Electronic and optical properties of Cu2-II-IV-VI4 (II=Zn،Cd; IV=Ge،Sn; VI=S،Se،Te) quaternary chalcogenides are calculated using the full potential linearized augmented plane wave (FP-LAPW) method within the density functional theory (DFT) and the calculated results are compared with the available experimental results. The real and imaginary parts of the dielecteric function ԑ (ω)، the electron energy loss function (EELS) and the optical absorption coefficient I (ω) are calculated within the random phase approximation (RPA). The prominent structures in the specrta of ԑ1 (ω)، ԑ2 (ω) and EELS are discussed in detail and the static dielectric constants of these compounds are calculated. The most prominent feature of these compounds is their high absorption coefficient and wide absorption spectrum. It is an appropriate parameter for using in solar cells. The band structures are calculated using Perdew et al.، Engel-Vosko and modified Becke-Johnson schemes and the effect of the exchange-correlation functional on the band gap of these compounds is investigated. It is shown that mBJ-GGA leads to a better result.

In this work we investigate the electronic, optical, dynamic and thermoelectric properties of ternary copper-based Chalcogenides CuSbX2 (X= S, Se) compounds. Calculations are based on density functional theory and the semi-classical Boltzmann theory. Computations have been carried out by using Quantum-Espresso (PWSCF) package and ab-initio pseudo-potential technique. To estimate the exchange-correlation functional various approximations were used,which among them GGA approximation led to better results. Density of state calculations indicates that CuSbSe2 and CuSbS2 compounds are semiconductors with a band gap of about 0.81 eV and 0.62 eV respectively. A lack of negative frequencies in the phonon dispersion curves of these compounds shows the stability of the compounds. The static refractive indices of CuSbSe2 compound are 4.38, 3.66 and 3.30 calculated within GGA, GGA and GGAmBJ approximations respectively and plasmon frequencies obtained from the peak of the loss function is occurred at energies around 16eV.A trend of electrical conductivity behavior against temperature verify the semiconducting n

In this study, the structural, electronic, and optical properties of strontium chalcogenides are investigated by the pseudopotential method in the framework of density functional theory and quantum espresso code. The calculations were performed with the LDA, GGA, and HSE approximations. The calculated structural parameters are in good agreement with available experimental and theoretical data. The results of the band structure show that these compounds in B1 phase are semiconductors with an indirect band gap. The band gap calculated for compounds in B1 phase in the LDA and GGA approximations is consistent with the theoretical data of others. Also, the band gap in HSE approximation for SrS, SrSe, and SrTe compounds were calculated 4.30, 3.86, and 2.96 eV, respectively, which is in agreement with the experimental data. The dielectric constant for SrS, SrSe, and SrTe compounds was calculated as 4.73, 5.02, and 5.86 in GGA and 5.27, 5.48, and 6.50 in the LDA approximation, respectively and these results are also consistent with available experimental and theoretical data.

In this research, a naturally occurring clay mineral, hectorite, was used as the support for several quaternary ammonium and phosphonium cations to measure and compare their catalytic activity in a triphase catalytic system. The intercalation of the catalysts in the clay has the advantage of easy catalyst recovery; the catalyst can be removed by a simple separation technique, such as filtration or centrifugation, upon completion of the reaction. The rate of conversion of $n$-butyl bromide to $n$-butyl chloride was measured in the presence of two classes of phase transfer catalyst: Quaternary ammonium and quaternary phosphonium cations. The rate of the reaction was measured for the biphase reactions (no supporting clay) and for the triphase catalytic system (with supporting clay). The results have shown that quaternary phosphonium catalysts are somewhat more reactive than the corresponding quaternary ammonium catalysts. It was also found that the intercalated catalysts could be used several times before losing their catalytic activity. Also, a remarkable increase in catalytic activity has been observed using a co solvent. However, it appears that there is a limit for the co-solvent concentration to be effective.

In this paper, the evidences of Quaternary deformation in the west of Shahrood, in an area starting from Deh-Molla valley and extending to Tazareh valley in the southern domain of eastern Alborz have been studied. The studied area is bounded on the North and South by two main faults that trends east- west and dips to north. In the field inspection, the evidences of Quaternary activity like cutting and displacing of Quaternary sediments in some localities such as Deh-Molla and Tazareh valleys have been observed. This study showed that the indications of Quaternary activity are present in the whole of the region; but the North fault with a dominantly left lateral strike slip mechanism that is the eastern continuation of Astaneh fault, has a main role in Quaternary deformation. The left lateral strike slip movement on South fault is finished to east where it connects to a normal transfer fault. This latter transfer fault trends north- south and dips to east.

Geomorphic evidence along the Siah kuh fault (North of Jajarm) shows this fault has been active during Quaternary. Faulted Quaternary deposits, deflected and offset streams and bisected alluvial fans are among such evidence. These together with fault scarps in Neogene and Quaternary strata reveal young left-lateral motions on the Siah kuh fault as a part of the Shahrud fault system. However, there are Paleozoic and Mesozoic Formations juxtaposed with Neogene and Quaternary deposits along the fault. Some of these old units have cropped out in northeastern termination and bends along the fault, while others are observed where there is not a bend. Therefore, thrust faulting must have brought them to the surface. Aeromagnetic maps show that Siah kuh fault coincides with an aeromagnetic lineament. Consequently, the geomorphic features suggest only the youngest slips on the fault. Therefore, the Siah Kuh has been a thrust fault whose kinematics change and initiation of left-lateral motions resulted from changes in stress regimes and a regional reorganization during Quaternary.

For geological surveys of different sections of the Quaternary deposits of Jam aquifer, using depth data of wells and geoelectric boreholes, 51 wells and boreholes were used to extract depth of sections. In the GMS software by selecting ID, Quaternary deposits were identified and coded in wells and Sondage. Based on geo-electric sections of the Jam Plain, Due to the prevailing electrical resistance (Ohm Meter) and analysis of sample Sondages, three classes of quaternary deposits including dry alluvial deposits(Q2), Juicy alluvial deposits(Q1) and the marl Bedrock were separated. After entering quaternary deposits data into ArcGIS software, by logarithm, normalizing the data was done. The results showed the Jam  aquifer bed rock in the northwest of pure red clay, in the northern part of the green marl and the middle part of the bed rock is pure marl. Surface layer contains alluvial deposits (Q2) and below it, the layer contains juicy alluvial deposits (Q1). Marl bed rock is seen all the way through the sections. The maximum height is 730 m in the northeastern plain and at least 630 meters in the northwest. The study showed that the major thickness of quaternary deposits Q2 is located in the northeastern region of the study area and in the middle and northwest of the plain, the thickness of Q2 has been reduced. Quaternary deposits thickness Q1 in the northwest to northeast, especially in the middle of the plain increase. The characteristics of quaternary deposits of the study area, lack of surface watery layers, high permeability and reduced clay impurities. The results of the study showed in dry alluvial deposits and Juicy alluvial deposits, there is a direct correlation between hydrodynamic coefficients and thickness variations of quaternary deposits. With reduction in the thickness of alluvial deposits, the hydrodynamic coefficients are also reduced.

Geologists on a global scale have called the fourth geological period the Quaternary period. The late Dr. Ahmad Motamed (1935-2016), a distinguished professor of Tehran University, is one of the scientists who have researched and studied the change of Quaternary processes in Iran. In many of his writings, coexistence with Quaternary has been recommended to his students and audiences. His scientific effort and theory can have a special aspect with elitist audiences and it is an extract of his known and intuitive knowledge. His death delayed the possibility of reaching the conclusion of his naturalistic thinking aligned with humanism and his virtuous thinking and social orientation. Criticism of thinking and ideas, epistemological criticism and practical criticism and the quality of the use of the natural environment by societies made them stronger in the Quaternary link with the policies and activities of politicians and civil engineers. Therefore, he tried to explain a theory based on a school, based on an ideal, based on a value and based on a science called "Quaternary". He saw the real needs of mankind and quaternary science as connected and related links. His systematic view is the beginning of scientific innovation in Iran's Quaternary knowledge. He tried to establish peaceful social relations of Quaternary.

In this paper systematics of the gastropods of the Quaternary deposits were studied in the Caspian Sea in an exploration well in the northern city of Aq Qala in Golestan province. In this subsurface studied, total thickness of Quaternary deposits is 2585m. A Total of 11 species, 8 genera of 5 families of gastropods are reported. The identified gastropods show that since the beginning of the Quaternary the contents of these gastropods in the Caspian Sea have been adapted to sea level fluctuations.

The present study investigated the possibility of implementing quaternary prevention using family physicians in Iran’s health system. The present study was a qualitative study conducted with a grounded theory approach. Thirty-four participants, who were faculty members and experts, were selected by purposive and theoretical sampling using the snowball approach until data saturation. The data were collected through semi-structured interviews. The interviews took 20 to 60 minutes each, based on the circumstances and the participant’s willingness to continue. Data analysis was performed along with data collection by Strauss and Corbin’s constant comparative analysis. Using Lincoln and Guba criteria, the accuracy and strength of this research were confirmed. The dimensions model of quaternary prevention using family physicians in Iran were specified in six axial categories: causal conditions, contextual conditions, intervening conditions, strategies, and outcomes. The phenomenon was the promotion of quaternary prevention, including defining quaternary prevention, family physicians, the philosophy of quaternary prevention, and the philosophy of family physicians—social, political, economic, cultural, and technological conditions as contextual and intervening conditions. Causal conditions were doctors, patients, and the health system. Two main strategies were intersectoral administration and intra-sectoral governance. Outcomes included efficiency and the provision of security for society. For quaternary prevention promotion and to offer ethically and rationally acceptable scientific services to the people, it is necessary to promote the position of the family physician as the primary implementer of quaternary prevention in healthcare. Getting to the PHC umbrella is achieved through intra-sectoral leadership and inter-sectoral governance, which supports the patient and reduces unnecessary care.