m. nakhaei

Groundwater is a vital resource that supplies water needs for various purposes. In recent years, with the increase in population growth, the demand for water along with climate change have led to excessive extraction of underground water and the quantitative and qualitative reduction of this valuable resource at the global level. With the increasing understanding of the interdependence of water and development, paying attention to the sustainable management of underground water in shared boundary aquifers to deal with threats such as lack of water, food, energy, loss of ecosystems and biodiversity and most importantly a decrease in human security, is a must-do act. Therefore, in order to achieve an increase in the level of cooperation for the fair and sustainable use of the country's shared boundary aquifers and also to prevent any disputes and conflicts in the future, the successful experiences of international cooperation between shared boundary aquifers such as the Geneva Aquifer Agreement (between France and Switzerland) has been used and suggestions have been made in this regard. The proposed solution includes an initial agreement contract for more cooperation in the field of identifying technical, socio-cultural, political, economic and legal parameters with the participation and activity of all governmental and non-governmental organizations, technical and specialist experts, academic and civil communities as a common set, provision of financial resources to achieve a comprehensive study of the common aquifer status, sharing reliable information in a common base, stablishing an organization agreed by the beneficiary countries and defining the necessary laws and obligations, forming an advisory committee in order to reduce disputes and to monitor the implementation of commitments, and finally, presenting a comprehensive framework in the form of a shared agreement between the beneficiary countries with a common aquifer.

living with post-traumatic stress disorder veterans imposes severe stress on veterans’ family members, especially veteran’s spouses. This study aimed to discover and explore coping strategies to advance and maintain the cohesion of life.

Current study was conducted in 2021 using a qualitative content analysis approach. Participants were selected purposely from post-traumatic stress disorder veterans’ spouses. Data were collected through semi-structured interviews with 15 post-traumatic stress disorder veterans’ spouses. And then analyzed according to Graneheim & Lundman's method.

Through analysis of transcribed interviews, 1 theme, 4 categories, and 8 subcategories were extracted. The theme was developing life meaning and categories including developing value base approach, altruistic preservation, beyond-defined gender roles, and mutually beneficial care.

In confronting with full of tension in life and lack of support, developing the meaning of life can be led to wide and deep changes in the encyclopedia and the meaning of wives' life, and these changes can make them better and more optimal in confronting life challenges.

Eshkaftouk bentonite mine is located in the northwest of Birjand and eastern part of Lut block. This bentonite is the product of alteration of Tertiary andesitic lavas and associated tuffs. Geochemical characteristics show that bentonite parent rocks have andesitic composition and bentonite samples have andesite to dacite-rhyodacite composition.The magmatic series of all samples is calc-alkaline type. Mineralogical analysis (XRD) shows that the main minerals forming of bentonites include montmorionite, anorthite, cristobalite, and quartz with small amounts of illite, muscovite, kaolinite, microcline and dolomite. Electron microscope images of bentonite samples show that smectite (montmorionite) is the most abundant mineral in these samples that are characterized by flaky morphology with rugged edges, honeycomb and cornflake. The results of energy dispersive spectroscopy (EDS) studies also indicate that the predominant mineral forming  of bentonites is sodium-calcium montmorionite, and accordingly, Eshkaftouk bentonite is Wyoming-type. Investigation of mass changes of major and trace elements of Eshkaftouk bentonite indicating loss of K2O, Na2O, CaO, MgO,MnO and LILE such as Ba, Rb, Sr and gains of SiO2, Al2O3 and Fe2O3.

In Zoolesk area, about 11km northeast of Sarbisheh city in South Khorasan Province, volcanic rocks including andesite, dacite and rhyolite have cropped out where andesitic lavas have the maximum distribution and have been studied in this research.The main textures of andesites are porphyry with microlitic-glassy groundmass, glomeroporphyry and vesicular. Minerals forming andesites include plagioclase, pyroxene, amphibole, biotite and rarely sanidine. Plagioclase phenocrysts have oscillatory zoning and sieve texture and so corrosion, rounding and resorption rims can be seen in the margin of some crystals. Based on microprobe analyses, the composition of plagioclases changes from Ab67,An33to Ab54, An46 and are andesine type. Clinopyroxene phenocrysts have augite with minor diopside composition (En39-41 Fs13-17 Wo43-47) and orthopyroxenes are enstatite (En41-74Fs13-43Wo2-3). The Mg# values in clinopyroxene and orthopyroxene are variable between 69-75 and 56-76 respectively. Thermometry studies showed that the crystallization temperature of clinopyroxenes is 1150 to 1200°C and for orthopyroxene is 1050 to 1100°C. The calculated pressure for genesis of clinopyroxene and orthopyroxene in the studied samples was less than 2 kbar.

nZVI particles are strong reducing agents, capable of degradation and detoxification of a wide range of organic and inorganic pollutants in contaminated aquifers. Understanding the transport and retention of these nanoparticles in subsurface environments is required for treatment systems and in situ groundwater remediation. During the last decade, several studies have been conducted to investigate the effect of different physicochemical conditions on the transport and retention of nZVI in saturated porous media. This study aimed to evaluate the effect of sand grain size and nanoparticle concentration on fundamental processes governing CMC-nZVI nanoparticle transport and retention in saturated porous media.

nZVI (NANOFER STAR, NANOIRON, s.r.o. Czech Republic was employed in this study. To prepare CMC-nZVI, nanoparticle, suspension and polymer solution was added by the relative dose of CMC to nZVI mass 1:2, in a 250-ml flask reactor. pH was fixed at 9.5 by NaOH and the solution was mixed for 144 h under ambient temperature condition at the absence of oxygen. Quartz sands with ∼ 99.38% SiO2 and 0.27 Fe2O3 based on XRF analysis, was used as the porous medium. The experiments were conducted using a cylindrical Plexiglas column 30 cm in length and 2.5 cm in inner diameter. In order to capture the effect of particle concentration and grain size, 12 tests were conducted with four different concentrations (C = 10, 200, 3000, 10000 mg/l) and three sizes of grain (dc = 0.297–0.5 mm, 0.5–1 mm, 1–2 mm). In each test, ∼4 PVs of nZVI suspension were introduced into the columns and to complete the test, ∼6 PVs of deionized water were flushed. The column effluent was collected every 2 min and analyzed for total Fe using UV-Vis. The normalized effluent iron concentration (C/C0) for each transport test was plotted as a function of pore volumes. The spatial distributions of retained CMC-nZVI in the sand columns were determined to right after the breakthrough experiment. The quartz sand in each column was carefully excavated in ~3 cm increments, transferred into 50 mL vials and analyzed for total Fe. The concentration of retained CMC-nZVI in all the sand columns was also plotted as a function of travel distance.

The breakthrough curves indicate that both grain size and nanoparticle concentration had a relevant impact on CMC-nZVI mobility, even if the influence of nanoparticle concentration was more evident. In all experimental conditions, the BTCs were not symmetrical, which indicates that attachment and detachment phenomena occurred in different modes. The breakthrough curves can be interpreted in two steps: injection and flushing times. The maximum relative concentration (C/C0) decreased, during injection time, for three different grain sizes while influent concentration increased from 10 to 10,000 mg/L, which can be attributed to the increase in particle-particle interaction (aggregation) and particle-sand interaction (attachment). The breakthrough curves, after the initial increase, showed a strong decline, which is a clear indication of the ripening phenomenon. This phenomenon affected the porous medium properties such as porosity and hydraulic conductivity. Moreover, At higher influent CMC-nZVI concentration, Na+ ion and subsequently ionic strength increases because of higher doses of Na-CMC. As a result, aggregation and deposition will occur under a shallower secondary energy minimum well, that they are reversible. At the same nZVI concentrations, the breakthrough curve decreased by a decrease in grain size. Decreases in grain size can lead to an increase in surface area, decrease in pore throat size; and consequently, retention of nanoparticles by straining phenomena. However, another behavior was governed during the flushing time. During the flushing time, a narrow sharp increase in C/C0 was observed called flushing peak. In this study, CMC-nZVI aggregates deposited onto surfaces of sands due to secondary energy minimum were eventually released during the flushing period of the column with DI water. The results suggest that the grain size and particle concentration can have a positive effect on this peak. The results of retention profiles demonstrate that the CMC-nZVI retention in low concentration (10 mg/L) is consistent with filtration theory; whiles the highly concentrated polymer-modified nZVI dispersions (especially 3000 and 10000 mg/l) contradicts filtration theory. Based on filtration theory (Elimelech et al. 1995; Tufenkji et al. 2004), if all factors affecting the transport of colloids are kept constant, grain size increase can lead to a decrease in surface area and attachment efficiency (α). The contradiction at high concentration can be explained by considering the effect of hydrodynamic forces (especially fluid shear) on agglomeration and disagglomeration and deposition and detachment. The size of stable aggregates formed in the pores of finer sands is smaller than when they are formed in the pores of larger sands because the magnitude of local shear is higher for narrower pores. This led to decreased retention in finer sand.

The results of this research show that during the injection time, ripening and straining phenomena are key retention mechanisms of nanoparticles by decreasing the sand size and increasing particle concentration. While during the flushing time, secondary energy minima and hydrodynamic forces play critical roles in the deposition and transport mechanisms of CMC-nZVI. At high particle concentration (3000 and 10000 mg/l), these factors can lead to an increase in nanoparticle mobility by decreasing sand size. However, the results of retention profiles were consistent with colloid filtration theory at low particle concentration (10 and 200 mg/l).