Addition of cellulolytic enzymes and phytase for improving ethanol fermentation performance and oil recovery in corn dry grind process

Application of hydrolytic and other enzymes for improving fermentation performance and oil recovery in corn dry-grind process was optimized. Non-starch polysaccharide enzymes (BluZy-P XL; predominantly xylanase activity) were added at stages prior to fermentation at optimum conditions of 50 ◦C and pH 5.2 and compared with conventional fermentation (30 ◦C, pH 4.0). Enzyme applications resulted in faster ethanol production rates with a slight increase in yield compared to control. The thin stillage yield increased by 0.7–5% w/w wet basis with corresponding increase in solids content with enzyme treatment after liquefaction. The oil partitioned in thin stillage was at 67.7% dry basis after treatment with hydrolytic enzymes during fermentation. Further addition of protease and phytase during simultaneous saccharification and fermentation increased thin stillage oil partitioning to 77.8%. It also influenced other fermentation parameters, e.g., ethanol production rate increased to 1.16 g/g dry corn per hour, and thin stillage wet solids increased by 2% w/w. This study indicated that treatments with non-starch hydrolytic enzymes have potential to improve the performance of corn dry-grind process including oil partitioning into thin stillage. The novelty of this research is the addition of protease and phytase enzymes during simultaneous saccharification and fermentation of corn dry-grind process, which further improved ethanol yields and oil partitioning into thin stillage

A decade of changes in nitrogen oxides over regions of oil and natural gas activity in the United States

Nitrogen oxides (NOx = NO2 + NO) are a highly regulated species that play a major role in the formation of photochemical smog. While NOx emissions are generally decreasing over the U.S. as a result of more stringent environmental policies and improved emissions control technologies, the shale oil and natural gas industry is reversing this rate of changes in certain regions. We present here a quantitative analysis of NOx levels over the seven main U.S. shale plays (Bakken, Eagle Ford, Permian, Niobrara-Codell, MarcellusUtica, Haynesville, and Barnett) between 2005 and 2015 using measurements of tropospheric NO2 from the Ozone Monitoring Instrument (OMI) aboard the NASA EOS-Aura aircraft. We develop and apply a methodology that seeks to maximise pollutant signals from oil and gas activities. For reference, we also examine the national trend averaged over the lower 48 states. Consistent with previous studies, we find NOx across the U.S. is generally declining. During the low-production phase of oil and natural gas production (2005–2009), we find declining trends in tropospheric NOx that are similar to the national trend (–4.6% yr–1) in 6 of the 7 study regions (–8 to –2% yr–1). In the high-production phase (2010–15), we find an increasing NOx trend in 5 of the 7 study basins (0.4 to 4.5% yr–1) while the national trend continued to decline (–0.3% yr–1). Over the most intensive oil-producing shale plays (Bakken, Eagle Ford, Permian and Niobrara-Codell), we observe a rapid growth (1–4.5% yr–1), which correlates well (r 2 = 0.6–0.9) with their annual oil production rates and/or drilling rigs. In contrast, trends across the mainly gas-producing regions (Haynesville, Barnett, and Marcellus-Utica) show decreases (–0.4 to –1.7% yr–1) similar to the national trend, with the exception of the Marcellus-Utica where a slight increase (0.4 ± 0.2% yr–1) may be an indication of a small regional increase. Our study shows the important decadal effect that shale oil and natural gas operations has had on the tropospheric NO2 levels, and the potential consequences for regional air quality

Cost-effectiveness analysis of single-session walk-in counselling

Background: An increasing number of family service agencies and community-based mental health service providers are implementing a single-session walk-in counselling (SSWIC) as an alternative to traditional counselling. However, few economic evaluations have been undertaken. Aims: To conduct a cost-effectiveness analysis of two models of service delivery, SSWIC compared to being waitlisted for traditional counselling. Methods: A quasi-experimental design was employed. Data were collected from two community-based Family Service Agencies, one using SSWIC and one using traditional counselling. Participants were assessed at baseline and four weeks after the baseline. Cost-effectiveness was estimated from the societal and payer’s perspective. Results: The societal and payer’s costs for SSWIC were higher than for those waiting for traditional counselling, and health outcomes were better. SSWIC is not cost-effective compared to being on the waitlist for traditional counselling (or, for a few patients, having received counselling, but after a wait of several weeks). Conclusions: SSWIC has the potential to reduce the pressure on the mental health care system by reducing emergency visits and wait lists for ongoing mental health services and eliminating costly-no shows at counselling appointments. Long-term studies involving multiple walk-in counselling services and comparison services are needed to support the findings of this study

Using Satellite Remote Sensing and Modelling for Insights into N02 Air Pollution and NO2 Emissions

Nitrogen oxides (NO(x)) are key actors in air quality and climate change. Satellite remote sensing of tropospheric NO2 has developed rapidly with enhanced spatial and temporal resolution since initial observations in 1995. We have developed an improved algorithm and retrieved tropospheric NO2 columns from Ozone Monitoring Instrument. Column observations of tropospheric NO2 from the nadir-viewing satellite sensors contain large contributions from the boundary layer due to strong enhancement of NO2 in the boundary layer. We infer ground-level NO2 concentrations from the OMI satellite instrument which demonstrate significant agreement with in-situ surface measurements. We examine how NO2 columns measured by satellite, ground-level NO2 derived from satellite, and NO(x) emissions obtained from bottom-up inventories relate to world's urban population. We perform inverse modeling analysis of NO2 measurements from OMI to estimate "top-down" surface NO(x) emissions, which are used to evaluate and improve "bottom-up" emission inventories. We use NO2 column observations from OMI and the relationship between NO2 columns and NO(x) emissions from a GEOS-Chem model simulation to estimate the annual change in bottom-up NO(x) emissions. The emission updates offer an improved estimate of NO(x) that are critical to our understanding of air quality, acid deposition, and climate change

Ba{1-x}KxMn2As2: An Antiferromagnetic Local-Moment Metal

The compound BaMn2As2 with the tetragonal ThCr2Si2 structure is a local-moment antiferromagnetic insulator with a Neel temperature TN = 625 K and a large ordered moment mu = 3.9 mu_B/Mn. We demonstrate that this compound can be driven metallic by partial substitution of Ba by K, while retaining the same crystal and antiferromagnetic structures together with nearly the same high TN and large mu. Ba_{1-x}K_xMn2As2 is thus the first metallic ThCr2Si2-type MAs-based system containing local 3d transition metal M magnetic moments, with consequences for the ongoing debate about the local moment versus itinerant pictures of the FeAs-based superconductors and parent compounds. The Ba_{1-x}K_xMn2As2 class of compounds also forms a bridge between the layered iron pnictides and cuprates and may be useful to test theories of high Tc superconductivity.Comment: 5 two-column typeset pages, 5 figures, 20 references; v2: minor revisions, 4 new references, published versio

Airborne MAX-DOAS Measurements Over California: Testing the NASA OMI Tropospheric NO2 Product

Airborne Multi-AXis Differential Optical Absorption Spectroscopy (AMAX-DOAS) measurements of NO2 tropospheric vertical columns were performed over California for two months in summer 2010. The observations are compared to the NASA Ozone Monitoring Instrument (OMI) tropospheric vertical columns (data product v2.1) in two ways: (1) Median data were compared for the whole time period for selected boxes, and the agreement was found to be fair (R = 0.97, slope = 1.4 +/- 0.1, N= 10). (2) A comparison was performed on the mean of coincident AMAX-DOAS measurements within the area of the corresponding OMI pixels with the tropospheric NASA OMI NO2 assigned to that pixel. The effects of different data filters were assessed. Excellent agreement and a strong correlation (R = 0.85, slope = 1.05 +/- 0.09, N= 56) was found for (2) when the data were filtered to eliminate large pixels near the edge of the OMI orbit, the cloud radiance fraction was2 km, and a representative sample of the footprint was taken by the AMAX-DOAS instrument. The AMAX-DOAS and OMI data sets both show a reduction of NO2 tropospheric columns on weekends by 38 +/- 24% and 33 +/- 11%, respectively. The assumptions in the tropospheric satellite air mass factor simulations were tested using independent measurements of surface albedo, aerosol extinction, and NO2 profiles for Los Angeles for July 2010 indicating an uncertainty of 12%