Piling-Induced Ground Motion: A Case Study Involving Hydrocarbon Exploitation Activities in the Niger Delta

The damage potential of piling-induced vibrations in the humid tropical soils of southeastern Nigeria has been evaluated. The vibration propagation was characterized by a fairly high attenuation coefficient, as evidenced by a rapid decrease of velocity amplitude with distance from source. It was also observed that the bulk of the peak velocity amplitudes measured or calculated fell within the safe limit for structural safety and human tolerance. This therefore implied that the zone of highest damage probability at the case study site did not extend across property line as suspected prior to commencement of piling. In general, the findings and results of this work should enhance the development of environmental impact assessment framework suitable for managing those oil production activities that generate transient-type vibrations

Auxiliary Winding Switching Circuit for Single-Phase Induction Motors

The most common practice for starting a single-phase induction motor is to connect a starting capacitor, in series, with the auxiliary winding. Here, the possibility of using an electronic switch in parallel with the starting capacitor, is discussed. This work relates particularly to a switching device for electrically connecting and removing the auxiliary winding and starting capacitor from the single-phase induction motor's circuitry. The starting capacitor with the auxiliary winding are disconnected by electronic means as the motor gains speed hence leaving only the main winding in the motor circuit for normal operation

Variasipenambahanekstrak Jahe Merah (Zingiber Officinale Var.rubrum) Terhadap Mutu Dan Antioksidan Bubuk Instan Akar Alang-alang

The research purposes was to evaluate of the quality and antioxidant of the instant powder of coarse grass root with the addition of red ginger extracts. The method used in this research was a Complete Random Design with 4 treatments and 4 replications. The treatments were P1 (90% coarse grass root extracts : 10% ginger extracts), P2 (80% coarse grass root extracts : 20% ginger extracts), P3 (70% coarse grass root extracts : 30% ginger extracts), P4 (60% coarse grass root extracts : 40% ginger extracts). The results show that the addition of various ginger extracts significantly influenced the total sugar content, antioxidant, descriptive value of aroma and taste of instant powder, but did not affect the moisture and ash contents, color, and texture of instant powder. The best treatment was P4 (60% coarse grass root extracts : 40% ginger extracts) with total sugar content of 57.75%, ash content 1.48%, moisture content 1.75%, hedonic organoleptic of color 3.63, flavor 3.83, taste 3.77, texture 3.57, as well as descriptive organoleptic of color 3.27, flavor 3.97, taste 4.27, texture 3.30 and over all acceptance test 3.80

Zeroing in on more photons and gluons

We discuss radiation zeros that are found in gauge tree amplitudes for processes involving multi-photon emission. Previous results are clarified by examples and by further elaboration. The conditions under which such amplitude zeros occur are identical in form to those for the single-photon zeros, and all radiated photons must travel parallel to each other. Any other neutral particle likewise must be massless (e.g. gluon) and travel in that common direction. The relevance to questions like gluon jet identification and computational checks is considered. We use examples to show how certain multi-photon amplitudes evade the zeros, and to demonstrate the connection to a more general result, the decoupling of an external electromagnetic plane wave in the ``null zone". Brief comments are made about zeros associated with other gauge-boson emission.Comment: 26 page

Kidnapping : A Lucrative Crime in 21st Century Nigeria

The rising incidence and prevalence of kidnapping in Nigeria have continually generated concern in both academic and non-academic circles The phenomenon of kidnapping constitutes a serious threat to life and serves as a major drawback to the nation s drive for sustainable economic growth anchored on direct foreign investment The paper relies on both primary and secondary sources and notes that kidnapping is caused by grinding poverty spiraling unemployment the criminal quest for material acquisition and a weak security system The paper recommends the initiation of pro-poor poverty eradication programs creation of employment opportunities strengthening of the security architecture enactment of appropriate laws and the adoption of capital punishment to stem the tide of kidnapping which has become a lucrative crime in 21st century Nigeri

Spatial encoding in primate hippocampus during free navigation.

The hippocampus comprises two neural signals-place cells and θ oscillations-that contribute to facets of spatial navigation. Although their complementary relationship has been well established in rodents, their respective contributions in the primate brain during free navigation remains unclear. Here, we recorded neural activity in the hippocampus of freely moving marmosets as they naturally explored a spatial environment to more explicitly investigate this issue. We report place cells in marmoset hippocampus during free navigation that exhibit remarkable parallels to analogous neurons in other mammalian species. Although θ oscillations were prevalent in the marmoset hippocampus, the patterns of activity were notably different than in other taxa. This local field potential oscillation occurred in short bouts (approximately .4 s)-rather than continuously-and was neither significantly modulated by locomotion nor consistently coupled to place-cell activity. These findings suggest that the relationship between place-cell activity and θ oscillations in primate hippocampus during free navigation differs substantially from rodents and paint an intriguing comparative picture regarding the neural basis of spatial navigation across mammals

Nomadic Base Station (NBS): a Software Defined Radio (SDR) based Architecture for Capacity Enhancement in Mobile Communications Networks

In this research work, the problem of congestion that leads to dropped calls at GSM cell sites and drastic reduction in network capacity is addressed. We designed a novel GSM base station architecture named Nomadic Base Station (NBS) which is based on Software Defined Radio (SDR) architecture and simulated the LNA for its receiver front-end. The NBS receiver LNA selects and amplifies GSM signal bursts operating at 900MHz and 1800MHz Radio Frequency Band. The later stages translate the Radio Frequency (RF) signal to Intermediate Frequency (IF) signal. This implements the SDR technology by digitizing the IF signal into bit streams that can be processed on generic Central Processing Unit (CPU) using custom written signal processing software

High-energy effective theory for matter on close Randall Sundrum branes

Extending the analysis of hep-th/0504128, we obtain a formal expression for the coupling between brane matter and the radion in a Randall-Sundrum braneworld. This effective theory is correct to all orders in derivatives of the radion in the limit of small brane separation, and, in particular, contains no higher than second derivatives. In the case of cosmological symmetry the theory can be obtained in closed form and reproduces the five-dimensional behaviour. Perturbations in the tensor and scalar sectors are then studied. When the branes are moving, the effective Newtonian constant on the brane is shown to depend both on the distance between the branes and on their velocity. In the small distance limit, we compute the exact dependence between the four-dimensional and the five-dimensional Newtonian constants.Comment: Updated version as published in PR

Mechanical properties and microstructure of fibre-reinforced clay blended with by-product cementitious materials

Clayey soils endure adverse changes in strength and volume due to seasonal changes in moisture content and temperature. It has been well recognised that high cement content has been successfully employed in improving the mechanical properties of clayey soils for geotechnical infrastructural purposes. However, the environmental setbacks regarding the use of high cement content in soil reinforcement have necessitated the need for a greener soil reinforcement technique by incorporating industrial by-product materials and synthetic fibres with a reduced amount of cement content in soil-cement mixtures. Therefore, this study presents an experimental study to investigate the mechanical performance of polypropylene and glass fibre-reinforced cement-clay mixtures blended with ground granulated blast slag (GGBS), lime and micro silica for different mix compositions and curing conditions. The unconfined compressive strength, linear expansion and microstructural analysis of the reinforced soils have been studied. The results show that an increase in polypropylene and glass fibre contents caused an increase in unconfined compressive strength but brought on the reduction of linear expansion of the investigated clay from 7.92% to 0.2% at fibre content up to 0.8% for cement-clay mixture reinforced with 5% Portland cement (PC). The use of 0.4–0.8% polypropylene and glass fibre contents in reinforcing cement-clay mixture at 5% cement content causes an increase in unconfined compressive strength (UCS) values above the minimum UCS target value according to American Society for Testing and Materials (ASTM) 4609 after 7 and 14 days curing at 20◦ C to 50◦ C temperature. Therefore, this new clean production of fibre-reinforced cement-clay mixture blended with industrial by-product materials has great potential for a wide range of applications in subgrade reinforcement