Synchronization Limits of Chaotic Circuits

Through system modeling with electronic circuits, two circuits were constructed that exhibit chaos over a wide ranges of initial conditions. The two circuits were one that modeled an algebraically simple “jerk” function and a resistor-inductor-diode (RLD) circuit where the diode was reverse-biased on the positive voltage cycle of the alternating current source. Using simulation data from other experiments, the waveforms, bifurcation plots, and phase space plots of the concrete circuit were verified. Identical circuits were then built containing variable components and coupled to their original, matching circuits. The variable components were used to observe a wide range of conditions to establish the desynchronization parameters and the range of synchronization

A Global Lottery and a Global Premium Bond

lottery, development finance, Millennium Development Goals

Role of Contacts in Capacitance Measurements of Solar Cells

The electronic properties of low cost, thin-film solar cells are complicated by the non-ideal nature of the semiconductor layers. Typically, the fundamental electronic properties of such materials are evaluated using current-voltage and capacitance-voltage measurements. However, in these devices, it is common for the back contact to be non-ohmic. We are exploring the impact of such a back contact on the outcome of standard capacitance-based characterization techniques. We compare computer models of capacitance response with measurements of simple model electronic circuits and of solar cell devices

Unions, Training, and Firm Performance

The present paper uses a combination of workplace and linked employee-workplace data from the 1998 Workplace Employee Relations Survey and the 2004 Workplace Employment Relations Survey to examine the impact of unions on training incidence, training intensity/coverage, and training duration. It also examines the impact of unions and training on earnings and a measure of establishment labour productivity. In addition, the implications of training for the firm’s bottom line are evaluated. Union effects on training emerge as fairly subtle, and are more positive when using individual rather than plant-wide training data. A positive impact of training on earnings is detected in both the individual and plant-wide wage data, albeit only for the earlier survey. Consistent with other recent findings, the effects of union recognition on earnings are today rather muted, while union-training interaction effects vary greatly. Instrumenting training provides positive results for the labour productivity outcome and, in the case of the earlier survey, for the financial performance indicator as well. However, some negative effects of unions are now also detected.earnings, training duration, training intensity/coverage, training Incidence, employer-provided training, bargaining structure, union recognition, financial performance, labour productivity

Unions, training and firm performance

"This paper uses data from two British workplace surveys to examine the impact of unions on several training measures. It also evaluates the impact of unions and training on earnings and two measures of firm performance. Union effects on training emerge as fairly subtle, and are more positive when using individual rather than plant-wide training data. A positive impact of training on earnings is detected in individual and plant-wide wage data, albeit for one of the datasets. Union influence on wages is also muted and union-training interaction effects vary greatly. However, instrumenting training provides positive results for labour productivity and, again for one survey, for financial performance as well." (Author's abstract, IAB-Doku) ((en)) Additional Information Kurzfassung (deutsch) Executive summary (English)betriebliche Weiterbildung, Gewerkschaftspolitik - Auswirkungen, Lohnhöhe, Unternehmenserfolg, Großbritannien

Ray methods for free boundary problems

We discuss the use of the WKB ansatz in a variety of parabolic problems involving a small parameter. We analyse the Stefan problem for small latent heat, the Black–Scholes problem for an American put option, and some nonlinear diffusion equations, in each case constructing an asymptotic solution by the use of ray methods

Stable isotope probing: Technical considerations when resolving ¹⁵N-labeled RNA in gradients

RNA based stable isotope probing (SIP) facilitates the detection and identification of active members of microbial populations that are involved in the assimilation of an isotopically labeled compound. ¹⁵N-RNA-SIP is a new method that has been discussed in recent literature but has not yet been tested. Herein, we define the limitations to using ¹⁵N-labeled substrates for SIP and propose modifications to compensate for some of these shortcomings. We have used ¹⁵N-RNA-SIP as a tool for analysing mixed bacterial populations that use nitrogen substrates. After incubating mixed microbial communities with ¹⁵N-ammonium chloride or ¹⁵N₂ we assessed the fractionation resolution of ¹⁵N-RNA by isopycnic centrifugation in caesium trifluoroacetate (CsTFA) gradients. We found that the more isotopic label incorporated, the further the buoyant density (BD) separation between ¹⁵N- and ¹⁴N-RNA, however it was not possible to resolve the labeled from unlabeled RNA definitively through gradient fractionation. Terminal-restriction fragment length polymorphism (T-RFLP) analysis of the extracted RNA and fluorescent in situ hybridisation (FISH) analysis of the enrichment cultures provided some insight into the organisms involved in nitrogen fixation. This approach is not without its limitations and will require further developments to assess its applicability to other nitrogen-fixing environments

By How Much Does Conflict Reduce Financial Development?

Financial development, conflict, financial regulation