Cu,Zn,Al layered double hydroxides as precursors for copper catalysts in methanol steam reforming – pH-controlled synthesis by microemulsion technique

By co-precipitation inside microemulsion droplets a Cu-based catalyst precursor was prepared with a Cu:Zn:Al ratio of 50:17:33. A pH-controlled synthesis was applied by simultaneous dosing of metal solution and precipitation agent. This technique allows for continuous operation of the synthesis and enables easy and feasible up-scaling. For comparison conventional co-precipitation was applied with the same composition. Both techniques resulted in phase pure layered double hydroxide precursors and finally (after calcination and reduction) in small Cu nanoparticles (8 nm) and ZnAl2O4. By applying the microemulsion technique smaller Cu/ZnAl2O4 aggregates with less embedded Cu particles were obtained. The microemulsion product exhibited a higher BET and specific Cu surface area and also a higher absolute catalytic activity in methanol steam reforming. However, the Cu surface area-normalized, intrinsic activity was lower. This observation was related to differences in interactions of Cu metal and oxide phase

Tax competition, location, and horizontal foreign direct investment

We develop a model of capital tax/subsidy competition in which imperfectly competitive firms choose both the number and the location of the plants they operate. The endogenous presence of horizontal multinationals is shown to attenuate the “race to the bottom” and yields some results that are opposite to traditional findings in the tax competition literature. First, in the presence of horizontal multinationals, increasing subsidies decrease firms' profits by exacerbating price competition due to more firms ‘going multinational’. Second, instead of being always subsidized, capital may actually be taxed in equilibrium. Third, taxes/subsidies become strategically independent policy instruments, instead of being strategic complements. Last, there may exist multiple equilibria with either low or high subsidies.capital tax competition; international trade; horizontal multinationals; foreign direct investment; imperfect competition

Transportation, freight rates, and economic geography

We investigate the role of the transport sector in structuring the location of economic activity within two-region economic geography models of the footloose capital and core-periphery types. In our setting, competitive carriers offer transport services for shipping manufactured goods across regions and freight rates are determined endogenously to clear transport markets. Each carrier commits to the maximum capacity for a round-trip and thus faces a simple logistic problem: there are costs associated with 'returning empty', and those costs increase the freight rates charged to manufacturing firms. Since demand for transport services depends on the spatial distribution of economic activity, agglomeration in one region raises freight rates to serve foreign markets, thus generating an additional dispersion force. We show that a more equal equilibrium distribution of firms prevails when freight rates are endogenously determined than when they are exogenous and that multiple equilibria (including partial agglomeration) usually coexist.transport sector, freight rates, economic geography, trade.

Solid-state combustion synthesis of ceramics and alloys in reduced gravity

Possible microgravity effects are explored in the combustion synthesis of ceramics and alloys from their constituent elements. Molten intermediates are typically present during the combustion process, thereby offering the chance for natural convection to take place. Numerical simulations suggest that the combustion front in concert with gravity may act as a partial zone-refinement mechanism which is attempting to sweep out porosity in the sample. Contrary to suggestions by dimensional analysis, no effects on the combustion rate are seen. An analytical model of the combustion velocity as a function of the gravitational field and the spreading rate of molten material gives the correct order of magnitude of the gravity effect as measured by centrifuge experiments

Transfer Pricing Rules, OECD Guidelines, and Market Distortions

We study the impact of transfer pricing rules on sales prices, firms’ organizational structure, and consumers’ utility within a two-country monopolistic competition model featuring source-based profit taxes that differ across countries. Firms can either become multinationals, i.e., they serve the foreign market through a fully controlled affiliate; or they can become exporters, i.e., they serve the foreign market by contracting with an independent distributor. Compared to the benchmark cases, where tax authorities are either unable to audit firms or where they are able to audit them perfectly, the use of the OECD’s Comparable Uncontrolled Price (CUP) or Cost-Plus (CP) rule distorts firms’ output and pricing decisions. The reason is that the comparable arm’s length transactions between exporters and distributors, which serve as benchmarks, are not efficient. We show that implementing the CUP or CP rules is detrimental to consumers in the low tax country, yet benefits consumers in the high tax country.Transfer pricing, OECD guidelines, multinationals and exporters, organizational choice, arm's length principle

Unions in Germany: Searching to regain the initiative

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Designing SANDRA: An autonomous tour guide robot for the University of Technology, Sydney

This paper describes how a team of final year mechatronic engineering students developed an autonomous robotic system intended to act as a tour guide during events such as University open days and explores the opportunities this project presented to extend their knowledge and skills. The specifications of the project required the system to localise and navigate autonomously within a known environment while avoiding collisions with any people or obstacles not included in the prior area map. In addition to these requirements, the system needed to locate humans as potential clients, approach and greet them, offer directions and if required take the guest on a guided tour of the university. While taking the subject Advanced Robotics the students were able to develop a functional first prototype of the system and carry out initial tests. Following the completion of the subject a small number of the students opted to continue working on the project developing a second prototype using the knowledge gained and further enhancing their learning experiences. While this project mainly involved integrating existing well known algorithms, software and hardware, it provided an excellent opportunity to enhance the mechatronic engineering skills of the students involved

On the structural relations of malachite. II. The brochantite MDO polytypes

The structural relation between malachite and the brochantite MDO (maximum degree of order) polytypes is discussed. It is demonstrated that the same building blocks which form the basis of brochantite polytypism also occur in malachite. The different arrangements of these building blocks in the two mineral structures are rationalized as a result of the different coordination geometries required by the respective non-metal atoms acting as linkers. The compound stoichiometries are discussed in light of a common structured formula scheme, in which pairs of H atoms can play a similar role as single non-H atoms. An overview on the occurrence of malachite-like building blocks in several other crystal structures is given