International Capital Mobility in Developing Countries vs. Industrial Countries: What do Saving-Investment Correlations Tell Us?

The finding of Feldstein and Horioka (1980) that countriesf investment rates are highly correlated with their national saving rates has by now been confirmed by many subsequent studies, even though their inference that international capital mobility nust be low has not been as widely accepted. This paper examines the statistical relationship between national saving and investment in a sample that includes not only 14 industrialized countries, but also 50 developing countries. The paper addresses some of the econometric critiques that have been aimed at the Feldstein-Horioka work. Contrary to what one would expect from consideration of capital mobility, the coefficient appears higher for industrialized countries than for developing countries, and higher after 1973 than before. Our interpretation of the saving-investment evidence is that the hypothesis of a high degree of substitutability for claims on physical capital located in different countries is not supported by the data. International substitutability for financial capital may be nigh, but this is a separate condition (which is properly tested by looking directly at rates of return). High international substitutability for bonds would imply high international substitutability for physical capital if capital were perfectly substitutable for bonds within each country, but there is no reason for this to hold, any more than there is for all goods to be perfect substitutes.

Studies towards the synthesis of hexacyclinic acid

Hexacyclinic acid is a polyketide isolated from Streptomyces cellulosae bacteria in 2001. It possesses a complex and challenging hexacyclic ring system with various oxygen functionalities throughout. Hexacyclinic acid has also demonstrated some cytotoxic activity, making it an attractive target for total synthesis. However to date no full synthesis has been reported. Previously within the group significant progress had been made towards the synthesis of hexacyclinic acid, with construction of the ABC 5/6/5 tricyclic core being achieved via a diastereoselective Michael addition and Snider radical cyclisation. The synthesis ran into difficulties however when hydrolysis of the ethyl ester could not be accomplished and removal of the superfluous carboxylic acid moiety could not be realised. The approach within the group for the formation of the ABC tricycle was to continue the current strategy, joining the A and C-rings via the diastereoselective Michael reaction, and the closure of the 6-membered B-ring by Snider radical cyclisation. Progress was made using the tert-butyl and 2,2,2-trimethylsilylethyl ester analogues in an attempt to improve diastereoselectivities Progress was also made on the synthesis of the CDEF tricyclic system, utilising (R)-isopropylcyclopentenone as a C-ring model system. The DEF framework was attached to the model by a Michael addition, with further functionalisation setting up the necessary functionalities for cyclisation. Conditions were attempted to effect a challenging aldol condensation to form the 9-membered ring, however all attempts effect this transformation were fruitless. It was discovered that 2,2,2-trifluoromethylacetophenone can act as a replacement for benzaldehyde in the synthesis of protected syn-1,3-diols from homoallylic alcohols, with comparable yields and easier purification. Finally, an investigation was also made into the use of a bispidine ligand as a replacement for (−)-sparteine in Crimmins asymmetric aldol reactions, with the bispidine shown to give superior yields and diastereoselectivity when compared to TMEDA

Biodiversity condition assessment for grazing lands

Using the ABCD Framework as a aurrogate for biodiversity condition

Manufacturing Assembly Time Estimation Using Structural Complexity Metric Trained Artificial Neural Networks

Assembly time estimation is traditionally a time-intensive manual process that requires detailed geometric and process information, which is often subjective and qualitative in nature. As a result, assembly time estimation is rarely applied during early design iterations. In this paper, the authors explore the possibility of automating the assembly time estimation process while reducing the level of design detail required. In this approach, they train artificial neural networks (ANNs) to estimate the assembly times of vehicle subassemblies using either assembly connectivity or liaison graph properties, respectively, as input data. The effectiveness of estimation is evaluated based on the distribution of estimates provided by a population of ANNs trained on the same input data using varying initial conditions. Results indicate that this method can provide time estimates of an assembly process with ±15% error while relying exclusively on the geometric part information rather than process instructions

Increasing renewable penetration on islanded networks through active network management : a case study from Shetland

The drive to reduce reliance on fossil fuel generation in meeting power system demand is encouraging network operators to develop novel methods of making greater use of available network capacity whilst maintaining stability and security. Challenges relating to network stability are particularly acute on islanded networks. The Northern Isles New Energy Solutions (NINES) project is implementing novel techniques for managing the power network on the Shetland Islands in the UK. Active Network Management is used to monitor and control the network and new wind generation in real time, and flexible demand is scheduled to minimise the use of conventional generation by reducing wind curtailment and minimising system losses. The flexible demand devices deployed also have the ability to respond to frequency therefore supporting system stability. This paper presents the development of two novel modelling techniques used in the design and deployment of NINES – an ‘envelope of stability wind generation’ and the use of Dynamic Optimal Power Flow to schedule flexible demand. A case study is presented which shows that an ANM scheme managing flexible demand has the potential to increase wind capacity connected on Shetland from the existing 4MW to 16.1MW. The management of domestic demand flexibility is shown to contribute up to 6.5GWh towards the reduction in conventional generation or up to 16.6GWh if domestic demand provides frequency response

Interrogating the Light-Induced Charging Mechanism in Li-Ion Batteries Using Operando Optical Microscopy

Photobatteries, batteries with a light-sensitive electrode, have recently been proposed as a way of simultaneously capturing and storing solar energy in a single device. Despite reports of photocharging with multiple different electrode materials, the overall mechanism of operation remains poorly understood. Here, we use operando optical reflection microscopy to investigate light-induced charging in LixV2O5 electrodes. We image the electrode, at the single-particle level, under three conditions: (a) with a closed circuit and light but no electronic power source (photocharging), (b) during galvanostatic cycling with light (photoenhanced), and (c) with heat but no light (thermal). We demonstrate that light can indeed drive lithiation changes in LixV2O5 while maintaining charge neutrality, possibly via a combination of faradaic and nonfaradaic effects taking place in individual particles. Our results provide an addition to the photobattery mechanistic model highlighting that both intercalation-based charging and lithium concentration polarization effects contribute to the increased photocharging capacity

Photo-Rechargeable Zinc-Ion Capacitor Using 2D Graphitic Carbon Nitride.

Off-grid energy storage devices are becoming increasingly important to power distributed applications, such as the Internet of things, and smart city ubiquitous sensor systems. To date, this has been achieved by combining an energy storage device, e.g., a battery or capacitor with an energy harvester, e.g., a solar cell. However, this approach inherently increases the device footprint and the output voltages of energy harvesters often do not match those required by energy storage device. Here we propose the first photo-rechargeable zinc-ion capacitors, where graphitic carbon nitride acts simultaneously as the capacitor electrode and light harvesting material. This approach allows light to be used to recharge the capacitor directly and they can be operated in a continuous light powered mode. These capacitors show a photo-rechargeable specific capacitance of ∼11377 mF g-1, a photo-charging voltage response of ∼850 mV, and a cyclability with ∼90% capacitance retention over 1000 cycles.Newton International Fellowship-Royal Society (UK) grant NIF∖R1∖181656 ERC MIGHTY - 866005 EPSRC Graphene CDT EP/L016087/1 Marie Skłodowska-Curie Actions MSCA-IF 79664

Capital Mobility and Exchange Market Intervention in Developing Countries

This paper develops a new technique for measuring changes in the degree of capital mobility confronting a developing country that has restrictions on capital flows and official ceilings on domestic interest rates. Because such official controls rule out the use of traditional interest rate parity conditions to measure changes in the degree of capital mobility, the analysis first examines an intertemporal model of an open economy. This model describes the linkages between the cost of undertaking disguised capital flows, the current account, capital controls, domestic and external financial market conditions, and the authorities' foreign exchange market interventions. The model suggests a means of measuring changes in the cost of undertaking disguised capital flows, based on the past history of differentials between external interest rates (adjusted for exchange rate changes) and domestic ceiling interest rates, provided that the authorities' foreign exchange market activities are incorporated into the analysis. Parameter estimates for Korea, Mexico, and the Philippines indicate that the real cost of undertaking disguised capital flows declined on average by nearly 70 percent between the early 1970s and the late 1980s.