Md. Faizul Huq Arif

DESIGN AND CHARACTERIZATION OF PHOTONIC CRYSTAL FIBER FOR SENSING APPLICATIONS

Purpose: this study aimed to analyze the epidemiological aspects and evaluate the impact of late diagnosis on prognosis of gastrointestinal surgical emergencies at the National Hospital of Zinder (Niger). Patients and method: this is a prospective study from 1 January to 31 December 2013. All patients underwent surgery for digestive emergency were included. Results: We collected 302 patients. Emergencies digestive surgery accounted for 22% of 1358 cases of surgical emergencies recorded over the period of the study period. The sex ratio is 3/1 in favor of men. The average age of patients was 23 years. Digestive surgical emergencies affect more children (45%) and young adults (43%). The majority (70%) of our patients did not attend school and 49% were from rural areas. The diagnosis delay rule, 171 patients (57%) arrived to emergency department more than 48 hours after onset of symptoms. Abdominal pain with or without other signs was the main reason for consultation (92% of patients). 182 patients had a poor general status. The etiologies were dominated by peritonitis (52%) followed by intestinal obstruction (28%), and abdominal trauma with 10% of cases. The parietal suppuration isolated or associated with other morbidities was the main postoperative (28%). The average length of hospital stay was 9 days. 36 patients (12%) had died. Almost half of the deaths (47%) occurred within the first 48 hours of admission. The delay of admission and the surgical management was statistically significant effect on the prognosis (P<0.006, p< 0.0001). Conclusion: The prognosis of gastrointestinal surgical emergencies is highly correlated with the speed of diagnosis leading to appropriate treatment as soon as possible. This promptness is the only guarantee of a decline in the high morbidity and mortality which is often linked to dysfunction of our hospitals and/or accessibility problems faced by patients.

Proposal of simple gas sensor based on micro structure optical fiber

This paper presents a simple structure of photonic crystal fiber (PCF) based gas sensors. Gas sensors can be used in gas production facilities for safe measurement. The index guiding properties of two rings circular PCF have been analysed for different wavelength with the variation of the diameters of air holes in core and cladding. Finite-element method has been applied for numerical analysis. At the wavelength λ=1.66μm obtained maximum sensitivity is 13.94% and at the same time the confinement loss of the fiber is 2.74×10-4 dB/m. The proposed structure is more flexible for its high sensitivity, low confinement loss and simple structure compare to early proposed high sensitivity chemical sensor PCFs with a hollow high index ring defect at the centre.

Highly sensitive simple structure circular photonic crystal fiber based chemical sensor

A circular photonic crystal fiber (C-PCF) structure is presented in this paper as a chemical sensor where both core and cladding are micro structured. Finite element method (FEM) has been applied to investigate the propagation characteristics of proposed C-PCF structure. Relative sensitivity and Confinement loss are numerically examined and optimized by varying the different parameters of the proposed structure. Finally, it is found that the simple 3 rings C-PCF structure shows higher sensitivity as well as lower confinement loss at the wavelength 1.33μm.

Application of microarray-core based modified photonic crystal fiber in chemical sensing

This study presents a simple type of modified PCF (M-PCF) as a chemical sensor where both core and cladding are micro-structured. Different guiding properties of proposed M-PCF have been investigated for a wide range of wavelength using full vectorial finite element method (FEM). By varying pitch and hole diameter both of inner and outer layers, the relative sensitivity, refractive index and confinement loss are numerically examined and compared. At the wavelength 1.33μm it is observed that the relative sensitivity is improved 1.45 times and confinement loss is also reduced than prior work. Fabrication process and cost will be low of proposed M-PCF because of its structural simplicity.

A comparative analysis of two different PCF structures for gas sensing application

Toxic or Flammable gases and leakage of the gas lines can be detected by photonic crystal fibers for avoiding pollution, explosion or fire. Two different structures of hollow core based Photonic crystal fiber (HC-PCF) has been presented in this paper. The sensitivity of the proposed structures was numerically investigated by finite element method (FEM) varying the optical and geometrical properties. The numerical results show that the proposed PCF with six air holes shows 2.22 times higher sensitivity than the PCF with eight air holes in the first layer. Both of the PCFs exhibit reduced confinement loss also. The proposed PCFs can sense the lower refractive index based gases (toxic/ flammable) at a wide range of wavelength 0.8 μm to 2μm.

Simulation based analysis of formalin detection through photonic crystal fiber

Formalin is a dangerous organic chemical substance in todays life. It is the solution of two substances; Formaldehyde and Water. Formalin is used forlong time preservation for various types of foods and other things from rotting. It affects human life to environmental ecology. Formalin detection is a challenging task. Without chemical experts, it is hard to detect and it is also a time consuming task. In this regard, a smart, reliable but simple detection technique is on demand. To detect it efficiently, the optical characteristic of Formalin such as refractive index is chosen for analysing. This paper presents a Photonic Crystal Fiber (PCF) based Formalin sensing technique. A simple PCF structure has been proposed to sense Formalin. The structure follows all the optical properties for the propagation of light energy. An intensive simulation has been done. The simulation results show that the proposed simple PCF structure is handy to detect Formalin with a remarkable sensitivity.

High sensitive PCF based chemical sensor for ethanol detection

In this paper, a high sensitive photonic crystal fiber structure has been presented for ethanol sensing. Optical properties of the guided mode have been analyzed using full vectorial finite element method. We have investigated the sensing properties varying different geometrical properties of the proposed structure. We have optimized the design parameters of the proposed PCF which are responsible for high sensitivity. The simulation results show that the sensitivity and the confinement loss of the proposed photonic crystal fiber are 34% and 1.2×10-4 dB/m respectively at the wavelength of 1.33μm.

On the analysis of RED algorithm in ZigBee network for queue management

ZigBee is a sensor based IEEE 802.15.4 wireless standard. ZigBee has taken a role in the utilization of wireless network for diverse applications in home, office or industrial automation. The vast use of ZigBee devices which bring forth a huge application traffic. ZigBee Coordinator processes the application traffic. This traffic waits to be executed in the Coordinator queue. Routers transfer the application traffic to the destination. These huge application traffic can be a cause of queuing drop which reduces throughput as well as increases delay. An active queue management is in demand for ZigBee Coordinator. In this paper, Random Early Detection (RED) algorithm is applied to maintain Coordinator queue for gaining high throughput as the lowest possible delay and data packet dropped. The simulation results show the performance of RED enabled network parameters are better. This analysis will be a convenient direction for the further development of ZigBee network.

Queue management of RED enabled ZigBee network based on packet size variations and distribution techniques

The IEEE 802.15.4 wireless communication standard named ZigBee is a wondering sensor. ZigBee is vastly used in device-to-device communication, both at home, office or industry for day-to-day applications. Zillions of devices are interconnected to set up a such an automotive system. These devices generate a massive amount of application traffic. ZigBees Coordinator Queue handles this application data traffic with the default traffic distribution and processing technique. Without applying an active queue management scheme, data traffic might be dropped that causes higher end-to-end delay, higher load, and lower throughput. This paper implements the popular Random Early Detection (RED) algorithm for maintaining ZigBees Coordinator queue with varying packet sizes and distribution techniques. The extensive simulation results show that the RED enabled ZigBee network has better performance in terms of the lower sized packet in uniform distribution. The analysis of this study will be a myopic direction for the further development of ZigBee network.