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This paper investigates the response of railway track to train loads while rested on an embankment. For this purpose, track structure was divided into two parts, in one of which the rail was modelled as a continuous Euler-Bernoulli beam and in another sleeper, ballast and embankment were considered as an integrated lumped masses system. To obtain the mass and stiffness of embankment, the 'ballast pyramid model' was developed and, consequently, the response of the whole track system was investigated. The vehicle was assumed to be a ten-degree-of-freedom lumped masses system. The dynamic equilibrium equations of the vehicle-track coupling system were solved in the time domain and the track response was evaluated against applied dynamic loads. As a part of the study, a sensitivity analysis was undertaken on embankment parameters, namely embankment height, stiffness and damping. The results of numerical modelling and sensitivity analysis reveal that, among the aforementioned parameters, embankment height had a remarkable effect on the track dynamic response. [ABSTRACT FROM AUTHOR]

This paper deals with the modeling of a vertically coupled vehicle-slab track using the finite element, method. The slab track system is represented by a two layer Euler-Bernoulli beam model, including a rail and a concrete slab. The vertical stiffness of the track bed is assumed to be a random variable using Monte Carlo simulation. The vehicle is simplified as a multi-body system with 10 degrees of freedom. The accuracy of the simulation is verified by deterministic and random approaches, as well. Sensitivity analyses of the various parameters such as slab thickness, coefficient of track bed stiffness and vehicle velocity are performed. It is demonstrated that the uncertainty in track bed stiffness has a major effect on rail and slab deflections. From a practical point of view, the obtained results of the present study can be utilized efficiently in the analysis and design of slab track systems. [ABSTRACT FROM AUTHOR]

Existence of soft soil layers and high ground water level in the Qom Salt Lake area have caused deflection more than allowable limitation in Tehran- Isfahan high speed track railway. Due to reduce deflection of track railway in this area, improving the stiffness and strength of the soil beneath will be done by means of concrete pile group. But also, due to the high speed of train, resonance phenomenon is expected to happen. Despite conducting some researches on the effect of improving soft ground by pile in recent years, but there are ambiguities about performance of pile on the increasing critical speed of the track-ground system which track has been experienced large dynamic amplification as the train speed approaches that speed. So first, the bearing capacity of pile and soil layers geotechnical parameters have been determined by comparing the numerical modeling results of single pile with data obtained from in situ compressive loading test on that in this paper. Afterwards, the effect of the geometrical dimension pile group on the dynamic behavior and critical speed of track-ground system has been investigated under various speed of train (60–450 km/h) using 3D finite element model. The results indicate that resonance phenomenon has been occurred at speed of 100 km/h, which is equal to Rayleigh speed of first subgrade layer. However, improving of soil layers by pile group increases the value of the critical speed to 250 km/h. • Improving the stiffness and strength of the salty soil beneath the high-speed railway by means of concrete pile group. • Determination of bearing capacity of single pile using both field load test and FE numerical simulation. • Assessing effect of geometrical dimensions of pile group on critical speed of track-ground system. • Improving of soil layers by pile group with S/D = 5 increases the value of the critical speed to 250 km/h. • Decreasing S/D lesser than 2 has no efficiency in increasing the critical speed over 300km/h. [ABSTRACT FROM AUTHOR]

Background and Objective: Amygdalin is likely to have analgesic and metabolic effects. In this study, the effects of chronic administration of amygdalin were investigated on the pain threshold, weight and blood sugar of mice. Materials and Methods: In this experimental study, formalin test was used as a chronic inflammatory model of pain. 60 mice (30-35 g) were divided into four groups (n=15) including: control and amygdalin 10, 25 and 50 mg /kgw groups. Amygdalin was solved in saline and injected intraperitoneally every day at 9-10DP. The control group received saline intraperitoneally for one week. After the last treatment, 40µl formalin (2.5%) was injected to the right hind paw of the mice and pain symptoms (frequency of collecting flinching of the back skin and licking injection site) were recorded for 60 min. Weight of the mice was measured before and after the last treatment with amygdalin. Blood glucose was also measured at the end of the experiment. Results were analyzed by using one way ANOVA and Tukey or paired t-test. Results: Intraperitoneal injection of 10, 25 and 50 mg/kgw doses of amygdalin reduced pain in male mice. In concentration of 50 mg/kg, not only the pain was completely inhibited but the animals' weight also decreased compared to pre-treatment period. Chronic injections of amygdalin had no impact on normal blood sugar levels. Conclusion: Chronic intraperitoneal injection of amygdalin increases pain threshold in mice and may also cause weight loss. [ABSTRACT FROM AUTHOR]

In this article, we describe the preparation procedure of poly(ether sulfone)/poly(vinyl alcohol) (PVA) composite membranes based on film casting and evaporation methods. The morphology and operation of these membranes in the ethylene/ethane separation process were investigated. AgNO3 and AgBF4 salts were applied in the PVA active layer as carrier agent providers. Salt addition to PVA solution weakened the hydroxyl bond potency and fortified the position of carrier agent in the active layer structure. Scanning electron microscopy with energy-dispersive X-ray spectrometry revealed that the distribution fluctuation of carrier agents in the active layer increased with increasing salt concentration. The glass-transition and α-relaxation temperatures of the salt-containing membranes were lower than those of salt-free membranes. In addition, the polymeric structure of the salt-containing membranes showed crystallinity during the heating process at temperatures higher than 160°C. Atomic force microscopy indicated that the surface roughness of composite membranes with smoother sublayers was greater than that of other membranes. The mechanical strength of membranes containing silver nitrate salt was higher than that of the salt-free membranes. Permeation tests demonstrated an increase in the gas permeation and membrane selectivity after salt incorporation. A performance improvement in the facilitated transport mechanism was associated with increasing salt concentration. However, a higher operational pressure had an inverse impact on it. The saturation of active sites with ethylene molecules at higher pressures and the low plasticity of the created complexes in the membrane structure decreased the performance of the facilitated transport mechanism. The addition of AgBF4 salt, with a lower lattice energy compared to AgNO3, increased the real performance of the membranes. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]

Highlights: [•] PPF reduces the compressive strength. [•] Both splitting tensile and flexural strengths increase first and then decrease with higher amount of fiber. [•] According to SEM, and XRD, fibers could not participate in any chemical reactions. [•] Fibers could reduce permeability and capillary porosity by pore blocking effect. [•] PPF has enhanced the durability of concrete. [Copyright &y& Elsevier]

The objective of this paper is to derive the mathematical model of two-dimensional heat conduction at the inner and outer surfaces of a hollow cylinder which are subjected to a time-dependent periodic boundary condition. The substance is assumed to be homogenous and isotropic with time-independent thermal properties. Duhamel's theorem is used to solve the problem for the periodic boundary condition which is decomposed by Fourier series. In this paper, the effects of the temperature oscillation frequency on the boundaries, the variation of the hollow cylinder thickness, the length of the cylinder, the thermophysical properties at ambient conditions, and the cylinder involved in some dimensionless numbers are studied. The obtained temperature distribution has two main characteristics: the dimensionless amplitude ( $$A$$) and the dimensionless phase difference ( $$\varphi $$). These results are shown with respect to Biot and Fourier and some other important dimensionless numbers. [ABSTRACT FROM AUTHOR]

Abstract: In this research, mixtures of Cu(NO3)2 and AgBF4 salts were used in preparation of poly(ethersulfone) (PES)/poly(ethylene oxide) (PEO) composite facilitated transport membranes. Reduction of carrier agent is known as the main challenge for this type of membranes. The effect of salt blending on the reduction behavior of silver carrier sites was analyzed through permeation and structural properties of composite membranes. Based on UV–Visible, mixed and ideal permeation experiments, the existence of copper divalent cations beside silver monovalent cations will result in delay in reduction time of silver cations. Therefore, the membrane selectivity is retained at higher values. However, starting selectivity of membranes containing silver salt ions (case 2) with concentration above threshold level is higher than other membranes containing both salts (case 1). TEM analysis proved that size and quantity of silver nanoparticles in the membranes of case 1 are less than membranes of case 2. Applying copper salt increased the potential of ions aggregated distribution in membranes structure according to FTIR–ATR analysis. Aggregation is one of the reasons for less initial separation potency in comparison with membranes without copper salt. Incorporation of cooper salt enhanced the surface roughness and mechanical strength of initial membranes containing silver salt alone. [Copyright &y& Elsevier]

ESMAEILI M., DEHGHAN-NAYERI N. & NEGARANDEH R. (2012) A review of the opportunities and challenges facing the nursing associations in Iran. International Nursing Review 59, 168-174 Background: Nursing associations and organizations are deemed to be effective tools in promoting the profession. Professional nursing associations are an essential part of the nursing culture. Examining the challenges and opportunities confronting the associations would pave the way for the identification of their limitations and also would lead to more interactions among the members and the associations. Methods: Following an extensive review of the literature and also examining the professional nursing associations in Iran, the common challenges facing the nursing associations are identified and their shared challenges with other associations in other countries have been explored. Lack of members and insufficient support from the associations, financial problems, non-professional activities of associations and lack of interactions among associations are among the important challenges that the nursing associations confront within Iran. The possibility for establishing specialized nursing associations for increasing teamwork activities can be pointed out as one of the available opportunities. Conclusion: Professional associations follow important priorities with regard to their objectives, which distinguishes each from the other. The clear introduction of objectives and pinpointing the convergences that might bring about clashes between them will lead to building confidence among nurses, and hopefully, increasing membership. Members' dynamic participation, and support and interactions between associations are among the measures for increasing the professional power. Researchers hope that this article could provide both nurses and professional associations with insights to support each other for the purpose of promoting professional development. Considering the insufficient research in the field, more studies are also suggested. [ABSTRACT FROM AUTHOR]

Paper-based conductive electrode materials of polypyrrole (PPy) and nanocellulose (NC) have received much attention lately for applications in non-metal-based energy storage devices, ion exchange, etc. The aim of this study was to study how the primary characteristics of NC raw materials impact and electrochemical properties of conductive NC-PPy composite sheets. Three NC raw materials were used: Cladophora cellulose (NC) produced at Uppsala University, Cladophora cellulose (NC) produced at FMC Biopolymer, and microfibrillated cellulose (NC) produced at Innventia AB. Composite paper sheets of PPy coated on the substrate NC material were produced. The NC raw materials and the composites were characterized with a battery of techniques to derive their degree of crystallinity, degree of polymerization, specific surface area, pore size distribution, porosity, electron conductivity, charge capacity and tensile properties. It was found that the pore size distribution and overall porosity increase upon coating of NC fibres for all the samples. The charge capacity of the composites was found to decrease with the porosity of the samples. It was further found that the mechanical strength of the pristine NC sheets was largely dependent on the overall porosity, with NC having the highest mechanical strength and lowest porosity in the series. The mechanical properties of the composite NC-PPy sheets were significantly diminished as compared with pristine NC sheets because of the impaired H-bonding between fibres and PPy-coated nanofibres. It was concluded that to improve the mechanical properties of PPy-NC sheets, a fraction of additive bare NC fibres is beneficial. Future study may include the effect of both soluble and insoluble additives to improve the mechanical strength of PPy-NC sheets. [ABSTRACT FROM AUTHOR]

Purpose: With the aim of facilitating core fistulectomy of high fistula-in-ano and reducing the risk of harmful injuries to sphincter muscles, we fabricated a novel fistulectomy set. Methods: The set circumferentially separates approximately 2.5 mm thickness of the tract by moving a special tubular blade along it and removes the separated tissues by rotating a special cannulated screw which is housed in the blade. A straight rigid probe is used for identifying the tract path and guiding the device along it. Results: We used this set for circumferential excision of fistula models created in cubic pieces of fresh cow muscle with excellent results. Conclusions: With regard to results of our tests, it is anticipated that the new set will provide significant advantages in treatment of high anal fistulas, namely noticeable reduction in the diameter of fistulectomy lumen, reducing the injuries to anal sphincters, minimizing the risk of faecal incontinence and shortening the convalescence period. [ABSTRACT FROM AUTHOR]

Abstract: Structural and permeation properties of PES/PVP electrolyte composite membranes including association and dissociation behavior of silver nitrate salt within the polymer structure, structural situation of electron donor groups of membranes, surface and structural charge of membranes, crystalline variation of membrane active layer before and after salt addition and permeation properties of these membranes at different pressures including low pressures were evaluated. Structural evaluation through FTIR analysis revealed that the distributional condition of carrier agents is affected by increasing the AgNO3 concentration. The efficiency of carriers for ethylene transportation is decreased by salt addition at molar concentrations more than 25%. However, according to the results obtained from zeta potential experiment, increasing the salt concentration enhances the surface and structure charge of membranes. Due to the salt crystals formation, the ascending trend of active layer crystallinity stopped at a salt molar concentration more than 25%. These physical and chemical reactions in the active layer structure caused the ethylene selectivity of final membranes to decrease at a salt molar concentration being more than 25%. The separation efficiency of a membrane with the AgNO3 concentration of 25% was the most efficient situation. Adding a very thin and flexible PDMS layer on the surface of PES/PVP membrane in order to increase the real and ideal ethylene selectivity in the separation process was effective. Moreover, blending AgBF4 and AgNO3 salts was a new method for selectivity increament, which was applied in this research. [Copyright &y& Elsevier]

Objective: Behçet's disease (BD) is an inflammatory disorder of unknown cause with higher prevalence along the ancient Silk Road. BD shares epidemiological and clinical features with familial Mediterranean fever (FMF). Moreover, association of BD and certain MEFV gene mutations has been described in recent decades. We studied the role of MEFV mutations in Iranian Azeri Turkish patients with BD. Methods: Fifty-three BD patients who met the International Study Group criteria for BD were analysed for five common MEFV mutations (M694V, V726A, M680I, M694I, and E148Q) using amplification refractory mutation system and polymerase chain reaction (PCR) restriction-digestion testing methods. A cohort of 200 healthy Azeri Turkish individuals who had been previously genotyped regarding the five common MEFV mutations served as the control group. Results: Eighteen patients were found to carry a single MEFV mutation and one additional patient was compound heterozygote. There was a statistically significant difference between the patient group and ethnically matched healthy individuals regarding M694V and M680I mutations (p  =  0.01 and p  =  0.04, respectively). Both BD groups (carriers and non-carriers of MEFV mutations) were similar in their clinical symptoms. Conclusion: Definite MEFV mutations seem to be a susceptibility factor for BD in our cohort of Iranian Azeri Turkish patients. [ABSTRACT FROM AUTHOR]

Abstract: Multi-domain network survivability is a key problem area and crankback signaling offers a very viable alternative for post-fault restoration. However, although some initial multi-domain crankback studies have been done, most have not considered post-fault recovery. Along these lines, this paper proposes a novel solution framework for joint intra/inter-domain crankback restoration in realistic MPLS/GMPLS network settings. Namely, dynamic link failure and intra-domain link-state routing information is coupled with the available inter-domain path/distance vector routing state to improve the recovery process. Mechanisms are also introduced to limit crankback overheads and delays. The performance of the proposed solution is then analyzed using simulation. [ABSTRACT FROM AUTHOR]

Aims: Colorectal cancer (CRC) is one of important malignancies in the world and is the most frequent gastro-intestinal cancer. There is limited data on epidemiologic features and related factors of this malignancy in Iran. The aim of this study was to investigate the epidemiologic features and survival analysis of colorectal cancer and some of its related factors in Iran. Materials & Methods: This case series descriptive study was performed on 241 colorectal cancer patients who referred to a hospital in Tehran from 2004 to 2009. Data collection was based on medical records and phone calls. Survival analyses were constructed using the Kaplan-Meier and Cox-regression methods in order to determine the survival and compare the survival rates in subgroups. Data was analyzed by SPSS 15 software. Results: Mean age of participants was 59.7±14.7 years, 22.4% were smoker and 24.5% had family history of CRC. Rectum cancer was the most common anatomic site of CRC and cancer grading reported well differentiation in most cases. 83.8% of study units were alive till the end of study. The mean survival time was 56.5±1.9 months. The lowest and highest mean survival time were 47.7±5.8 for secum cancer and 61.1±3.2 for non smokers respectively. The highest odds ratio of survival was 2.12 (95% CI: 0.28-15.87) and belonged to patients with rectum cancer. Conclusion: The mean survival time for CRC is about 5 years and depends on some risk factors. Evaluation of these risk factors seems to be necessary in lower ages. [ABSTRACT FROM AUTHOR]

Aims: Ischemic preconditioning is a powerful physiological process in which previous exposure to transient cardiac ischemia provides protection against lethal ischemia. Several pharmacological agents can induce the same effects as this process, including drugs used in anesthesia that one of them is Remifentanil. The purpose of this study was to evaluate the effect of Remifentanil preconditioning on coronary artery bypass graft patients. Materials & Methods: This study is a randomized clinical trial which was performed on 54 patients, Scheduled for elective CABG surgery in year 2009. Patients were randomly divided into two groups. The Remifentanil group received Remifentanil and the control group received normal saline. Then 5 samples were taken from patients at pre-induction, 2, 6, 12 and 24 hours after the release of aortic cross clamp in order to measure cardiac troponin I (cTnI). Postoperative inotropic use in ICU, length of ICU admission and hospital stay were recorded. Data was analyzed using inferential statistical tests including exact Fisher, Chi square, multiple measurements and independent t-test, by SPSS 14 software. Results: There was no significant statistical difference between troponin I level, inotorpe use, and hospital and ICU lengths of stay between the two groups. Conclusion: The protective effect of Remifentanil on myocardium was not proved in this study. Further studies with higher sample volume are necessary for definite confirmation. [ABSTRACT FROM AUTHOR]

Abstract: A low-complexity method for constructing a large class of high-rate girth-8 quasi-cyclic low-density parity-check (LDPC) codes with moderate length is presented. This method is based on combining configurations with incidence matrices composed of cyclic permutation matrices and Tanner graph girth at least 8. Shortened lattice codes of length and girth 8 are employed as component codes. From the performance perspective, the resulting codes are comparable to their counterparts such as random-like and shortened array LDPC codes. [Copyright &y& Elsevier]

Abstract: Next-generation SONET/SDH provides carriers with new capabilities for building advanced Ethernet data services. Along these lines, numerous Ethernet-over-SONET studies have been done, with most focusing on point-to-point private line type services. This paper introduces the more challenging problem of provisioning multi-point-to-multi-point Ethernet LAN services over inverse-multiplexing networks and proposes novel overlay strategies based upon star, bus, and minimum spanning tree topologies. Multi-tiered protection schemes are also developed to help set up these respective overlay designs. Detailed simulation results are then presented along with directions for future work. [Copyright &y& Elsevier]

Abstract: A class of maximum-girth geometrically structured quasi-cyclic (QC) low-density parity-check (LDPC) codes with column-weight is presented. The method is based on the slope concept between two circulant permutation matrices and the concept of slope matrices. A LDPC code presented by a parity-check matrix , consisting of matrices each of which is either a circulant permutation matrix or a matrix with no nonzero entry, is called a -circulant LDPC code, or just a -circulant LDPC code. Let be a configuration; that is it has points, its blocks are of size , and any two points are contained by at most one block. A -circulant LDPC code with a parity-check matrix is called a configuration-based code if the set together with is a configuration where is the subset of specifying the set of nonzero block positions of the th block-column of . Let be a matrix over . Under a certain condition, the matrix is called a -slope-matrix (-SM) over a given configuration . To any -SM over a configuration , with blocks, a -based -circulant LDPC code, referred to as a slope matrix (SM) code, is associated. It is shown that the maximum girth achieved by SM codes over a large class of configurations, including any balanced incomplete block design, is 18. A low-complexity algorithm producing such LDPC codes with girth is given. As a few examples, a set of SM codes based on the Steiner triple systems STS(9) and STS(13), the 15-points integer lattice, denoted , and a 12-points configuration, denoted , obtained from the 16-points affine plane Aff(16) are constructed. These codes have rates at least 0.25, 0.5, 0.4 and 0.37, respectively. From performance perspective, the constructed codes with girth and length from 34,000 to 92,000 bits and the mentioned rates outperform the random-like LDPC codes of the same lengths and rates, and have a waterfall at about BER and 1.5dB of . [Copyright &y& Elsevier]

Hydatid disease is a common and major public health issue caused by parasite Echinococcus granulosus. The highest prevalence of the parasite can be found in different parts of world like Africa, Australia, and South America. This infection can occurs in almost any part of the body. Here we present clinical, radiological, histological features and treatment of a multi vesicular osseous hydatid disease of the mandible in an Afghan 5 year old boy with a firm swelling in the right side of mandible. [ABSTRACT FROM AUTHOR]

We report the results from detailed optical spectroscopy from MOCVD grown GaN/AlGaN multiple quantum wells (MQWs), as opposed to most previous studies where MBE was employed by means of photoluminescence (PL) technique. In this paper we will present theoretical and experimental results demonstrating how polarization induced electric fields and bound interface charges in GaN/AlGaN MQWs affect the emission peak energy, PL line shape, as well as the emission line width. Theoretically estimated fields in this work are consistent with experimental data. Transition energy of the heavy hole and electron ground state Ee-hh in GaN/AlGaN MQWs were calculated and it is found that it stays in good agreement with the experimental data. [ABSTRACT FROM AUTHOR]

Abstract: Due to many important applications, the group III-nitride semiconductors have recently attracted remarkable attention among the semiconductor researchers and engineers. In this paper, we report on the impact of the extrinsic and temporal carriers on the screening of the polarization internal fields. The optical efficiency of GaN/AlGaN multiple quantum well (MQW) nanostructures were studied by means of photoluminescence (PL) and time-resolved PL measurements. Extrinsic carriers come from Si doping in the barriers while temporal carriers originate when the samples are excited by the laser beam. The emission peaks of MQWs in PL spectra of the undoped and low-doped samples show a shift towards higher energy levels as excitation intensity increases, while the other samples do not exhibit such a phenomenon due to the dominance of the extrinsic carriers. The transient data confirm the results of the PL measurements. [Copyright &y& Elsevier]

Familial Mediterranean fever (FMF) is an autosomal recessive autoinflammatory disorder with more than 60 disease-associated mutations in the responsible gene, MEFV. In the present study, we determined 15 MEFV mutations in Iranian Azeri Turkish FMF patients. Five hundred and twenty-four unrelated patients were tested for 15 known mutations in the MEFV gene using amplification refractory mutation system-polymerase chain reaction and polymerase chain reaction-restriction fragment length polymorphism methods. Thirty-five different genotypes were characterized among the studied patients. Of the alleles investigated, the most common mutation was p.M694V (42.4%), followed by p.V726A (17%), p.E148Q (16.2%), and p.M680I (c.2040G>C) (15.2%). The p.R761H mutation (4.7%) was found to be the most frequent among the rare mutations. The mutations p.M680I (c.2040G>A), p.I692del, p.M694del and p.K695R were not found in this cohort. The remaining mutations account for 7.7% of the identifiable mutations. Five different types of complex alleles were also identified. The results show the diversity and the frequency of the mutations in the Iranian Azeri Turkish FMF patients. The p.R761H mutation is rather prevalent in Azeri Turks; therefore, it should be included in the routine molecular diagnosis of FMF patients from this ethnic group. [ABSTRACT FROM AUTHOR]

This paper presents a low-complexity recursive and systematic method to construct good well-structured low-density parity-check (LDPC) codes. The method is based on a recursive application of a partial Kronecker product operation on a given γ × q, q ≥ 3 a prime, integer lattice L(γ × q). The (n - 1)- fold product of L(γ × q) by itself, denoted Ln(γ × q), represents a regular quasi-cyclic (QC) LDPC code, denoted Cγxqn, of high rate and girth 6. The minimum distance of Cγxq1 is equal to that of the core code Cγxq1 introduced by L(γ x q). The support of the minimum weight codewords in Cγ×qn are characterized by the support of the same type of codewords in Cγ×q1. From performance perspective the constructed codes compete with the pseudorandom LDPC codes. [ABSTRACT FROM AUTHOR]

The unsteady flow of blood through stenosed artery, driven by an oscillatory pressure gradient, is studied. An appropriate shape of the time-dependent stenoses which are overlapped in the realm of the formation of arterial narrowing is constructed mathematically. A msathematical model is developed by treating blood as a non-Newtonian fluid characterized by the Oldroyd-B and Cross models. A numerical scheme has been used to solve the unsteady nonlinear Navier-stokes equations in cylindrical coordinate system governing flow, assuming axial symmetry under laminar flow condition so that the problem effectively becomes two-dimensional. Finite difference technique was used to investigate the effects of parameters such as pulsatility, non-Newtonian properties and the flow time on the velocity components, the rate of flow, and the wall shear stress through their graphical representations quantitatively at the end of the paper in order to validate the applicability of the present improved mathematical model under consideration. [ABSTRACT FROM AUTHOR]

We have investigated optical properties of Ga0.64In0.36N0.006As0.994/GaAs single quantum-well structures using photoluminescence technique. We have found that nitrogen creates potential fluctuations in the InGaNAs structures, so it is the cause of trap centres in these structures and leads to localized excitons recombination dynamics. The near-band edge PL at 2 K exhibited a blueshift with an increase in excitation intensity of a sample but there is not such a shift in the PL peak position energy of same sample at 150 K. It has been found that PL spectra have a large full width at half maximum (FWHM) value at 2 K. These results are discussed in terms of carrier localization. Additionally, our results suggest decreasing PL integrated intensity in this structure, possibly due to non-radiative recombination. It has been shown that thermal annealing reduces the local strain created by nitrogen. By annealing process, a blue shifted emission can be observed. [ABSTRACT FROM AUTHOR]