The effect of heavy metals on thiocyanate biodegradation by an autotrophic microbial consortium enriched from mine tailings

Bioremediation systems represent an environmentally sustainable approach to degrading industrially generated thiocyanate (SCN−), with low energy demand and operational costs and high efficiency and substrate specificity. However, heavy metals present in mine tailings effluent may hamper process efficiency by poisoning thiocyanate-degrading microbial consortia. Here, we experimentally tested the tolerance of an autotrophic SCN−-degrading bacterial consortium enriched from gold mine tailings for Zn, Cu, Ni, Cr, and As. All of the selected metals inhibited SCN− biodegradation to different extents, depending on concentration. At pH of 7.8 and 30 °C, complete inhibition of SCN− biodegradation by Zn, Cu, Ni, and Cr occurred at 20, 5, 10, and 6 mg L−1, respectively. Lower concentrations of these metals decreased the rate of SCN− biodegradation, with relatively long lag times. Interestingly, the microbial consortium tolerated As even at 500 mg L−1, although both the rate and extent of SCN− biodegradation were affected. Potentially, the observed As tolerance could be explained by the origin of our microbial consortium in tailings derived from As-enriched gold ore (arsenopyrite). This study highlights the importance of considering metal co-contamination in bioreactor design and operation for SCN− bioremediation at mine sites

Prosthodontic using Rapid Prototyping

Rapid prototyping is a set of technicality which applied to create a scale model of a physical part or assembly rapidly utilizing three-dimensional computer aided design (CAD) data. 3D printing or "additive layer manufacturing" technology was used to Develop the part or assembly. It is a CAD/CAM technology which was created initially to manufacture prototypes for industrial purposes. RP technology   encouraged the configuration and quick generation of mass quantities of precise parts by the industrial  manufacturing in a convenient time with exactness and pace. In the previous two decades this technology was utilized  efficiently in the medical field with a promising results. In this review the technique, methods and various uses of this fast emerging technology regarding prosthodontic will be discussed

Process−microstructure−properties relationship in Al−CNTs−Al2O3 nanocomposites manufactured by hybrid powder metallurgy and microwave sintering process

Al−2CNTs−xAl2O3 nanocomposites were manufactured by a hybrid powder metallurgy and microwave sintering process. The correlation between process-induced microstructural features and the material properties including physical and mechanical properties as well as ultrasonic parameters was measured. It was found that physical properties including densification and physical dimensional changes were closely associated with the morphology and particle size of nanocomposite powders. The maximum density was obtained by extensive particle refinement at milling time longer than 8 h and Al2O3 content of 10 wt.%. Mechanical properties were controlled by Al2O3 content, dispersion of nano reinforcements and grain size. The optimum hardness and strength properties were achieved through incorporation of 10 wt.% Al2O3 and homogenous dispersion of CNTs and Al2O3 nanoparticles (NPs) at 12 h of milling which resulted in the formation of high density of dislocations and extensive grain size refinement. Also both longitudinal and shear velocities and attenuation increase linearly by increasing Al2O3 content and milling time. The variation of ultrasonic velocity and attenuation was attributed to the degree of dispersion of CNTs and Al2O3 and also less inter-particle spacing in the matrix. The larger Al2O3 content and more homogenous dispersion of CNTs and Al2O3 NPs at longer milling time exerted higher velocity and attenuation of ultrasonic wave

Cage culture of tilapia in some water resources (farm and agriculture ponds) of Bafq, Iran

Tilapia is the second cultured fish in the world. Up to 135 countries produces tilapia. Intensive culture systems of tilapia such as cage culture are recently developed because of limitations of water resources. In Iran, studies about tilapia were started in National Research Center of Saline Water Aquatics from November 2008 and some aspects of tilapia aquaculture and culture systems are surveyed. Investigation about cage culture of Nile tilapia, Oreochromis niloticus was performed in two culture periods of 2012 and 2014 in fresh and brackish water conditions of Iran for the first time. Stocking densities of fish in the cages were 25, 50, 75, 100, 125 and 150 fish/m^3. 100g fish stocked reached 272-331 g during 80 days in the first study. However, 50g fish stocked reached 329-450 g during 145 days in the second study. Results of cage culture of tilapia in fresh and brackish water conditions showed ranges of FCR: 1.56-3.72 and 1.08-1.87, DGR: 1.63-2.91 and 2.14-2.92 g/day, SGR: 0.63-1.12 and 1.29-1.54, production: 5.98-38 and 7.17-41.6 kg/m^3, respectively. Stocking densities 75-125 fish/ m^3 were appropriate especially in fish reared in brackish water cages

Le centre du Dialogue des civilisations (étude politico-sociologique d'une nouvelle institution en Iran)

Cette rechercher s inscrit dans une étude sociologique, en particulier dans le domaine organisationnel en Iran. L'étude proposée souhaiterait analyser les interactions entre l'institution et les hommes. Du côté institutionnel, ceci comprend les objectifs du Centre, ses stratégies mises en œuvre pour y parvenir, mais aussi le type de pouvoir exercé et son évolution, ou encore les différents acteurs, ainsi que leurs pouvoirs respectifs. On s'intéressera également aux différentes activités dont le Centre avait l initiative, et à l image qu' il présentait de la société iranienne ainsi que des multiples acteurs. Le corps du travail s'articule en trois parties: 1- L idée de dialogue des civilisations ; Étude du champ politique et social et ensuite l idée principale de créature du Centre. 2- La réalisation de l'action de dialogue en deux parties; comment l'acteur relance, exécute ou transforme les orientations. Et puis nous étudions la réalisation et le développement de l'action du dialogue. 3- L interaction du Centre sur son environnement, avec les aspects tant intérieurs qu extérieurs (son personnel et sa production). L'étude de sa vie interne à travers des femmes et leurs rôles importants dans ce Centre nous dirige vers ce qu'on a nommé l'interaction non-officielle. Le Centre avait ambitionné une relation qui se voulait proche de différentes couches sociales, nous allons mettre en lumière les effets de l'activité du Centre sur son environnement. En cela, nous parlons d interaction officielle du Centre avec son environnement. En résumé, ce travail veut analyser le fonctionnement du Centre à l'intérieur et son rôle dans la sociétéThis thesis is presented as a part of a sociological study and particularly focuses on the organizational field in the Iran, This work would analyze the interaction between the organization and individual. On the organizational side, it includes the Centre's objectives, strategies implemented to achieve these objectives, but also the type of authority and its evolution, or the various actors and their powers. It will also touch on different activities which the Centre had initiated, and the image it presented of Iranian society. The body of this research is presented in three parts: 1 -The idea of "dialogue of civilizations". Including the political and social environment and in the second part, we study the idea of the creature of the Centre. 2 -The action of the dialogue; how the principal actors perform, revival or changes instructions. Then, we study the implementation and development of the action of the dialogue. 3 -Interaction of Center and its environment in both internal and external aspects (staff and production). The study of the inner life is through the women employed because of their important roles in the Center. We consider it as the unofficial interaction. The effects of the activity of the Centre in its environment (society) is consider as the official interaction. ln summary, this work aims to analyze the functioning of the Centre and its role in the societyPARIS3-BU (751052102) / SudocSudocFranceF

Mechanisms of Signal Transduction Utilized by Growth Hormone

In recent years, significant progress has been made in elucidating the signaling pathways activated by the growth hormone (GH) receptor. This chapter provides a discourse on the structural and functional characteristics of the GH receptor, as well as the signaling pathways demonstrated to be utilized by GH. Activation of these pathways results in various biochemical and biological outcomes, which are rapidly being elucidated and ultimately provide a basis for understanding GH action. Accordingly, c-Src, in addition to JAK2, has emerged as a key component of GH signaling, with the ability to mediate the activation of distinct signaling pathways independently of JAK2. Together with the occurrence of both positive and negative regulators, this adds further complexity to the signal transduction mechanisms utilized by GH

Application of Image Processing for Determination of Contaminant Plume in Porous Media

Determination of the extent and growth rate of contamination zones in water resources is a crucial stage in remediation studies. The process is especially complicated due to the multiplicity of the variables involved and the limited access to groundwater aquifers. The present study uses the image processing technique to define the contaminant plume and to analyze diffusivity coefficients for seepage flows in porous media. The image processing algorithm was developed in MATLAB software and the least squares method was used to solve the diffusion equation. Thus, the hydrodynamic dispersion coefficients in porous media were calculated without any turbulence over wide ranges of time and place with an acceptable accuracy. Analysis and verification of the data thus obtained confirmed the accuracy of the proposed model and revealed a limited error range of less than 11%. It may, therefore, be claimed that the proposed method is an effective means for studying diffusivity. The equations for estimating diffusivity coefficients were developed as a function of both the porous media characteristics and the Péclet number.Using the equations, diffusivity coefficients in the range of 0.002 to 0.0028 m were obtained for a porous medium with a grain size varying from 0.5 to 3 mm

Bond strength of self-adhesive resin cement to base metal alloys having different surface treatments

Background: This study aimed to assess and compare the shear bond strength of self-etch and self-adhesive resin cement to nickel-chromium-cobalt alloy with different surface treatments. Materials and Methods: In this in vitro study, a total of 120 disks were fabricated of VeraBond II base metal alloy. Specimens were divided into 15 groups of 8 based on the type of cement and surface treatment. The five surface treatments studied included sandblasting alone, application of Alloy Primer with and without sandblasting, and application of Metal Primer II with and without sandblasting. The three cement tested included Panavia F2.0, RelyX Unicem (RU), and G-Cem (GC). After receiving the respective surface treatments, the specimens were thermocycled for 1500 cycles and underwent shear bond strength testing. Data were analyzed using SPSS 20.0 and three-way analysis of variance. P values of the significant level of 0.05 were reported. Results: The results exhibited that the mean bond strengths in sandblasted groups were higher than nonsandblasted one. These differences were significantly higher in the sandblasted groups of Panavia F2.0 and RU cement (P 0.05). The highest bond strength was recorded for Panavia F2.0 with the surface treatment of both sandblasting and Metal Primer II. Conclusion: Based on the results, sandblasting improves the shear bond strength of self-etch and self-adhesive resin cement to base metal alloys. The best results can be achieved with a combination of sandblasting and metal primers. The performance of resin cement depends on to their chemical composition, not to the type of system

On the role of molybdenum on the microstructural, mechanical and corrosion properties of the GTAW AISI 316 stainless steel welds

A comparative study was carried out on GTAW AISI 316 welds fabricated by three different filler metals including ER-317M, ER-316 and ER-308. Filler metals were selected in a way to induce varying Molybdenum (Mo) concentrations in the weld metal, so that the effect of Mo on the microstructural, mechanical and corrosion behavior of the welds was investigated. Microstructural studies revealed that as Mo concentration increased in the weld metal, the dendritic morphology of this zone gradually was changed from cellular dendritic to columnar dendritic and a noticeable amount of austenitic phase and precipitations were formed. Mo-containing ER-316 and ER-317M welds showed appreciable amount of Mo- and Cr-rich carbides such as (Fe,Cr)23C6 which formed at the grain boundaries of δ-ferrite phase resulting in increased the hardness and strength of welded samples. The highest microhardness value of 188 HV and yield strength of 330 MPa belonged to ER-317M welds containing the highest Mo concentration. Also, corrosion resistance of the welds significantly improved by increasing Mo concentration and a minimum corrosion rate of 4.178 mm/year was accounted for ER-317M welds in which, the formation of passive film was more facilitated due to the higher concentration of Mo