Kooperativer Bibliotheksverbund

Berlin Brandenburg

and
and

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Article  (36)
  • Engineering
Type of Medium
  • Article  (36)
Language
Year
  • 1
    Language: English
    In: Environmental Technology, 02 September 2017, Vol.38(17), pp.2130-2142
    Description: Raw municipal wastewater from a full-scale wastewater treatment plant was physicochemically pretreated in a large pilot-scale system comprising coagulation, flocculation, microsieve and microfiltration operated in various configurations. The produced microsieve filtrates and microfiltration...
    Keywords: Forward Osmosis ; Non-Biological Treatment ; Microfiltration ; Microsieve ; Physicochemical Pretreatment ; Wastewater Treatment ; Engineering
    ISSN: 0959-3330
    E-ISSN: 1479-487X
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Language: English
    In: Environmental Technology, 01 February 2018, Vol.39(3), pp.264-276
    Description: Municipal wastewater treatment commonly involves mechanical, biological and chemical treatment steps to protect humans and the environment from adverse effects. Membrane technology has gained increasing attention as an alternative to conventional...
    Keywords: Biogas Production ; Forward Osmosis ; Membrane Filtration ; Seawater ; Wastewater Treatment ; Engineering
    ISSN: 0959-3330
    E-ISSN: 1479-487X
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Language: English
    In: Environmental Technology, 17 September 2017, Vol.38(18), pp.2295-2304
    Description: Municipal wastewater treatment involves mechanical, biological and chemical treatment steps for protecting the environment from adverse effects. The biological treatment step consumes the most energy and can create greenhouse gases. This study investigates municipal wastewater treatment without...
    Keywords: Biomimetic Membrane ; Forward Osmosis ; Membrane Fouling ; Microfiltration ; Microsieving ; Wastewater Treatment ; Engineering
    ISSN: 0959-3330
    E-ISSN: 1479-487X
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Language: English
    In: Advances in Water Resources, 2011, Vol.34(2), pp.314-325
    Description: ► Stochastic reconstruction with a combination of multi-point statistics. ► Good rendition of connectivity with Minkowski functions and Chord length distributions. ► Transport behavior compares well between reference media and reconstructed media. ► Pressure field tends to bridge local discontinuities within highly conductive regions. Flow and transport in porous media is determined by its structure. Beside spatial correlation, especially the connectivity of heterogeneous conductivities is acknowledged to be a key factor. This has been demonstrated for well defined random fields having different topological properties. Yet, it remains an open question which morphological measures carry sufficient information to actually predict flow and transport in porous media. We analyze flow and transport in classical, two-dimensional random fields showing different topology and we determine a selection of structural characteristics including classical two-point statistics, chord-length distribution and Minkowski functions (four-point statistics) including the Euler number as a topological measure. Using the approach of simulated annealing for global optimization we generate analog random fields that are forced to reproduce one or several of theses structural characteristics. Finally we evaluate in how far the generated analogons reproduce the original flow and transport behavior as well as some more elaborate structural characteristics including percolation probabilities and the pair connectivity function. The results confirm that two-point statistics is insufficient to capture functional properties since it is not sensitive to connectivity. In contrast, the combination of Minkowski functions and chord length distributions carries sufficient information to reproduce the breakthrough curve of a conservative solute. Hence, global topology provided by the Euler number together with local clustering provided by the chord length distribution seems to be a powerful condensation of structural complexity with respect to functional properties.
    Keywords: Simulated Annealing ; Solute Transport ; Minkowski Functionals ; Chord Length Distribution ; Local Percolation Probability ; Pair Connectivity Function ; Engineering
    ISSN: 0309-1708
    E-ISSN: 1872-9657
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Language: English
    In: Advances in Water Resources, August 2012, Vol.44, pp.101-112
    Description: ► New averaging approach that conserves hydraulic non-equilibrium during rapid infiltration of water. ► New indicators to describe hydraulic non-equilibrium quantitatively. ► Direct link between front morphology and hydraulic non-equilibrium. ► Insights into how structural connectivity affects hydraulic non-equilibrium. ► Shortcomings of an upscaled Richards model extended by hydraulic non-equilibrium. Water infiltration into heterogeneous, structured soil leads to hydraulic non-equilibrium across the infiltration front. That is, the water content and pressure head are not in equilibrium according to some static water retention curve. The water content increases more rapidly in more conductive regions followed by a slow relaxation towards an equilibrium state behind the front. An extreme case is preferential infiltration into macropores. Since flow paths adapt to the structural heterogeneity of the porous medium, there is a direct link between structure and non-equilibrium. The aim of our study is to develop an upscaled description of water dynamics which conserves the macroscopic effects of non-equilibrium and which can be directly linked to structural properties of the material. A critical question is how to define averaged state variables at the larger scale. We propose a novel approach based on flux-weighted averaging of pressure head, and compare its performance to alternative methods for averaging. Further, we suggest some meaningful indicators of hydraulic non-equilibrium that can be related to morphological characteristics of infiltration fronts in quantitative terms. These methods provide a sound basis to assess the impact of structural connectivity on hydraulic non-equilibrium. We demonstrate our approach using numerical case studies for infiltration into two-dimensional heterogeneous media using three different structure models with distinct differences in connectivity. Our results indicate that an increased isotropic, short-range connectivity reduces non-equilibrium, whereas anisotropic structures that are elongated in the direction of flow enforce it. We observe a good agreement between front morphology and effective hydraulic non-equilibrium. A detailed comparison of averaged state variables with results from an upscaled model that includes hydraulic non-equilibrium outlines potential improvements in the description of non-equilibrium dynamics including preferential flow in simplified, upscaled models based on Richards equation.
    Keywords: Transient Flow ; Upscaling ; Pressure Head Averaging ; Hydraulic Non-Equilibrium ; Preferential Flow ; Connectivity ; Engineering
    ISSN: 0309-1708
    E-ISSN: 1872-9657
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Language: English
    In: Information and Computation, 15 March 2002, Vol.173(2), pp.123-131
    Description: Consider the problem of computing a function given only an oracle for its graph. For this problem, we present optimal trade-offs between serial and parallel queries. In particular, we give a function for which parallel access to its own graph is exponentially more expensive than sequential access. © 2002 Elsevier Science (USA).
    Keywords: Engineering ; Computer Science
    ISSN: 0890-5401
    E-ISSN: 1090-2651
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Language: English
    In: PLoS ONE, 2010, Vol.5(12), p.e14213
    Description: Due to the use of organophosphates (OP) as pesticides and the availability of OP-type nerve agents, an effective medical treatment for OP poisonings is still a challenging problem. The acute toxicity of an OP poisoning is mainly due to the inhibition of acetylcholinesterase (AChE) in the peripheral and central nervous systems (CNS). This results in an increase in the synaptic concentration of the neurotransmitter acetylcholine, overstimulation of cholinergic receptors and disorder of numerous body functions up to death. The standard treatment of OP poisoning includes a combination of a muscarinic antagonist and an AChE reactivator (oxime). However, these oximes can not cross the blood-brain barrier (BBB) sufficiently. Therefore, new strategies are needed to transport oximes over the BBB. ; In this study, we combined different oximes (obidoxime dichloride and two different HI 6 salts, HI 6 dichloride monohydrate and HI 6 dimethanesulfonate) with human serum albumin nanoparticles and could show an oxime transport over an BBB model. In general, the nanoparticulate transported oximes achieved a better reactivation of OP-inhibited AChE than free oximes. ; With these nanoparticles, for the first time, a tool exists that could enable a transport of oximes over the BBB. This is very important for survival after severe OP intoxication. Therefore, these nanoparticulate formulations are promising formulations for the treatment of the peripheral and the CNS after OP poisoning.
    Keywords: Research Article ; Biotechnology ; Neurological Disorders ; Pharmacology -- Drug Development
    E-ISSN: 1932-6203
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Language: English
    In: Journal of Contaminant Hydrology, December 2016, Vol.195, pp.31-39
    Description: Engineered nanoparticles released into soils may be coated with humic substances, potentially modifying their surface properties. Due to their amphiphilic nature, humic coating is expected to affect interaction of nanoparticle at the air-water interface. In this study, we explored the roles of the air-water interface and solid-water interface as potential sites for nanoparticle attachment and the importance of hydrophobic interactions for nanoparticle attachment at the air-water interface. By exposing Ag nanoparticles to soil solution extracted from the upper soil horizon of a floodplain soil, the mobility of the resulting “soil-aged” Ag nanoparticles was investigated and compared with the mobility of citrate-coated Ag nanoparticles as investigated in an earlier study. The mobility was determined as a function of hydrologic conditions and solution chemistry using column breakthrough curves and numerical modeling. Specifically, we compared the mobility of both types of nanoparticles for different unsaturated flow conditions and for pH = 5 and pH = 9. The soil-aged Ag NP were less mobile at pH = 5 than at pH = 9 due to lower electrostatic repulsion at pH = 5 for both types of interfaces. Moreover, the physical flow field at different water contents modified the impact of chemical forces at the solid-water interface. An extended Derjaguin-Landau-Verwey-Overbeek (eDLVO) model did not provide satisfactory explanation of the observed transport phenomena unlike for the citrate-coated case. For instance, the eDLVO model assuming sphere-plate geometry predicts a high energy barrier (〉 90 ) for the solid-water interface, indicating that nanoparticle attachment is less likely. Furthermore, retardation through reversible sorption at the air-water interface was probably less relevant for soil-aged nanoparticles than for citrate-coated nanoparticles. An additional cation bridging mechanism and straining within the flow field may have enhanced nanoparticle retention at the solid-water interface. The results indicate that the mobility of engineered Ag nanoparticles is sensitive to solution chemistry, especially pH and the concentration of multivalent cations, and to the unsaturated flow conditions influencing particle interaction at biogeochemical interfaces.
    Keywords: Unsaturated Transport ; Water Dynamics ; Cation Bridging ; Amphiphilic ; Edlvo ; Engineering ; Environmental Sciences ; Geography
    ISSN: 0169-7722
    E-ISSN: 1873-6009
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Language: English
    In: IEEE transactions on medical imaging, June 2009, Vol.28(6), pp.951-67
    Description: Electromagnetic tracking is currently one of the most promising means of localizing flexible endoscopic instruments such as flexible laparoscopic ultrasound transducers. However, electromagnetic tracking is also susceptible to interference from ferromagnetic material, which distorts the magnetic field and leads to tracking errors. This paper presents new methods for real-time online detection and reduction of dynamic electromagnetic tracking errors when localizing a flexible laparoscopic ultrasound transducer. We use a hybrid tracking setup to combine optical tracking of the transducer shaft and electromagnetic tracking of the flexible transducer tip. A novel approach of modeling the poses of the transducer tip in relation to the transducer shaft allows us to reliably detect and significantly reduce electromagnetic tracking errors. For detecting errors of more than 5 mm, we achieved a sensitivity and specificity of 91% and 93%, respectively. Initial 3-D rms error of 6.91 mm were reduced to 3.15 mm.
    Keywords: Electromagnetic Fields ; Laparoscopy -- Methods ; Surgery, Computer-Assisted -- Instrumentation ; Ultrasonography -- Instrumentation
    ISSN: 02780062
    E-ISSN: 1558-254X
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Language: English
    In: AEUE - International Journal of Electronics and Communications, 2006, Vol.60(1), pp.13-19
    Description: A federation approach for security in future distributed service delivery platforms for mobile users offers some key advantages over an integrated solution relying on a common choice of a standardized authentication technology. By agreeing on an exchange protocol for security assertions rather than on the detailed security mechanisms, Service Aggregators and Access Network Operators will be able to federate their customer offerings flexibly and jointly offer services. The consumer will find formerly separate offerings combined, and Service Operators will enjoy open interfaces towards the network's service delivery platform. Through the use of Security Assertion Markup Language (SAML), standardized assertion statements can be made not only for the user's identity, but also on attributes and authorizations associated with it. This will allow a seamless personalized service experience offering single sign-on across separate operational domains. An example from automobile telematics is used to illustrate the concepts.
    Keywords: Security ; Assertion ; Single Sign-on ; Saml ; Open Service Provisioning ; Telematics ; Automotive ; Engineering
    ISSN: 1434-8411
    E-ISSN: 1618-0399
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. Further information can be found on the KOBV privacy pages