Capacity fade in Sn-C nanopowder anodes due to fracture

Sn based anodes allow for high initial capacities, which however cannot be retained due to the severe mechanical damage that occurs during Li-insertion and de-insertion. To better understand the fracture process during electrochemical cycling three different nanopowders comprised of Sn particles attached on artificial graphite, natural graphite or micro-carbon microbeads were examined. Although an initial capacity of 700?mAh?g(-1) was obtained for all Sn-C nanopowders, a significant capacity fade took place with continuous electrochemical cycling. The microstructural changes in the electrodes corresponding to the changes in electrochemical behavior were studied by transmission and scanning electron microscopy. The fragmentation of Sn observed by microscopy correlates with the capacity fade, but this fragmentation and capacity fade can be controlled by controlling the initial microstructure. It was found that there is a dependence of the capacity fade on the Sn particle volume and surface area fraction of Sn on carbon.     

αV Integrin Expression and Localization in Male Germ Cells

Integrins are transmembrane receptors that facilitate cell adhesion and cell–extracellular matrix communication. They are involved in the sperm maturation including capacitation and gamete interaction, resulting in successful fertilization. αV integrin belongs to the integrin glycoprotein superfamily, and it is indispensable for physiological spermiogenesis and testosterone production. We targeted the gene and protein expression of the αV integrin subunit and described its membrane localization in sperm. Firstly, in mouse, we traced αV integrin gene expression during spermatogenesis in testicular fraction separated by elutriation, and we detected gene activity in spermatogonia, spermatocytes, and round spermatids. Secondly, we specified αV integrin membrane localization in acrosome-intact and acrosome-reacted sperm and compared its pattern between mouse, pig, and human. Using immunodetection and structured illumination microscopy (SIM), the αV integrin localization was confined to the plasma membrane covering the acrosomal cap area and also to the inner acrosomal membrane of acrosome-intact sperm of all selected species. During the acrosome reaction, which was induced on capacitated sperm, the αV integrin relocated and was detected over the whole sperm head. Knowledge of the integrin pattern in mature sperm prepares the ground for further investigation into the pathologies and related fertility issues in human medicine and veterinary science.     

The Role of the LINC Complex in Sperm Development and Function

The LINC (LInker of Nucleoskeleton and Cytoskeleton) complex is localized within the nuclear envelope and consists of SUN (Sad1/UNc84 homology domain-containing) proteins located in the inner nuclear membrane and KASH (Klarsicht/Anc1/Syne1 homology domain-containing) proteins located in the outer nuclear membrane, hence linking nuclear with cytoplasmic structures. While the nucleoplasm-facing side acts as a key player for correct pairing of homolog chromosomes and rapid chromosome movements during meiosis, the cytoplasm-facing side plays a pivotal role for sperm head development and proper acrosome formation during spermiogenesis. A further complex present in spermatozoa is involved in head-to-tail coupling. An intact LINC complex is crucial for the production of fertile sperm, as mutations in genes encoding for complex proteins are known to be associated with male subfertility in both mice and men. The present review provides a comprehensive overview on our current knowledge of LINC complex subtypes present in germ cells and its central role for male reproduction. Future studies on distinct LINC complex components are an absolute requirement to improve the diagnosis of idiopathic male factor infertility and the outcome of assisted reproduction.     

Production of hydrogen for fuel cells by catalytic partial oxidation of ethanol over structured Ni catalysts

Cordierite monoliths, ceramic foams made from mullite and zirconia–alumina as well as γ-Al₂O₃ pellets were employed as supports for Ni/La₂O₃ structured catalysts for the production of hydrogen by catalytic partial oxidation of ethanol. Although all catalysts were very active for ethanol conversion and very selective towards the desired products, the one supported on the zirconia–alumina ceramic foam produced slightly better results. Tested under a wide variety of process conditions, the catalyst supported on the monolith exhibited excellent catalytic performance and long-term stability. In addition to this catalyst, which was prepared by washcoating the active phase on the support, catalysts were prepared on monoliths by adsorption and sol–gel techniques. Adsorption from solutions produced the catalyst with the weakest performance while the sol–gel method resulted in a catalyst with intriguing behavior. Overall, catalysts produced by washcoating on cordierite monoliths are the most promising candidates for the production of hydrogen by partial oxidation of ethanol. Other supports and preparation methods have the potential to produce better catalytic materials but require further optimization.     

Upgrading Vienna's wastewater treatment plant - linking point source emissions to Environmental Quality Standards

The new water quality protection approach of the EU combines the control of emissions with instream Environmental Quality Standards (=EQS). Since 1 April 2006 and actually relevant in the version of 2010 in Austria, priority substances from list A of the EUROPEAN DIERECTIVE 76/464 and further EQS of relevant chemical substances (list B), identified by a national risk assessment, have to be reached to achieve a good ecological state in the surface water (Edict for Water Quality Standards, 2006; changes to the Edict for Water Quality Standards 2010). The practical assessment of these substances after point source emissions is prescribed in the Edict, but rarely carried out. In this paper, two substances, namely: (1) ammonium (list B); and (2) nonylphenol, an endocrine disrupting compound (list A) are presented to discuss: (i) the improvement of treatment efficiency due to the upgrade of a large Waste Water Treatment Plant (=WWTP); (ii) the relevance of mixing processes and modelling as a method to control EQS after point source emissions; and (iii) the improvement of water quality in the ambient surface waters. It is shown that the improved treatment in the case of nonylphenol leads to emission values which fall below the EQS, making an assessment unnecessary. In the case of ammonium emission, values are significantly reduced and violation of EQS is avoided, while mixing modelling is shown to be a suitable instrument to address the resulting instream concentrations at different border conditions.     

Pellet starters in layering technique using concentrated drug solution

Characteristics of inert starters in drug solution layering are important for successful active pellet formation. Four types of starters composed of sucrose or microcrystalline cellulose (MCC) or lactose and MCC were compared in our study. The active pellets were prepared using Wurster type apparatus. Yield and pellet quality parameters were determined. The highest yield (85.66-89.41%) was obtained for cores composed of MCC due to their insolubility in water (the drug solvent) and good mechanical properties. On the contrary, soluble and brittle sucrose cores dissolved partially during the process forming undesirable agglomerates and giving lower yield (76.2%). All pellet samples showed good flow properties and drug content from 82.4 to 94.5% of the theoretical drug amount.     

Experimental performance investigation of natural,mechanical and hybrid ventilation in urban environment

An experimental investigation of the performance of natural, mechanical and hybrid ventilation systems was carried out in an urban measurement campaign during summer period 2002 in Athens, Greece. Three building apartments characterized by different geometry and located in two street canyons with different orientation were studied. The aim was to show the impact of the urban environment on the ventilation efficiency of natural and hybrid systems. The tracer gas decay method has been applied during the experimental procedures with one (N₂O) and two tracer gases (N₂O and SF₆). Based on the results of air-exchange rates using multizone methods from a previous study, a further analysis is performed in the present work for the evaluation of the performance of different ventilation systems in urban conditions, with emphasis on the ventilation efficiency. A methodology to estimate the air-exchange efficiency, on the basis of room mean age of air, in multitracer gas experiments is introduced. In spite of the reduced wind speeds due to the canyon effect, appreciable ventilation rates can be obtained with natural ventilation, especially when cross-ventilation with two or more windows is measured. For single-sided ventilation or under calm conditions, hybrid ventilation has only a slight advantage over natural, either in terms of air-exchange rates or of air-exchange efficiencies.