Determinants of Trade Balance in Somalia: Regression Analysis using Time Series Data

The study focuses on the Analysis of the Main determinants that have an impact on trade balance. Specifically this study focus on the main cause of Trade deficit in Somalia by analyzing the impact of Foreign Direct Investment (FDI), exchange rate and inflation rate; In this study The Ordinary Least Square method (OLS) under the E-View 7.1 software has been used for the econometric analysis with a sample period spanning from 1970-2010. This study adopted the two-country imperfect substitute model of Rose and Yellen which analyses the relationship of the real exchange rate and the trade balance.The regression result showed that there is only foreign direct investment variable impact on trade balance in Somalia. Foreign direct investment had negative impact on trade balance in Somalia. The other factors include exchange rate and inflation rate had no impact on trade balance in Somalia. According to the result, there are some recommendations to solve the trade deficits problem in Somalia. The government should keep the policies stable to attractive more investors and should have policies to support export such as investment incentive and taxes incentive. Keywords: FDI, trade balance, Somalia, exchange rat

On the initial development of rare earth doped fiber using chelate delivery system

In this paper, the initial work on the development of Rare Earth (RE) doped fiber is presented. This work was done using standard MCVD process equipped with chelate delivery system. Later, the characteristics of the developed RE doped fiber parameter and the amplifier performance were analyzed. In this work, Erbium is chosen as the active material due to its sufficient information for analysis and the availability of test equipments. The beam profile and the absorption spectrum of the RE doped fiber is also included to show the level of interaction between pump and signal beam inside the fiber core. High overlap factor between the pump and the signal beam is found to be necessary to achieve sufficient amplification. This is proved by the poor amplifier performance exhibited by the developed doped fiber. This work provides useful information for the development of other RE doped fiber implementation such high power or upconversion fiber laser

Small and Medium Enterprises (SMEs) future development: a comprehensive review on customer retention programme in retaining customer loyalty

No AbstractKeywords: small and medium enterprises (SMEs); customer retention program; loyalty;  advantage card; monetary rewar

Multiple soaking with different solution concentration in doped silica preform fabrication using modified chemical vapor deposition and solution doping

Incorporation of alumina (Al2O3) into a silica matrix by modified chemical vapor deposition and a solution doping technique is investigated in this study. Multiple soaking cycles were used to increase the aluminum content in the core layer. The effect of alumina retention in silica matrix soot is focused by multiple cycles of soaking with different solution concentrations, while the effect of the adsorption mechanism is fixed by maintaining the soot deposition process (such as temperature [1,800°C], precursor, total gas flow, and soaking time). The deposited soot is examined for porosity characteristics and effective surface area by a gas adsorption technique with Brunauer-Emett-Teller surface area analysis and the surface and cross-section morphology using scanning electron microscopy. Three different concentrations are used in this work (0.3, 0.7, and 1.2 M) with multiple cycles of soaking. Sintering and the collapsing process is controlled for each preform. The result shows that the alumina content is increased substantially as the number of soaking processes is increased, which may be due to the retention effect as only a small amount of adsorption process takes place as indicated by the slight decrease in the surface area of soot. The collapsed preforms are analyzed using a preform analyzer. Energy dispersive x-ray spectrometry is used to check aluminum content and distribution into the core layer

Aluminum doped silica preform fabrication using MCVD and solution doping technique: effects of various aluminum solution concentrations

This work is described for solution doping in Modified Chemical Vapor Deposition (MCVD) used for silica optical fiber fabrication. This paper will concentrate on aluminum solution doping and the effect of different solution concentrations. The effect of three different concentrations of aluminum (O.3M, O.7M and 1.2M) with the soot undergo heat treatment are studied while the other parameters of MCVD and solution doping are fixed such as deposition temperature, SiCI4 flow, and soaking time. The refractive index profile (RIP) of each doped preform is measured using preform analyzer to investigate aluminum distribution in the core region. Further investigation about Al distribution across the core sintered layer is also examined by EDX techniques

Design and performance of an S-band thulium doped modified silica fiber amplifier

A new design of an S-band Thulium-doped modified Silica fiber co-doped with aluminum is presented. The design goal is high gain and low noise figure in the wavelength range of 1450 - 1520 nm. The optimization considers design parameters such as the cut-off wavelength, dopant concentration, waveguide structure, index profile and numerical aperture. These design parameters are optimized to achieve long fluorescence lifetime, high overlap factor and selected mode excitation. The amplifier performance is theoretically modelled and simulated considering the proposed design optimization. We show that the amplifier can achieve a gain of 16 dB and 3dB noise figure

Fabrication of Tm2O3/Al2O3-silica preform by improved MCVD-chelate delivery system

The fabrication of Tm/Al-doped silica preforms by an improved MCVD method with metal chelate precursors is discussed. Two fabrication techniques are employed, namely; simultaneous soot-dopant deposition (or standard MCVD) and stepwise soot-dopant deposition. The preforms are characterized by refractive index profiler and EPMA. The results show that the stepwise soot-dopant technique has a higher incorporation of Al2O3 and Tm2O3 as compared to the simultaneous soot-dopant method. This is due to the drawbacks of our chelate delivery system such as the temperature gradient and flow design. For the stepwise technique, the measured index difference of the preform is 0.006 with 0.8 wt% (maximum) Tm incorporated in the core

On the fabrication of aluminum doped silica preform using MCVD and solution doping technique

This paper provides detailed discussions on the fabrication of aluminum doped silica preform using solution doping technique and modified chemical vapor deposition (MCVD). The porous core layer was deposited at 1750°C with 30cm in deposition length. The soot formed at the inlet and outlet segment of the deposited length is analyzed using SEM for soot size and BET for pore size distribution. Refractive index profile of the doped preform is measured using preform analyzer. The refractive index difference obtained at the outlet and inlet segments shows uniform distribution of Al2O3, in agreement with the pore size distribution

All fiber optical band-pass filter using macro-bending approach

A new method for optical bandpass filters using macro bending approach is proposed. The proposed optical bandpass filter leverages on bending loss of higher order modes for shorter wavelengths. For longer wavelengths, the filter banks on fiber bending loss as the fundamental mode `tail' is lost in the cladding. The combination of wavelength dependent loss at longer and shorter wavelength gives rise to the optical bandpass filter characteristics. We report both simulation and experimental results, which demonstrates agreement in the spectral response

Effect of GeCl4/SiCl4 flow ratio on germanium incorporation in MCVD process

Germanium and Silica co-deposition in MCVD process is studied with varying the flow ratio of GeCl4/SiCl4 at high temperature without phosphorus. The range of ratio is from 0.1 to 0.6 with temperature deposition 2100°C. The incorporation of germanium in silica matrix is deduced from the EPMA SEM-EDX. The experimental result is compared to theory such as thickness deposited layer and mole fraction of germanium in silica