The synthesis of some 5-arylazo-2,4,6- trichloropyrimidines and 4-arylamino-5-arylazo-2,6- dichloropyrimidines and their application as disperse reacti

Diazotised arylamines were coupled with barbituric acid to give 5-arylazo-6-hydroxypyrimidine-2,4-diones which were then refluxed with phosphorus oxychloride to give 5-arylazo-2,4,6-trichloropyrimidine dyes. The condensation of some of these with arylamines at low temperature gave 4-arylamino-5-arylazo-2, 6-dichloropyrimidine dyes. The dyes were applied to polyamide fibres as disperse reactive dyes and their fastness properties studied.     

Electron transfer processes in collisions of highly charged energetic (0.1–1.0 MeV/nucleon) ions with helium atoms

We have investigated charge transfer in collisions of energetic (0.1−1 MeV/nucleon) highly charged ions with helium atoms with the principal aim of clarifying the nature of two-electron processes. The sensitivity of partial charge-changing cross sections (i.e., single- and double-charge transfer, transfer ionization (TI), and single and double ionization) to core configuration and scaling rules for one- and two-electron process were investigated with iodine ions (q=5+ → 26+) and uranium ions (q=17+ → 44+) using an ion-charge state, recoil-ion coincidence method. Using zero-degree electron spectroscopy in coincidence with charge transfer, we found that at the higher energies, as in the case of 0.1 MeV/nucleon ions previously reported, TI involves the transfer of two electrons to a higher correlated state followed by loss of one electron to the continuum. In addition, we observe very high Rydberg electrons in coincidence with TI, implying a possible up-down correlation in the pair transfer. In addition, we made measurements of VUV photons emitted at the collision in coincidence with He⁺ and He²⁺ recoils. The results show that TI leads to capture into lower n states than single-charge transfer.     

In situ hydrothermal synthesis of Y-TiO2/graphene heterojunctions with improved visible-light-driven photocatalytic properties

The Y-TiO₂/graphene heterojunctions were prepared using a facile one-pot hydrothermal method. The SEM and TEM images showed that titanium dioxide and flaky graphene were tightly bound together, and XPS indicated that yttrium was doped uniformly into the complex. The crystal phase of titanium dioxide in Y-TiO₂/graphene composite was anatase, and the yttrium doping caused distortion of the titanium dioxide lattice, resulting in a new valence type and more defects. An appropriate amount of yttrium doping and graphene modification significantly improved the separation of photogenerated electron-hole pairs. In the degradation of rhodamine B, the co-modification of yttrium and graphene effectively improved the photocatalytic activity under visible and UV–vis light irradiation. With the amount of yttrium increasing, the photocatalytic activity of the Y-TiO₂/graphene complex first increased and reached the highest level of 40% and 63% for visible and ultraviolet-visible light, respectively, when the ratio of yttrium was increased to 1.0%. The enhancement of photocatalytic activity can be explained by the presence of yttrium ions increased the visible light absorption of titanium dioxide. Besides, the synergistic effect between yttrium ions and graphene effectively improved the separation rate of photoinduced electron-hole pairs.     

Self-doped conducting polymers

The sodium salts and the ‘proton salts’ (acids) of poly-3-(2-ethanesulfonate)thiophene and of poly-3-(4-butanesulfonate)thiophene are the first known examples of water-soluble conducting polymers. In these polymers the counterions are covalently bound to the polymer backbone, leading to the self-doping concept. In a self-doped conjugated polymer, charge injected into the π-electron system is compensated by proton (or Li⁺, Na⁺, etc.) ejection, leaving behind the oppositely charged counterion.     

Maize and pigeon pea sole crop and intercrop nutrient response functions for Tanzania

The development of ecological circular agriculture has been highly encouraged by the Chinese government to recycle agricultural wastes, reduce mineral fertilizer input, and protect the environment. Biogas slurry, a byproduct of biogas engineering developed in rural areas of China, could be used as N fertilizer for crop growth. The field experiments were conducted in 2014 and 2015 to study the plant growth responses and environmental impacts of applying biogas slurry to two-season Zizania aquatica Turcz. growth. The potential factors that restrict the rational use of biogas slurry were also clarified. Mineral N fertilizer can be completely or partly substituted by N fertilizer from biogas slurry to satisfy Z. aquatica plant growth. It was not at the cost of sacrificing yield, dry matter accumulation, N accumulation and physiological N use efficiency in the above-ground parts. However, the growth inhibition occurs when the N quantity in biogas slurry was 2 or 2.7 times higher than that of mineral N fertilizer. Vitamin C in non-shell swollen culms (as edible part) of Z. aquatica significantly increased after biogas slurry application. Biogas slurry application substantially increased the N concentrations, i.e., total N, NH₄ ⁺–N, and NO₃ ^?–N in floodwater and delayed the time to reach national discharge standards. However, biogas slurry application did not affect the N concentrations in percolating water compared with the treatment with mineral N fertilizer only. Applying biogass slurry did not generate potential pollution risks by trace elements (Cu, Zn, Pb, Cr, Cd, As, and Hg) in the non-shell swollen culm and soil, and did not increase the nitrate content in non-shell swollen culm. We found the NH₄ ⁺–N concentration in biogas slurry can account for 77–93% of total N and reflects the N level in biogas slurry to a great degree. Semi-quantitative color-based colorimetric methods possessing simple and fast characteristics should be developed to determine the NH₄ ⁺–N concentration with the purpose of promoting reasonable use of biogas slurry in area of crop cultivation. Otherwise, excessive use of biogas slurry can adversely affect crops and increase environmental risks.     

Carbonation of geothermal grouts — Part 3: CO2 attack on grouts containing bentonite

Addition of several percent bentonite to geothermal grout formulations allows high W/S ratios to be used providing slurries with low densities and high fluidity. The hardened grouts barely meet the API requirements for permeability and require high silica additions to do this. Release of aluminum ions from the clay/Ca(OH)₂ interaction produces Al-substituted tobermorite which persists to 250°C. This phase does provide a strong impermeable binder when the grouts are water cured, but it is rapidly carbonated. All grouts which contained tobermorite showed large increases in permeability when carbonated and low durability in the presence of carbonated fluids.     

Mixing and segregation in binary-solid liquid fluidised beds

Force balance considerations enable 'solid concentration relationships' to be evaluated for binary-solid particulate fluidisation which define the set of solid component volumetric concentrations that can coexist at axial locations in the fluidised state; these relationships are verified experimentally and applied to the analysis of mixing and segregation in water fluidised beds.     

Lactococcus lactis phages from the perspective of their diversity,thermal and biocidal resistance

Lactic acid bacteria (LAB), particularly Lactococcus lactis, are of great significance in dairy fermentations. Many LAB strains are susceptible to attack by phages that affect their technological, biochemical and physiological functions. Phages of L. lactis are a serious concern because of the economic importance of this bacterium in the dairy industry. Members of L. lactis phages belonging to the P335, 936 and c2 groups are more problematic for the dairy industry. Many phages of the 936 group are resistant to various thermal and biocidal treatments commonly used in the dairy industry. This article reviews the diversity of L. lactis bacteriophages of the P335, 936 and c2 groups and discusses their interaction with their bacterial hosts. In addition, this review provides an overview of the resistance of L. lactis phages to thermal treatments and chemical biocides, and highlights some novel strategies to destroy these phages.     

Methodology for screening bottled water for the presence of indicator and pathogenic bacteria

At present in Canada, analysis of bottled water includes the use of pour plates for determination of aerobic colony counts (ACC); most probable numbers (MPNs) for the determination of coliforms and Escherichia coli; and filtering of 100-ml aliquots of the water for the determination of Aeromonas hydrophila and Pseudomonas aeruginosa. Generally, such analyses of bottled water products are time-consuming, costly, and often pointless as properly manufactured bottled water (especially those treated with ozonation and carbonation) will contain little or no bacteria. The ideal analysis would include the use of an enrichment broth that would resuscitate injured bacteria and allow them to multiply in the presence of an indicator system that would detect the presence of ‘indicator micro-organisms’ such as coliforms and/or pathogens. The use of such a broth would simplify the analyses and reduce costs associated with the testing of bottled water. The present study compared the recovery of stressed or low numbers of indicator and pathogenic bacteria from bottled water by i) determining if the standard method for coliforms/E. coli would isolate other indicator micro-organisms; ii) comparing the use of presence absence broth, nutrient broth and buffered peptone water as resuscitation/isolation broths; and iii) comparing recovery of indicator micro-organisms on a variety of selective agars. Its purpose was to make recommendations concerning the methodology for analysing bottled water; and to subsequently make recommendations as to the ‘best’ indicator for bottled water. Recommendations for the use of resuscitation broths in screening procedures are presented.     

Synergistic effect of particle size,shear rate and driving-force during microfiltration of fruit juices: Toward a relevant choice of pretreatments and filtration conditions

With an objective to recommend relevant operating conditions for fruit juice microfiltration, the combined effect of particle size, shear rate and driving-force on fouling was studied. The filterability of three orange juices with different granulometry was estimated at pilot scale under different shear rates and driving forces (flux or TMP, in immersed and side-stream membrane configuration respectively). In flux-driven filtrations, fluxes to avoid an intense fouling were identified (below 5–10 L.h⁻¹.m⁻² for studied juices) and the role of juice granulometry on fouling highlighted. In TMP-driven filtrations, whatever the juice granulometry, steady-state fluxes were TMP-independent but shear rate dependent (around 10 and 30 L.h⁻¹.m⁻², for 4500 s⁻¹ and 15500 s^-1 respectively). The results demonstrated that, whatever their granulometry, juice filterability was higher in low shear rate flux-driven filtrations, than in high shear rate TMP-driven ones, which relativizes the relevance of crossflow filtration.