المحكم والمتشابه وموقف المفسر منهما

The Mohkam and Mutashabeh is a renowned terminology of the Quranic Sciences and commentators of the Holy Quran described it in details, according to root words of Mohkam, it means Stopping and perfecting the things, this basic meaning can be seen in all the types and variations of this word. On the other hand we have the word Mutashabeh which root meaning is complication and unclearness. If we discuss both of the words as a terminology of the Quranic sciences, we can define Mohkam as “one which define itself without any other thing” or “one which has no need to be defined by something else” and Mutashabeh is “one which can’t define itself and need to be explained by someone else”. We will move on to discuss both terms in Holy Quran as a terminology to describe its multiple variations in the Holy Quran, its types and further we will discuss that why the Holy Quran contains both terms, in other words, we can say which are the logics and reasons of including Mutashabeh verses in the Holy Quran. In addition, we will mention the point of views of various renowned commentators and fields experts which give us a clear and sound concept about both of the terms.

Structural, Morphological and Mechanical Properties of Laser Irradiated Bio-Materials

Calcium Hydrogen Phosphate biomaterials were prepared by solid state sintering method. Pellets were dried in vacuum to remove the water molecules using oven for 4 hours at 120°C. The dried pellets were sintered attemperature 450 °C and 750 °C using muffle furnace Vulcan A-550 for varying time periods6,12,18, and 24 hours to get the gamma and beta phases, respectively. Nd: Yag laser used as an irradiation source for biomaterials. The analysis of samples (morphological and structural) was carried out before and after laser irradiation using X-Ray diffractometer and SEM. Before using Nd: YAG laser irradiation, a slight shift in 2θ values of XRD. It was observed that peaks become sharper as the biomaterials are irradiated. Major variations were not investigated in the XRD parameter of the materials investigated after laser exposure. The homogeneity and crystallinity of the pellets was observed before laser irradiation. After exposing the sample by laser, a slight change in the peak intensity was investigated. Before the SEM heating, the surface of the sample was smooth, grains were compact and size of grains was very large. As a result of sintering, the physical appearance of the pellets changed. Micro-cracks due to thermal shocks at 450 and 750 °C were observed. Compactness of the material and crytalline growth also disturbed badly. Densification of the material is greatly affected due to temperature variations. These effects results to formation of columnar structures. After laser effect on porosity of the materials due to minor changes in the surface volume was observed. The absence of pore is beneficial which causes an increase in mechanical strength of biomaterial and structural fractures. The prepared Ca2P2O7 samples at 450 and 750 °C carried out in the range of 500–4000 cm-1. FTIR of the prepared samples before and after laser showed formation of peaks at 720 –1211 cm-1, which is attributed to the presence of P-O-P linkage stretching mode in Ca2P2O7. After the use of laser, FTIR gives some peaks with lower intensity. The EDX analysis was carried out to confirm the elemental composition of the sample after laser. Mechanical properties of the prepared and sintered samples at 450°C and 750 °C for 6, 12, 18, and 24 hours before laser shows low values of compressive strength, and results shows no fracture strength, The compressive strength of the biomaterial improved from0.03–0.24MPa with the increase in temperature. However, the laser exposure of the material becomes mechanically weak and its compressive strength decreases from 0.19 – 0.059 MPa.