Study on optical properties of l-valine doped ADP crystal.

Single crystal of l-valine doped ammonium dihydrogen phosphate has been grown by slow evaporation method at room temperature. The crystalline nature of the grown crystal was confirmed using powder X-ray diffraction technique. The different functional groups of the grown crystal were identified using Fourier transform infrared analysis. The UV-visible studies were employed to examine the high optical transparency and influential optical constants for tailoring materials suitability for optoelectronics applications. The cutoff wavelength of the title crystal was found to be 280nm with wide optical band gap of 4.7eV. The dielectric measurements were carried to determine the dielectric constant and dielectric loss at room temperature. The grown crystal has been characterized by thermogravimetric analysis. The second harmonic generation efficiency of the grown crystal was determined by the classical Kurtz powder technique and it is found to be 1.92 times that of potassium dihydrogen phosphate. The grown crystal was identified as third order nonlinear optical material employing Z-scan technique using He-Ne laser operating at 632.8nm.

Interventions for children with dyslexia: A review on current intervention methods

@#Introduction: Dyslexia is a neurobiological impairment that primarily affects reading ability. It is commonly known as a reading disorder which is likely to be present at birth and is generally identified at pre-school level. Dyslexia is manifested through difficulties with accurate word recognition and also by poor performance in reading and writing. Method: The main objective of this paper is to review the various methods or treatments that are used to manage the literacy and cognitive abilities for children with dyslexia particularly in Malaysia. The articles were obtained from online databases such as PubMed, Ebscohost and Medline during the time frame of six years starting from 2000 until 2016. An initial count of 300 articles were generated but only 13 articles met the inclusive criteria. Results: There are a few types of interventions such as the multisensory method, the phonological intervention, and the cognitive training method which can be used to improve literacy and cognitive deficits among children with dyslexia. In Malaysia, most of the treatments are focused on the aspects of language such as word mastery, alphabet identification and writing skills. The cognitive training were carried out to improve specific domain such as visuospatial skills, memory skills and psychomotor skills. Conclusion: There is yet no studies which has employed the comprehensive method of combining the intervention of cognitive functions and linguistics-literacy deficits. It is imperative that researchers in Malaysia go beyond literacy skills and take into consideration the underlying cognitive functions which contribute to the specific reading and writing difficulties of Malaysian children with dyslexia.