Assessment of German nitrous oxide emissions using empirical modelling approaches

Direct nitrous oxide (N₂O) emissions from agricultural soils contribute considerably to anthropogenic GHG emissions. Albeit a key source of emissions in many countries, direct N₂O emissions are still calculated and reported to the United Nations Convention on Climate Change using default emission factors defined in the IPCC guidelines (IPCC 1996, 2006). It is known that processes controlling production and transport of N₂O are highly sensitive to environmental conditions defined by weather, soil and management. The accuracy of N₂O emission budgets and the efficiency of mitigation can be improved if those dependencies are considered with regionalized emission factors. In this study an empirical method originating from soft computing techniques based on measured data is developed and applied to quantify direct N₂O emissions from agricultural soils at field and national level in Germany between 1990 and 2005. The method is used to derive maps of emission factor distribution of direct N₂O emissions of agricultural land in Germany. Model results are compared with alternative empirical approaches from literature. Results from developing empirical models show that grassland and cropland have to be differentiated according to the key controls driving N₂O emissions. N₂O emissions of German croplands are highly influenced by climatic conditions and soil properties. The variability of N₂O fluxes on grasslands is mainly driven by the fertilizer N applied. The model comparison using measured European N₂O emissions exhibits profound discrepancies between the models used on a regional scale. The nationwide budgets derived span a narrow range of −8 to 28% relative to direct N₂O emissions quantified by the German national inventory report. The emission factor of German agriculture estimated by the developed model is 0.91% of fertilizer N applied.     

Effect of blend ratio and elongation flow on the morphology and properties of epoxy resin‐poly(trimethylene terephthalate) blends

The effect of processing conditions on the morphology of polymer blends is a topic of tremendous practical interest especially for thermoset–thermoplastic blends. The effect of blend ratio and the nature of the flow field (shear flow vs. elongation flow) on the morphology is followed here using blends of diglycidyl ether of bisphenol A (DGEBA)‐poly(trimethylene terephthalate) (PTT). Morphology of the blends prepared by the conventional melt mixing technique is compared with that prepared by using an elongation mixer (RMX device invented by Muller et al.). The blends prepared by the elongation mixer showed excellent transparency and higher storage modulus at room temperature than the conventional mixer. In the case of samples prepared by the RMX device T_g of the epoxy phase has been shifted to lower temperatures indicating a molecular level mixing between PTT and DGEBA. However the conventional melt mixed samples showed only a marginal shift in T_g to low temperatures indicating that the system is not as miscible as that prepared by the RMX device. The use of RMX device for thermoset–thermoplastic blends is novel and no work has been reported in this relation. The properties of the blends were strongly affected by the composition and the crystallization of the semicrystalline PTT phase. POLYM. ENG. SCI., 55:1679–1688, 2015. © 2014 Society of Plastics Engineers     

Probiotics, prebiotics infant formula use in preterm or low birth weight infants: a systematic review

Malnutrition is a significant factor in predicting cancer patients?? quality of life (QoL). We systematically reviewed the literature on the role of nutritional status in predicting QoL in cancer. We searched MEDLINE database using the terms ??nutritional status?? in combination with ??quality of life?? together with ??cancer??. Human studies published in English, having nutritional status as one of the predictor variables, and QoL as one of the outcome measures were included. Of the 26 included studies, 6 investigated head and neck cancer, 8 gastrointestinal, 1 lung, 1 gynecologic and 10 heterogeneous cancers. 24 studies concluded that better nutritional status was associated with better QoL, 1 study showed that better nutritional status was associated with better QoL only in high-risk patients, while 1 study concluded that there was no association between nutritional status and QoL. Nutritional status is a strong predictor of QoL in cancer patients. We recommend that more providers implement the American Society of Parenteral and Enteral Nutrition (ASPEN) guidelines for oncology patients, which includes nutritional screening, nutritional assessment and intervention as appropriate. Correcting malnutrition may improve QoL in cancer patients, an important outcome of interest to cancer patients, their caregivers, and families.     

Simulation Based Investigation of Triple Heterojunction TFET (THJ-TFET) for Low Power Applications

Silicon - We designed a new model tunnel field-effect transistor (TFET) based on Triple Heterojunction Tunnel Field Effect Transistor (THJ-TFET) is investigated and designed in this paper. This...     

The effects of vitamin E and selenium intake on oxidative stress and plasma lipids in hamsters fed fish oil

The aim of the present work was to test the effects of large-dose supplementation of vitamin E (Vit E) and selenium (Se), either singly or in combination, on fish oil (FO)-induced tissue lipid peroxidation and hyperlipidemia. The supplementation of Se has been shown to lower blood cholesterol and increase tissue concentrations of the antioxidant glutathione (GSH); however, the effects of Se supplementation, either alone or in combination with supplemental Vit E, on FO-induced oxidative stress and hyperlipidemia have not been studied. Male Syrian hamsters received FO-based diets that contained 14.3 wt% fat and 0.46 wt% cholesterol supplemented with Vit E (129 IU d-α-tocopheryl acetate/kg diet) and/or Se (3.4 ppm as sodium selenate) or that contained basal requirements of both nutrients. The cardiac tissue of hamsters fed supplemental Se showed increased concentrations of lipid hydroperoxides (LPO) but decreased oxidized glutathione (GSSG) concentrations. The higher concentrations of LPO in the hearts of Se-supplemented hamsters were not lowered with concurrent Vit E supplementation. In the liver, Se supplementation was associated with higher Se-dependent glutathione peroxidase activity and an increase in the GSH/GSSG ratio, whereas a lower hepatic non-Se-dependent glutathione peroxidase activity was seen with Vit E supplementation. Supplemental intake of Se was associated with lower plasma concentrations of total cholesterol and low density lipoprotein cholesterol plus very low density lipoprotein cholesterol. In view of the pro-oxidative effects of Se supplementation on cardiac tissue, a cautionary approach needs to be taken regarding the plasma lipid-lowering properties of supplemental Se.     

Catalytic combustion over platinum group catalysts: fuel-lean versus fuel-rich operation

Performance data are presented for methane oxidation on alumina-supported Pd, Pt, and Rh catalysts under both fuel-rich and fuel-lean conditions. Catalyst activity was measured in a micro-scale isothermal reactor at temperatures between 300 and 800 °C. Non-isothermal (near adiabatic) temperature and reaction data were obtained in a full-length (non-differential) sub-scale reactor operating at high pressure (0.9 MPa) and constant inlet temperature, simulating actual reactor operation in catalytic combustion applications.

Under fuel-lean conditions, Pd catalyst was the most active, although deactivation occurred above 650 °C, with reactivation upon cooling. Rh catalyst also deactivated above 750 °C, but did not reactivate. Pt catalyst was active above 600 °C. Fuel-lean reaction products were CO₂ and H₂O for all three catalysts.

The same catalysts tested under fuel-rich conditions demonstrated much higher activity. In addition, a ‘lightoff’ temperature was found (between 450 and 600 °C), where a stepwise increase in reaction rate was observed. Following ‘lightoff’ partial oxidation products (CO, H₂) appeared in the mixture, and their concentration increased with increasing temperature. All three catalysts exhibited this behavior.

High-pressure (0.9 MPa) sub-scale reactor and combustor data are shown, demonstrating the benefits of fuel-rich operation over the catalyst for ultra-low emissions combustion.     

In‐line monitoring of the injection molding process by dielectric spectroscopy

In recent years, electrical techniques like microdielectrometry have increasingly been utilized for their ability to continuously monitor, in a nondestructive way, the advancement of the reaction of thermoset resins under cure. This paper discusses an extension of this technique for the “in‐situ” monitoring of the crystallization of thermoplastics applied during an injection molding process. Electric sensors were positioned at the walls of the mold cavity so that an analysis of the volume dielectric properties of material during the filling, the post‐filling, and the cooling steps could be carried out. Poly(vinylidene fluoride) was chosen for this study. A correlation between the evolution of the dielectric parameters and the succession of the steps in this process was undertaken. The dielectric response was sufficiently sensitive to identify the steps of the closing of the mold, filling, post‐filling, cooling, and ejection of the part. In addition, information concerning the crystallization phenomenon near the wall or in the middle of the sample was collected. The gradual filling of the cavity of the mold was also identified by dielectric measurements. The temperature dependence of dielectric properties of the sample was beneficial in evaluating the increase of the temperature of the mold with the succession of injection cycles. The influence of the packing pressure has been clearly identified and confirms the usefulness of the dielectric method as a probe for detecting the shrinkage of the part during the optimization phase of the machine parameters. The dielectric method detailed herein provides a new non‐invasive technique and could be applied to a closed‐loop control of the injection molding process.