Tanzanian manufacturing performance in comparative perspective

This paper presents a summary of new estimates of employment, nominal and real GDP in Tanzanian Manufacturing, 1961-1995. Time series of GDP and employment are placed in comparative perspective by linking them to benchmark level comparisons of GDP and employment for 1989. The first part of the paper (sections 2-4) deals with adjustments to nominal GDP, based on in depth analysis of the data of the 1989 industrial census, earlier census data and industrial surveys. Adjustments are made for undercoverage, omitted establishments, non-response and conceptual adjustments in the concept of value added. After adjustment, nominal manufacturing value added in establishments with 10 is substantially higher. The adjustments vary from 3% in 1978 to 127% in 1988. On average the upward adjustment is 52 per cent. New consistent time series of nominal GDP are presented both for aggregate 10+ manufacturing (1961-1995) and for six branches of manufacturing (1965-1995) The second part of the paper (section 5) focuses on the construction of a consistent long term index of industrial production, using weighted quantity relatives. The index is constructed for aggregate 10+ manufacturing and six branches. Corresponding indices of employment are derived, using the same adjustments for undercoverage, omitted establishments and non-response as in the case of GDP. The third section of the paper (section 6) presents a benchmark comparison of real value added relative to world manufacturing productivity leader, the USA. The benchmark uses average unit value ratio’s to convert value added for purposes of real comparisons. These unit value ratio’s are derived from the industrial census product listings in Tanzania and the USA, according to the industry of origin methodology of the international comparisons of output and productivity project (ICOP). Census listings contain quantity and value information, which are used to make product matches. In 1965 comparative labour productivity in aggregate manufacturing was around 9 per cent of the US level. It increased until 1973 to 11 per cent, followed by a long period of decline. By 1989 labour productivity stood at 3.7 of the US level.

Reversible electrowetting and trapping of charge: model and experiments

We derive a model for voltage-induced wetting, so-called electrowetting, from the principle of virtual displacement. Our model includes the possibility that charge is trapped in or on the wetted surface. Experimentally, we show reversible electrowetting for an aqueous droplet on an insulating layer of 10 micrometer thickness. The insulator is coated with a highly fluorinated layer impregnated with oil, providing a contact-angle hysteresis lower than 2 degrees. Analyzing the data with our model, we find that until a threshold voltage of 240 V, the induced charge remains in the liquid and is not trapped. For potentials beyond the threshold, the wetting force and the contact angle saturate, in line with the occurrence of trapping of charge in or on the insulating layer. The data are independent of the polarity of the applied electric field, and of the ion type and molarity. We suggest possible microscopic origins for charge trapping.Comment: 13 pages & 5 figures; the paper has been accepted for publication in Langmui

Detection of beet soil-borne virus and beet virus Q in sugarbeet in Greece

Sugar beet plants with typical rhizomania symptoms were collected from the five major cultivation zones of Greece. The presence of Beet necrotic yellow vein virus (BNYVV), the primary causal agent of the disease, was ascertained by DAS-ELISA in 38 out of 40 fields surveyed and the positive samples were subsequently examined for the presence of other soil-borne viruses which are frequently associated with rhizomania, using a multiplex RT-PCR assay targeting BNYVV, Beet soilborne virus (BSBV) and Beet virus Q (BVQ). The occurrence of BSBV and BVQ was confirmed in 9 and 23 rhizomania-infected fields, respectively. In contrast to surveys conducted in other countries, the presence of BVQ prevailed throughout Greece in dual infections with BNYVV, whereas BSBV was restricted to rhizomania-infected fields from only two sugarbeet cultivation areas. Nine of the samples tested were infected with all three viruses. BSBV was always found in triple infections. To our knowledge, this is the first report of BSBV and BVQ in Greece. The future assessment of the impact of each of these viruses on sugarbeet could prove significant for bleeding objectives in terms of achieving a more durable resistance to the rhizomania syndrome

Neuronal and glial changes in white and grey matter of Multiple Sclerosis patients

Geurts, J.J.G. [Promotor]Vries, H.E. de [Promotor]Dam, A.M.W. van [Copromotor]Drukarch, B. [Copromotor

Thermal behavior of Quantum Cellular Automaton wires

We investigate the effect of a finite temperature on the behavior of logic circuits based on the principle of Quantum Cellular Automata (QCA) and of ground state computation. In particular, we focus on the error probability for a wire of QCA cells that propagates a logic state. A numerical model and an analytical, more approximate, model are presented for the evaluation of the partition function of such a system and, consequently, of the desired probabilities. We compare the results of the two models, assessing the limits of validity of the analytical approach, and provide estimates for the maximum operating temperature.Comment: 15 pages, 7 figures, uses revte

Spin-dependent transport in metal/semiconductor tunnel junctions

This paper describes a model as well as experiments on spin-polarized tunnelling with the aid of optical spin orientation. This involves tunnel junctions between a magnetic material and gallium arsenide (GaAs), where the latter is optically excited with circularly polarized light in order to generate spin-polarized carriers. A transport model is presented that takes account of carrier capture in the semiconductor surface states, and describes the semiconductor surface in terms of a spin-dependent energy distribution function. The so-called surface spin-splitting can be calculated from the balance of the polarized electron and hole flow in the semiconductor subsurface region, the polarized tunnelling current across the tunnel barrier between the magnetic material and the semiconductor surface, and the spin relaxation at the semiconductor surface. Measurements are presented of the circular-polarization-dependent photocurrent (the so-called helicity asymmetry) in thin-film tunnel junctions of Co/Al2O3/GaAs. In the absence of a tunnel barrier, the helicity asymmetry is caused by magneto-optical effects (magnetic circular dichroism). In the case where a tunnel barrier is present, the data cannot be explained by magneto-optical effects alone; the deviations provide evidence that spin-polarized tunnelling due to optical spin orientation occurs. In Co/τ-MnAl/AlAs/GaAs junctions no deviations from the magneto-optical effects are observed, most probably due to the weak spin polarization of τ-MnAl along the tunnelling direction; the latter is corroborated by bandstructure calculations. Finally, the application of photoexcited GaAs for spin-polarized tunnelling in a scanning tunnelling microscope is discussed.

Educational strategies for architectural design management : the design of a new curriculum

This paper is about the design of a new curriculum on Architectural Design Management Systems. This curriculum is embedded in the Stan Ackermans lnstitute(SAI). The SAI is a school for continuing post graduate education on technological design. First some recent developments in the building industry will be discussed. These developments form the background tor the definition of a new specialist: the design manager. Within the context of this background the design tor a new curriculum is discussed