Multi Input Dynamical Modeling of Heat Flow With Uncertain Diffusivity Parameter

Cataloged from PDF version of article.This paper focuses on the multi-input dynamical modeling of one-dimensional heat conduction process with uncertainty on thermal diffusivity parameter. Singular value decomposition is used to extract the most significant modes. The results of the spatiotemporal decomposition have been used in cooperation with Galerkin projection to obtain the set of ordinary differential equations, the solution of which synthesizes the temporal variables. The spatial properties have been generalized through a series of test cases and a low order model has been obtained. Since the value of the thermal diffusivity parameter is not known perfectly, the obtained model contains uncertainty. The paper describes how the uncertainty is modeled and how the boundary conditions are separated from the remaining terms of the dynamical equations. The results have been compared with those obtained through analytic solution

Acid Rain in Niger Delta Region: Implication on Water Resources Quality and Crisis

This research focused on the effect of acid rain on the water quality of the Niger Delta region of Nigeria. Three hundred water samples were collected: 100 water samples from rain, 100 from open wells and 100 from rivers. The water samples were analysed using the paired t-test and multiple correlation analysis to ascertain their level of variation and relationship. Hydrochemical analysis revealed moderately low pH values of 4.98 > 5.12 > 5.23 for rain, river and well water resources in the Niger Delta region. The anions, cations and microbiological characteristics in river and well water sources before rain events were generally greater after down pours. This indicates that the pH values of rain water resources correlated significantly (r = 0.80) with gas flaring, an activity connected with petroleum exploration activities in the Niger Delta region. The acid content in the rainwater not only lowers the quality of rainwater sources for domestic use, but also the quality of well and river water sources in the region. This has led to acute drinking water shortages in the region and has exacerbated struggles for the few existing clean water sources. The cessation of gas flaring as well as the provision of adequate potable water supply to locals is highly recommended. Additionally liming of the water resources and other methods of cleansing acidic water may be employed in the interim.Keywords: Acid rain, well, river and water crisi

Length-weight Relationship and Condition Factor of Sarotherodon Melanotheron (Perciformes: cichlidae) from Forcados River Estuary, Niger Delta, Nigeria

Length-weight relationship (LWR), condition factor (k) of the black chin tilapia, Sarotherodon melanotheron (Rüppel, 1852) from Forcados River estuary Nigeria was investigated. The fish were collected monthly from fishermen for a period of 24 months (between April 2012 and March 2014). 699 specimens of the fish species were collected. The Length-weight relationship (LWR) of the fish was evaluated using the equation: W = a Lb while the condition factor of the fish was determined using the equation; K = 100W Lb . The standard length of sampled S. melanotheron ranged from 4.15 to 18.92 cm, total length 6.01 and 22.5 cm while the weight ranged from 7.85 - 286.71 g. The b value 2.1299 was less than 3 indicating that the growth pattern of the fish was allometric. The correlation co-efficient (r) value for S. melanotheron was 0.7528. The condition factor for the combined sexes fluctuated monthly. The length-weight relationships and condition factor of S. melanotheron in Forcados river estuary indicated that the fish were above average condition

Early phases of different types of isolated neutron star

Two Galactic isolated strong X-ray pulsars seem to be in the densest environments compared to other types of Galactic pulsar. X-ray pulsar J1846-0258 can be in an early phase of anomalous X-ray pulsars and soft gamma repeaters if its average braking index is ~1.8-2.0. X-ray pulsar J1811-1925 must have a very large average braking index (n~11) if this pulsar was formed by SN 386AD. This X-ray pulsar can be in an early phase of evolution of the radio pulsars located in the region P~50-150 ms and \.{P}~10$^{-14}-10^{-16}$ s/s of the P-\.{P} diagram. X-ray/radio pulsar J0540-69 seems to be evolving in the direction to the dim isolated thermal neutron star region on the P-\.{P} diagram. Possible progenitors of different types of neutron star are also discussed.Comment: to appear in the International Journal of Modern Physics

Effect of heat treatment on in situ rumen degradability and in vitro gas production of full-fat soyabeans and soyabean meal

The objective of this study was to determine the effect of the heat treatment of full-fat soyabean (FFSB) and solvent extracted soyabean meal (SBM) on the in situ dry matter (DM) and protein degradability, and in vitro gas production kinetics of the protein sources. Ruminal disappearance of DM and crude protein (CP), and in vitro gas production were determined after 0, 4, 8, 16, 24, 48 and 72 h incubation using the in situ ruminal degradation and in vitro gas production techniques, respectively. In situ DM and CP disappearances were fitted to the exponential equation p = a + b (1-e-ct), where a is the rapid degradable fraction and b is the slow degradable fraction. In vitro gas production data were fitted to the equation, y = A {1 – exp [- b (t-T) – c (√t - √T)]}. Where b and c are the initial gas production rate constant (h-1) and later gas production rate constant (h-1/2), respectively. The two protein sources were heat treated both with steam pressure in an autoclave at 120 °C and in an oven at 150 °C for 20 min. Heat treatment had a significant effect on effective DM degradability (EDMD), effective CP degradability (ECPD) and in vitro gas production. Although the heat treatments reduced the EDMD, ECPD and the amount of gas produced, the results were inconsistent between protein sources. The heat treatments applied in the autoclave and the oven reduced the ECPD0.02 of FFSB by 12.5% and 10.9%, respectively. On the other hand, heat treatment applied through the autoclave decreased the ECPD0.02 of SBM by 13.9%, but by 18.7% when heat was applied through the oven. Heat treatment of SBM using the oven seemed to be more effective than using autoclaving. Heat treatments in the autoclave and oven reduced the total gas production from FFSB by 7.25 and 7.32%, respectively, and from SBM by 12.69 and 7.91%, respectively. It was concluded that heat treatment is an effective method of altering the rumen degradation characteristics of DM and CP in SBM and FFSB. Both methods could be used to increase the proportion of the rumen non-degradable protein fraction in protein sources which would then reach the small intestines unaffected by ruminal fermentation. Keywords: Full-fat soyabean; soyabean meal; heat treatment; in situ protein degradation; in vitro gas production South African Journal of Animal Sciences Vol. 35 (3) 2005: pp.186-19

Relationship Between the Use of Mobile Telephone, Intimate Relationships and Interpersonal Conflict In Nigeria

The responses of 121 Nigerian public servants in Abuja metropolis, the country’s capital city, to a survey instrument were used to determine the extent to which mobile telephone use impacted the intimate relationship and interpersonal conflicts in Nigeria. The data showed that partners in intimate relationships experience a number of problems to which they adopt the full range of options for resolving conflicts including negotiation, mediation, and arbitration. Furthermore, mobile telephone use was said to relate directly to mistrust between parties in intimate relationships aside from being generally rated in a positive light. In addition, mobile telephone use was perceived to have impacted on aspects of human behavior including participation in social, cultural, and religious affairs as well as limiting social support to and from families of partners in a relationship. These findings were discussed in terms of dysfunctional patterns of adjustments to what can still be described as new technology and the transition from tradition to modernity in this part of the world. It was suggested among others; that people need to be educated about the distrust, disconnection, and other relational problems associated with mobile telephone use and the need to engage professionals to resolve problems of mistrust in intimate relationships and interpersonal conflicts

1 mJ pulse bursts from a Yb-doped fiber amplifier

Cataloged from PDF version of article.We demonstrate burst-mode operation of a polarization-maintaining Yb-doped fiber amplifier capable of generating 60 mu J pulses within bursts of 11 pulses with extremely uniform energy distribution facilitated by a novel feedback mechanism shaping the seed of the burst-mode amplifier. The burst energy can be scaled up to 1 mJ, comprising 25 pulses with 40 mu J average individual energy. The amplifier is synchronously pulse pumped to minimize amplified spontaneous emission between the bursts. Pulse propagation is entirely in fiber and fiber-integrated components until the grating compressor, which allows for highly robust operation. The burst repetition rate is set to 1 kHz and spacing between individual pulses is 10 ns. The 40 mu J pulses are externally compressible to a full width at half-maximum of 600 fs. However, due to the substantial pedestal of the compressed pulses, the effective pulse duration is longer, estimated to be 1.2 ps. (C) 2012 Optical Society of Americ

A COMPARATIVE ANALYSIS OF 802.11b AND 802.11g NETWORK

Recent advances in wireless technology has led to the introduction of new devices utilizing the 2.4GHz industrial scientific and medical (ISM) unlicensed band traditionally used by Wireless LANS (WLAN). The increasing demand of higher data rate in WLANs has prompted the continual emergence of different 802.11 protocols with increased performance. Interoperability and coexistence between these networks become key issues and must be catered for, to guarantee satisfactory performance of both networks. 802.11 refer to a family of specifications developed by the International Institute of Electrical Electronics Engineering (IEEE) for wireless LAN technology. IEEE accepted the specification for 802.11 in 1997. Wireless Local Area Network (WLAN) has become popular in the home due to ease of installation, and the increasing popularity of laptop computers. WLAN is based on IEEE 802.11 standard and is also known as Wireless Fidelity (Wi-Fi) [1]. In this paper, the comparative analysis of IEEE 802.11b and IEEE 802.11g networks are x-rayed. KEYWORDS: 802.11b, 802.11g, WLAN, IEEE, OFDM, LRWPANS, Wireless Fidelity, Wireless Medium Access Control, Physical Layer