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Background: Traditional teaching methods have faced many shortcomings that the technical advances and requirements of today's world, has necessitated the need for a new approach to education that the need for a mobile education approach is felt. Aims: The aim of this study was to determine the effect of education using reverse learning on the learning of sixth grade elementary students in the course of experimental sciences. Methods: In terms of purpose of this research as applied research and in terms of implementation and data collection method, the quasi-experimental method of pretest-posttest design with control group was used. The statistical population of the present study included all 3,000 elementary school students in Lamerd city. Sampling method in this study was available which included 60 students and were selected through available sampling. Thus, two classes of 30 people were selected from the sixth grade elementary schools of Lamerd city. In order to collect information, a researcher-made learning test of science course was used. Univariate analysis of covariance (ANCOVA) was used to infer the hypotheses. Results: The results of data analysis showed that reverse learning is effective on students 'learning (P

In this investigation, a novel nano-adsorbent based on magnetic graphene oxide nanocomposite was used for dispersive solid-phase microextraction (D-SPME) of melamine in environmental water samples. The m@GO-RAFT agents were synthesized by surface modification of Fe3O4 nanoparticles with graphene oxide via surface reversible addition-fragmentation chain transfer (RAFT) copolymerization, as characterized by electron microscopy (SEM and TEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and vibrating sample magnetometer (VSM). Several parameters affecting extraction performance, including the extraction solvent, amount of nano-adsorbent, contact time and back-extraction time, and sample pH were evaluated and optimized. Under the optimum conditions, analytical figures of merit such as linearity, limit of detection (LOD) and limit of quantitation (LOQ) were found to be 0.03–100 µg/L, 0.011 µg/L, and 0.027 µg/L, respectively.

The presence of chromium in drinking water and the entry of industrial wastewater into groundwater resources endangers human health and the environment. This study was done to investigate the effect of leonardite to remove Cr+6, Cr+3 from aqueous environments. The optimal values of factors were determined by the surface response model and the central composite design. Adsorption data were fitted with the pseudo-first order and pseudo-second order kinetic models. In addition, the effects of interfering cations and anions on chromium adsorption were determined. The results showed that the contact time, amount of leonardite and pH significantly affect chromium sorption. Chromium kinetic data were well fitted (R2=0.995) to the pseudo second order equation. The capacity (qe) and adsorption coefficient (Kads) parameters for Cr3+ were higher than Cr6+. As a large amount of Cr3+ was adsorbed by leonardite in a short time. Fe3+ and SO42- as interfering ions reduced the removal of Cr3+ and Cr6+ by leonardite respectively. It is concluded that Leonardite, as a biodegradable adsorbent, is suitable for remove of chromium from contaminated waters.

Introduction: There has been growing interest in using environmentally friendly methods of synthesizing nanoparticles without using substances risky to the environment and human health. The aims of this study were biosynthesis of silver nanoparticles using different tree gum extracts and evaluation of the toxicity of nanoparticles and their salts against two bacteria: Escherichia coli and Staphylococcus aureus. Materials & Methods: In this study, silver nanoparticles (SNPs) synthesized from manna of Quercus, Cerasus avium, and Prunus armeniaca gum extracts were investigated for their antibacterial activity. Silver nanoparticles were prepared from the reduction of silver nitrate. Copper nanoparticles (CuNPs) were formed by reduction of CuCl2 with L-ascorbic acid. Prepared nanoparticles were characterized by ultraviolet-visible spectroscopy and TEM techniques. Antibacterial activities of the nanoparticles were tested against Staphylococcus aureus and Escherichia coli. Findings: In the present study, biosynthesis and characterization of SNPs using Cerasus avium and Prunus armeniaca gum extracts is reported for the first time. The spectrum of the reaction mixture showed a strong absorption peak at 420 nm. TEM image showed that Ag-NPs (SNPs) formed were well dispersed with a spherical structure and 10 to 30 nm particle size range. Bacteria (E. coli and S. aureus) showed clear hypersensitivity to silver and copper nanoparticles, and the effects of SNPs were more notable than those of CuNPs. Data analysis showed that CuCl2 and AgNO3 nanoparticles had a lower inhibitory effect. Discussion & Conclusions: Our results showed these microorganisms had sensitivity against the tested nanoparticles; however, E. coli showed higher sensitivity than S. aureus to both nanoparticles.

Abstract: The present research studies sedimentary succession of Oligocene Asmari Formation at Tang-e Moshkan stratigraphic section aimed at evaluating lithostratigraphy, biostratigraphy and determining microfacies, microfacies class, sub-environments, and sedimentary environment. The mentioned section at southern flank of Tamar anticline from of Sub-coastal Fars sub-basin located in folded Zagros. It was selected in boundary of Fars and Kohgiluyeh and Boyer-Ahmad provinces with a Thickness over than 350m consisting of limestone and marly limestone strata. In this section, lower and upper boundaries of Asmari Formation are continuously located over Pabdeh and under Razak Formations as homoclinal ones, respectively. The studied thickness of Pabdeh and Razak Formations are respectively 241m and 9m in this section. Biostratigraphy studies conducted on 195 thin sections resulted in identification of 37 genus and 44 species of bentic foraminifera, 4 genus and 4 species of planktonic foraminifera along with some non-foraminifera, determination of Oligocene (Rupelian - Chattian), and Introduction of two assemblage zones that old to new, respectively: 1- Nummulites vascus - Nummulites fichteli Assemblage Zone 2- Archaias asmaricus / hensoni - Miogypsinoides complanatus Assemblage Zone Results of high resolution field and laboratory of observations and studies were embedded as recognition and classification of 8 microfacies class in 3 lagoon, shoal and open marine sedimentary sub-environments, all deposited on a carbonated platform of a homoclinal ramp.

Abstract: The present research studies sedimentary succession of Oligocene Asmari Formation at Tang-e Moshkan stratigraphic section aimed at evaluating lithostratigraphy, biostratigraphy and determining microfacies, microfacies class, sub-environments, and sedimentary environment. The mentioned section at southern flank of Tamar anticline from of Sub-coastal Fars sub-basin located in folded Zagros. It was selected in boundary of Fars and Kohgiluyeh and Boyer-Ahmad provinces with a Thickness over than 350m consisting of limestone and marly limestone strata. In this section, lower and upper boundaries of Asmari Formation are continuously located over Pabdeh and under Razak Formations as homoclinal ones, respectively. The studied thickness of Pabdeh and Razak Formations are respectively 241m and 9m in this section. Biostratigraphy studies conducted on 195 thin sections resulted in identification of 37 genus and 44 species of bentic foraminifera, 4 genus and 4 species of planktonic foraminifera along with some non-foraminifera, determination of Oligocene (Rupelian - Chattian), and Introduction of two assemblage zones that old to new, respectively: 1- Nummulites vascus - Nummulites fichteli Assemblage Zone  2- Archaias asmaricus / hensoni - Miogypsinoides complanatus Assemblage Zone Results of high resolution field and laboratory of observations and studies were embedded as recognition and classification of 8 microfacies class in 3 lagoon, shoal and open marine sedimentary sub-environments, all deposited on a carbonated platform of a homoclinal ramp.