The objective of this study is to determine the efficacy of class V Er:YAG laser (2940 nm) cavity preparation and conventional bur cavity preparation regarding Intrapulpal temperature rise during cavity preparation in extracted human premolar teeth. Twenty non carious premolar teeth extracted for orthodontic purposes were used and class V cavity preparation was applied both buccal and lingual sides for each tooth .Samples were equally grouped into two major groups according to cavity depth (1mm and 2mm). Each major group was further subdivided into two subgroupsof ten teeth for each (twenty cavities for each subgroup). TwinlightEr:YAG laser (2940 nm) with 500mJ pulse energy, P.R.R of 10 Hz and 63.69 J/cm2 energy density was used. The analysis of the data collected revealed that there was highly significant difference between subgroups of each group, i.e., (Er:YAG laser and conventional bur cavity preparation). Also there was a highly significant difference between both group1 and group 2 subgroups (with 1mm and 2mm cavity depth). Best results were obtained from subgroup A which represents class V cavities prepared using Er:YAG laser with energy density of 63.69 J/cm2 .Er:YAG laser cavity preparation with energy density of 63.69 J/cm2 was less temperature rise than conventional bur cavity preparation taking into account the invitro temperature rise of class V cavity preparation.
Nine new compounds of 2-amino-5-chlorobenzothiazole derivatives were synthesized. These new compounds were formed through the reaction of 2-amino-5-chlorobenzothiazole 1 with ethyl chloroacetate and KOH, which gave an ester derivative 2, followed by refluxing compound 2 with hydrazine hydrate to afford hydrazide derivative 3. The reaction of compound 3 with CS2 and KOH gave 1,3,4-oxadiazole-2-thiol derivative 4, and then the reaction of compound 2 with thiosemicarbazide to produce compound 5 then treated it with 4%NaOH led to ring closure to provide 1,2,4-triazole-3-thiol derivative
... Show MoreLos lingüistas no árabes suelen quedar perplejos a la hora de interpretar el fenómeno de Al-ḍdad, −normalmente traducido en español como palabras autoantónimas (1)− en la lengua árabe, en el que los arabistas, y entre ellos los españoles, han quedado sombrosos ante este fenómeno. El jefe del tribunal de la defensa de mi tesis me pidió que le explicara este fenómeno según mi teoría “El esquema básico de la referencia”; pues me dijo que no podía imaginar que una palabra tuviera dos significados opuestos, y en ese momento le expliqué la palabra albayn البين que significa la separación, o la relación o el enlace que comentar
... Show Moreالبحث معني بظاهرة اللجوء من العالم الاسلامي الى العالم الغربي وما يحيط بهذه الظاهرة من تحديات سواء كانت سلبية او ايجابية والبحث يوضح احكام العقيدة الاسلامية للحكم على هذه الظاهرة التي اصبحت من النوازل في هذا العصر
Phonological metathesis can be defined as an alternation in the normal sequence of two sounds under certain conditions. The present paper is intended to give a detailed synchronic description of phonological metathesis in Iraqi Arabic dialect. For data collection, the researchers have adopted two naturalistic techniques, viz., observation and notes taking. A synchronic analysis is carried out to provide some evidence that describe the sequential change of phonological metathesis in the dialect under investigation. Such sequential changes of metathesized sounds are presented and tabulated. The study concludes with the following finding that this process is not limited to cases where two consonant sounds are transposed, but three consonant
... Show MoreThis study aims at identifying the reality of alternative assessment for teachers of the first cycle of the basic education in the Sultanate of Oman with respect to the degree of teachers' use of alternative assessment strategies, level of self-efficacy for alternative assessment strategies, and attitude towards alternative assessment, and their relationship with other variables. To achieve the aims of the study, a descriptive research approach was utilized. A 5-point self-rated questionnaire was developed. It consists of three sections: Actual use of alternative assessment strategies (21 items), self-efficacy for alternative assessment strategies (21 items), and attitude towards alternative assessment (27 items). The psychometric proper
... Show MoreThin films of (CdO)x (CuO)1-x (where x = 0.0, 0.2, 0.3, 0.4 and 0.5) were prepared by the pulsed laser deposition. The CuO addition caused an increase in diffraction peaks intensity at (111) and a decrease in diffraction peaks intensity at (200). As CuO content increases, the band gap increases to a maximum of 3.51 eV, maximum resistivity of 8.251x 104 Ω.cm with mobility of 199.5 cm2 / V.s, when x= 0.5. The results show that the conductivity is ntype when x value was changed in the range (0 to 0.4) but further addition of CuO converted the samples to p-type.