Nowadays, the fundamental role of having a purpose for life in physical and mental health has been confirmed. According to victor frankl, presence of a purpose in life gives life a meaning and increases resilience against pains and traumas. The importance of the purpose in life construct reveals the need for a reliable and valid tool to measure it. Crumbaugh and Maholick's purpose in life questionnaire is the first and one of the most applied tools for the assessment of life's purposefulness. The aim of this research is to determine the factor structure of purpose in life questionnaire. The questionnaire was administered on 206 students who were selected through random stratified sampling at Ferdowsi University of Mashhad. Exploratory factor analysis showed that there are two factors "comprehension" and "purpose" and this finding were confirmed by confirmatory factor analysis. Altogether results of this research showed factor validity of the purpose in life questionnaire with a two factor pattern

This work is focused on the effect of amorphous SiO2 addition on the phase transformation and microstructural evolution of ZrO2 particles. Considering the structural similarities between the amorphous ZrO2 and its tetragonal structure, XRD results showed initial nucleation of metastable tetragonal ZrO2 from its amorphous matrix upon heat treatment. This metastable phase is unstable in pure ZrO2 sample and transforms to a stable monoclinic phase at around 600 oC. However, addition of amorphous SiO2 to ZrO2 structure causes metastable tetragonal phase to remain stable up to around 1100 oC. The temperature range for stability of metastable tetragonal ZrO2 structure increased from about 150 oC in pure ZrO2 particles to around 500 oC in ZrO2-10 mol. % SiO2 composite powders. A further increase in SiO2 content up to 30 mol. % did not change the stabilization temperature range but the average particle size reduced around 1. 6 times compared to pure ZrO2 particles. Stabilization of metastable tetragonal ZrO2 explained by constrained effect of SiO2 layer surrounding zirconia nuclei. The thickness of this SiO2 layer enhanced by increasing SiO2 content which limited the growth of ZrO2 nuclei resulting in finer particle sizes.

The samples studied through this research were collected from active black smokers located in the mid-oceanic ridge from a depth of 2276m by a sea-born ship “Academician Mstislav Keldysh” (2002), in its 47th research mission. The collected samples were studied by microscopic, microprobe and X-ray analysis (Debye-sherer). These samples were in the form of narrow pipes with zoned structure, which included the following zones from the core to the margin: isocobanite, Chalcopyrite, Bornite and cupper sulfide zones. For the first time, it has been observed that tetragonal phase within the cupper-sulfide zone in recent sulfide, deposits. Tetragonal phase of Cu2S, which is an unstable form of chalcocite, is stable only at high pressures (more than 0.8 Kb) and temperatures higher than 102 oC. The tetragonal form of Cu2S in one of the studied samples was associated with Chalcocite-Djurleite mixture and in another studied sample was associated with chalcocite-Bornite mixture. Its average chemical composition was also determined as Cu2.02S. It is likely that the emergence of this unstable phase in young hydrothermal deposits, which are formed at 250-350 oC, is not odd but after hydrothermal activity and temperature reduction it is changed to more stable phases. Evaluation of older black smokers showed no trace of tetragonal phase.

The stabilized zirconia with different Cu contents synthesized via sol-gel method. The samples were prepared by hydrolysis and condensation of orgnomatelic sol. After that the result gels were dried at 800C and then calcined at various temperatures. Tِhe differential thermal analysis (DTA), X-ray diffraction (XRD), field emission scanning electronic microscopy (FESEM) and transmission electronic microscopy (TEM) were used to determine the characteristics of nanoparticles. Unlike the stable pure ZrO2 that has monoclinic structure at room temperature, the synthesized pure ZrO2 and ZrO2-CuO powders have been cubic and tetragonal structure at room temperature after calcinations. Moreover, it is obtained those changes in the crystallite size affect the stabilization of tetragonal or cubic structure at room temperature, and increase in content of dopant favored decrease of the crystallite size and metastabilization of both tetragonal and cubic polymorphs.

In this paper, the contribution of Sr and Hf atoms in piezoelectric properties of tetragonal SrHfO3 with P4mm space group, were investigated by using first principle calculations based on density functional perturbation theory. Lattice constants, Born effective charges, piezoelectric constant and Sr and Hf contributions in total polarization and piezoelectric coefficient were calculated. Our results show that tetragonal SrHfO3 has piezoelectric property and its polarization and piezoelectricity mainly come from Hf atoms. The effect of lattice constant changes on polarization and piezoelectric constant were also studied. It was found that polarization and piezoelectric constant enhance by increasing lattice parameter and at c=4. 5 Å , Sr atom contributes 50% of the total piezoelectric constant. This behavior assigns to significant covalent bonding between Sr and surrounding O atoms.

Tetragonal zirconia (t-ZrO2) nanoparticles were synthesized from the zirconium chloride using the co-precipitation technique and characterized by various measurement techniques. FESEM analysis further revealed spherical shaped NPs and HR-TEM analysis determined the size of the particles in the range of 14. 5 nm. The band gap energy was estimated 4. 0 eV. The UV (350 nm) emission was observed from PL spectrum. The photocatalytic degradation of the as-prepared ZrO2 nanoparticles were studied under UV light irradiation using ciprofloxacin (CIP) as a model organic pollutant. Results showed that 50% degradation were achieved within 15 min.