conditional Spectrum (CS) is a target spectrum (with conditional mean and conditional standard deviation) that links seismic hazard information with ground motion selection for nonlinear dynamic analysis. Probabilistic seismic hazard analysis (PSHA) estimates the ground motion hazard by incorporating the aleatory uncertainties in all earthquake scenarios and resulting ground motions as well as the epistemic uncertainties in ground motion prediction models (GMPMs) and seismic source models. Typical CS calculations to date are produced for a single earthquake scenario using a single GMPM, but more precise use requires consideration of at least multiple causal earthquakes and multiple GMPMs that are often considered in a PSHA computation. This paper presents the mathematics underlying these more precise CS calculations. Despite requiring more effort to compute than approximate calculations using a single causal earthquake and GMPM, the proposed approach produces an exact output that has a theoretical basis. To demonstrate the results of this approach and compare the exact and approximate calculations, several example calculations are performed for real sites in the western U.S. (WUS). The results also provide some insights regarding the circumstances under which approximate results are likely to closely match more exact results. To facilitate these more precise calculations for real applications, the exact CS calculations can now be performed for real sites in the U.S. using new deaggregation features in the U.S. Geological Survey hazard mapping tools. Details regarding this implementation are discussed in this paper

Shifting Responsibility for Learning From the Teacher to the Student

This paper discusses a personal approach to teaching ESL which encourages greater student responsibility in the learning process. The project is designed to assist teachers who are interested in developing a teaching style which increases student initiative with the goal of helping students become increasingly independent, self-directed learners. The project is organized into two main sections. The first is a discussion of the rationale and implications for teachers and students in this approach to teaching. Included also is a discussion regarding the necessity of meeting the affective needs of the learner. The second section presents a variety of different activities and techniques the author has used in the classroom to implement an approach of this kind

The Use of Visible Geostationary Operational Meteorological Satellite Imagery in Mapping the Water Balance over Puerto Rico for Water Resource Management

A solar insolation satellite remote sensing product for Puerto Rico, the US Virgin Islands (USVI), Dominican Republic, Haiti, Jamaica, and Cuba became available in 2009 through a collaboration between the University of Puerto Rico-Mayagüez Campus and the University of Alabama in Huntsville. Solar insolation data are available at 1 km resolution for Puerto Rico and the USVI and 2 km resolution for the other islands, as derived from 500 m resolution GOES-16 visible imagery. The insolation data demonstrate the powerful utility of satellite-derived fields for water resource applications, specifically the routine production of potential and reference evapotranspiration. This chapter describes the theoretical background and technical approach for estimating components of the daily water and energy balance in Puerto Rico. Useful information can be obtained from the model, which benefits disaster and emergency management, agriculture, human health, ecology, coastal water management, and renewable energy development at the island scale

Estimando evapotranspiración en Puerto Rico

The United Nations Food and Agriculture Organization (FAO) has recommended the Penman-Monteith method as the single method for estimating reference evapotranspiration throughout the world. A disadvantage of the method, however, is its relatively high data requirement. Measurements of wind speed, humidity (or dew point temperature) and radiation tend to be the least available of the required parameters; therefore, the FAO has presented estimation procedures for these parameters. The purpose of this study was to evaluate estimation procedures for climate data to be used in the Penman-Monteith method for estimating long-term daily reference evapotranspiration, and to verify the accuracy of the procedures at four locations in Puerto Rico. Comparison of reference evapotranspiration determined by using the estimated and measured climate data shows reasonably good agreement. The methods presented in this paper are potentially valuable for calculating the long-term average daily reference evapotranspiration at any location in Puerto Rico. An example is provided to illustrate the use of the proposed estimation procedures for climate parameters. This study presents a comparison of reference evapotranspiration calculated by the Penman-Monteith method, with estimates previously made by using the Hargreaves-Samani method, for thirty-four locations in Puerto Rico. In addition, estimated peak evapotranspiration from the Soil Conservation Service (SCS) (now Natural Resources Conservation Service) Irrigation Guide for the Caribbean Area, the SCS Blaney-Criddle method and the Penman-Monteith method were compared for six vegetable crops at three locations in Puerto Rico. The results suggest that some irrigation systems may have been under-designed in terms of flow capacity in Puerto Rico.La Organización de Alimentos y Agricultura de las Naciones Unidas (FAO, por sus siglas en inglés) ha recomendado el método de Penman-Monteith como el único método de calculación que se debería usar para estimar evapotranspiración de referencia a través del mundo. Sin embargo, una desventaja del método es que requiere un número alto de datos. Las medidas de la velocidad del viento, la humedad (o la temperatura de punto de rocío) y la radiación tienden a ser los parámetros requeridos más difíciles de obtener; por ello, la FAO ofrece procedimientos alternos de estimación para estos parámetros. El propósito de este estudio fue evaluar los procedimientos de estimación de los datos del clima requeridos por el método de Penman-Monteith para estimar (a evapotranspiración de referencia promedio diaria a largo plazo y verificar la exactitud de los procedimientos en cuatro zonas de Puerto Rico. Se encontró una alta correlación entre la evapotranspiración de referencia calculada con los datos estimados (FAO) y la calculada con los datos observados del clima. Los métodos presentados son potenciatmente valiosos para calcular la evapotranspiración de referencia promedio diaria en cualquier zona de Puerto Rico. Se provee un ejemplo para ilustrar el uso del procedimiento propuesto para estimar parámetros del clima. Se presenta una comparación de la evapotranspiración de referencia calculada por el método de Penman-Monteith y resultados estimados previamente por el método de Hargreaves-Samani para 34 zonas en Puerto Rico. Además, el estimado máximo de evapotranspiración de la Guía de Riego del Servicio de Conservación de Suelos (SCS) (ahora Servicio de Conservación de Recursos Naturales) para el Área def Caribe, el método de Blaney-Criddfe (SCS) y él método de Penman-Monteith se compararon para seis vegetales en tres localidades en Puerto Rico. Los resultados indican que algunos sistemas de riego no tienen suficiente capacidad para suplir agua en Puerto Rico

Diverse Stellar Haloes in Nearby Milky Way-Mass Disc Galaxies

We have examined the resolved stellar populations at large galactocentric distances along the minor axis (from 10 kpc up to between 40 and 75 kpc), with limited major axis coverage, of six nearby highly-inclined Milky Way-mass disc galaxies using HST data from the GHOSTS survey. We select red giant branch stars to derive stellar halo density profiles. The projected minor axis density profiles can be approximated by power laws with projected slopes of between $-2$ and $-3.7$ and a diversity of stellar halo masses of $1-6\times 10^{9}M_{\odot}$, or $2-14\%$ of the total galaxy stellar masses. The typical intrinsic scatter around a smooth power law fit is $0.05-0.1$ dex owing to substructure. By comparing the minor and major axis profiles, we infer projected axis ratios $c/a$ at $\sim 25$ kpc between $0.4-0.75$. The GHOSTS stellar haloes are diverse, lying between the extremes charted out by the (rather atypical) haloes of the Milky Way and M31. We find a strong correlation between the stellar halo metallicities and the stellar halo masses. We compare our results with cosmological models, finding good agreement between our observations and accretion-only models where the stellar haloes are formed by the disruption of dwarf satellites. In particular, the strong observed correlation between stellar halo metallicity and mass is naturally reproduced. Low-resolution hydrodynamical models have unrealistically high stellar halo masses. Current high-resolution hydrodynamical models appear to predict stellar halo masses somewhat higher than observed but with reasonable metallicities, metallicity gradients and density profiles.Comment: 26 pages, 17 figures. Accepted for publication in MNRA

Desarrollo de modelos lineales para la determinación del área foliar en habichuela (Phaseolus vulgaris L.) a partir de medidas directas de hojas

Plant leaf area is an important physiological trait, and direct, non-destructive methods for estimating leaf area have been shown to be effective while allowing for repeated plant sampling.The objective of this study was to evaluate direct, non-destructive leaflet measurements as predictors of actual leaflet area (LA), to test previously developed models, and to develop genotype-specific linear models for leaflet area estimation in common bean (Phaseolus vulgaris L.). For development of appropriate regression models for leaflet area estimation, four common bean genotypes were evaluated under greenhouse conditions: BAT 477, 'Morales', SER 16, and SER 21. The greenhouse-derived models were evaluated under field conditions. Previously developed models were tested and found to overestimate or underestimate leaflet area. Leaflet measurements included maximum leaflet width (W) and maximum leaflet length (L) and L X W. The measurements with the highest values for the coefficient of determination (R2) were W or L X W for BAT 477, SER 16, and Morales (0.97, 0.95, and 0.95, respectively), and L X W for SER 21 (R2 = 0.96). The linear models developed were shown to be effective and robust for predicting leaflet area under both greenhouse and field conditions during both vegetative and reproductive stages of plant development.El área foliar es una medida importante de la fisiología de las plantas, y los métodos indirectos y no-destructivos para medir el área foliar han demostrado ser muy eficientes a la vez que permiten la toma de medidas repetidas en el tiempo. El objetivo del presente estudio fue evaluar directamente métodos no destructivos para la estimación del área foliar en habichuelas (Phaseolus vulgaris L.) a partir de la medida de las hojas, probar modelos previos, y desarrollar modelos lineales específicos para cada genotipo. Se evaluaron cuatro genotipos: BAT 477, Morales, SER 16, y SER 21, bajo condiciones de invernadero y de campo. Los modelos desarrollados en invernadero se aplicaron y evaluaron bajo condiciones de campo durante dos años. Los modelos previos reportados por otros autores fueron evaluados, y se encontró que sobre-o sub-estimaban el área foliar. Los modelos desarrollados en este estudio incluyeron el ancho máximo de la hoja (W), y la longitud máxima (L), los que fueron empleados para calcular un tercer factor, L X W. Los modelos con mayores coeficientes de determinación (R2) fueron W or L X W para BAT 477, SER 16 y Morales (0.97, 0.95, y 0.95, respectivamente) y L X W para SER 21 (R2 = 0.96). Los modelos de regresión desarrollados mostraron ser eficientes en la predicción del área foliar bajo condiciones de campo e invernadero, en las fases vegetativas y reproductivas, para cada uno de los genotipos evaluados

Career Transitions in Sport

The transition out of sport prompts an identity change for the athlete. When putting an end to their sporting career, an athlete loses an important part of themselves, particularly if they have been training and competing in their sport for much of their life. This may apply to the youth athlete who will not compete in college, the collegiate athlete who will not compete professionally, and the professional athlete who is retiring. Because athletes spend a great deal of time training and devoting themselves to their sport, they may not have time for exploration of activities or careers outside of sport. This leads to identity foreclosure and a strong athletic identity, which has been associated with difficulty adjusting following sport career termination (Murphy, Petitpas, & Brewer, 1996)