Phase feeding for growing and finishing pigs (OK-Net Ecofeed Practice Abstract)

Benefits Phase feeding will more closely match the pig’s nutrient requirements and minimise the over- and underfeeding of nutrients. The feed will be better utilised by the pigs, in favour of both production economy and reduced N-emissions. Practical recommendation • To get the maximum benefit from phase feeding, diets and feeding should be established based on actual animal performance and profitability/performance goals for each stage of production. It is easier to develop with a small number of pigs per batch (to manage heterogeneity) • Diets should be formulated on a digestible amino acid basis rather than on a total amino acid or crude protein basis, crude protein should preferably be kept at a low level and ingredients should be analysed for their nutrient contents. • A phase feeding system is complex and factors such as the availability of high-quality protein feed ingredients, the managing and ordering of feed as well as the need for additional feed bins on the farm must be considered. • Consult with an advisor or nutritionist to adjust the feeding plan accordingly to meet the production goals

A parallel genetic algorithm for the Steiner Problem in Networks

This paper presents a parallel genetic algorithm to the Steiner Problem in Networks. Several previous papers have proposed the adoption of GAs and others metaheuristics to solve the SPN demonstrating the validity of their approaches. This work differs from them for two main reasons: the dimension and the characteristics of the networks adopted in the experiments and the aim from which it has been originated. The reason that aimed this work was namely to build a comparison term for validating deterministic and computationally inexpensive algorithms which can be used in practical engineering applications, such as the multicast transmission in the Internet. On the other hand, the large dimensions of our sample networks require the adoption of a parallel implementation of the Steiner GA, which is able to deal with such large problem instances

Leveraging Program Analysis to Reduce User-Perceived Latency in Mobile Applications

Reducing network latency in mobile applications is an effective way of improving the mobile user experience and has tangible economic benefits. This paper presents PALOMA, a novel client-centric technique for reducing the network latency by prefetching HTTP requests in Android apps. Our work leverages string analysis and callback control-flow analysis to automatically instrument apps using PALOMA's rigorous formulation of scenarios that address "what" and "when" to prefetch. PALOMA has been shown to incur significant runtime savings (several hundred milliseconds per prefetchable HTTP request), both when applied on a reusable evaluation benchmark we have developed and on real applicationsComment: ICSE 201

Foderförsörjning och välfärd i ekologisk grisköttproduktion

Foder i ekologisk produktion ska till huvuddelen vara hemmaproducerat. Begränsade möjligheter att använda tillgängliga foderresurser och fodertillsatser innebär svårigheter när det gäller att tillgodose djurets behov av livsnödvändiga aminosyror. Detta kan försämra produktionen och ger ett försämrat proteinutnyttjande med förluster av kväve till miljön som följd. En viktig del i ekologisk grisproduktion är att djuren kan utföra sina naturliga beteenden. Tillgången till grovfoder ger längre ättider och bidrar till minskad förekomst av aggressioner och stress. Hälsoläget hos grisar påverkas av inhysningsform och klimat och kan därför skilja mellan utomhus- och inomhusproduktion. Projekt Eko-gris syftar bl.a. till att undersöka hur lägre innehåll av aminosyror i fodret samt hur olika inhysningssystem påverkar slaktsvinens produktion, slaktkroppsegenskaper, köttkvalitet och grisarnas beteende. Vidare studeras förekomst av parasiter och infektionssjukdomar. Produktion och beteende påverkades inte av fodrets aminosyrainnehåll, men skiljde mellan ute- och innegrisar. Lägre aminosyranivå inverkade inte negativt på grisarnas dagliga viktökning. Varken foderutnyttjande eller slaktkroppskvalitet skiljde signifikant mellan grupperna. Inte heller påverkades grisarnas beteenden av fodrets aminosyranivå. Grisarna i utomhussystemet växte snabbare än inomhusgrisarna (910 mot 821 g; p<0,001), men ingen skillnad förelåg i foderutnyttjande (34,3 mot 35,5 MJ/kg viktökning; p=0,203). Inte heller fanns någon signifikant skillnad i slaktkroppens köttinnehåll (56,8 mot 57,9 %; p=0,134). Beteendestudierna visade att utomhusgrisarna rörde sig betydligt mer än inomhusgrisarna. Det fanns även en tendens till att de bökade mer. ”Nosa”, ”nafsa”, ”knuffa” och ”bita-svans” förekom oftare inne än ute

Primary to secondary organic aerosol: evolution of organic emissions from mobile combustion sources

A series of smog chamber experiments were conducted to investigate the transformation of primary organic aerosol (POA) and formation of secondary organic aerosol (SOA) during the photooxidation of dilute exhaust from a fleet of gasoline and diesel motor vehicles and two gas-turbine engines. In experiments where POA was present in the chamber at the onset of photooxidation, positive matrix factorization (PMF) was used to determine separate POA and SOA factors from aerosol mass spectrometer data. A 2-factor solution, with one POA factor and one SOA factor, was sufficient to describe the organic aerosol for gasoline vehicles, diesel vehicles, and one of the gas-turbine engines. Experiments with the second gas-turbine engine required a 3-factor PMF solution with a POA factor and two SOA factors. Results from the PMF analysis were compared to the residual method for determining SOA and POA mass concentrations. The residual method apportioned a larger fraction of the organic aerosol mass as POA because it assumes that all mass at <i>m / z</i> 57 is associated with POA. The POA mass spectrum for the gasoline and diesel vehicles exhibited high abundances of the C_<i>n</i>H_2<i>n</i>+1 series of ions (<i>m / z</i> 43, 57, etc.) and was similar to the mass spectra of the hydrocarbon-like organic aerosol factor determined from ambient data sets with one exception, a diesel vehicle equipped with a diesel oxidation catalyst. POA mass spectra for the gas-turbine engines are enriched in the C_<i>n</i>H_{2<i>n</i>&minus;1} series of ions (<i>m / z</i> 41, 55, etc.), consistent with the composition of the lubricating oil used in these engines. The SOA formed from the three sources exhibits high abundances of <i>m / z</i> 44 and 43, indicative of mild oxidation. The SOA mass spectra are consistent with less-oxidized ambient SV-OOA (semivolatile oxygenated organic aerosols) and fall within the triangular region of <i>f</i>₄₄ versus <i>f</i>₄₃ defined by ambient measurements. However there is poor absolute agreement between the experimentally derived SOA mass spectra and ambient OOA factors, though this poor agreement should be expected based on the variability of ambient OOA factors. Van Krevelen analysis of the POA and SOA factors for gasoline and diesel experiments reveal slopes of −0.50 and −0.40, respectively. This suggests that the oxidation chemistry in these experiments is a combination of carboxylic acid and alcohol/peroxide formation, consistent with ambient oxidation chemistry

Reactive intermediates revealed in secondary organic aerosol formation from isoprene

Isoprene is a significant source of atmospheric organic aerosol; however, the oxidation pathways that lead to secondary organic aerosol (SOA) have remained elusive. Here, we identify the role of two key reactive intermediates, epoxydiols of isoprene (IEPOX = β-IEPOX + δ-IEPOX) and methacryloylperoxynitrate (MPAN), which are formed during isoprene oxidation under low- and high-NO_x conditions, respectively. Isoprene low-NO_x SOA is enhanced in the presence of acidified sulfate seed aerosol (mass yield 28.6%) over that in the presence of neutral aerosol (mass yield 1.3%). Increased uptake of IEPOX by acid-catalyzed particle-phase reactions is shown to explain this enhancement. Under high-NO_x conditions, isoprene SOA formation occurs through oxidation of its second-generation product, MPAN. The similarity of the composition of SOA formed from the photooxidation of MPAN to that formed from isoprene and methacrolein demonstrates the role of MPAN in the formation of isoprene high-NO_x SOA. Reactions of IEPOX and MPAN in the presence of anthropogenic pollutants (i.e., acidic aerosol produced from the oxidation of SO_2 and NO_2, respectively) could be a substantial source of “missing urban SOA” not included in current atmospheric models

Secondary organic aerosol formation from in-use motor vehicle emissions using a potential aerosol mass reactor.

Secondary organic aerosol (SOA) formation from in-use vehicle emissions was investigated using a potential aerosol mass (PAM) flow reactor deployed in a highway tunnel in Pittsburgh, Pennsylvania. Experiments consisted of passing exhaust-dominated tunnel air through a PAM reactor over integrated hydroxyl radical (OH) exposures ranging from ∼ 0.3 to 9.3 days of equivalent atmospheric oxidation. Experiments were performed during heavy traffic periods when the fleet was at least 80% light-duty gasoline vehicles on a fuel-consumption basis. The peak SOA production occurred after 2-3 days of equivalent atmospheric oxidation. Additional OH exposure decreased the SOA production presumably due to a shift from functionalization to fragmentation dominated reaction mechanisms. Photo-oxidation also produced substantial ammonium nitrate, often exceeding the mass of SOA. Analysis with an SOA model highlight that unspeciated organics (i.e., unresolved complex mixture) are a very important class of precursors and that multigenerational processing of both gases and particles is important at longer time scales. The chemical evolution of the organic aerosol inside the PAM reactor appears to be similar to that observed in the atmosphere. The mass spectrum of the unoxidized primary organic aerosol closely resembles ambient hydrocarbon-like organic aerosol (HOA). After aging the exhaust equivalent to a few hours of atmospheric oxidation, the organic aerosol most closely resembles semivolatile oxygenated organic aerosol (SV-OOA) and then low-volatility organic aerosol (LV-OOA) at higher OH exposures. Scaling the data suggests that mobile sources contribute ∼ 2.9 ± 1.6 Tg SOA yr(-1) in the United States, which is a factor of 6 greater than all mobile source particulate matter emissions reported by the National Emissions Inventory. This highlights the important contribution of SOA formation from vehicle exhaust to ambient particulate matter concentrations in urban areas

Production of Secondary Organic Aerosol During Aging of Biomass Burning Smoke From Fresh Fuels and Its Relationship to VOC Precursors

After smoke from burning biomass is emitted into the atmosphere, chemical and physical processes change the composition and amount of organic aerosol present in the aged, diluted plume. During the fourth Fire Lab at Missoula Experiment, we performed smog-chamber experiments to investigate formation of secondary organic aerosol (SOA) and multiphase oxidation of primary organic aerosol (POA). We simulated atmospheric aging of diluted smoke from a variety of biomass fuels while measuring particle composition using high-resolution aerosol mass spectrometry. We quantified SOA formation using a tracer ion for low-volatility POA as a reference standard (akin to a naturally occurring internal standard). These smoke aging experiments revealed variable organic aerosol (OA) enhancements, even for smoke from similar fuels and aging mechanisms. This variable OA enhancement correlated well with measured differences in the amounts of emitted volatile organic compounds (VOCs) that could subsequently be oxidized to form SOA. For some aging experiments, we were able to predict the SOA production to within a factor of 2 using a fuel-specific VOC emission inventory that was scaled by burn-specific toluene measurements. For fires of coniferous fuels that were dominated by needle burning, volatile biogenic compounds were the dominant precursor class. For wiregrass fires, furans were the dominant SOA precursors. We used a POA tracer ion to calculate the amount of mass lost due to gas-phase oxidation and subsequent volatilization of semivolatile POA. Less than 5% of the POA mass was lost via multiphase oxidation-driven evaporation during up to 2 hr of equivalent atmospheric oxidation

Visual Literacies and Young Children’s Writing: Creating Spaces for Young Children’s Voices and Engaging in Authentic Writing Experiences

Young children engage in multimodal written expression. The research in this study explores the spaces that were created, and the stories created by children in an after-school comic club. The club utilized the Writer’s Workshop model to support the Being a Writer program that is used in the Ocean View School District (Ocean View School District is a pseudonym). I created a supplemental writing program that utilized visual literacy instruction and taught the lessons in the club. The theoretical framework incorporated developmentally appropriate writing instruction, visual literacy elements, and sociocultural theory. This study employed an action research methodology with multiple data collection points. The coding of data points used provisional (a priori) coding and open coding. Students created multimodal artifacts as part of the club and were able to create authentic and purposeful drawings and writings. The students were able to make meaning using pictures and words. The student writers’ stories were shared in an Author Celebration. The roles of collaboration, drawing, and writing were major components of the work that the student writers engaged in and the processes through which they produced their work

Experimental study of mercury removal from exhaust gases

An initial study has been made of the use of synthetic zeolites for mercury capture from exhaust gases. Synthetic zeolites (Na-X and Na-P1), and for comparison a natural zeolite (clinoptilolite) and activated carbon with bromine (AC/Br) were tested for mercury uptake from a gaseous stream. The materials were subjected to mercury adsorption tests and their thermal stability was evaluated. The untreated synthetic zeolites had negligible mercury uptake, but after impregnation with silver, the adsorption of mercury was markedly improved. The synthetic zeolite Na-X impregnated with silver adsorbed significantly more mercury before breakthrough than the activated carbon impregnated with bromine, indicating the potential of zeolite derived from coal fly ash as a new sorbent for capture of mercury from flue gases