The 1979 Nigerian elections reflected the dedication of Nigerians to pursue democratic governance and the severe challenges to be overcome. The sweeping victory of the NPN, and the election of Alhaji Shehu Shagari as president, required a last-minute manipulation of the formula for achieving victory in the first round. After...
In the years preceding the 1979 national elections, ideology featured prominently in political debates and consultations regarding the new constitutional order. Proponents of a social democratic system were particularly prominent. However, the actual formation of political parties, governed by the new requirements for national representation, and the resurgence of veteran...
A half-century of high revenues from petroleum export has failed to elevate more than a small percentage of Nigerians above the poverty level. The failure to manage the vicissitudes of global oil markets, and to grow other sectors of the economy, has led to constant budget deficits and unsustainable national...
The issues discussed in this essay - the fundamental objectives of the Nigerian state, public accountability, and a code of conduct for state officials - have been central concerns throughout its post- colonial history. Underlying these debates have been differing views about the best political economy model for Nigeria. The...
This paper describes proposed schemes for describing and indexing two image collections and requirements for the software that would give the end-user access to thesaurus terms and a graphical display of the faceted classification structures of indexing records. Editorial cartoons comprise one collection, dance videos the other.
The gradual evolution of the material properties of a cement-based material, i.e. the stiffness of cement paste, is the result of the continuous change of the microstructure with the progress of the hydration process. Based on an existing micromechanical model for the simulation of the shear and elastic modulus of...
In this paper, the correlation of reflection loss measured by an ultrasonic shear wave reflection
method and the microstructure in cement-based material is investigated. Three cement pastes
(Portland cement type I) with different water-cement ratios (0.35, 0.50 and 0.60) cured at 25
°C were examined. The ultrasonic shear wave reflection...
The paper deals with the behavior of fluid cement pastes, formulated from Self Consolidating Concretes (SCCs), and the experimental correlation of fundamental rheological properties, such as the yield stress and the viscosity, with measurements from field tests, such as the mini-cone slump flow test. As a matter of fact, several...
Gentrification - the process in which higher income (and often younger) households displace lower income residents of a city neighborhood - has been occurring in many urban neighborhoods over the last few decades. This process changes the demographics, and often the essential character, of the neighborhood. As a result, we...
An empirical procedure for fitting a complementary error function (erfc) to settlement and lateral ground movement data in a direction parallel to an excavation support wall is proposed based on extensive optical survey data obtained around a 12.8 m excavation in Chicago. The maximum ground movement and the height and...
Several three-dimensional effects were observed in the performance monitoring data collected during excavation for the Ford Engineering Design Center (FEDC) in Evanston, Illinois. These responses are related to lateral deformations of the soil around the excavation walls, forces in the cross-lot and diagonal bracing that supported the temporary wall and...
This paper presents the results of 159 finite element simulations conducted to define the effects of excavation geometry, i.e., length, width and depth of excavation, wall system stiffness, and factor of safety against basal heave on the 3-dimensional ground movements caused by excavation through clays. The results of the analyses...
Successful use of monitoring data to update performance predictions of supported excavations depends equally on reasonable numerical simulations of performance, the type of monitoring data used as observations, and the inverse analysis techniques used to minimize the difference between predictions and observed performance. This paper summarizes each of these factors...
Two numerical procedures are described that quantitatively identify a set of constitutive parameters that best represents observed ground movement data associated with a deep excavations in urban environments. This inverse problem is solved by minimizing an objective (or error) function of the weighted least-squares type that contains the difference between...
This paper describes developments of integrated tools for predicting, monitoring, and controlling ground movements associated with excavations in urban areas. Successful use of monitoring data to update performance predictions of supported excavations depends equally on reasonable numerical simulations of performance, the type of monitoring data used as observations, and the...
This paper reviews the new field of geo-measurement with metallic cable time domain reflectometry (TDR) for surveillance of transportation facilities. TDR is radar in a coaxial cable, and is especially advantageous for remote monitoring because of its inherently digital nature. Advances can be separated into those that leverage use of...
This paper describes qualification of devices to measure sub micro-meter changes in crack width, which is the basis of autonomous crack monitoring for control of blasting vibrations. Performance of LVDT, eddy current and potentiometer sensors to monitor long-term and transient displacements will be described. Potentiometers are attractive for wireless measurement,...
Crack and structural response to construction trench blasting was measured in a woodframe house with a stucco exterior. Blasts at distances between 232 m to 368 m produced peak particle velocities (PPV) and air blast over pressures (AB) of 9 mm/sec and 0.02 kPa (123 dB), respectively. Structural response velocities...
A unique judicial opportunity allowed measurement of the response of three cracks in residential structure to blasting for underground aggregate mining. Instrumented cracks were located in the interior basement CMU mortar and upstairs dry wall as well as exterior brick work. The dynamic environment was unusual. Even though the blasting...