Uncertainty in the learning rates of energy technologies: An experiment in a global multi-regional energy system model

The diffusion of promising energy technologies in the market depends on their future energy production–cost development. When analyzing these technologies in an integrated assessment model using endogenous technological learning, the uncertainty in the assumed learning rates (LRs) plays a crucial role in the production–cost development and model outcomes. This study examines the uncertainty in LRs of some energy technologies under endogenous global learning implementation and presents a floor-cost modeling procedure to systematically regulate the uncertainty in LRs of energy technologies. The article narrates the difficulties of data assimilation, as compatible with mixed integer programming segmentations, and comprehensively presents the causes of uncertainty in LRs. This work is executed using a multi-regional and long-horizon energy system model based on “TIMES” framework. All regions receive an economic advantage to learn in a common domain, and resource-ample regions obtain a marginal advantage for better exploitation of the learning technologies, due to a lower supply-side fuel-cost development. The lowest learning investment associated with the maximum LR mobilizes more deployment of the learning technologies. The uncertainty in LRs has an impact on the diffusion of energy technologies tested, and therefore this study scrutinizes the role of policy support for some of the technologies investigated.     

Balancing nutrient inputs to Lake Kivu

The primary production in meromictic Lake Kivu is sustained by external nutrient inputs and by internal loading due to upwelling caused by sub-aquatic sources. We present here the results of external loading of phosphorus (P), nitrogen (N) and silica (Si) by rivers and atmospheric deposition measured from 2006 to 2008. These external inputs are compared to internal loading. The input of soluble-reactive P (SRP), supplied in equal parts from rivers and atmospheric deposition, adds up to 230 t P yr^− 1, 20 times less than total P load. Ammonium (mainly via rainwater) and nitrate (mainly via rivers) are primary sources of the dissolved N load (5400 t N yr^− 1), with both species contributing ∼ 50%. Dissolved Si input (40,000 t Si yr^− 1) is unique in that only ∼ 60% enters by rivers, while the remaining ∼ 40% comes from sub-aquatic sources and atmospheric deposition is negligible. Based on the molar nutrient ratios, we identify P as the limiting factor for algae production. Despite the strong anthropogenic impact on the catchment and the high particle erosion (74 t km^− 2 yr^− 1), the area-specific nutrient mobilization is rather low. The external nutrient input is therefore not the cause for the reported increase of methane production in the last decades. External loading to the epilimnion plays a lesser role for all three nutrients (∼ 10% for SRP, ∼ 25% for dissolved N and ∼ 45% for dissolved Si), as compared to the lake-internal loading by upwelling (90%, 75% and 55%, respectively). Lake Kivu, therefore, is similar to other East African large lakes in that the internal loading exceeds the external loading. Despite the substantial uncertainty of the load estimates of up to 50%, we can conclude that the observed nutrient input is consistent with the primary production of 260 g C m^− 2 yr^− 1 recently measured by Sarmento et al. (2006) and also consistent with the lake-internal fluxes established by Pasche et al. (in press).     

Technologische Eigenschaften von Stählen im europäischen Vergleich

The object of this contribution is the comparison of the statistical characteristics of yield strength, ultimate strength and ductility of Austrian and Czech steels. In an independent manner, basic material characteristics of steel products of both Austrian and Czech producers were statistically evaluated at the Vienna and the Brno Universities to guarantee the maximum objectivity of the results obtained and of the conclusions drawn from them. The influence of material characteristics on the reliability of a steel structure designed according to the design standards is reasoned.     

ATM‐based wireless broadband access in the local loop

Broadband networks using wireless transmission techniques are a quick and flexible means of implementing subscriber access. Unoccupied frequency bands with sufficient bandwidth to allow the transmission of digital signals at very high bit rates are found only in the microwave bands. Because the path loss is fairly high at these frequencies, the diameter of radio cells is limited to a maximum of a few kilometres. This results in a microcellular system, which is best implemented in the form of a point‐to‐multipoint system, where one radio‐base station serves all subscribers registered in that radio cell. An interactive, broadband, ATM‐based radio local loop has undergone successful trials in Munich. Copyright © 2001 John Wiley & Sons, Ltd.     

On the possibilities and limitations of rational protein design to expand the specificity of restriction enzymes: a case study employing EcoRV as the target

The restriction endonuclease EcoRV has been characterized instructural and functional terms in great detail. Based on thisdetailed information we employed a structure-guided approachto engineer variants of EcoRV that should be able to discriminatebetween differently flanked EcoRV recognition sites. In crystalstructures of EcoRV complexed with d(CGGGATATCCC)₂ and d(AAAGATATCTT)₂,Lys104 and Ala181 closely approach the two base pairs flankingthe GATATC recognition site and thus were proposed to be a reasonablestarting point for the rational extension of site specificityin EcoRV [Horton,N.C. and Perona,J.J. (1998) J. Biol. Chem.,273, 21721–21729]. To test this proposal, several single(K104R, A181E, A181K) and double mutants of EcoRV (K104R/A181E,K104R/A181K) were generated. A detailed characterization ofall variants examined shows that only the substitution of Ala181by Glu leads to a considerably altered selectivity with botholigodeoxynucleotide and macromolecular DNA substrates, butnot the predicted one, as these variants prefer cleavage ofa TA flanked site over all other sites, under all conditionstested. The substitution of Lys104 by Arg, in contrast, whichappeared to be very promising on the basis of the crystallographicanalysis, does not lead to variants which differ very much fromthe EcoRV wild-type enzyme with respect to the flanking sequencepreferences. The K104R/A181E and K104R/A181K double mutantsshow nearly the same preferences as the A181E and A181K singlemutants. We conclude that even for the very well characterizedrestriction enzyme EcoRV, properties that determine specificityand selectivity are difficult to model on the basis of the availablestructural information.     

The technology assessment and forecast program of the United States patent and trademark office

Often overlooked is the wealth of information in patents that makes patents useful to public policy making agencies and corporate management, among others. The source of this information is the bibliographic and classification data associated with each patent. much of which is required by law and hence is extremely accurate. These data serve to fingerprint the increment of technological activity disclosed in a patent. Possible ways of using the data include: — identification of emerging technologies — Monotoring foreign activity — identification of “actors” in the technology — tracking applications and impacts of a technologyThe objective of the technology assessment and forecast program of the United States Patent and Trademark Office is to stimulate the use of the patent file of the Office. The Office of Technology Assessment and Forecast (OTAF), which administers the program has assembled a master data base covering all U.S. patents. It periodically updates this base and adds new data items to it.     

Design and implementation of a planar helix for traveling wave tubes based on package compatible ball grid array technology

In this article, a novel planar helix traveling wave tube structure is proposed for S/X-band amplification. The planar helix structure is developed between two printed circuit boards such that they utilize solder balls to connect each other. This technique which comes originally from microelecronic packaging technology called ball grid array. To evaluate the performance of the proposed structure, one period of its geometry is modeled and the cold test parameters are calculated in CST microwave studio^TM. The fundamental space harmonic mode overlaps well with the beam-line in the dispersion diagram for both bands. The in- and out-coupler ports are also designed in the form of coplanar waveguides having good matching. For 150 periods of the planar helix, the 15 dB gain is obtained in particle-in-cell simulations for both bands. Finally, the fabrication process is implemented and the cold test is done.

     

Herausforderungen und Chancen für die Arbeit der Akademie für Ethik in der Medizin angesichts der COVID-19-Pandemie

Ethik in der Medizin -