Search

The radiative response of antenna structures highly depends upon the extinction efficiency of the structures and the major parameter for the optimization of nanoantenna designs. To optimize the radiative response of the plasmonic antenna design, i.e., the oblique scattering of the THz radiation form, graphene‐coated gold (Au) nanowires have been studied. The present work provides a universal solution for the graphene‐coated cylindrical geometries. The optical conductivity of graphene has been modeled by the use of Kubo formalism, while the analytical modeling of the gold (Au) is done by employing Drude's model. The Jacobi–Anger expansion method has been adopted for the transformation of electromagnetic fields in terms of series of cylindrical waves and has been modeled in terms of cylindrical vector wave functions (CVWFs). The analytical formulation has been presented for both polarizations, i.e., parallel polarization (TM) and perpendicular polarization (TE). The unknown scattering coefficients have been calculated by applying impedance boundary conditions at graphene‐gold nanowire interface. The analytical and numerical results have been computed for extinction efficiency (Qext) under parallel and perpendicular polarization states. The Qext under different parameters of graphene, diameter of metallic nanowire (R) and angle of incidence θi, has been computed. It is reported that the graphene‐coated Au nanorod supports the localized surface plasmon resonance (LSPR) under perpendicular polarization at a high THz frequency range. The surface plasmon resonance can be actively controlled under suitable parameters, i.e., graphene parameters, core size, and angle of incidence. The numerical results reveal that the radiative response of the plasmonic structures can be tuned actively from THz to Far‐IR frequency range under appropriate parameters. The provided results have potential applications in subwavelength devices and plasmonic antenna designs. [ABSTRACT FROM AUTHOR]

The blending technology makes it possible to rebuild high molecular weights of partial polymers, thus to improve the product performance together with improvement of specific properties. Pure Carboxymethylcellulose (CMC) film and CMC (80%) doped Polyacrylic Acid (PAA) (20%) films were prepared by using a solution casting method. The influence of PAA polymer addition on the structural and optical properties of CMC polymer was investigated systematically. From X-ray diffraction patterns, adding a polymer PAA to a polymer CMC can lead to the appearance of peaks in polymer blend. FESEM image for CMC/ PAA film showed the formation of small spherical grains for PAA into CMC that insured the existence of some peaks in XRD pattern of PAA in CMC film which means the improvement of the microstructure of the polymer matrix. No chemical interactions were observed between CMC and PAA polymers from results of FTIR spectrum, so that incorporation of PAA into CMC polymer will results physical reaction only. The results of the UV spectrum have shown that the absorbance, absorption coefficient, extinction coefficient, refractive index, real and imaginary dielectric constants were increased in blend polymer compared with the pure polymer. The energy gap and transmittance of blend polymer compared with the pure polymer were reduced.

One of the main objectives of studying intellectual disability (ID) in children is to explore its causes. A specific aetiological diagnosis is important in determining the prognosis, nature and extent of services needed to support affected children. Aetiology and risk factors in mild ID were studied in a cohort of longitudinally followed children (6-10 years of age, n=40) in four population groups in and around Lahore, Pakistan. The overall prevalence of mild ID was 6.2%. In 22% of the cases the onset of mild ID was prenatal with small for gestational age and multifactorial inheritance as the main underlying factors. During the postnatal period (28% of the cases), social deprivation and malnutrition were the major causes of ID. In a substantial proportion of the cases (50%), the cause of ID could not be traced. The present study indicates a clear relationship of mild ID with prenatal and postnatal malnutrition and social deprivation. Two independent variables, maternal illiteracy and small head circumference at birth, showed a clear association with the development of mild mental disability among children in the study population.

Objective: To compare mean postoperative pain score and analgesia requirement in thyroid surgery with or without use of Ligasure. Study Design: Randomized Control Trial. Setting: Department of Surgical, Allied Hospital, Faisalabad. Period: one year March 2018 to March 2019. Material & Methods: All included patients were randomly allocated into two groups. Group 'L' underwent thyroid surgery with Ligasure without diathermy and group 'C' patients underwent thyroid surgery with conventional knot and tie technique using sutures and diathermy. Data was entered in questionnaire. Results: Comparison of mean pain score shows that 2.2+0.66 in Group-L and 2.88+0.77 in Group-C, p value was 0.0001. Comparison of postoperative analgesia requirement in thyroid surgery with or without use of Ligasure shows that analgesia requirement in Group-L was 7.5% (n=6) and 23.75 % (n=19) in Group-C, p value was 0.004. Conclusion: The mean postoperative pain score and analgesia requirement in thyroid surgery with the use of Ligasure was significantly reduced when compared to those without it. [ABSTRACT FROM AUTHOR]