Archives-December  

Major ions as well as pH and conductivity were analysed in about 52 rainwater samples collected daily from the rain station of GhanaAtomic Energy Commission for a period of April, 2009- June, 2010. Results for the major cations analyses indicate a trend of K⁺>Na⁺>Ca²⁺>Mg²⁺ and the major anions show a trend of HCO₃^->Cl^->SO₄^2->NO₃^-.The values of pH range from 4.62-8.64 and conductivity from 5.74-1274µS/cm.Contribution to the acidity of rain in this area is mostly by SO₄^2- instead of NO₃^- due to the reason that the study area lies in the Accra Plains which is a highly industrialized area. Ratios of mean annual concentrations of major ions (Cl^-, K⁺, Mg²⁺, Ca²⁺ and SO₄^2-) to Na⁺ in the rainwater samples were higher in comparison to   sea water. This suggests that there are other sources of these ions apart from the sea. High concentrations of most of the elements were recorded in months with smaller amounts of rainfall and so it was concluded that continuous rainfall may have washed away so many of the elements suspended in the atmosphere.

The proposed system presents power-control strategies of a grid-connected hybrid generation system with versatile power transfer. This hybrid system allows maximum utilization of freely available renewable energy sources like wind and photovoltaic energies. For this, an adaptive MPPT algorithm along with standard perturbs and observes method will be used for the system. Also, this configuration allows the two sources to supply the load separately or simultaneously depending on the availability of the energy sources. The turbine rotor speed is the main determinant of mechanical output from DG energy and Solar cell operating voltage in the case of output power from solar energy.The inverter converts the DC output from non-conventional energy into useful AC power for the connected load. In order to utilization distributed generation (DG) unit interfacing converters to actively compensate harmonics, this paper proposes an enhanced current control approach, which seamlessly integrates system harmonic mitigation capabilities with the primary DG power generation function. As the proposed current controller has two well- decoupled control branches to independently control fundamental and harmonic DG currents, local nonlinear load harmonic current detection and distribution system harmonic voltage detection are not necessary for the proposed harmonic compensation method. Moreover, a closed-loop power control scheme is employed to directly derive the fundamental current reference without using any phase-locked loops (PLL). The proposed power control scheme effectively eliminates the impacts of steady-state fundamental current tracking errors in the DG units. Thus, an accurate power control is realized even when the harmonic compensation functions are activated hybrid system operates under normal conditions which include normal room temperature in the case of solar. The simulation results are presented to illustrate the operating principle, feasibility and reliability of this proposed system.

Gnosticism has been considered among human, in order to answer human’s needs. It is necessary to learn the secrets of Gnosticism, in order to step in the intellectual way. It is in the same way that some of great men. Such as Hafiz and Molana are well known for their literary, mystical approaches which should be differentiated, at first, we compare them, we come to the fact that their Gnosticism has been less considered.

Today’s pulp and paper industry is rapidly becoming a globalized industry which belongs to the Red category that is positioning itself to deliver low-cost, high-value, fiber-based products to consumers. Employing advanced chemical- and mechanical-based technologies. pulp, paper, and tissue manufacturers have sought to provide high-quality consumer. To overcome the challenges, new synthetic nonrenewable materials have been developed that have now begun to challenge the traditional dominance paper products has had in many applications. This paper will review emerging developments of these technologies and how these new research avenues will change paper from a pass. This presentation deals the vital role of Nano technology in pulp and paper manufacturing sector.

The proximate, antinutrient, mineral and amino acid composition of ripe and unripe Blighia sapida (ackee) seed were quantified using standard analytical techniques. Fat, fibre and ash were higher in the unripe seed while protein and carbohydrate were more in the ripe seed. The protein content of the ripe and unripe Ackee seed were 11.67% and 9.63% respectively; values obtained for fat were 18.00% and 22.50%, ash 2.83 and 4.17%, fibre 9.33% and 14.33%, moisture values 9.17% and 7.00%, carbohydrate 49.00% and 41.19%. The mineral constituents (mg/kg) for sodium 12.85±0.45, phosphorus 7.14±0.32, Zinc 3.10±0.09, and potassium 16.55±0.05 were higher in the ripe ackee seed while iron 43.75±1.16, manganese 3.09±2.81, calcium 2.85±0.15 and copper 2.15±0.45 were higher in the unripe ackee seed respectively. Eighteen amino acids were found in the samples in this study; 9 essential amino acids with histidine and 9 non-essential amino acids. Glutamate, aspartate and leucine, were the most abundant amino acids in the samples. The ratios of essential amino acids (EAA) to non-essential amino acids (NEAA) in the ripe and unripe ackee seeds was 0.71. The values of the common antinutrients; cyanide, phytate and oxalate were similar in both seed samples; however, trypsin inhibitory activity was higher in the unripe ackee seed. This study shows that ackee seeds can be a potential alternative source of livestock feed.

Internet is widely used in the fast growing world and there are many limitations in the network. There are two main failures that occur in the network they are wireless packet loss and congestion. The performance of SCTP in wireless network is considered as the active area. Finding the failure in the wireless network is very important and it is analysed in this paper. So in this paper the route is established by on demand routing technique in which many features like the energy of the node, location, bandwidth of the packet are analysed. So when the packets need to be send it analyses all the features and establishes the route with the efficient node that has one hop count by using the SCTP transport protocol. On transmitting the packets some energy from the node gets reduced so there is a high chance of congestion since the capacity of the node is reduced. This can be avoided by the proactive approach by reducing the traffic send by the source when the node level reaches threshold. By using the multi-homing technique in the SCTP approach the packets can be sending till the alternate route is re-established. Thus the packet loss rate and end-end delay is reduced and QOS is increased in the system.

Orthogonal Frequency Division Multiplexing is a key contender for broadcasting standards, due to its immunity towards multipath fading and ease of implementation. Here a scheme to exploit the frequency diversity within OFDM subcarriers has been proposed which further increases the bit error rate performance. The diversity is achieved by circularly shifting the OFDM subcarrier coefficients in pseudorandom manner. Thus we notice a significant performance improvement without any additional bandwidth requirements.

The in vitro antimicrobial activity of crude methanolic extracts of various plant parts of Phyllanthus niruri was investigated. The extracts exhibited antimicrobial activities with zones of inhibition ranging from 6 to 16 mm. All the extracts exhibited appreciable activity against all the clinically important bacterial and fungal species clinically investigated. Maximum Inhibition zone (16mm) was observed in seeds against Staphylococcus aureus and minimum in roots (5mm) against E. coli. Phytochemical screening revealed the presence of carbohydrates, proteins, alkaloids and flavonoids in the extracts. The antimicrobial activity of the extract was compared with the standard drugs. The ability of the crude extracts of P. niruri plant parts to inhibit the growth of various bacteria and fungi showed its broad spectrum antimicrobial potential, which may be employed in the management of microbial infections.

This applied research deals with not only the preparation and characterization of nano-structured solar fins but also the evaluation of efficiency of solar collector integrated with the nano-structured fins. In this connection, fins in standard sizes were procured and the nano-structured coating with the composition of carbon and aluminium oxide was deposited on them. The coatings on fins were characterized through X-ray diffraction (XRD) and scanning electron microscopy (SEM) and the fins were subjected to thermal analysis. The coated fins were integrated in a solar collector and thermal performances of the collector were experimentally found for a set of inlet temperatures of working fluid. The overall thermal performance of the collector was calculated through a graph that was generated as per standard specifications. It was found that the sizes of the grains in the coating were in nano range with orthorhombic structure. It was also found that the temperature enhancement on the solar fins with carbon and aluminium coating of 75:25 compositions in stagnant conditions had the maximum value 109.1?. While the maximum instantaneous thermal performance was found to be 73%, the overall thermal performance of the solar collector was found to be 70%. On the basis of the generated results in the present investigation, it could be concluded that nano-carbon and aluminium oxide coated fins would be used in solar collectors so as to reap enhanced thermal performances.

Rumeli Fortress has a unique place in the history of world with Its properties. This study gives information about the castle and Fatih period, explains the aspects of the castle which is thought to be important and mentions the gradually ruined or transformed parts. Essential actions to do about these parts which have become ruin and restored without being loyal to Its origins is presented. It is discussed to preserve the ruined castle originally.