International Journal of
Physical Sciences

  • Abbreviation: Int. J. Phys. Sci.
  • Language: English
  • ISSN: 1992-1950
  • DOI: 10.5897/IJPS
  • Start Year: 2006
  • Published Articles: 2556

IJPS Articles

The Hodgkin-Huxley neuron model on the fast phase plane

May 2013

In this paper, we showed a simplified version of the Hodgkin-Huxley neuron model, the so called fast plane-phase case. We first describe the circuit model of axon membrane with four parallel branches described by Hodgkin and Huxley and then we apply the Kirchhoff´s laws to obtain a system ordinary differential equations. We obtain numerical solutions to it with the aid of Mathematica. We also study this...

Author(s): William Aristizabal Botero, Alvaro H. Salas and Silvia Janeth Gonzalez Colorado

Control response of electric demand by means of fuzzy logic using programmable logic controller (PLC)

May 2013

This paper presents a controller of the electricity energy consumption for intelligent buildings. Special reference is made to a fuzzy control structure implemented in a programmable logic controller (PLC). Here the function of PLC is not only to connect and disconnect loads in the building, but to make use of vague terms from fuzzy reasoning. Using the class schedule, estimated consumption demand and the actual...

Author(s): J. L. Rojas-Rentería, G. Macias-Bobadilla, R. Luna-Rubio, C. A. Gonzalez-Gutierrez, A. Rojas-Molina and J. L. González-Pérez

A novel bandwidth efficient technique for ICI cancellation in OFDM system

May 2013

A well-known problem of orthogonal frequency division multiplexing (OFDM) is its sensitivity to offset between the transmitted and received carrier frequencies. In OFDM communication systems, the frequency offsets in mobile radio channels deform the orthogonality between subcarriers which causes inter carrier interference (ICI). ICI causes power leakage among subcarriers and it further degrades the system performance....

Author(s): Alka Kalra and Rajesh Khanna

Triangular fuzzy based classification of IP request to detect spoofing request in data network

May 2013

In data nework data packets are normally forwarded from one router to another through networks until it gets to reach its destination node. According to the internet architecture routers in the internet do not perform any security verification of the source IP address contained in the IP packets. The lack of such a verification opens the door for variety of network security vulnerabilities like Denial-of-Service (DoS)...

Author(s): Narayanan Arumugam and Chakrapani Venkatesh

The efficiency of recyclable energies for building design: Cooling system supply for buildings using traditional wind catchers used in the dry and hot climate of Iran and its combination with solar chimney technology

May 2013

In recent years, the concept of the usage of new energies for cooling and heating in buildings has attracted the attention of engineers. In this study, the combination of solar chimneys with wind catchers has been suggested to provide natural and pleasant ventilation. It explains the increased efficiency of wind catchers for cooling through the help of solar chimneys. In addition, with the use of solar energy for moving...

Author(s): Hourieh Abna, Mohammad Iranmanesh, Iman Khajehrezaei and Mohammad Aghaei

Simulation of circular jet outfalls using artificial neural network

May 2013

In the present article, outfall of the circular jet in the stagnant ambient fluid has been investigated. First, dimensional analysis for eleven involved parameters in the process, results in four dimensionless numbers including; relative length of jet trajectory, x/dp; jet convergence angel, θc; geometry number of jet, Di/dp and Densimetric Froude Number, Frd. Furthermore, using an experimental setup in the...

Author(s): Seyed Habib Musavi-Jahromi and Javad Ahadiyan

Eco-partitioning and indices of heavy metal accumulation in sediment and Tilapia zillii fish in water catchment of River Niger at Ajaokuta, North Central Nigeria

May 2013

In this study the distribution and accumulation indices of some heavy metals in sediments and Tilapia zillii fish in freshwater catchment of River Niger by Ajaokuta Steel Company (ASC), North Central Nigeria were investigated. Water, bottom sediments and Tilapia zilliifish samples were collected upstream and downstream of the drainage column by ASC, Ajaokuta. The sample were digested according to...

Author(s): Olatunde Stephen Olatunji and Oladele Osibanjo

Evaluation of properties of coal slurry from different solvents

May 2013

Coal slurries were separately prepared with benzene, ethanol, hexane and water, and the fuel properties of the slurries were examined. The ability of the solvents to dissolve the coal was also evaluated using spectrophotometer in the ultra-violet and visible regions. Some of the slurry properties indicated that the liquid coal have comparable properties to petroleum-based conventional diesel oil. Benzene and hexane were...

Author(s): Ugwu K. E. and Ofomatah A. C.

Numerical investigation on the effect of different parameters on the performance and the emission of a spark ignition (SI) engine

May 2013

In this work, NISSAN Z24 engine was simulated numerically and valves and ignition timings were modified in order to improve the engine performance and emissions. The engine was simulated using a version of the Los Alamos code KIVA-3V2 which is a computer program for the numerical calculation of transient, two and three dimensional chemically reactive flows with sprays. The computational grid was generated by the...

Author(s): H. Mirgolbabaei, M. Bozorgi and M. M. Etghani

Unsteady magnetohydrodynamic (MHD) thin film flow of a third grade fluid with heat transfer and no slip boundary condition down an inclined plane

May 2013

An investigation is made for unsteady magnetohydrodynamic (MHD) thin film flow of a third grade fluid down an inclined plane. The non-linear partial differential equation governing the flow and heat transfer are reduced to a system of non-linear algebraic equations using implicit finite difference approximation to obtain velocity and temperature profile. The effect of various physical parameter on both velocity and...

Author(s): Aiyesimi Y. M. , Okedayo G. T.  and Lawal O. W.

Water defluoridation by bauxite-gypsum magnesite (B-G-Mc) based filters calcined at 350 – 500°C

May 2013

Research was carried out at Ngurdoto research station in Tanzania to ascertain the potential development of a water filter made of bauxite, gypsum and magnesite in an attempt to enhance the availability of low-fluoride water. The materials were sourced within Tanzania. The X-Ray fluorescence technique showed that the major components of the materials were: bauxite: Al2O3 (30.33%), SiO2 (15.0%) and...

Author(s): Thole B., Masamba W. R. L. and Mtalo F. W.

Mineral and heavy metal by inductively coupled plasma optical emission spectrometer in traditional Turkish yogurts

May 2013

Yogurt, a traditional Turkish dairy product is common in all region of Turkey. The different heavy metals were determined in commercial yogurts by inductively coupled plasma optical emission spectrometer (ICP–OES). Concentrations of calcium (Ca), phosphorus (P), sodium (Na), magnesium (Mg), aluminum (Al), zinc (Zn), iron (Fe), copper (Cu), manganese (Mn), boron (B), molybdenum (Mo), cadmium (Cd), cobalt (Co),...

Author(s): Zekai Tarakçı and BeÅŸir DaÄŸ    

Principally supplemented module and lifting property

May 2013

The purpose of this paper is to further study the concept of a very important module theory namely principally supplemented modules. Therefore, our work presents some properties of the relation between lifting property and principally supplemented module. Also we will focus on quasi-discrete module to study principally supplemented in general way. We prove that if R be principal ideal ring and if M be indecomposable...

Author(s): Majid Mohammed and Abd Ghafur

Fuzzy cell mapping on dynamical systems

May 2013

Fuzzy cell mapping is a novel computational technique that combines fuzzy logic and a simple cell mapping method. In a simple cell mapping method, the information about mapping locations of image cells is never incorporated into the method. This limits the usage of a simple cell mapping method. In our fuzzy cell mapping method, we account for the mapping locations of image cells and incorporate the information by...

Author(s): Y. Song, D. Edwards and V. S. Manoranjan

Iris localization through Hough clustering

May 2013

Occlusion, reflections and iris shape deformations are the obstacles that stand in the way of a complete solution to iris localization problem. How to reject outliers caused by occlusion and reflections as much as possible before ellipse or spline fitting is a key challenge. For this reason, we proposed a Hough clustering method, which utilizes the shape configuration of iris edge points and their local appearance...

Author(s): Lili Pan and Mei Xie

Enhancement of cutting tool surface coating quality using ionized gaseous medium (IGM)

May 2013

The use of ionized gaseous medium (IGM) to prepare a hard alloy material surface by grinding and its effect on the coating quality was investigated. During grinding, IGM was fed to the cutting area by different methods namely: clockwise (longitudinal), anticlockwise (opposed) and transverse (Cross) feeding, respectively. Thereafter, the samples were coated with a titanium nitride on a modern vacuum, ionizing apparatus...

Author(s): S. O. Yakubu

Dimensional stability of mirror materials for opto-mechanical reference system

May 2013

Sensors, IR beams and lasers used in many opto-mechanical systems have stringent alignment retention requirements for use over an extended temperature range. Thermal effects are the primary cause for alignment drift during operation. Thermal expansion and contraction of materials can result in dimensional instability of mirror surfaces. This paper focuses on the importance of dimensional stability of mirror materials in...

Author(s): R. Baskaran, P. Sivakumar and D. Arivuoli

The effects of various drip fertigated water quantities on flavonoid and anthocyanin content on hydroponically cultivated Cucumis sativa L.

May 2013

The effects of various quantities of water were assessed on their potential to influence the content of flavonoid and anthocyanin contents in different tissues of cucumber plants grown hydroponically in the greenhouse. The treatments included supplying eight different water quantities 2, 4, 6, 8, 10, 12, 14 and 16 L/h. The plants received water five times a day, making it 10, 20, 30, 40, 50, 60, 70 and 80 L/day. The...

Author(s): Donavon Sonnenberg, Patrick A. Ndakidemi and Charles Laubscher

The effects of adding the aluminum sulfate to the urea formaldehyde adhesive applied on plywood

May 2013

In the present study, the effects of adding the aluminum sulfate to the urea-formaldehyde (UF) adhesive, on the bonding characteristics and free formaldehyde content, have been studied. Experiments were conducted on the three layered plywood of ekaba (Tetraberlinia bifoliolata) and poplar (Populus x eureamericana), prepared by adding aluminum sulfate to the adhesive mixtures of these tree species in certain amounts....

Author(s): Murat Ozalp, Hasan Kabak, Abdi Atilgan and Hüseyin Peker

Combustion properties of Rowan wood impregnated with various chemical materials

May 2013

The common use of Rowan wood (Sorbus aucuparia Lipsky) in the forest products industry of Turkey, was evaluated for some of the combustion properties after impregnation with various chemical materials. For this purpose, the wood test samples prepared from Rowan wood materials according to TS 345 were treated with Tanalith-E, Vacsol-Azure, Imersol-Aqua and Boron compounds (Borax and Boric asid) by the vacuum...

Author(s): Hakan Keskin, Neslihan Süzer Ertürk, Mustafa Hilmi ÇolakoÄŸlu and Süleyman Korkut

The effects of heat treatment on some mechanical properties of laminated black pine (Pinus nigra)

May 2013

Black pine (Pinus nigra) has high industrial usage potential and large plantation in Turkey. Larch wood was treated with heat to determine its mechanical properties, such as bending strength and pressure and order to determine its adhesion strength. Laminating adhesives are used for the construction of polyvinyl acetate and polyurethane. Heat treatment was applied to the samples at 100-150°C for 4 h in drying oven....

Author(s): Mustafa ORDU⊃, Abdi ATILGAN⊃, Murat OZALP⊃ and Huseyin PEKER⊃

Production and evaluation of activated carbon from palm kernel shells (PKS) for economic and environmental sustainability

May 2013

Activated carbon (AC) was produced from palm kernel shells (PKS) by acid activation method at temperature of 600°C. The effects of carbonization and acid impregnation time on the adsorption potential of the ACs on purification of contaminated rain and flowing river water bodies were examined. The results were compared with results of similar analysis based on commercial AC purchased from a nearby chemical shop. The...

Author(s): Okoroigwe, E. C., Ofomatah, A. C., Oparaku, N. F. and Unachukwu, G. O.

Synthesis of nickel ferrite nanoparticles by co-precipitation chemical method

May 2013

In this research work, we have prepared nickel ferrite nanoparticles by using chemical route. Nanoparticle materials are characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometer (VSM),transmission electron microscopes (TEM) and energy dispersive X-ray (EDX) systems. We have determined magnetic properties, size,...

Author(s): Aliahmad, M., Noori, M., Hatefi Kargan, N. and Sargazi, M.    

High power Bessel-like laser beam by thin disk geometry

May 2013

We have numerically shown that a high power Bessel-Gauss beam can be generated by a solid state thin disk laser using an axicon-based resonator. Ytterbium ions doped in the Yttrium Aluminum Garnet (YAG) crystal was utilized in this configuration as an active medium. We obtained the output power, the intensity as well as phase profiles on the output coupler and the active medium.   Key...

Author(s): R. Aghbolaghi, S. Batebi and J. Sabaghzadeh

A learning automata-based algorithm using stochastic minimum spanning tree for improving life time in wireless sensor networks

May 2013

Several algorithms have already been provided for problems of data aggregation in wireless sensor networks, which somehow tried to increase networks lifetimes. In this study, we dealt with this problem using a more efficient method by taking parameters such as the distance between two sensors into account. In this paper, we presented a heuristic algorithm based on distributed learning automata with variable actions set...

Author(s): Chamran Asgari, Rohollah Rahmati Torkashvand and Masoud Barati

Performance evaluation of broadband access network based on subcarrier multiplexing (SCM): Spectral amplitude coding optical code division multiple access

May 2013

A hybrid spectrally amplitude coded (SAC) optical code division multiple access (CDMA) with subcarrier multiplexing (SCM) scheme is a potential candidate for future broadband access solutions in the communication network. In this work, the performance of hybrid technique is investigated. Theoretical derivations are developed based on the zero cross correlation (ZCC) code. The performances are evaluated taking into...

Author(s): Junita Mohd Nordin, Syed Alwee Aljunid, Anuar Mat Safar, Amir Razif Arief, Rosemizi Abd Rahim, R. Badlishah Ahmad and Naufal Saad

Feature subset selection using association rule mining and JRip classifier

May 2013

Feature selection is an important task in many fields such as statistics and machine learning. It aims at preprocessing step that include removal of irrelevant and redundant features and the retention of useful features. Selecting the relevant features increases the accuracy and decreases the computational cost. Feature selection also helps to understand the relevant data, addressing the complexity of dimensionality. In...

Author(s): Waseem Shahzad, Salman Asad and Muhammad Asif Khan

Hybrid wavelength division multiplexing/time domain multiplexed (WDM/TDM) using radio over fiber technique with 16QAM at 2.5 Gbps

May 2013

There is growing demand for higher bit rates in the access domain due to the emergence of bandwidth-hungry applications such as video-on-Demand and file sharing. Gigabit-capable passive optical network (GPON) is the most important PON. In a hybrid wave division multiplexing/time division multiplexing (WDM/TDM passive optical network (PON), Quadrature amplitude modulation (QAM) is proposed as a way to achieve...

Author(s): A. O. Aldhaibani, S. A. Aljunid, Hilal A. Fadhil and M. S. Anuar

New monitoring method based principal component analysis and fuzzy clustering

May 2013

This work concerns the principal component analysis applied to the supervision of quality parameters of the flour production line. Our contribution lies in the combined use of the principal component analysis technique and the clustering algorithms in the field of production system diagnosis. This approach allows detecting and locating the system defects, based on the drifts of the product quality parameters. A...

Author(s): Khaled Ouni, Hedi Dhouibi, Lotfi Nabli and Hassani Messaoud

An investigation to compare the effectiveness of packet loss based on proposed methods in literature

May 2013

Optical flow routing is an optical networks that technique used to ensure that the packet is always in the sequence order. This research is intended to ensure that the network traffic is enhanced of the quality of service (QoS). An analytical method is used in order to show its effectiveness of flow routing. There are three cases that have been investigated in this research investigation namely, packet discards (PD),...

Author(s): A. A. Rahman, K. A. Noordin and H. M. Farhad

Application of vertical electrical sounding and horizontal profiling methods to decipher the existing subsurface stratification at river Segen dam site, Tigray, Northern Ethiopia

May 2013

The study area Segen river dam site is situated in the southeastern zone of Tigray National Regional State in between Hintalo Wajirat and Enderta Weredas. It is geographically located at 37P between 541400 to 542600 UTME Latitude and 1481600 to 1482600 UTMN Longitude about 35 km southwestern part of Mekelle, the capital of Tigray National Regional State. The study was conducted having an objective of the geophysical...

Author(s): Abraham Bairu, Yirgale G/her and Gebrehiwot G/her

Culmination of the Quantum theory in Sri Aurobindo’s poetic consciousness

May 2013

The Quantum theory visualizes that uncertainty is the ultimate truth behind the dualism of wave and particle at the sub-atomic plane of Matter. It does not find any physical law capable of explaining the physical state in which the conversion of wave into particle and vice-versa takes place at the sub-atomic plane of Matter. In fact, the conversion evades all the physical laws on account of which Werner Heisenberg...

Author(s): Nikhil Kumar

Magnetic Field Effects on Entropy Generation in Heat and Mass Transfer in Porous Cavity

May 2013

The entropy generation for natural convection heat and mass transfer in a two dimensional porous cavity subjected to a magnetic field is selected for numerical investigation. The Darcy model is used in the mathematical formulation of the fluid flow in porous media. The mathematical model is derived in dimensionless form and the governing equations are solved using the finite volume method. The governing parameters arise...

Author(s): Nawaf H. Saeid

Applications of Schrödinger equation in general Besov spaces

May 2013

In this paper, we obtain solution of Schrödinger equation in general Besov spaces. Precise results on  and general Besov estimates of the maximal function of the solutions to the Schrodinger equation are given. The obtained results improve some recent results. Further, we shall consider estimates of general -norm and the general Besov type norm of integrals of this kind by means of the...

Author(s): Essam Edfawy

Comparison study between differential transform method and Adomian decomposition method for some delay differential equations

May 2013

A numerical method based on the differential transform method (DTM) and the Adomian decomposition method (ADM) is introduced in this paper for the approximate solution of delay differential equation (DDE). The algorithm is illustrated by studying an initial value problem. The results obtained are presented and show that only few terms are required to obtain an approximate solution which is found to be accurate and...

Author(s): K. R. Raslan, and Zain F. Abu Sheer

On the Fekete-Szegö like inequality for meromorphic functions with fixed Residue

May 2013

In the present paper, we will consider the class of meromorphic starlike functions with fixed residue .   Silverman et al. (2008) has obtained sharp upper bounds for Fekete-Szegö like functional  for certain subclasses of meromorphic functions. In this paper, we will find sharp upper bounds for  for the class meromorphic starlike functions with fixed residue . The aim of the...

Author(s): Sultan AYTAÅž and H. Ozlem GUNEY

On three-dimensional quasi-Sasakian manifolds admitting semi-symmetric metric connection

May 2013

The object of the present paper is to study three-dimensional quasi-Sasakian manifold equipped with semi-symmetric metric connection. The geometrical properties of conformal curvature tensor and the conservative quasi-conformal curvature tensor are discussed with such connection. Among other we have deal the conservative properties of quasi-conformal curvature with respect to semi-symmetric metric...

Author(s): Sunil Yadav and D. L. Suthar

On enhanced control charting for process monitoring

May 2013

The information on auxiliary characteristics helps significantly in increasing the efficiency of control charts for detecting shifts in process parameters. In this study we proposed Shewhart type control charts, namely the  chart, the  chart and the  chart, which utilizes information on two auxiliary characteristics (X and Z) for improved monitoring of process location parameter...

Author(s): Saddam Akber Abbasi and Muhammad Riaz 

Frame structure for Mobile multi-hop relay (MMR) WiMAX networks

May 2013

Mobile Multi-hop Relay (MMR) WiMAX network uses Relay stations (RSs) to extend the cell coverage, and enhances the link quality and the throughput. In MMR WiMAX networks, the number of hops between the Subscriber stations (SSs) and the Base station (BS) is allowed to be more than two hops when Non transparent RS (NT-RS) is used. However, this requires modification to the frame structure of NT-RS to reduce the delay of...

Author(s): F. E. Ismael, S. K. Syed-Yusof, M. Abbas, N. Fisal and N. Muazzah  

Mobile agent based clustering and maintenance using secure routing protocol for mobile ad hoc network

May 2013

Routing in mobile ad hoc network is the challenging task due to the dynamic nature and resource limitations of network. Network clustering deals with partitioning network into clusters based on some rules. Clustering guarantees limited resource utilization and network scalability. In this paper, we mainly focused on using mobile agents for collecting information about cluster members and cluster maintenance. Ensuring...

Author(s): R. Pushpa Lakshmi and A. Vincent Antony Kumar

Multi-band meta-material structures based on hexagonal shaped magnetic resonators

May 2013

In this paper, we propose a new multi band meta-material structure composed of a unit cell that has multiple hexagonal-shaped metal rings printed one inside the other. The introduced meta-material composition exhibits multi-resonant behavior due to distinct magnetic resonances caused by the self and mutual coupling of each inclusion. The number of distinct magnetic resonances is determined...

Author(s): H. Benosman and N. Boukli Hacene      

A method of dual-process sample selection for feature selection on gene expression data

May 2013

A method of dual-process sample selection based on support vector machine (SVM) is proposed to select informative features in this paper. Samples in a training set are used to train a SVM model, and the samples excluding support vector samples are chosen to select critical features in the procedure of recursive feature elimination (RFE). The effect of the dual-process sample selection method on feature selection is...

Author(s): Quanjin Liu, Zhimin Zhao, Ying-xin Li and Xiaolei Yu

Mechanical properties of microwave sintered 8 mol% yttria stabilized zirconia

May 2013

This paper reports the synthesis and characteristics of nano sized 8 mol% yttria stabilized zirconia (8YSZ). The nano sized 8YSZ powder (15 nm) has been prepared by the sol-gel technique. The phase formation was confirmed by the X-Ray Diffraction (XRD) analysis and the particle size verified by transmission electron microscope (TEM). The prepared 8YSZ green samples were sintered in a microwave furnace at 1500°C for...

Author(s): P. Ganesh Babu, and P. Manohar  

Regional variation of columnar refractivity with meteorological variables from climate monitoring satellite application facility (CM SAF) data over Nigeria

May 2013

Data from satellite application facility on climate monitoring (CM SAF) have been used to estimate and study seasonal variation of columnar refractivity in relation with relative humidity and temperature for twenty six stations categorized into four climatic regions (coastal, Guinea savannah, midland and sub Sahel regions) over Nigeria. Mean, standard error, maximum, minimum values and ranges of these...

Author(s): I. Emmanuel, B. Adeyemi and K. D. Adedayo

Lead contamination of traditional hand-dug wells in parts of Kwale County, Kenya

May 2013

People’s health, behavior and intellect to a certain extent are a function of their environment. One important component of this environment is water, a basic necessity that human beings cannot do without. The water available, however, is not always safe for human consumption due to contamination. Among the many water contaminants, lead (Pb) is one of the most dangerous due to its bio-accumulative nature and high...

Author(s): M. W. Chege, N. O. Hashim, A. S. Merenga and J. Tschiersch

Toxicity of arsenic (As) on seed germination of sunflower (Helianthus annuus L.)

May 2013

The effect of different levels (2, 4, 6, 8 and 10 mg/L) of arsenic (as sodium arsenate and sodium arsenite) on germination percentage, mean germination time, days to 50% germination, plumule and radicle length and seedling vigour index of four sunflower cultivars (FH-331, FH-385, FH-405 and FH-415) was determined under laboratory conditions. Germination percentage was gradually decreased with the increase in arsenic...

Author(s): Muhammad Asif Imran, Muhammad Nawaz Ch, Rass Masood Khan, Zulfiqar Ali,and Tariq Mahmood

Decomposition method for fractional partial differential equation (PDEs) using Laplace transformation

April 2013

In this Paper, we propose an efficient combination for the solution of partial differential equations (PDEs). In a similar context, decomposition coupled with Laplace transform is applied to solve partial differential equations of fractional order. It is observed that the proposed technique is highly suitable for such problems. The results of the proposed scheme are highly encouraging and efficient. It is also...

Author(s): Naveed Imran and Syed Tauseef Mohyud-Din

Environmental production of fashion colors from natural dyes

April 2013

Dyeing is one of the most delightful textile arts which are an important branch in fashion design. Natural dye is a fascinating phenomenon that enticed researchers to their chemistry and production of fantastic novel hues to explore the point that no other dyes provide a better opportunity teaching how to protect and respect the environment. In this research, silk fabric was dyed by a mixture of different percentages of...

Author(s): Khadijah Q. and Heba M.,

A preliminary investigation of the signal-to-noise ratio of Toro and Nsukka stations in Nigeria

April 2013

Preliminary investigation of Toro and Nsukka stations from the Nigerian National Network of Seismographic Stations (NNNSS) with respect to Signal-to-Noise-Ratios (SNR) has been performed from noise observation and numerically. The results showed that Toro has higher SNR compared to Nsukka. Six months data collected from the stations in 2012 were used for the study. Nsukka Station in the southern part of Nigeria...

Author(s): Kadiri Umar Afegbua and F. O. Ezomo

Widely tunable micro electromechanical systems (MEMS)-vertical-cavity surface-emitting lasers with single transverse mode operation

April 2013

In this paper, a micro electromechanical systems vertical-cavity surface-emitting laser (MEMS-VCSEL) with asymmetric double oxide aperture and highly strained GaInNAsSb quantum wells for widely tunable, single mode and high temperature operation has been investigated. The MEMS-VCSEL is based on an integrated two-chip concept which allows us to extend the single wavelength performance to a continuously tunable,...

Author(s): Seyed Mahdi Hatamian, Vahid Ahmadi and Elham Darabi

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