Highly efficient synthesis of coumarin derivatives in the presence of H14[NaP5W30O110] as a green and reusable catalyst

A variety of heteropolyanions including: Keggin, Dawson, Preyssler, mixed addenda and sandwich types, catalyzed the formation of 4-methylnaphtho-(1,2-b)-pyran-2-one (coumarin) from the condensation of α-naphthol and ethylacetoacetate in a solvent free system and under heating conditions. Our data vividly indicate that sodium30–tungsto pentaphosphate, [NaP₅W₃₀O₁₁₀]¹⁴⁻, which so-called Preyssler’s anion, with high hydrolytic (pH 0–12) and thermal stability is the catalyst of choice. This catalyst catalyzed the synthesis of other coumarin derivatives in high yields and good selectivity.     

Highly efficient synthesis of benzopyranopyridines via ZrP2O7 nanoparticles catalyzed multicomponent reactions of salicylaldehydes with malononitrile and thiols

ZrP₂O₇ nanoparticles as an efficient catalyst have been used for the preparation of benzopyrano[2,3-b]pyridines from the four-component condensation reaction of salicylalde-hydes, thiols, and 2 equiv. of malononitrile under reflux conditions in ethanol in excellent yields and short reaction times.     

Nickel‐Catalyzed Reductive Benzylation of Aldehydes with Benzyl Halides and Pseudohalides

The reductive benzylation of aromatic and aliphatic aldehydes with benzylic halides is reported using a nickel/zinc catalyst system. In addition to benzylic halides, the first report on the addition of benzylic triflates, acetates, tosylates and tritylates to aldehydes is also presented. By this new method a range of alcohols was synthesized efficiently from aldehydes and benzylic substrates at room temperature in moderate to high yields. The mild reaction conditions and good functional group tolerance make this nickel‐catalyzed process synthetically useful for the synthesis of diverse benzylic alcohols.

     

Effect of ionic strength on the reactivity ratios of acrylamide/acrylic acid (sodium acrylate) copolymerization

The ionic strength (IS) of polyelectrolyte solutions plays an important role in influencing reaction kinetics. The largely unstudied effect of IS on monomer reactivity ratios and copolymerization rates of acrylamide (AAm) and acrylic acid (AAc), in the form of sodium acrylate (NaAc), is investigated. Salt addition affects the nature of overall charges of the polyelectrolyte solution and diminishes the electrostatic repulsions between reacting chains. Therefore, changing the IS of the solution by incorporating salts affect not only the point estimates of the monomer reactivity ratios but also the overall behavior of the copolymerization (with a transition to azeotropic behavior). Experimental results on copolymerization rates confirm the observed trends in reactivity ratio behavior. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40949.     

The effect of Protexin on prevention of ileocecal infection by Mycobacterium avium subspecies paratuberculosis in dairy calves

The objective of this study was to evaluate the effect of Protexin (Probiotics International Ltd., South Petherton, UK) in the prevention of ileocecal infection by Mycobacterium avium ssp. paratuberculosis (MAP) in dairy calves in the field situation. Forty Holstein bull calves whose dams were paratuberculosis negative (confirmed by serum ELISA test and fecal nested PCR) were randomly selected in 2 groups. All calves were fed raw milk collected from the bulk tank in a paratuberculosis-infected dairy farm, which was confirmed by PCR. The treatment group (20 calves) was given 2 g of Protexin from birth until weaning (90 d). The control group (20 calves) did not consume Protexin. The calves were culled at 12 mo of age and the ileocecal lymph nodes were sampled. The lymph nodes were tested by nested PCR to evaluate MAP infection. In the treatment group, 2 out of 20 calf (10%) ileoceca were infected by MAP, whereas in the control group, 8 out of 20 calf (40%) ileoceca were infected by MAP. A significant difference existed between ileocecal infection by MAP in treatment and control groups. Thus, Protexin showed a significant effect in decreasing the ileocecal infection by MAP.     

Fusion reactions in high-density hydrogen: A fast route to small-scale fusion?

High-density atomic hydrogen, which is believed to be a quantum liquid, can be formed by heterogeneous catalysis at the surface of hydrogen-transfer metal oxide catalysts. Extensive studies have been made of the hydrogen phase named H(1), with interatomic distance of 150 pm found by Coulomb explosion measurements. This bond distance corresponds to a material density of 0.5–0.7 kg dm⁻³. The use of this material as fusion target for inertial confinement fusion (ICF) is proposed in J Fusion Energy 2008;27:296–300. A much denser hydrogen (deuterium) material D(−1) also exists with an interatomic distance of 2.3 pm. This material is probably the inverse of metallic D(1), where nuclei and electrons exchange their roles. The ICF process would be greatly simplified if the intended initial multi-laser compression stage was not necessary. The close-packed density of D(−1) is calculated from the bond distance as >130 kg cm⁻³. This is much higher than that required for “fast ignition” laser-driven fusion (>0.3 kg cm⁻³). It may mean that a method already exists to prepare dense hydrogen fuel for small-scale laser-driven fusion. The high energy particles observed experimentally (up to 150 keV/atomic mass unit in the peak or 10⁹ K) indicate that high energy processes exist at relatively low laser intensities.     

A CUSUM-based method for monitoring simple linear profiles

In most statistical process control applications, the quality of a process or product is characterized by univariate or multivariate quality characteristics and monitored by the corresponding univariate and multivariate control charts, respectively. However, sometimes, the quality of a process or a product is better characterized by a relationship between a response variable and one or more explanatory variables. This relationship, which can be linear, nonlinear, or even a complicated model, is referred to as a profile. So far, several methods have been proposed for monitoring simple linear profiles. In this paper, a new method based on cumulative sum statistics is proposed to enhance monitoring of linear profiles in phase II. The performance of the proposed method is evaluated by average run length criterion. A comprehensive comparison is also conducted between the performance of the proposed method and the existing methods for monitoring simple linear profiles. The results show that the proposed method performs satisfactorily. In addition, the effects of reference value, sample size, and corrected sum of squares of explanatory variables on the performance of the proposed method are investigated.