项目分类

在过去14个月的专栏文章里我阐述了如何提高组织的项目管理能力,该主题的系列文章已告一段落,从这期开始我将转而讨论项目经理的领导能力.目前我正在参与一项由美国项目管理协会(PMI)赞助的研究项目,研究项目经理的领导能力,在这里我愿意与大家分享我们的一些研究成果.我们尤其研究了不同的领导风格在不同类型的项目中是否适用.     

Begrenzung der Rissbreite nach Eurocode 2

Crack width control according to Eurocode 2 – Explanatory notes on factor k _c Reinforced concrete members are designed now according to EC2 [1]. A significant aspect is the determining of the minimum reinforcement area specified in section 7.3.2. Due to the shortened illustrations of the equations (7.1) and (7.2), the mechanical background is difficult to be highlighted. This often results in inaccurate use of the model parameters, which might lead to an unsafe design, particularly for members predominantly reinforced only by the minimum reinforcement. Therefore the mechanical background of the equations (7.1) and (7.2) is focused on in this contribution. Proper discussions and explanations might help the structural engineer in the practical design.     

Tolerance,Adaptation, and Cell Response Elicited by Micromonospora sp. Facing Tellurite Toxicity: A Biological and Physical-Chemical Characterization

The intense use of tellurium (Te) in industrial applications, along with the improper disposal of Te-derivatives, is causing their accumulation in the environment, where oxyanion tellurite (TeO₃²⁻) is the most soluble, bioavailable, and toxic Te-species. On the other hand, tellurium is a rare metalloid element whose natural supply will end shortly with possible economic and technological effects. Thus, Te-containing waste represents the source from which Te should be recycled and recovered. Among the explored strategies, the microbial TeO₃²⁻ biotransformation into less toxic Te-species is the most appropriate concerning the circular economy. Actinomycetes are ideal candidates in environmental biotechnology. However, their exploration in TeO₃²⁻ biotransformation is scarce due to limited knowledge regarding oxyanion microbial processing. Here, this gap was filled by investigating the cell tolerance, adaptation, and response to TeO₃²⁻ of a Micromonospora strain isolated from a metal(loid)-rich environment. To this aim, an integrated biological, physical-chemical, and statistical approach combining physiological and biochemical assays with confocal or scanning electron (SEM) microscopy and Fourier-transform infrared spectroscopy in attenuated total reflectance mode (ATR-FTIR) was designed. Micromonospora cells exposed to TeO₃²⁻ under different physiological states revealed a series of striking cell responses, such as cell morphology changes, extracellular polymeric substance production, cell membrane damages and modifications, oxidative stress burst, protein aggregation and phosphorylation, and superoxide dismutase induction. These results highlight this Micromonospora strain as an asset for biotechnological purposes.     

Vehicle Contribution to Ambient Carbonaceous Aerosols by Scaled Thermograms

Carbon thermograms, which classify carbon aerosol according to its volatility, were obtained for fine-particle samples from an isolated highway vehicle source and a vehicle-dominated ambient site. The thermograms from the sites were compared after scaling by the carbon monoxide concentration. The high- and low-volatility carbon fractions in the ambient sample agreed to within 10% of the corresponding fractions in the highway vehicle sample. Excess carbon in the range of intermediate volatility comprised 15 to 19% of the ambient carbon mass and is attributed to aerosols from secondary processes and nonvehicular primary sources. When lead was used as a tracer to scale the thermograms, the high- and low-volatility ambient carbon fractions were underestimated by a factor of 2. The low volatility fraction (“black carbon”) present in the atmospheric sample was evolved at lower temperatures than the equivalent fraction in the isolated highway vehicle sample. This creates an ambiguity in defining the low-volatility fraction, which is a problem if black carbon is used as a tracer. The scaling technique described in this work avoids the problem because it does not require an estimation of the low-volatility carbon fraction.