The Relationship between Traditional Laws and Modern Law in Africa : A Comparative Study of the Tswana, Xhosa, and Oromo

The main scholarly goal of this thesis is to identify the different types of relationship indigenous traditional laws and traditional governance structures have with the laws and institutions of the modern state in Africa. The aim is to distil lessons, insights, and observations which have comparative relevance for the study of (non-Western) constitutions and constitutionalism. The case-studies from Botswana, South Africa, and Ethiopia are part of this search for potentially generalisable patterns which hold across both time and place. The investigation is thus, both a) a comparison across three case-studies and b) a historic comparison across time. That is, each case-study contains a comparison of the different legal and political mechanisms managing the relationship between the traditional and the modern during the different constitutional phases spanning precolonial, colonial, and post-colonial periods. For each case-study investigation starts with the international and regional levels of analysis and then moves down to the national and local levels. After examining nation-wide constitutional and political factors, the focus is directed on the traditional laws and governance structures in three select locations: i) the Bakgatla Batswana of Botswana; ii) the Transkei amaXhosa of the Eastern Cape; and iii) the Guji/Borana Oromo of Ethiopia. The three case-studies epitomise three different paths to empowering indigenous African constitutionalism. In Botswana we see early recognition, domestication, and continuity; in South historical distortion, manipulation, followed by democratic rebirth; and in Ethiopia we see how an idealised version of indigenous Oromo constitutionalism is in resurgence after its near extinction in recent history.Thesis (LLD)--University of Pretoria, 2021.Public LawLLDUnrestricte

Effects of mediated social touch on affective experiences and trust

This study investigated whether communication via mediated hand pressure during a remotely shared experience (watching an amusing video) can (1) enhance recovery from sadness, (2) enhance the affective quality of the experience, and (3) increase trust towards the communication partner. Thereto participants first watched a sad movie clip to elicit sadness, followed by a funny one to stimulate recovery from sadness. While watching the funny clip they signaled a hypothetical fellow participant every time they felt amused. In the experimental condition the participants responded by pressing a hand-held two-way mediated touch device (a Frebble), which also provided haptic feedback via simulated hand squeezes. In the control condition they responded by pressing a button and they received abstract visual feedback. Objective (heart rate, galvanic skin conductance, number and duration of joystick or Frebble presses) and subjective (questionnaires) data were collected to assess the emotional reactions of the participants. The subjective measurements confirmed that the sad movie successfully induced sadness while the funny movie indeed evoked more positive feelings. Although their ranking agreed with the subjective measurements, the physiological measurements confirmed this conclusion only for the funny movie. The results show that recovery from movie induced sadness, the affective experience of the amusing movie, and trust towards the communication partner did not differ between both experimental conditions. Hence, feedback via mediated hand touching did not enhance either of these factors compared to visual feedback. Further analysis of the data showed that participants scoring low on Extraversion (i.e., persons that are more introvert) or low on Touch Receptivity (i.e., persons who do not like to be touched by others) felt better understood by their communication partner when receiving mediated touch feedback instead of visual feedback, while the opposite was found for participants scoring high on these factors. The implications of these results for further research are discussed, and some suggestions for follow-up experiments are presented

Superabsorbent Polymers for Internally Cured Concrete

Two commercial superabsorbent polymer (SAP) formulations were used to internally cure cement pastes, mortars, and concretes with a range of water-to-cement ratios (w/c 0.35–0.52). The following properties were determined as a function of cement chemistry and type, use of chemical admixtures, use of slag, and batching parameters: SAP absorption capacity, fresh mixture workability and consistency, degree of hydration, volumetric stability, cracking tendency, compressive and flexural strength, and pumpability. SAP internal curing agents resulted in cementitious mixtures with improved hydration, accelerated strength gain, greater volumetric stability, and improved cracking resistance while maintaining sufficient workability to be pumped and placed without sacrificing compressive or flexural strength. When using SAP, batching adjustments prioritized the use of water reducing admixture instead of extra water to tune workability. While the benefits of SAP internal curing agents for low w/c mixtures were expected, SAP-containing mixtures with w/c ≥ 0.42 displayed accelerated strength development and decreased cracking tendency

High-repetition-rate and high-photon-flux 70 eV high-harmonic source for coincidence ion imaging of gas-phase molecules

Unraveling and controlling chemical dynamics requires techniques to image structural changes of molecules with femtosecond temporal and picometer spatial resolution. Ultrashort-pulse x-ray free-electron lasers have significantly advanced the field by enabling advanced pump-probe schemes. There is an increasing interest in using table-top photon sources enabled by high-harmonic generation of ultrashort-pulse lasers for such studies. We present a novel high-harmonic source driven by a 100 kHz fiber laser system, which delivers 10$^{11}$ photons/s in a single 1.3 eV bandwidth harmonic at 68.6 eV. The combination of record-high photon flux and high repetition rate paves the way for time-resolved studies of the dissociation dynamics of inner-shell ionized molecules in a coincidence detection scheme. First coincidence measurements on CH$_3$I are shown and it is outlined how the anticipated advancement of fiber laser technology and improved sample delivery will, in the next step, allow pump-probe studies of ultrafast molecular dynamics with table-top XUV-photon sources. These table-top sources can provide significantly higher repetition rates than the currently operating free-electron lasers and they offer very high temporal resolution due to the intrinsically small timing jitter between pump and probe pulses

High Harmonic Generation in Mixed Xuv and Nir Fields at a Free-Electron Laser

We Present the Results of an Experiment Investigating the Generation of High-Order Harmonics by a Femtosecond Near-Infrared (NIR) Laser Pulse in the Presence of an Extreme Ultraviolet (XUV) Field Provided by a Free-Electron Laser (FEL), a Process Referred to as XUV-Assisted High-Order Harmonic Generation (HHG). Our Experimental Findings Show that the XUV Field Can Lead to a Small Enhancement in the Harmonic Yield When the XUV and NIR Pulses overlap in Time, while a Strong Decrease of the HHG Yield and a Red Shift of the HHG Spectrum is Observed When the XUV Precedes the NIR Pulse. the Latter Observations Are in Qualitative Agreement with Model Calculations that Consider the Effect of a Decreased Number of Neutral Emitters but Are at Odds with the Predicted Effect of the Correspondingly Increased Ionization Fraction on the Phase Matching. Our Study Demonstrates the Technical Feasibility of XUV-Assisted HHG Experiments at FELs, Which May Provide New Avenues to Investigate Correlation-Driven Electron Dynamics as Well as Novel Ways to Study and Control Propagation Effects and Phase Matching in HHG

Spong3d: 3D printed facade system enabling movable fluid heat storage

Spong3D is an adaptive 3D printed facade system that integrates multiple functions to optimize thermal performances according to the different environmental conditions throughout the year. The proposed system incorporates air cavities to provide thermal insulation and a movable liquid (water plus additives) to provide heat storage where and whenever needed. The air cavities have various dimensions and are located in the inner part of the system. The movable liquid provides heat storage as it flows through channels located along the outer surfaces of the system (on the indoor and outdoor faces of the façade). Together, the composition of the channels and the cavities form a complex structure, integrating multiple functions into a singular component, which can only be produced by using an Additive Manufacturing (AM; like 3D printing) technology

Spong3d: 3D printed facade system enabling movable fluid heat storage

Spong3D is an adaptive 3D printed facade system that integrates multiple functions to optimize thermal performances according to the different environmental conditions throughout the year. The proposed system incorporates air cavities to provide thermal insulation and a movable liquid (water plus additives) to provide heat storage where and whenever needed. The air cavities have various dimensions and are located in the inner part of the system. The movable liquid provides heat storage as it flows through channels located along the outer surfaces of the system (on the indoor and outdoor faces of the façade). Together, the composition of the channels and the cavities form a complex structure, integrating multiple functions into a singular component, which can only be produced by using an Additive Manufacturing (AM; like 3D printing) technology

Atherosclerosis and liver inflammation induced by increased dietary cholesterol intake: a combined transcriptomics and metabolomics analysis

With increasing dietary cholesterol intake the liver switches from a mainly resilient to a predominantly inflammatory state, which is associated with early lesion formation

XUV double-pulses with femtosecond to 650 ps separation from a multilayer-mirror-based split-and-delay unit at FLASH

Extreme ultraviolet (XUV) and X-ray free-electron lasers enable new scientific opportunities. Their ultra-intense coherent femtosecond pulses give unprecedented access to the structure of undepositable nanoscale objects and to transient states of highly excited matter. In order to probe the ultrafast complex light-induced dynamics on the relevant time scales, the multi-purpose end-station CAMP at the free-electron laser FLASH has been complemented by the novel multilayer-mirror-based split-and-delay unit DESC (DElay Stage for CAMP) for time-resolved experiments. XUV double-pulses with delays adjustable from zero femtoseconds up to 650 picoseconds are generated by reflecting under near-normal incidence, exceeding the time range accessible with existing XUV split-and-delay units. Procedures to establish temporal and spatial overlap of the two pulses in CAMP are presented, with emphasis on the optimization of the spatial overlap at long time-delays via time-dependent features, for example in ion spectra of atomic clusters