Impacts of Biodiesel on Pollutant Emissions of a JP-8–Fueled Turbine Engine

Abstract

The impacts of biodiesel on gaseous and particulate matter (PM) emissions of a JP-8–fueled T63 engine were investigated. Jet fuel was blended with the soybean oil-derived methyl ester biofuel at various concentrations and combusted in the turbine engine. The engine was operated at three power settings, namely ground idle, cruise, and takeoff power, to study the impact of the biodiesel at significantly different pressure and temperature conditions. Particulate emissions were characterized by measuring the particle number density (PND; particulate concentration), the particle size distribution, and the total particulate mass. PM samples were collected for off-line analysis to obtain information about the effect of the biodiesel on the polycyclic aromatic hydrocarbon (PAH) content. In addition, temperature-programmed oxidation was performed on the collected soot samples to obtain information about the carbonaceous content (elemental or organic). Major and minor gaseous emissions were quantified using a total hydrocarbon analyzer, an oxygen analyzer, and a Fourier Transform IR analyzer. Test results showed the potential of biodiesel to reduce soot emissions in the jet-fueled turbine engine without negatively impacting the engine performance. These reductions, however, were observed only at the higher power settings with relatively high concentrations of biodiesel. Specifically, reductions of ～15% in the PND were observed at cruise and takeoff conditions with 20% biodiesel in the jet fuel. At the idle condition, slight increases in PND were observed; however, evidence shows this increase to be the result of condensed uncombusted biodiesel. Most of the gaseous emissions were unaffected under all of the conditions. The biodiesel was observed to have minimal effect on the formation of polycyclic aromatic hydrocarbons during this study. In addition to the combustion results, discussion of the physical and chemical characteristics of the blended fuels obtained using standard American Society for Testing and Materials (ASTM) fuel specifications methods are presented.     

International perspectives on the implementation of reproductive carrier screening

Reproductive carrier screening started in some countries in the 1970s for hemoglobinopathies and Tay-Sachs disease. Cystic fibrosis carrier screening became possible in the late 1980s and with technical advances, screening of an ever increasing number of genes has become possible. The goal of carrier screening is to inform people about their risk of having children with autosomal recessive and X-linked recessive disorders, to allow for informed decision making about reproductive options. The consequence may be a decrease in the birth prevalence of these conditions, which has occurred in several countries for some conditions. Different programs target different groups (high school, premarital, couples before conception, couples attending fertility clinics, and pregnant women) as does the governance structure (public health initiative and user pays). Ancestry-based offers of screening are being replaced by expanded carrier screening panels with multiple genes that is independent of ancestry. This review describes screening in Australia, Cyprus, Israel, Italy, Malaysia, the Netherlands, Saudi Arabia, the United Kingdom, and the United States. It provides an insight into the enormous variability in how reproductive carrier screening is offered across the globe. This largely relates to geographical variation in carrier frequencies of genetic conditions and local health care, financial, cultural, and religious factors.     

Physiological and immunological conditions of wild populations of <Emphasis Type="Italic">Farfantepenaeus duorarum </Emphasis>from the campeche sound (Crustacea,Penaeidae)

To assess the health status of aquatic ecosystems, specialized tools and strategies are needed to study the changes induced in oceanic systems by human activity. The Gulf of Mexico has a tremendous ecological importance because of its biological diversity. The present paper defines baseline levels of blood metabolites and immune components for wild tropical populations of F. duorarum: an important shrimp species of the Gulf of Mexico. Osmotic pressure (OP), osmotic capability (OC), oxy hemocyanin (OxyHc), glucose, digestive gland glycogen, proteins, cholesterol, lactate, acylglycerols (AG) were used as indicators of physiological and nutritional status; phenoloxidase activity, quantification of hemocytes, as well as respiratory burst, were used to assess the immunological status. There were no differences between sexes in either live weight or physiological and nutritional conditions. Only total blood protein, oxy hemocyanin, and digestive gland glycogen showed normally distributed data. All the remaining blood parameters were right- or left-skewed. A median live weight of 9.5 g was registered for the sampled population. Median values of 955 and −91.85 mOsm/kg (OP and OC, respectively) were obtained, indicating that shrimp were slightly hypo-osmotic in relation to sea water. A proportion of 27% of OxyHc of the total protein (OxyHc/Prot) was calculated for the F. duorarum population. ProPO and PO showed no normal distribution and were not different between sexes. A right-skewed distribution was observed. Total hemocytes, hyaline (HC) and granular cells (GC) showed differences between sexes, with higher values in females than males. A similar proportion of HC (69%) and GC (30%) of total cells were observed between sexes. Basal and activated respiratory burst showed differences between sexes with higher values for females than for males. The current results provide indicators of the nutritional and immune status of F. duorarum that can be used to detect changes in trophic relations and health at a population level.     

Evaluation of a soil‐amendment process demonstration for reducing the bioavailability of lead

The U.S. Environmental Protection Agency (EPA) evaluated an in‐situ application of a soil‐amendment process at a residential site that was contaminated with lead. The goal of the evaluation was to determine if the soil‐amendment process resulted in lower concentrations of bioavailable lead in the contaminated soils. The relative bioavailability of lead (bioaccessible lead) was measured by an in vitro test procedure that uses a highly acidic extraction procedure to simulate human digestive processes. The soil‐amendment demonstration showed that the 11.2 percent mean reduction in bioavailable lead concentration between untreated and treated soils was not statistically different. © 2002 Wiley Periodicals, Inc.     

Vertical distribution of early and competent larvae of Concholepas concholepas in two systems of Chilean inland seas

The transport of marine invertebrate larvae is strongly influenced by their distribution in the water column, which could be affected by the biological features of the larvae and environmental variables. Larvae can modify their swimming behavior throughout their planktonic cycle, thereby changing the observed distributional patterns. This ability, coupled with oceanographic features, could induce landward or seaward transport. We studied the vertical distribution of C. concholepas larval stages in two differently stratified systems in Chilean inland seas; Refugio Channel (a strongly stratified channel, where previously has been described as a frontal system) and Guaitecas (a gently stratified system). Combinations of 12–24 h larval collection experiments were done simultaneously with fixed temperature and salinity profiles; meteorological data were also obtained. The results suggest that both salinity and day period influence the C. concholepas distributional patterns in the water column. Early veliger and competent larvae are concentrated in different parts of the water column, probably related to their transport capacities. The upper layer of the water column at the Refugio site, unlike the Guaitecas site, showed a stratified regime, which could affect larval density and larval length between the two sites. Finally, our results suggest that Refugio may be a sink habitat for C. concholepas.     

Use of Nutshells as Fillers in Polymer Composites

Nutshells are agricultural waste products that can be procured at relatively low cost. In this work we examined the possibility of using these biodegradable materials as fillers in poly(lactic acid) and low density polyethylene. The nutshells were ground into powder, blended with the polymer, and then injection molded with final weight varying from 10 to 40 weight %. The mechanical and thermal properties of the composites were then studied. In general, the addition of fillers caused reductions in mechanical properties to varying extents, but thermal properties were only slightly affected. The use of maleic anhydride and peroxide with the fillers had a negative effect on poly(lactic acid) but a slightly positive effect on the stiffness of polyethylene. The results suggested that polymer-nutshell composites may be usable in applications where cost is a concern and where some reductions in mechanical properties are acceptable.