Auswahl von Sorbenzien für die Gasphasenadsorption

Selection of Sorbents for Gas Phase Adsorption. For gas phase adsorption processes it is almost always necessary to select a suitable sorbent by experiment, i.e. a sorbent that is suitable for adsorption as well as for desorption. Therefore sorbents from the group of activated carbons, adsorbent resins and zeolites have been tested and compared with each other under adsorption and desorption conditions. The sorbents have also been checked for reliable function. Operational disturbances are often caused by components such as water vapor or (irreversibly adsorbing) high boiling components. In any case it is useful to select adsorbents which are not susceptible to interference by these components. The co-adsorption of water vapor, undesirable in practice, normally leads to a reduced adsorbent capacity. It is also shown that a single high boiling component, present in traces in the gas, loads the adsorbent to the same extent as the pure main component, so that there is hardly any capacity left for the main component. The range of investigation was insufficient to draw up general rules for the different groups of sorbents referring to the points considered.     

Context-adaptive forwarding in mobile opportunistic networks

When two opportunistic network peers encounter, utility functions are generally employed to select the messages that have to be exchanged, with the purpose of maximizing message delivery probability and reduce congestion. These functions compute weighted sums of various parameters, like centrality, similarity, and trust. Most of the existing solutions statically compute the weights based on offline observations and apply the same values regardless of a node’s context. However, mobile networks are not necessarily constant in terms of behavior and characteristics, so the classic approach might not be suitable. The network might be split into sub-networks, which behave differently from each other. Thus, in this paper, we show that, by dynamically adjusting the behavior of a node based on its context, through the adjustment of the utility function on the fly, the opportunistic forwarding process can be improved. We show that nodes behave differently from each other and have different views of the network. Through real-life trace-based simulations, we prove that our solution is feasible and is able to improve an opportunistic network’s performance from the standpoint of hit rate, latency, and delivery cost.     

SEM/EDS comparison of polar and seasonal temperate ice

We have developed a method employing a scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy for examining uncoated ice specimens. By permitting the ice to sublimate in the SEM at temperatures between -115 degrees and -60 degrees C, enough ions are produced to prevent specimen charging. The absence of a conductive coating permits both the acquisition of uncompromised X-ray spectra, and a dynamic view of impurities as the ice sublimates. The method has enabled us to examine the microstructure and impurities in ice in ways not possible through standard melt chemistry measurements or even through using a SEM to study coated samples. Soluble impurities appeared either as white spots in grain interiors, grain boundaries, and triple junctions, or as filaments in grain boundaries. Inclusions of insoluble impurities have also been observed in natural ice. Thus, we have been able to compare the microstructural location and concentration of impurities in ice from different terrestrial locations. Even when ion chromatography of the melt from two core sections reveals similar levels of impurities, the morphology and location of the impurity aggregates can be quite different. Analysis of impurity type and location can provide clues to the depositional environment and history of the ice.     

Wittig-Horner reactions on styrene-divinylbenzene supports with benzaldehyde side-groups

Summary A styrene-divinylbenzene copolymer functionalized with aldehyde was prepared under phase transfer catalyzed (PTC) conditions. A statistical method for the calculation of the degree of functionalization with aldehyde groups is proposed. The degree of functionalization with aldehyde groups is relatively high. Styrene-divinylbenzene polymers functionalized with benzaldehyde groups were used in Wittig-Horner reaction, in order to introduce double bonds on polymers. The reactions were carried out using PTC method, solid-liquid-solid (s-l-s) (K₂CO₃, tetrahydrofuran, tetraethylammonium iodide) system. Phase transfer catalyzed reactions are often more easily and cheaply carried out than conventional method and they are therefore of particular interest.     

Current Trends in Neurodegeneration: Cross Talks between Oxidative Stress,Cell Death,and Inflammation

The human body is highly complex and comprises a variety of living cells and extracellular material, which forms tissues, organs, and organ systems. Human cells tend to turn over readily to maintain homeostasis in tissues. However, postmitotic nerve cells exceptionally have an ability to regenerate and be sustained for the entire life of an individual, to safeguard the physiological functioning of the central nervous system. For efficient functioning of the CNS, neuronal death is essential, but extreme loss of neurons diminishes the functioning of the nervous system and leads to the onset of neurodegenerative diseases. Neurodegenerative diseases range from acute to chronic severe life-altering conditions like Parkinson’s disease and Alzheimer’s disease. Millions of individuals worldwide are suffering from neurodegenerative disorders with little or negligible treatment available, thereby leading to a decline in their quality of life. Neuropathological studies have identified a series of factors that explain the etiology of neuronal degradation and its progression in neurodegenerative disease. The onset of neurological diseases depends on a combination of factors that causes a disruption of neurons, such as environmental, biological, physiological, and genetic factors. The current review highlights some of the major pathological factors responsible for neuronal degradation, such as oxidative stress, cell death, and neuroinflammation. All these factors have been described in detail to enhance the understanding of their mechanisms and target them for disease management.     

Experimental research on ultrasonic softening in cold-rolled steel strips

The possibility of obtaining the effect of ultrasonic softening through laboratory experiments in hardened cold-rolled steel strips has been shown. The rolling of metal strips using ultrasonic activation is promising for increasing the deformation degree in comparison with conventional rolling as well as for the growth of the rolling rate, which supposes greater productivities. The text was submitted by the authors in English.     

Color variation of stained wood products in association to near infrared spectroscopy scans

The research aimed to test the hypothesis that near infrared reflectance (NIR) scans could detect surface characteristics associated with uneven coloring before staining red alder (Alnus rubra Bong), cherry (Prunus sp.), pine (Pinus sp.) and maple (Acer sp.) boards. NIR spectra were successfully correlated with average scanned area data of grain angle, density, pre- and post-staining 8-bit color values, and the difference in color induced by staining when combinations of either three, two or one of the tested wood species were used as input parameters. Difficulties were encountered when both cherry and maple were clustered together with the other two species in a generalized model, however, when both were excluded, the model produced very high R² values (over 0.98).     

Direct Visualization of Local Spin Transition Behaviors in Thin Molecular Films by Bimodal AFM

Thin films of the molecular spin‐crossover complex [Fe(HB(1,2,4‐triazol‐1‐yl)₃)₂] undergo spin transition above room temperature, which can be exploited in sensors, actuators, and information processing devices. Variable temperature viscoelastic mapping of the films by atomic force microscopy reveals a pronounced decrease of the elastic modulus when going from the low spin (5.2 ± 0.4 GPa) to the high spin (3.6 ± 0.2 GPa) state, which is also accompanied by increasing energy dissipation. This technique allows imaging, with high spatial resolution, of the formation of high spin puddles around film defects, which is ascribed to local strain relaxation. On the other hand, no clustering process due to cooperative phenomena was observed. This experimental approach sets the stage for the investigation of spin transition at the nanoscale, including phase nucleation and evolution as well as local strain effects.