Leave No Trace Education: A Case Study on the Educational Methods Utilized by the Leave No Trace Center for Outdoor Ethics

Leave No Trace (LNT) is imperative in the field of outdoor recreation to protect natural spaces and preserve them for generations to come. Exposure to LNT is pivotal in the development of environmental stewardship in children and adults. The purpose of this study was to examine the educational methods utilized by the LNT Center for Outdoor Ethics to determine the best practices to cultivate and instill the principles of LNT. The research was conducted using a best practices instrument, developed by the researcher, to evaluate the attributes present in LNT educational methods by the LNT Center. This study found that LNT educational programs that are skills-based, location-, activity-, behavior-, context-, and age-specific are the most effective forms of LNT education. This study can function as a guide in developing effective frontcountry and backcountry LNT educational programs

A long breathing lean NOx trap for diesel after-treatment supplemental energy reduction

A long breathing strategy was investigated as a method for reducing the supplemental energy consumption of a diesel lean NOx trap (LNT). Empirical tests were performed on a heated flow bench set-up. The test results indicated that the LNT adsorption (breathing) time increased exponentially when the nitrogen oxide (NOx) level in the feed gas was reduced. Longer adsorptions led to supplemental energy savings due to less frequent LNT regeneration. In these tests, supplemental energy savings of over 70% were achieved with a long breathing LNT compared to a traditional LNT. Additional empirical tests investigated the concept of on-board hydrogen generation due to its potential benefits to an after-treatment system. The test findings revealed that the reformer temperature was a critical factor for on-board hydrogen generation. Further numerical and empirical tests revealed the benefits of utilizing a flow reversal system for hydrogen generation

Correlation of electrical properties and acoustic loss in single crystalline lithium niobate-tantalate solid solutions at elevated temperatures

Electrical conductivity and acoustic loss Q−1 of single crystalline Li(Nb,Ta)O3 solid solutions (LNT) are studied as a function of temperature by means of impedance spectroscopy and resonant piezoelectric spectroscopy, respectively. For this purpose, bulk acoustic wave resonators with two different Nb/Ta ratios are investigated. The obtained results are compared to those previously reported for congruent LiNbO3. The temperature dependent electrical conductivity of LNT and LiNbO3 show similar behavior in air at high temperatures from 400 to 700 °C. Therefore, it is concluded that the dominant transport mechanism in LNT is the same as in LN, which is the Li transport via Li vacancies. Further, it is shown that losses in LNT strongly increase above about 500 °C, which is interpreted to originate from conductivity-related relaxation mechanism. Finally, it is shown that LNT bulk acoustic resonators exhibit significantly lower loss, comparing to that of LiNbO3

Investigation on Lean NOx Trap Regeneration Using Alcohol Fuels

The impacts of automotive pollutants on local air quality, human health, and climate change are a major concern worldwide. Therefore, the internal combustion engine (ICE) powered automobiles are expected to be able to meet the increasingly stringent emission and fuel efficiency standards. The reduction in oxides of nitrogen (NOx) in lean burn and diesel-fueled compression ignition (CI) engines is a major challenge. In this research, the use of alcohol fuel such as n-butanol and ethanol is studied in a CI engine. With the application of moderate exhaust gas recirculation (EGR), low engine-out NOx and soot emissions are achieved simultaneously. However, to meet NOx emission regulations, the use of only alternative fuels is not sufficient for a wide range of engine operating conditions. Therefore, lean NOx trap (LNT) after-treatment system is used for further NOx reduction using a reductant. In this study, an investigation on the performance of long breathing LNT is performed using ethanol, n-butanol, and diesel as reductants. The LNT regeneration experiments are conducted on a heated flow bench under simulated engine exhaust like conditions. Ethanol and n-butanol are found to be more effective compared to diesel as a reductant in terms of NOx conversion, ammonia (NH3) slip, nitrogen dioxide (N2O) slip, and hydrogen (H2) formation, during the LNT regeneration period at the tested conditions. The formation of NH3 and N2O during the LNT regeneration is not desired. Albeit, the NH3 generated during the LNT regeneration can be utilized to further reduce NOx using a selective catalytic reduction (SCR) convertor downstream of the LNT catalyst. In this study, the combined LNT-SCR tests are performed to investigate overall NOx reduction using n-butanol as a reductant

Safety of lacto-N-tetraose (LNT) produced by derivative strains of Escherichia coli BL21 (DE3) as a Novel Food pursuant to Regulation (EU) 2015/2283

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on lacto-N-tetraose (LNT) as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF is a powdered mixture mainly composed of the human-identical milk oligosaccharide (HiMO) LNT, but it also contains d-lactose, lacto-N-triose II and para-lacto-N-hexaose, and a small fraction of other related saccharides. The NF is produced by fermentation with two genetically modified strains of Escherichia coli BL21 (DE3), the production strain and the optional degradation strain. The information provided on the manufacturing process, composition and specifications of the NF does not raise safety concerns. The applicant intends to add the NF to a variety of foods, including infant and follow-on formula, food for infants and young children, food for special medical purposes and food supplements. The target population is the general population. The anticipated daily intake of LNT from the NF at the maximum proposed use levels does not exceed the intake level of naturally occurring LNT in breastfed infants on a body weight basis. The intake of LNT in breastfed infants on a body weight basis is expected to be safe also for other population groups. The intake of other carbohydrate-type compounds structurally related to LNT is also considered of no safety concern. Food supplements are not intended to be used if other foods with added LNT or human milk are consumed on the same day. The Panel concludes that the NF is safe under the proposed conditions of use

Generalized Lyapunov Exponent and Transmission Statistics in One-dimensional Gaussian Correlated Potentials

Distribution of the transmission coefficient T of a long system with a correlated Gaussian disorder is studied analytically and numerically in terms of the generalized Lyapunov exponent (LE) and the cumulants of lnT. The effect of the disorder correlations on these quantities is considered in weak, moderate and strong disorder for different models of correlation. Scaling relations between the cumulants of lnT are obtained. The cumulants are treated analytically within the semiclassical approximation in strong disorder, and numerically for an arbitrary strength of the disorder. A small correlation scale approximation is developed for calculation of the generalized LE in a general correlated disorder. An essential effect of the disorder correlations on the transmission statistics is found. In particular, obtained relations between the cumulants and between them and the generalized LE show that, beyond weak disorder, transmission fluctuations and deviation of their distribution from the log-normal form (in a long but finite system) are greatly enhanced due to the disorder correlations. Parametric dependence of these effects upon the correlation scale is presented.Comment: 18 pages, 11 figure