INDUCTIVE PARAMETRIC EDDY-CURRENT TRANSDUCER (IPEP) FOR MEASURING ELECTRICAL AND TEMPERATURE PARAMETERS OF WASTEWATER FROM BREWING PRODUCTION

The possibility of using the theory of operation of a differential inductive parametric eddy-current transducer (IPET) for measuring the electrical and temperature parameters of a sample of acidic and alkaline wastewater is investigated. The need for the development of new informative methods for measuring the physicochemical parameters of wastewater is proved, in the realization of which a promising method of purification is selected. On the basis of a differential scheme for switching on two parametric converters: with exemplary purified water and a converter in which a test tube with a sample of waste water from a brewing production is placed, a differential informative method for measuring the electrical and temperature parameters of the liquid under study is proposed, which is based on the analysis of the components of the difference signal of phase shift angles measured electrical components of the switching circuit signals. The basic relationships that describe the operation of the IPET with the sample of the controlled liquid are given. The scheme of switching on differential IPET with a liquid sample, which is placed in a glass test tube, is considered; the differential scheme provides for heating the sample during measurements to simulate the production conditions of brewing production. Universal transformation functions are given that relate the components of the IPET signals with the specific electrical conductivity χt.s. and the temperature t of the wastewater sample from brewing production, that is, the dependence of the phase difference signal Δj on the generalized parameter A and the dependence of the absolute increment in the specific electrical conductivity Δχ on the temperature t of the wastewater sample, in the investigated temperature range.

Toxicological and behavioral impacts of atrazine on Trichogrammatidae (Hymenoptera) in choice tests

Weeds should be controlled with low impact methods and selective agrochemicals that have little or no effect on non-target organisms. This study aimed to evaluate the effect of the herbicide atrazine (triazine class) on 10 Trichogrammatidae (Hymenoptera) species. A female of 10 species of these natural enemies was individually placed in a glass test tube (free-choice test) with two paper cards containing 45 Anagasta (Ephestia) kuehniella (Lepidoptera: Pyralidae) eggs (treatment and control), with 10 replications. The cards were sprayed with the herbicide atrazine at 8.07 L/ha; the control was sprayed with distilled water. Parasitism by these natural enemies was allowed for 48 h. Atrazine changes the behavior of female parasitoids, reducing the parasitism (≈ 71 %) and emergence (≈ 74 %) rates and sex ratio (≈ 74 %) of the Trichogrammatidae species, except for Trichogramma galloi and T. bennetti. No females emerged from eggs parasitized by T. acacioi, Trichogrammatoidea annulata, T. atopovirilia, T. bruni, T. brasiliensis, T. demoraesi, and T. soaresi with atrazine. The results revealed that atrazine herbicide is harmless to T. bennetti and T. galloi, but it was moderately harmful (80 – 99 % reduction) to the other Trichogrammatidae species based on the parasitism and emergence rates.

Nonconventional driving force for selective oxidative C–C coupling reaction due to concurrent and curious formation of Ag0

Is it possible to ‘explore’ metal’s intrinsic property—a cohesive interaction—which naturally transform M0 into an aggregate or a particle or film for driving oxidative C–C bond formation? With this intention, reduction of [Ag(NH3)2]+ to Ag0 with concurrent oxidation of different phenols/naphthols to biphenyls was undertaken. The work is originated during careful observation of an undergraduate experiment—Tollens’ test—where silver mirror film deposition takes place on the walls of borosilicate glass test tube. When the same reaction was carried out in polypropylene (plastic-Eppendorf) tube, we observed aggregation of Ag0 leading to floating Ag-particles but not silver film deposition. This prompted us to carry out challenging cross-coupling reaction by ONLY changing the surface of the reaction flask from glass to plastic to silicones. To our surprise, we observed good selective oxidative homo-coupling on Teflon surface while cross-coupling in Eppendorf vial. Thus, we propose that the formation of biphenyl is driven by the macroscopic growth of Ag0 into [Ag-particle] orchestrated by Ag…Ag cohesive interaction. To validate results, experiments were also performed on gram scale. More importantly, oxidation of β-naphthol carried out in quartz (chiral) tube which yielded slight enantioselective excess of BINOL. Details are discussed.

Pandy's reaction

As is known, the reaction proposed in 1910 by Pandy has long been widely used in neuropathology, the technique of which is very simple: 1 cubic meter is poured into a narrow glass test tube (7 cm long and 1 cm in diameter). sant. saturated solution of carbolic acid (1 hour carbol, crystall. for 15 hours of distillation of water), and a drop of the studied cerebrospinal fluid is introduced into it with a pipette, and the appearance of a blue white cloud throughout the contact of the drop with the reagent indicates a positive result reactions.