Rate processes on fractals: Theory, simulations, and experiments

Heterogeneous kinetics are shown to differ drastically from homogeneous kinetics. For the elementary reaction A + A → products we show that the diffusion-limited reaction rate is proportional to t − h[A] 2 or to [A] x , where h=1- d s /2, X=1+ 2/d s =(h-2)(h-1 ), and d s is the effective spectral dimension. We note that for d = d s =1, h =1/2 and X = 3 , for percolating clusters d s = 4/3, h = 1/3 and X = 5/2 , while for “dust” d s h > 1/2 and ∞ > X > 3. Scaling arguments, supercomputer simulations and experiments give a consistent picture. The interplay of energetic and geometric heterogeneity results in fractal-like kinetics and is relevant to excitation fusion experiments in porous membranes, films, and polymeric glasses. However, in isotopic mixed crystals, the geometric fractal nature (percolation clusters) dominates.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45150/1/10955_2005_Article_BF01010846.pd

Non-nociceptive roles of opioids in the CNS: opioids' effects on neurogenesis, learning, memory and affect.

Mortality due to opioid use has grown to the point where, for the first time in history, opioid-related deaths exceed those caused by car accidents in many states in the United States. Changes in the prescribing of opioids for pain and the illicit use of fentanyl (and derivatives) have contributed to the current epidemic. Less known is the impact of opioids on hippocampal neurogenesis, the functional manipulation of which may improve the deleterious effects of opioid use. We provide new insights into how the dysregulation of neurogenesis by opioids can modify learning and affect, mood and emotions, processes that have been well accepted to motivate addictive behaviours

Influence of salts on the coexistence curve and protein partitioning in nonionic aqueous two-phase micellar systems

Aqueous two-phase micellar systems (ATPMS) can be exploited in separation science for the extraction/purification of desired biomolecules. Prior to phase separation the surfactant solution reaches a cloud point temperature, which is influenced by the presence of electrolytes. In this work, we provide an investigation on the cloud point behavior of the nonionic surfactant C10E4 in the presence of NaCl, Li2SO4 and KI. We also investigated the salts' influence on a model protein partitioning. NaCl and Li2SO4 promoted a depression of the cloud point. The order of salts and the concentration that decreased the cloud point was: Li2SO4 0.5 M > NaCl 0.5 M ≈ Li2SO4 0.2 M. On the other hand, 0.5 M KI dislocated the curve to higher cloud point values. For our model protein, glucose-6-phosphate dehydrogenase (G6PD), partitioning experiments with 0.5 M NaCl or 0.2 M Li2SO4 at 13.85 °C showed similar results, with KG6PD ~ 0.46. The lowest partition coefficient was obtained in the presence of 0.5 M KI (KG6PD = 0.12), with major recovery of the enzyme in the micelle-dilute phase (%Recovery = 90%). Our results show that choosing the correct salt to add to ATPMS may be useful to attain the desired partitioning conditions at more extreme temperatures. Furthermore, this system can be effective to separate a target biomolecule from fermented broth contaminants.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)University of São Paulo School of Pharmaceutical Sciences Department of Biochemical and Pharmaceutical TechnologyUniversidade Estadual Paulista School of Pharmaceutical Sciences Department of Bioprocess and BiotechnologyUniversidade Estadual Paulista School of Pharmaceutical Sciences Department of Bioprocess and Biotechnolog

Scientific Automation Rises the Productivity of Production Facilities

Part 5: Standardization and Knowledge Management/DevelopmentsInternational audienceManufacturer of production facilities and operating companies are subjected to increase competitive constraints. To be successful production facilities should work more productively and more environmentally friendly. Furthermore the quality of the produced goods should rise. To reach this manufacturer of production facilities ask for more efficient and intelligent automation technology. In the project “ScAut – Scientific Automation” the Beckhoff Automation GmbH – a producer and vendor of open automation systems based on PC Control technology – meets these requirements with Scientific Automation. Scientific Automation is the integration of automation software with findings from engineering science, which go beyond the limits of conventional control. The basis for this is the continually increasing performance of PCs. The power of the PC Control philosophy offers sufficient capacity to integrate numerous advanced functions beyond standard control. Scientific Automation complements the conventional areas of control technology such as PLC, Motion Control and control technology, for instance, with precise and fast measurement technology and the associated engineering algorithms

Interdisciplinary system architecture for intelligent technical systems

Nowadays, mechanical engineering products change from mechatronic products, characterized by the close interplay of mechanics, electronics, control and software engineering to Intelligent Technical Systems (ITS). Intelligent Technical Systems are mechatronic systems with inherent partial intelligence. Mechanical engineering products will be a symbiosis of information technology and mechanical parts. This will entail a rising complexity of technical systems and its development. Therefore we introduce an approach to improve system architectures of mechanical engineering products to realize Intelligent Technical Systems. Our approach meets the following challenges: creating a domain-spanning description of the system with Model-Based Systems Engineering (MBSE); designing an interdisciplinary and modular system architecture by using the technological concept of Intelligent Technical Systems; identifying and implementing solution elements as reusable modules. Validated by a separator, our results clarify the benefits of MBSE and the technological concept of ITS to improve system architectures of mechanical engineering products to realize Intelligent Technical Systems