Synthesis Luminescent Plasmonic Silver Nanoparticles and The Chemical Affinity towards sulphur atom in Sulphide and Thiourea molecules: Ab-Initio DFT Study

Three different luminescent silver nanoparticles(AgNPs) were synthesized by simple reduction method with the different mole ratios of L-ascorbic/citrate solution and stabilized with CTAB. The prepared three AgNPs were characterized by UV, fluorescence, FTIR, dynamic light scattering measurements and Scanning Electron Microscopy. The plasmon bands of AgNPs- reddish-brown (RB), green (G) and reddish-green (RG) were centered at 565, 587 and 592 nm, respectively. The highly luminescence emission was observed for AgNPs(G). The size diameters of the prepared AgNPs-G, RG and (RB) were measured by dynamic light scattering (DLS) method at 24.3 nm, 66.28 nm and 103.46 nm, respectively. The electrochemical properties of AgNPs-RG was recorded the oxidative part of AgNPs into Ag+ at +0.23 V and the reduction part of Ag+ into Ag0 was recorded at -0.49 V vs. Ag/AgCl). Cetyl trimethylammonium bromide (CTAB) was stabilized AgNPs(RG) which recorded in infrared and scanning electron microscope measurements. The concentration of thiourea, sodium sulphide was detected by the electrochemical sensitivity of AgNPs(RG)-CTAB. A calibration curve between electrochemical sensitivity of AgNPs-CTAB vs concentration of sulphur molecule. The limit of detection (LOD) was founded 2.10 and 1.90 µmole L-1 of sodium sulphide and thiourea, respectively (R2=0.94, n=3). The computational calculations are used to illustrated the chemical affinity of sulphur atom in sodium sulphide or thiourea towards AgNPs(RG).

Emergency Treatment on Gartland Type III Pediatric Supracondylar Humeral Fractures: a Retrospective Analysis of Therapeutic Consequences of Surgery

Objective: The objective of this analysis was to investigate the effect of emergency treatment by simple reduction within 8 h of injury for Gartland type III pediatric supracondylar humeral fractures.Methods: One hundred twenty children with Gartland type III supracondylar humeral fractures were studied. All 120 patients had extension-type fractures and each was classified into one of two groups as follows: group A (n = 90), treated by closed reduction; group B (n = 30), treated by open reduction. Both groups underwent Kirschner wire internal fixation within 1 to 5 d after reduction. Information on the emergency treatments within 8 h of the fracture and the duration of the subsequent surgeries was collected and compared between the two groups. Results: There was no significant difference between the two patient groups in terms of the demographic parameters. Compared to non-emergency surgery, emergency surgery required shorter operation time and fewer complications (P<0.05). Nevertheless, the fracture healing time was significantly less (P＜0.05), and Flynn scores were higher in the closed reduction group compared to the open reduction group (P<0.05).Sixty-six of the 90 patients in group A received emergency treatment with an average subsequent surgery duration of 40 min. The remaining 24 patients did not receive emergency treatment and had an average surgery duration of 65 min. Of the 30 patients in group B, four received emergency treatment with a subsequent average surgery duration of 70 min. The remaining 26 patients did not receive emergency treatment and had an average surgery duration of 91 min. Conclusion: Emergency treatment by simple reduction within 8 h of fracture was important for subsequent surgical procedures and duration. Lack of this treatment could increase the risks during open reduction. Emergency treatment within 8 h of fracture could increase the healing rate and reduce the duration of the subsequent surgery.

IMPROVEMENT OF THE MARKETING COMPLEX OF THE INDUSTRIAL ENTERPRISE

This article considers the issues on improvement of marketing complex of industrial enterprise, with the purpose of stabilization of its activity and strengthening of competitive positions. It is proposed to improve the activities of industrial enterprises on the basis of the formation of measures that will ensure the current support of domestic enterprises in difficult economic conditions. One of the ways of improving the performance of the company is to change the model “4P” into a model of marketing complex “5P” and use personnel (“Personal”) as one of the tools. On the basis of the conducted research the influence of external environment factors was evaluated on the basis of the model of the marketing complex “4P”. As a result, it was found that the surveyed company has low competitive advantages, but these competitive advantages may not be valid without preservation of highly qualified personnel, because of the instability of the activities of the company, constant differences in production, simple, reduction of workers or voluntary migration of manpower and as a result of the loss of highly qualified workers and the position of the leader in the field of machine building. The evolution of the marketing complex depending on the influence of factors of the marketing environment is examined. The application of the marketing complex not only contributes to satisfaction of needs of potential organizations in the framework of target markets, but also allows maximizing the efficiency of industrial enterprises’ activity. Practical relevance of the research carried out in the article lies in the fact that using recommendations and directions of upgrading the marketing complex of industrial enterprise will ensure stabilization of its activity on the market due to the influence of regressive external factors.

Air Passengers’ Preferences for Aviation Voluntary Carbon Offsetting: A Co-benefits Perspective

Co-benefits are positive outcomes from voluntary carbon offsetting (VCO) programs beyond simple reduction in carbon emissions, which include biodiversity, air quality, economic, health, and educational benefits. Given the rates of aviation VCOs remain at less than 10%, this study investigated air passengers’ preferences for co-benefits as well as certification, location, and cost of VCO programs. Using discrete choice modeling, this study shows that aviation VCO programs with higher levels of co-benefits, particularly biodiversity and health benefits, are preferred by air passengers and confirms a preference for domestically based and certified VCO programs. The latent class choice model identified three classes with different preferences for VCO program attributes and demographic characteristics. The results of this study contribute to the knowledge of VCO co-benefits and imply that airlines should take note of this preference for biodiversity and health co-benefits when designing VCO programs and differentiate between market segments to increase the uptake of VCOs.

Simplifications of Uniform Expressions Specified by Systems

In this article, we study the impact of applying simple reduction rules to random syntactic formulas encoded as trees. We assume that there is an operator that has an absorbing pattern and prove that if we use this property to simplify a uniform random expression with [Formula: see text] nodes, then the expected size of the result is bounded by a constant. The same holds for higher moments, establishing the lack of expressivity of uniform random expressions. Our framework is quite general as we consider expressions defined by systems of combinatorial equations. For our proofs, we rely on Drmota’s multidimensional theorem for systems of generating functions.

Metal-based Heterogeneous Catalysts for One-Pot Synthesis of Secondary Anilines from Nitroarenes and Aldehydes

Recently, N-substituted anilines have been the object of increasing research interest in the field of organic chemistry due to their role as key intermediates for the synthesis of important compounds such as polymers, dyes, drugs, agrochemicals and pharmaceutical products. Among the various methods reported in literature for the formation of C–N bonds to access secondary anilines, the one-pot reductive amination of aldehydes with nitroarenes is the most interesting procedure, because it allows to obtain diverse N-substituted aryl amines by simple reduction of nitro compounds followed by condensation with aldehydes and subsequent reduction of the imine intermediates. These kinds of tandem reactions are generally catalyzed by transition metal-based catalysts, mainly potentially reusable metal nanoparticles. The rapid growth in the last years in the field of metal-based heterogeneous catalysts for the one-pot reductive amination of aldehydes with nitroarenes demands for a review on the state of the art with a special emphasis on the different kinds of metals used as catalysts and their recyclability features.

k-Means: Outliers-Resistant Clustering+++

The k-means problem is to compute a set of k centers (points) that minimizes the sum of squared distances to a given set of n points in a metric space. Arguably, the most common algorithm to solve it is k-means++ which is easy to implement and provides a provably small approximation error in time that is linear in n. We generalize k-means++ to support outliers in two sense (simultaneously): (i) nonmetric spaces, e.g., M-estimators, where the distance dist(p,x) between a point p and a center x is replaced by mindist(p,x),c for an appropriate constant c that may depend on the scale of the input. (ii) k-means clustering with m≥1 outliers, i.e., where the m farthest points from any given k centers are excluded from the total sum of distances. This is by using a simple reduction to the (k+m)-means clustering (with no outliers).