Optical Channel Capacity Upgrade Based on Multiwavelength Conversion XGM Using Semiconductor Optical Amplifier for Access Networks

This paper demonstrates a 10 Gb/s one-to-two-wavelength conversion configuration based on cross-gain modulation for optical access networks using a single TW-SOA. The method is capable of converting a signal data of specific wavelength 1541 nm to certain wavelengths of CW’s laser 1554 nm and 1558 nm with 4 nm spacing. The pump power level was classified due to channel response. A result obtained was the best power level offering wavelength converter between −6 and 3 dBm. The conversion efficiency achievement provided an acceptable result for probe signals. The findings of Q-factor performance were investigated. The Q values were found to be more than 9 for point to point transmission and 20 km fiber configurations for the original and converted signal. The technique implemented at 20 km and the power of all channels were adequate to provide a splitting ratio of 1/64 for the launched pump power 3 dBm

Esophageal tuberculosis; A rare cause of odynophagia: A case report

AbstractWe present a rare case of esophageal tuberculosis causing odynophagia. Tuberculosis of the esophagus is a rare condition, even in countries with a high incidence of tuberculosis (TB) and studies estimate that it constitutes about 0.3% of gastrointestinal TB cases. The case emphasizes the diverse ways tuberculosis can present

Surface Roughness Evaluation Of Experimental Dental Nanocomposite After Bleaching

Bleaching or tooth whitening is getting more popular in this world that concerns esthetic [1]

Kinetic and Thermodynamics of Methylene Blue Adsorption onto Zero Valent Iron Supported on Mesoporous Silica

Zero valent iron supported on mesoporous silicanano particles (NZVI/MSNs) was prepared by the aqueous phase borohydride reduction methods. Prior to the reduction, mesoporous silica nanoparticles (MSNs) were prepared through the activation of fumed silica with concentrated HCl by refluxing at 90 °C. FTIR, XRD, FESEM, EDX and BET were used to characterize theadsorbents prepared. BET surface areas of MSNs, NZVI, and NZVI/MSNs were 126, 41, and 72 m2/g for, respectively. The performance of NZVI/MSNs as adsorbent was examined by adsorption of methylene blue (MB), performed in series of batch experiments. In the kinetic studies, pseudo first order and pseudo second order kinetic models were examined. The pseudo second order equation provided the best fit with the experimental data. Thermodynamic studies indicated that the adsorption process is endothermic with ΔH° was 90.53 kJ/mol. Positive ΔS° (300 J/mol) and negative ΔG° (-6.42 kJ/mol) was recorded, indicating the spontaneous of the adsorption process and naturally favorable.

Characterization of Anisotropic Damage Behaviour of Recycled Aluminium Alloys AA6061 Undergoing High Velocity Impact

It is impossible to ignore the realm of the topics related recycling aluminium scraps. The recycled form of this material can be a good replacement for the primary resources due to the economic and environmental benefits. Numerous investigation must be conducted to establish the mechanical behaviour before the specific applications can be identified. In this research, Taylor Cylinder Impact tests used to investigate anisotropic damage behaviour in recycled aluminium alloy is presented. To be specific, by performing Taylor Cylinder Impact test at velocities ranging from 190m/s to 300m/s, anisotropic and damage characteristics can be observed in the samples as a function of the large stress, strain, and strain-rate gradient. The application of Taylor Cylinder Impact test as a technique to validate both the constitutive and dynamic fracture responses in such materials is also discussed. The structure of recycled aluminium AA6061 including the damage initiation and evolution are observed under optical microscope (OM) and scanning electron microscope (SEM). The results revealed that the damage evolution of the material change with the increasing impact velocity. Further, the digitised footprint analysis showed a pronounced anisotropic characteristic of the recycled aluminium AA6061

Kinetic And Thermodynamics Of Methylene Blue Adsorption Onto Zero Valent Iron Supported On Mesoporous Silica

Zero valent iron supported on mesoporous silicanano particles (NZVI/MSNs) was prepared by the aqueous phase borohydride reduction methods. Prior to the reduction, mesoporous silica nanoparticles (MSNs) were prepared through the activation of fumed silica with concentrated HCl by refluxing at 90 °C. FTIR, XRD, FESEM, EDX and BET were used to characterize theadsorbents prepared. BET surface areas of MSNs, NZVI, and NZVI/MSNs were 126, 41, and 72 m2/g for, respectively. The performance of NZVI/MSNs as adsorbent was examined by adsorption of methylene blue (MB), performed in series of batch experiments. In the kinetic studies, pseudo first order and pseudo second order kinetic models were examined. The pseudo second order equation provided the best fit with the experimental data. Thermodynamic studies indicated that the adsorption process is endothermic with ÄH° was 90.53 kJ/mol. Positive ÄS° (300 J/mol) and negative ÄG° (-6.42 kJ/mol) was recorded, indicating the spontaneous of the adsorption process and naturally favorable

Towards Islamic worldview based corporate governance framework

Codes on corporate governance (CG) mainly derive recommendations from the concept of agency theory. The said theory and one of the earliest reports on CG, i.e. Cadbury Report (1992) in UK focused specifically on shareholder oriented nature of governance. Later on, the accountability of directors has been extended to other stakeholders. Therefore, if the trend of the evolution of the corporate governance is observed, shareholder-centred role of the directors has been integrated with responsibilities towards the stakeholders. It can be summarized that the current CG guidelines are a combination of the concepts of stakeholder theory and agency theory. Hence, overall progress of the development of the conventional CG codes has been done with a problem solving approach by tackling emerging problems. However, even with the existence of the guidelines, CG failures still exist. Thus, the effectiveness of the existing codes are questionable since they are not concrete solutions. It might be for the reason that they are man-made guidelines and based on the human reasoning after examining past events and predicting possible future problems. Therefore, it should be concluded that only Islamic worldview based corporate governance framework (IWBCGF) will guide the directors to perpetual solutions of the current and future CG problems

Uneventful Disappearance of a Large Left Atrial Ball Thrombus with Enoxaparin in a Patient with Mitral Stenosis Associated with Pregnancy

An atrial thrombus is a relatively common echocardiographic finding in patients with mitral valve stenosis (MVS) and atrial fibrillation (AF). However, a “ball thrombus” or floating thrombus in the left atrium is a rare and specific entity associated with MVS. A 24-year-old woman with rheumatic MVS presented with complaints of progressive dyspnea and inferior limbs edema that began 23 days earlier after a caesarean operation for stillbirth carried out at 8 months of pregnancy. At the time of hospitalization, she was in New York Heart Association functional class III and the ECG showed sinus rhythm. Transthoracic color-flow Doppler echocardiography revealed a thick, stenotic mitral valve with a valvular area of 0.9 cm2, and an echogenic large left-atrial mass diagnosed as a free-floating left-atrial thrombus that was corroborated by transesophageal echocardiography. She refused surgery and was treated medically, and low molecular weight heparin (LMWH) (enoxaparin 80 mg/12 h) was given for 14 days and was discharged uneventfully on coumarin. Two days before discharge, a transthoracic and transesophageal ecocardiography showed disappearance of the ball thrombus uneventfully leaving spontaneous echo contrast inside the left atrium. To the best of our knowledge, this is the first case showing disappearance of a giant left atrial ball thrombus with LMWH treatment in a patient with severe MVS during sinus rhythm associated with pregnancy

Plastic anisotropic and damage evolution analysis of recycled aluminium alloy AA6061 at high rate of strain

Aluminium alloys have been widely used in many applications, and its usage is increasing yearly due to its distinctive properties. Nevertheless, it required high energy consumption and pollution during the production of primary sources. This leads to the attention in producing secondary sources to substitute the primary aluminium. Recycling of aluminium alloys adopted in automotive structures is a great option to save thousands of energy and prevent tons of CO2from being released to the atmosphere. Numerous investigations must be conducted to establish the mechanical behaviour before the specific applications can be identified. However, there is a challenge for such recycled aluminium to achieve the same application as the primary sources due to material properties degradation related to damage. It is still an open study area to be explored for a better understanding of the behaviours of recycled aluminium. Thus, in this work, the Taylor Cylinder Impact test is used to investigate anisotropic-damage behaviour of recycled aluminium alloy AA6061 undergoing high-velocity impact from 190m/s to 300 m/s using two length-to-diameter (L/D) ratios. The recovered samples are observed under an optical microscope (OM) andscanning electron microscope (SEM). A strong strain rate dependency can be seen as the damage evolution is increasing as the impact velocity increase. Further, the corresponding digitized footprints analysis exhibit plastic anisotropic and localized plastic strain in such recycled material. This can be clearly observed from the development of a non-symmetrical footprint within the impact surface. This test is the first to explore the deformation behaviour of recycled materials using high-velocity cylinder impact in a high rate of strain deformation regime