Impact of grey energy on optimal wall insulation thickness

For decades efforts have been made to reduce the greenhouse gases emissions of buildings by reducing their energy demand with governmental regulations in Europe, pushing towards very low thermal transmittances (U-values) with ever thicker insulation layers for new buildings. However, there is no linear relationship between the insulation thickness and the heat losses. Therefore, above a certain thickness the consumption of buildings does not decrease significantly. Hereafter a life cycle analysis, including emissions before the building becomes operational is applied to evaluate the impact of the increasing thickness of components on the overall emissions. Publicly available product data sheets are used to compare four insulation materials under three scenarios. These analyses yield interesting results showing that energy-intensive insulation materials lead to a negative impact in the overall energy balance after a certain thickness. Even though there is not always a pronounced optimum insulation thickness, it is logical that further reductions in U-value for new buildings should hence be carefully evaluated. The results show that the optimal thickness is around 20 cm for most materials, while the important major savings come from the first 10 cm.     

Apple Allergy: The cDNA Sequence of the Major Allergen of Apple,Determined by Performing PCR with a Primer Based on the N-Terminal Amino Acid Sequence,is Highly Homologous to the Sequence of the Major Birch Pollen Allergen

Considering the known N-terminal amino acid sequence of the major apple allergen, a polymerase chain reaction (PCR) primer was selected to amplify cDNA encoding this protein. A single PCR product was obtained, cloned into Escherichia coli and subsequently sequenced. The missing 5′-end of the apple cDNA sequence was obtained by a 5′-RACE method. The cDNA sequence showed 72% identity with the coding region of one of the known isoforms of Bet v 1, the major allergen of birch pollen. The deduced amino acid sequence resulted in a 158-residue protein with a calculated molecular mass of 17·5 kDa and 63% amino acid sequence identity to Bet v 1. In addition, further protein alignments showed a high degree of identity with allergens from other tree pollens and some ‘pathogenesis-related proteins’ from food plants. According to international regulations the allergen was termed Mal d 1 for this protein, it being the first major allergen discovered and characterised in fruits of apple (Malus domestica).     

Analysis of a 26 756 bp segment from the left arm of yeast chromosome IV

The nucleotide sequence of a 26·7 kb DNA segment from the left arm of Saccharomyces cerevisiae chromosome IV is presented. An analysis of this segment revealed 11 open reading frames (ORFs) longer than 300 bp and one split gene. These ORFs include the genes encoding the large subunit of RNA polymerase II, the biotin apo-protein ligase, an ADP-ribosylation factor (ARF 2), the ‘L35’-ribosomal protein, a rho GDP dissociation factor, and the sequence encoding the protein phosphatase 2A. Further sequence analysis revealed a short ORF encoding the ribosomal protein YL41B, an intron in a 5′ untranslated region and an extended homology with another cosmid (X83276) located on the same chromosome. The potential biological relevance of these findings is discussed. The sequence was submitted to the EMBL database under Accession Number X96876.     

Online gasoline blending with EPA Complex Model for predicting emissions

The empirical Complex Model developed by the US Environmental Protection Agency (EPA) is used by refiners to predict the toxic emissions of reformulated gasoline with respect to gasoline properties. The difficulty in implementing this model in the blending process stems from the implicit definition of Complex Model through a series of disjunctions assembled by the EPA in the form of spreadsheets. A major breakthrough in the refinery-based Complex Model implementation occurred in 2008 and 2010 through the use of generalized disjunctive and mixed-integer nonlinear programming (MINLP). Nevertheless, the execution time of these MINLP models remains prohibitively long to control emissions with our online gasoline blender. The first objective of this study is to present a new model that decreases the execution time of our online controller. The second objective is to consider toxic thresholds as hard constraints to be verified and search for blends that verify them. Our approach introduces a new way to write the Complex Model without any binary or integer variables. Sigmoid functions are used herein to approximate step functions until the measurement precision for each blend property is reached. By knowing this level of precision, we are able to propose an extremely good and differentiable approximation of the Complex Model. Next, a differentiable objective function is introduced to penalize emission values higher than the threshold emissions. Our optimization module has been implemented and tested with real data. The execution time never exceeded 1 s, which allows the online regulation of emissions the same way as other traditional properties of blended gasoline.     

Occurrence of pyrrolizidine alkaloids in animal- and plant-derived food: results of a survey across Europe

Pyrrolizidine alkaloids (PAs) are secondary metabolites of plant families such as Asteraceae or Boraginaceae and are suspected to be genotoxic carcinogens. Recent investigations revealed their frequent occurrence in honey and particularly in tea. To obtain a comprehensive overview of the PA content in animal- and plant-derived food from the European market, and to provide a basis for future risk analysis, a total of 1105 samples were collected in 2014 and 2015. These comprised milk and milk products, eggs, meat and meat products, (herbal) teas, and (herbal) food supplements collected in supermarkets, retail shops, and via the internet. PAs were detected in a large proportion of plant-derived foods: 91% of the (herbal) teas and 60% of the food supplements contained at least one individual PA. All types of (herbal) teas investigated were found to contain PAs, with a mean concentration of 460 µg kg^?1 dry tea (corresponding to 6.13 µg L^?1 in [herbal] tea infusion). The highest mean concentrations were found in rooibos tea (599 µg kg^?1 dry tea, 7.99 µg L^?1 tea infusion) and the lowest in camomile tea (274 µg kg^?1 dry tea, 3.65 µg L^?1 tea infusion). Occurrence of PAs in food supplements was found to be highly variable, but in comparable ranges as for (herbal) tea. The highest concentrations were present in supplements containing plant material from known PA-producing plants. In contrast, only 2% of the animal-derived products, in particular 6% of milk samples and 1% of egg samples, contained PAs. Determined levels in milk were relatively low, ranged between 0.05 and 0.17 µg L^?1 and only trace amounts of 0.10–0.12 µg kg^?1 were found in eggs. No PAs were detected in the other animal-derived products.     

Comparable Characterization of Nanocellulose Extracted from Bleached Softwood and Hardwood Pulps

In this study, the characteristics of nanocellulose extracted from bleached softwood and hardwood pulps by formic acid hydrolysis followed by TEMPO-mediated oxidation were compared using transmission electron microscopy (TEM), atomic force microscopy (AFM), Fourier transform infrared analysis (FT-IR), X-ray diffraction (XRD), and thermal gravimetric analysis (TGA). The experimental results showed that the nanocellulose products derived from spruce pulp exhibited a relatively larger particle size, higher crystallinity, and higher thermal stability, compared with the corresponding products obtained from aspen pulp under the same conditions. Furthermore, the study helped establish that the properties of the nanocellulose products were highly dependent on the nature of the starting materials under identical processing conditions.     

Structural Features of a Full-Length Ubiquitin Ligase Responsible for the Formation of Patches at the Plasma Membrane

Plant U-box armadillo repeat (PUB-ARM) ubiquitin (Ub) ligases have important functions in plant defense through the ubiquitination of target proteins. Defense against pathogens involves vesicle trafficking and the formation of extracellular vesicles. The PUB-ARM protein SENESCENCE ASSOCIATED UBIQUITIN E3 LIGASE1 (SAUL1) can form patches at the plasma membrane related to tethering multi-vesicular bodies (MVBs) to the plasma membrane. We uncovered the structure of a full-length plant ubiquitin ligase and the structural requirements of SAUL1, which are crucial for its function in patch formation. We resolved the structure of SAUL1 monomers by small-angle X-ray scattering (SAXS). The SAUL1 model showed that SAUL1 consists of two domains: a domain containing the N-terminal U-box and armadillo (ARM) repeats and the C-terminal ARM repeat domain, which includes a positively charged groove. We showed that all C-terminal ARM repeats are essential for patch formation and that this function requires arginine residue at position 736. By applying SAXS to polydisperse SAUL1 systems, the oligomerization of SAUL1 is detectable, with SAUL1 tetramers being the most prominent oligomers at higher concentrations. The oligomerization domain consists of the N-terminal U-box and some N-terminal ARM repeats. Deleting the U-box resulted in the promotion of the SAUL1 tethering function. Our findings indicate that structural changes in SAUL1 may be fundamental to its function in forming patches at the plasma membrane.     

Social organization,constraints and opportunities for kitchen garden implementation: ScalA and ScalA-FS assessment tools in Morogoro and Dodoma,Tanzania

Tanzania is the second largest country in East Africa with about 50 million inhabitants in 2014, and it is also considered as one of the poorest countries in the world. The country strongly depends on agriculture production. Like many other poor countries in sub-Saharan Africa, Tanzania sees food security as a central part of development and poverty reduction efforts. This work aims to investigate the opportunities and constraints of implementing a policy of “Kitchen Gardens” as a practice for two regions of Tanzania. The research was carried out with a qualitative approach through a first round of semi-structured interviews using a Scaling up Assessment Tool (ScalA), and a second round with a questionnaire survey, using a Scaling up Assessment Tool for Food Security (ScalA-FS) by Tanzanian and German experts from the Trans-SEC project. The experts assessed implementation suitability and the institutional requirements of Kitchen Garden across the food value chains in two Tanzanian regions with different climate regions, namely Dodoma (semi-arid) and Morogoro (sub-humid). Kitchen Garden assessments did not differ significantly between these regions. The ScalA tools provided a range of statements that allowed an overview of the structural situation to be obtained, which could enable Kitchen Garden activity to be incentivized and scaled up. However, a number of specific aspects, potentials, challenges, and likely bottlenecks of implementation related to their feasibility and institutional requirements, were indicated, which should be carefully monitored during implementation. Adopting the recommended strategies could help to close gaps in implementation, enhance community empowerment and social network development, reduce food insecurity and improve the health of the communities.     

适度硬化表面淬火钢的加工和应用(一)

表面淬火钢的硬化程度对变速器零件的加工和应用起到决定性的作用.硬化程度主要取决于材料的化学成分,是选择表面淬火钢淬火温度的主要标准,因为稳定的材料质量是高效率大规模生产的保证.顶端淬火样品的变形和热处理条件对测量结果具有决定性的影响.由于明显的不确定性,必须考虑到顶端淬火试验测定的硬化程度和材料化学成分之间的不同.在狭窄的硬化程度范围内对表面淬火钢的热处理确保了可预测和可再现的大规模生产.一些实例表明,由于稍稍偏离所需的硬化程度范围造成不规则的热处理变形,并因成本问题而被放弃.