Amenability of heap leaching technology on uranium extraction from Gattar and El Missikat area, Eastern Desert, Egypt: A kinetic approach

Studies of uranium heap leaching from different uranium mineralization situated in Eastern Desert of Egypt was investigated via batch experiments, followed by its optimum condition applicationon column percolationtests.The optimum process operating parameters were implemented on large column scale in order to make more condition control and evaluate the time and reagents needed in the large scale. The results show thatleaching efficiency of GIIattained about 78.3% with 34kg/ton acid consumption in a 44 days period, while leaching efficiency of El-Missikat attained about 86.6% with 28kg/ton acid consumption in a 40 days period.Kinetics reaction models of column tests have been investigated to optimize the column leaching behavior. Based on the leaching results of two mineralized samples, the rate of the uranium metal dissolution is controlled by the chemical reaction and the diffusion reaction but diffusion reaction control was more predominate than a chemical reaction control

New Algorithm for Drawings of 3-Planar Graphs

Graphs arise in a natural way in many applications, together with the need to be drawn. Except for very small instances, drawing a graph by hand becomes a very complex task, which must be performed by automatic tools. The field of graph drawing is concerned with finding algorithms to draw graph in an aesthetically pleasant way, based upon a certain number of aesthetic criteria that define what a good drawing, (synonyms: diagrams, pictures, layouts), of a graph should be. This problem can be found in many such as in the computer networks, data networks, class inter-relationship diagrams in object oriented databases and object oriented programs, visual programming interfaces, database design systems, software engineering…etc. Given a plane graph G, we wish to find a drawing of G in the plane such that the vertices of G are represented as grid points, and the edges are represented as straight-line segments between their endpoints without any edge-intersection. Such drawings are called planar straight-line drawings of G. An additional objective is to minimize the area of the rectangular grid in which G is drawn. In this paper we introduce a new algorithms that finds an embedding of 3-planar graph. Keywords: 3- Planar Graph; Graph Drawing; drawing on grid

Stimuli-responsive hydrogels: smart state of-the-art platforms for cardiac tissue engineering

Biomedicine and tissue regeneration have made significant advancements recently, positively affecting the whole healthcare spectrum. This opened the way for them to develop their applications for revitalizing damaged tissues. Thus, their functionality will be restored. Cardiac tissue engineering (CTE) using curative procedures that combine biomolecules, biomimetic scaffolds, and cells plays a critical part in this path. Stimuli-responsive hydrogels (SRHs) are excellent three-dimensional (3D) biomaterials for tissue engineering (TE) and various biomedical applications. They can mimic the intrinsic tissues’ physicochemical, mechanical, and biological characteristics in a variety of ways. They also provide for 3D setup, adequate aqueous conditions, and the mechanical consistency required for cell development. Furthermore, they function as competent delivery platforms for various biomolecules. Many natural and synthetic polymers were used to fabricate these intelligent platforms with innovative enhanced features and specialized capabilities that are appropriate for CTE applications. In the present review, different strategies employed for CTE were outlined. The light was shed on the limitations of the use of conventional hydrogels in CTE. Moreover, diverse types of SRHs, their characteristics, assembly and exploitation for CTE were discussed. To summarize, recent development in the construction of SRHs increases their potential to operate as intelligent, sophisticated systems in the reconstruction of degenerated cardiac tissues

Environmental pressures and eco-innovation in manufacturing SMEs: the mediating effect of environmental capabilities

Purpose: Although environmental pressures have been covered in great detail in prior literature as the drivers of eco-innovation, there remains inconsistency in the empirical results concerning the effects of these pressures on eco-innovation behaviour. Hence, this paper aims to investigate the impact of environmental pressures, namely, regulatory pressure, green demand and competitive pressure, on eco-innovation among manufacturing SMEs. Moreover, it examined the mediating role of environmental capabilities on the environmental pressure–eco-innovation relationship. Design/methodology/approach: Quantitative data were collected using an online self-reported questionnaire survey to test the hypothesised model. A total of 183 valid questionnaires were collected from managers and owners of manufacturing SMEs in Egypt. Findings: The results of the data analysis using the Smart-PLS software package revealed that among environmental pressures, only green demand had a direct effect on eco-innovation. In addition, environmental capabilities only mediated the effect of competitive pressure on eco-innovation. Originality/value: This study has been one of the few addressing the issue of how the drivers of eco-innovation interact. It has also provided the managers and owners of SMEs and policymakers with practical implications

Institutional pressure and eco-innovation: The mediating role of green absorptive capacity and strategically environmental orientation among manufacturing SMEs in Egypt

With the growing concern about climate change, businesses have been under increasing pressure from regulatory agencies and customers to implement proactive environmental practices such as eco-innovation. While environmental pressures have been extensively discussed in the literature as drivers of eco-innovation, empirical evidence on the influence of these pressures on eco-innovation behaviour remains inconsistent. Therefore, the current study essentially aims to investigate the direct effect of institutional pressures, namely, regulation, eco-friendly product demand, and competitive pressure on eco-innovation, coupled with the indirect effect of these pressures by mediating internal drivers of eco-innovation including green absorptive capacity and strategically environmental orientation among manufacturing SMEs in Egypt. Based on a sample of 176 managers and owners of these enterprises, a cross-sectional survey is conducted to collect data related to research constructs. The results of data analysis using Smart-PLS show that all external pressures are not directly associated with eco-innovation. Of the six indirect hypothesized effects, only four indirect effects are supported. The results illustrate that green absorptive capacity mediates the relationship between institutional pressure (eco-friendly product demand and competitive pressure) and eco-innovation. The results also show that strategically environmental orientation mediates the relationship between institutional pressure (regulation and competitive pressure) and eco-innovation. This study provides an in-depth understanding of firms’ responses to institutional pressures as well as the notable implications for SMEs managers, policymakers and future researchers

Appraisal on the Wound Healing Potential of Deverra tortuosa DC. and Deverra triradiata Hochst Essential Oil Nanoemulsion Topical Preparation

Deverra tortuosa (Desf.) DC. and Deverra. triradiata Hochst. ex Bioss are perennial desert shrubs widely used traditionally for many purposes and they are characteristic for their essential oil. The objective of the present study was to investigate the in vivo wound healing activity of the essential oil (EO) of D. tortuosa and D. triradiata through their encapsulation into nanoemulsion. EO nanoemulsion was prepared using an aqueous phase titration method, and nanoemulsion zones were identified through the construction of phase diagrams. The EO was prepared by hydrodistillation (HD), microwave-assisted hydrodistillation (MAHD), and supercritical fluid extraction (SFE) and analyzed using GC/MS. D. tortuosa oil is rich in the non-oxygenated compound, representing 74.54, 73.02, and 41.19% in HD, MADH, and SFE, respectively, and sabinene represents the major monoterpene hydrocarbons. Moreover, D. triradiata is rich in oxygenated compounds being 69.77, 52.87, and 61.69% in HD, MADH, and SFE, respectively, with elemicin and myristicin as major phenylpropanoids. Topical application of the nanoemulsion of D. tortuosa and D. triradiata (1% or 2%) exhibited nearly 100% wound contraction and complete healing at day 16. Moreover, they exhibit significant antioxidant and anti-inflammatory effects and a significant increase in growth factors and hydroxyproline levels. Histopathological examination exhibited complete re-epithelialization accompanied by activated hair follicles and abundant collagen fibers, especially at a concentration of 2%. Therefore, the incorporation of the two Deverra species into nanoemulsion could professionally endorse different stages of wound healing

Beyond the looking glass: recent advances in understanding the impact of environmental exposures on neuropsychiatric disease

The etiologic pathways leading to neuropsychiatric diseases remain poorly defined. As genomic technologies have advanced over the past several decades, considerable progress has been made linking neuropsychiatric disorders to genetic underpinnings. Interest and consideration of nongenetic risk factors (e.g., lead exposure and schizophrenia) have, in contrast, lagged behind heritable frameworks of explanation. Thus, the association of neuropsychiatric illness to environmental chemical exposure, and their potential interactions with genetic susceptibility, are largely unexplored. In this review, we describe emerging approaches for considering the impact of chemical risk factors acting alone and in concert with genetic risk, and point to the potential role of epigenetics in mediating exposure effects on transcription of genes implicated in mental disorders. We highlight recent examples of research in nongenetic risk factors in psychiatric disorders that point to potential shared biological mechanisms—synaptic dysfunction, immune alterations, and gut–brain interactions. We outline new tools and resources that can be harnessed for the study of environmental factors in psychiatric disorders. These tools, combined with emerging experimental evidence, suggest that there is a need to broadly incorporate environmental exposures in psychiatric research, with the ultimate goal of identifying modifiable risk factors and informing new treatment strategies for neuropsychiatric disease