Ferritsius O.,Mid Sweden University |
Morseburg K.,PFI |
Ferritsius R.,Mid Sweden University |
Ferritsius R.,Stora Enso
International Mechanical Pulping Conference, IMPC 2014, part of PulPaper 2014 Conference | Year: 2014
Sixteen TMP/CTMP lines aimed for publication and board grades have been compared for energy efficiency with respect to pulp quality development. The pulp property profile and the process design differed substantially, even for similar product grades. A given level of a specific pulp property was reached over a wide range in specific energy. The most energy efficient lines operated at the highest production rates and with high relative speed of the refiner discs. With respect to the final pulp quality there was no obvious influence of how the screen room was equipped. It was possible to develop the fibers in a proper way just by refining of the whole pulp stream.
Nordli H.R.,Norwegian University of Science and Technology |
Chinga-Carrasco G.,PFI |
Rokstad A.M.,Norwegian University of Science and Technology |
Pukstad B.,Norwegian University of Science and Technology
Carbohydrate Polymers | Year: 2016
Wood cellulose nanofibrils (CNF) have been suggested as a potential wound healing material, but its utilization is limited by FDA requirements regarding endotoxin levels. In this study a method using sodium hydroxide followed by TEMPO mediated oxidation was developed to produce ultrapure cellulose nanofibrils, with an endotoxin level of 45 endotoxin units/g (EU/g) cellulose. Scanning transmission electron microscopy (S(T)EM) revealed a highly nanofibrillated structure (lateral width of 3.7 ± 1.3 nm). Assessment of cytotoxicity and metabolic activity on Normal Human Dermal Fibroblasts and Human Epidermal Keratinocytes was done. CNF-dispersion of 50 μg/ml did not affect the cells. CNF-aerogels induced a reduction of metabolic activity by the fibroblasts and keratinocytes, but no significant cell death. Cytokine profiling revealed no induction of the 27 cytokines tested upon exposure to CNF. The moisture-holding capacity of aerogels was relatively high (∼7500%), compared to a commercially available wound dressing (∼2500%), indicating that the CNF material is promising as dressing material for management of wounds with a moderate to high amount of exudate. © 2016 Elsevier Ltd. All rights reserved.
Paunonen S.,Norwegian University of Science and Technology |
Lenes M.,PFI |
Gregersen O.,Norwegian University of Science and Technology
Packaging Technology and Science | Year: 2011
Solid fibreboard is used mainly in highly demanding packaging applications. One solid fibreboard quality having six paper and paperboard layers, a thickness of 1.7 mm and polyethylene coating was studied. Several material tests on liquid water and water vapour penetration were done to assess the environmental moisture sources that change the material moisture content after the lamination process. The in-plane diffusion coefficient of the combined board was determined based on an integrated unsteady state moisture transport equation and moisture sorption measurements. The transverse diffusion coefficient of the polyethylene coated kraft paper and the solid fibreboard medium were based on water vapour transmission rate measurements. The original moisture content of the solid fibreboard sheet was measured gravimetrically 2 days after the lamination at the mill. The results show that high relative humidity (RH) conditions during the transportation (4°C/90% RH) change the moisture content of the transportation box made from a solid fibreboard sheet very little in 8 days. Local moister (or drier) areas are created near the sheet edges due to in-plane moisture transport through open material edges. The in-plane diffusivity for the solid fibreboard grade in question was 5.87 Ã - 10-10 m2/s. Copyright © 2011 John Wiley & Sons, Ltd. Solid fibreboard is used mainly in highly demanding packaging applications. Moisture penetration into a laminated solid fibreboard grade having polyethylene coating was studied. The results show that high relative humidity (RH) conditions during the transportation (4°C/90% RH) change the moisture content very little in 8 days. Local moister or drier areas are created near the sheet edges. The in-plane diffusion coefficient (5.87*timese; 10-10 m2/s) was determined based on an integrated unsteady state moisture transport equation and moisture sorption measurements. Copyright © 2011 John Wiley & Sons, Ltd.
« HeidelbergCement and Joule partnering to explore carbon-neutral fuel application in cement manufacturing | Main | New $7M XPRIZE competition for rapid and unmanned ocean exploration; $1M bonus from NOAA » Researchers from Tsinghua University and Peking University have investigated the effects of fuel properties on particulate emissions gasoline direct injection engines (GDI). The study results, reported in the journal Fuel, demonstrated that the fuel composition has a significant on particulate emissions from GDI engines. Although turbocharged GDI engines offer the attractive combination of both increased fuel efficiency and performance due to their higher volumetric efficiencies at high load, they also tend to produce more PM than PFI engines, with PM mass levels exceeding those of diesels equipped with diesel particulate filters, as well as conventional port-fuel injected vehicles. (Storey et al., 2014). A recent open access study published in Nature’s Scientific Reports (Zhang & Cao, 2015) found that only 25 out of 190 cities in China could meet the National Ambient Air Quality Standards of China; the population-weighted mean of PM in Chinese cities is 61 μg/m3—about 3 times as high as global population-weighted mean, highlighting a high health risk. According to data released by the Beijing Environmental Protection Bureau (EPB) in 2014, motor vehicles were responsible for 31% of local PM emissions in 2014. In the introduction to their paper, the Tsinghua/Peking team noted that in GDI operation, gasoline is injected into the cylinder during the intake stroke, leaving insufficient time for the gasoline to evaporate and to mix with air before ignition. This inhomogeneity unavoidably leads to diffusion flame, in which soot-like particulates are formed. It is known that vehicular particulate emissions can be affected by the fuel properties, such as aromatics, olefin, sulfur content, volatility and oxygenate. … The objective of this research work is to investigate different fuel compositions impacts on primary particulate emissions, VOCs and conventional gaseous emissions from gasoline powered vehicles (including both PFI and DIG). Since it is known that secondary particulate emission is a significant contributor to air quality, this research work also takes this into consideration. In the new paper, the research team blended six test fuels with different aromatics, olefin, sulfur, Methyl-cyclopentadienyl Manganese Tricarbonyl (MMT) and ethanol content to use with a GDI engine (certified to China Phase 4, equivalent to Euro 4) produced by a Chinese OEM to examine the influences on primary particulate emission including mass; number; size distribution; compounds including Polycyclic Aromatic Hydrocarbons (PAHs); and the toxicity of PAHs emissions. Fuel composition—especially aromatics content—had a significant impact on PM emissions. Higher aromatics in gasoline resulted in much higher PM (mass), PN (particle number) and PAHs emissions, with higher toxicity to human health. The researchers concluded that reducing aromatics content is an important means to reduce primary particulate emissions and improve air quality. Reducing olefin content resulted in reduced PM and PN emissions especially under high-load operation, but did not improve PAHs emissions levels by much. It did, however, contribute to the reduction of toxicity of PAHs. E10 showed limited improvement on PM emissions compared with the effect of reducing aromatics and olefin content. Additionally, E10 increased PN emissions under low-load conditions. Typical China Phase V gasoline did not definitely reduce vehicle emissions versus the typical Phase IV gasoline with higher sulfur ( The GDI tailpipe particulates consist mainly of EC (elemental carbon), OM (organic matter) and small amounts of inorganic ions. The mass percentage of EC in the total tailpipe PM increased as load increased. Three-way catalysts have a significant impact on PM, helping to reduce OM greatly (67–85%), resulting in an increase of mass percentage of EC in the the total PM of post-TWC versus pre-TWC configurations.
« Hyundai Heavy introduces first Tier III-compliant high pressure SCR for 2-stroke marine engines | Main | HRL Laboratories achieves 1st demo of GaN CMOS FET technology » A study of emissions from gasoline direct injection (GDI) vehicles in an urban near-road environment in Toronto over a wide range of weather conditions (February 2014 to January 2015) found that—other than for NO and CO—the GDI engines had elevated emissions compared to the Toronto fleet. In four campaigns over the year-long study, the team from the University of Toronto measured emissions 15 meters from the roadway, then converted the measurements to fuel-based emission factors (EFs). BC (black carbon) EFs were in the 73rd percentile; BTEX (benzene, toluene, ethylbenzene-xylenes) EFs were in the 80–90th percentile; and size-resolved PN (particle number) EFs were in the 75th percentile during wintertime measurements. For three campaigns, a second platform for measuring PN and CO was placed 1.5–3 meters from the roadway to quantify changes in PN with distance from point of emission. Mean PN EFs at 15 m from the roadway were up to 300% higher than EFs at 1.5 m from the roadway. This microscale spatial variability was highest in the winter and smallest in the summer, indicating that the relative increase in particle emissions is influenced by ambient temperature. In comparison, average PN EFs from a PFI vehicle exhibited less spatial variability, with mean PN EFs 15 m from the roadway 17% lower than those measured 3 m from the roadway. One response by automakers to increasingly stringent fuel economy requirements is the use of GDI engines, which offer up to a 25% improvement in fuel economy compared to port fuel injection (PFI) engines. Market share of GDI vehicles is increasing rapidly; between model years 2009 and 2014 there was a 10-fold increase in GDI engine sales. Some projections expect the 2016 market share of new LDVs with GDI engines to exceed 50%. It is already well-known that GDI engines emit substantially more particulate matter than PFI engines due to incomplete fuel volatilization causing fuel impingement on cylinder and piston surfaces and incomplete fuel mixing with air resulting in pockets of fuel rich combustion. Accurately characterizing GDI PM is also a measurement challenge; compared to diesel, the University of Toronto team noted, the large aromatic fraction in gasoline is expected to produce PM with a larger organic mass fraction and with higher volatility. Hence, GDI PM mass loadings and chemical composition may vary depending on the measurement environment or exhaust conditioning. The researchers carried out their campaigns at the Southern Ontario Centre for Atmospheric Aerosol Research (SOCAAR) Field Measurement Facility in downtown Toronto, Canada. The sampling site is north of a four-lane roadway that experiences relatively high traffic volumes ranging from 16,000−25,000 cars per day. All measurements for the study were taken from 3:00 am to 6:00 am when traffic volume was at a minimum to isolate the signal from the GDI vehicle and to eliminate the effects of photochemistry. The vehicles in the study were 7 2013 Ford Focus light-duty SE sedans equipped with gasoline direct injection (GDI) engines fueled with commercially available gasoline. For the winter 2014 and spring 2014 campaigns, the researchers used a 2000 Honda CR-V equipped with a PFI engine to compare GDI and PFI PN emissions. From this study, it can be concluded that particles in GDI vehicles have PN, BC, and BTEX EFs in the upper end of the fleet distribution and the exhaust plumes exhibit dynamic behavior in the near-road (15 m) region, with increasing PN EFs at increasing distance from the roadway. This suggests that as GDI vehicle market penetration increases, there may be negative impacts on local air quality, especially in urban environments near roadways. The observed near-road PN dynamics were unique to GDI vehicles, as the same effects were not observed for heavy-duty diesel garbage trucks or a PFI-equipped vehicle.