The molecular structure of anionic species of 2,4,5,7‐tetranitrofluorescein as studied by electrospray ionisation,nuclear magnetic resonance and X‐ray techniques

Among the fluorescein dyes, the behaviour of their nitro derivatives in solution is most unusual, and yet at the same time rarely studied. In this study, their ¹³C nuclear magnetic resonance and electrospray spectra are reported, which confirm, in concert with their ultraviolet‐visible spectra, the molecular structures of the neutral and ionic species of 2,4,5,7‐tetranitrofluorescein observed in different solvents and at various pH values. A peculiar property of this dye consists in its lactonisation of the double‐charged anion, contrary to the well‐known coloured and fluorescent dianions of fluorescein, eosin, etc. Also, this dianion‐lactone exhibits high ability for opening the pyran ring. This cleavage takes place at much lower pH values as compared with those for fluorescein and its halogen derivatives. The ruptured species can be formed as either lactone or carbinol; the latter appears as a result of the nucleophilic attack of a HO^? on the central carbon atom. The corresponding molecular structures are identified via the electrospray method and X‐ray analysis. The behaviour of some other nitrofluoresceins in alkaline media is also considered.     

Novel crosslinked AB‐type polyphenylquinoxaline membranes for high‐temperature proton exchange membrane fuel cells

AB‐type polyphenylquinoxaline (ABPPQ) membranes exhibit great mechanical properties and thermal properties for high‐temperature proton exchange membranes (PEMs). However, they dissolve in high‐concentration phosphoric acid (PA) during acid doping. In order to improve the PA resistant of ABPPQ, crosslinked ABPPQ membranes were prepared using sulfuric acid. The crosslinked ABPPQ membranes showed high PA resistance. The acid content of PA‐doped membranes decreased slightly with crosslinking, but the crosslinked polyphenylquinoxaline (CPPQ)‐20 membrane could reach 2.5 × 10^?2 S/cm proton conductivity at 160°C. Membrane electrode assemblies were fabricated with an active area of 4 cm² and Pt loading of 1 mg/cm². A startup and shutdown test (operated at 150°C with 0.2 A/cm² for 12 h and then 12 h off at room temperature) and a 30‐day long‐term durability test (150°C with 0.2 A/cm²) were conducted. In the startup and shutdown test, the crosslinked membranes showed a low open‐circuit voltage decay rate of 0.15 mV/h. In the 30‐day long‐term durability test, the voltage decay rate was 0.039 mV/h. In both tests, the crosslinked membranes showed a stable performance. Therefore, the crosslinked ABPPQ membranes can be regarded as a novel material for high‐temperature PEM fuel cells. POLYM. ENG. SCI., 59:2169–2173, 2019. © 2019 Society of Plastics Engineers     

Synthesis and corrosion inhibition mechanism of ammonium-based ionic liquids on API 5L X60 steel in sulfuric acid solution

A novel class of four new-free-halide-ionic liquids (ILs) derived from ammonium was synthesized and characterized via spectroscopic methods such as ¹H NMR and ¹³C NMR. The synthesized compounds were evaluated as corrosion inhibitors (CIs) of API 5L X60 steel in 1 M sulfuric acid by means of the potentiodynamic polarization and weight loss techniques. The results confirmed that the inhibition efficiency displayed by the four ILs is a function of their concentration and molecular structure. The obtained inhibition efficiency (η) ranged from 51 to 89%, confirming that the new class of ILs is good for corrosion inhibition purposes. The analysis of the potentiodynamic results showed that these compounds inhibit the corrosion of steel, classifying them as mixed-type CIs. The adsorption process of these new CIs on the API 5L X60 steel surface, which obeyed the Langmuir isotherm, was found to be physical and chemical. The SEM and EDX analyses confirmed the protection of steel in the corrosive medium.     

Ontological foundations for experimental science knowledge bases

The framework for representing domain ontologies presented in this paper extends existing ontological models and traditional frame-based formalisms. This work was motivated by the representational challenges posed by the domains of experimental sciences (biology, chemistry, physics) and the task of intelligent text retrieval. A detailed ontology for the field of experimental molecular biology is presented, which is used to illustrate the need for and application of the features of the framework. An extended frame-based formalism is defined to support these features. The ability of the framework to support intelligent retrieval from a knowledge base of molecular-biology research papers is demonstrated by providing answers to queries that could not be fully answered using previous approaches. The extensions to ontological framework include : category conversions, processes that change the category or identity of their participants; object histories to track substances through a series of experimental processes, including category conversions; object complexes, temporary configurations of objects with properties of their own; and process complexes, groups or sequences of interrelated actions that comprise an experimental technique or procedure. Features of the frame-based formalism include: slot groups for identifying sets of relations that license common inferences; and open-filler classes that combine knowledge of likely slot values with the ability to handle unexpected values. Evaluation techniques that are used to assess the adequacy of the ontology are presented: the ontology's conceptual coverage of the domain, its potential usefulness in improving the quality of query answering, and its formal consistency and reusability by the knowledge-sharing community are evaluated.     

Prevention of hyperthermia with silk of the oriental hornet, Vespa orientalis: a hypothesis

Wasps apparently develop normally even under extreme thermal conditions, including deserts. We deemed it worthwhile to set up an experiment wherein wasp brood combs containing a full gamut of brood ranging from eggs up to pupae and a few adults were kept in an incubator whose temperature was gradually raised to 45 degrees C, and the response of the disparate brood to such warming was photographed via Infra Red camera. The finding of this experiment showed that for open brood (i.e., eggs, larvae at various instars, and empty cells) the temperature was close to the ambient temperature, but in the silk coated pupae, the temperature was lower than the ambient by up to 4 degrees C. This lower temperature was retained for at least 90 min of incubation. For comparison we evaluated the relative contribution of the pupae to the phenomenon, by warming also a vacant, (i.e., a broodless and silkless comb) in parallel to a comb from which the pupae had been extricated but the silk weave retained and left behind. We found that the totally empty comb heated up under these conditions to nearly 110 degrees C, whereas the silk-containing vacant cells only heated up to about 40 degrees C. These finding are discussed from two aspects, namely the importance for wasps to maintain a constant temperature throughout the pupating process, and the manner in which the silk weave contributes to such a goal.     

Novel biodegradable low-density polyethylene–poly(lactic acid)–starch ternary blends

The ternary powder blends based on low-density polyethylene (LDPE) and two polymers of natural origin poly(lactic acid) (PLA) and starch are obtained in a rotor disperser under conditions of shear deformations. The dependence of the final powder dispersity on the composition is explored. A comparative analysis of the mechanical properties of the ternary blends with those of the LDPE–PLA and PLA–starch binary blends previously obtained has revealed that the presence of two rigid polymers PLA and starch leads to an increase in the elastic modulus and a decrease in the tensile strength and elongation at break. In the study of the blend biodegradability, it is found that the presence of two polymers of natural origin in the system with a total mass fraction of 60% promotes intensive biodegradation.     

Assessment of GHG mitigation measures in Ukraine

This paper presents the main results of a comprehensive assessment of GHG mitigation options in Ukraine. The primary focus is the energy sector. According to the prognosis of the baseline scenario, which assumes that the GDP reaches the level of 1990 in the 2005–2010 period, net GHG emissions would exceed the 1990 level by around 2005. The baseline scenario includes implementation of national programs to promote the adoption of technologies and practices that improve the efficiency of energy use. A mitigation scenario was created that includes widespread adoption of such technologies and practices in all sectors. Energy-saving technologies play the most important role in reducing emissions in this scenario. Relative to the baseline scenario, net GHG emissions in 2015 are 46% lower. The estimated incremental capital investment required for the mitigation scenario is $30–35 billion.     

Self‐Disclosure in Social Media: Extending the Functional Approach to Disclosure Motivations and Characteristics on Social Network Sites

This article introduces the functional model of self‐disclosure on social network sites by integrating a functional theory of self‐disclosure and research on audience representations as situational cues for activating interpersonal goals. According to this model, people pursue strategic goals and disclose differently depending on social media affordances, and self‐disclosure goals mediate between media affordances and disclosure intimacy. The results of the empirical study examining self‐disclosure motivations and characteristics in Facebook status updates, wall posts, and private messaging lend support to this model and provide insights into the motivational drivers of self‐disclosure on SNSs, helping to reconcile traditional views on self‐disclosure and self‐disclosing behaviors in new media contexts.     

Teachers’ perceptions of Kinder Training: Acceptability, integrity, and effectiveness.

Kinder Training is a play-based professional development training model designed for early elementary school teachers (kindergarten through Grade 2). The goals of Kinder Training include strengthening the teacher-child relationship, developing students’ adaptive skills, increasing academic engagement, and enhancing teachers’ classroom management skills (White et al., 1997). There has been limited research on the effectiveness of Kinder Training, but studies that have been conducted showed promising results. The current study utilized a qualitative approach to examine the acceptability, integrity, and perceived effectiveness of Kinder Training. Findings indicated that the elementary school teachers perceived the Kinder Training model to be acceptable and effective (e.g., improved classroom management skills, improved student behavior, and enhanced teacher-child relationships). In addition, observations were used to document that the intervention was implemented with integrity. Future research may further examine the cross-relationships among acceptability, integrity, and effectiveness of Kinder Training interventions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A thermoregulatory center in hornets: IR photography

In the Oriental hornet Vespa orientalis (Hymenoptera, Vespinae), there is on the dorsal side of the thorax, beneath the mesoscutum plate of the prothorax and around the median notal suture, a lump that, in the course of hornet activity, is warmer by 9 degrees C from the surrounding milieu and by up to 6 degrees C from other body parts of the hornet. This lump is about 1 mm in diameter, butterfly-shaped, and its upper, posterior border abuts the base of the forewings. During hornet activity and via Infra Red photography one can observe heat extensions stemming from the center of the lump and proceeding forward in the direction of the head, downward toward the legs and backwards toward the bases of the wings. The warmest region is the center of the lump, with its margins showing a lower temperature. As for the legs of the hornet, their upper part is warmer than the other parts. The temperature gradients along the hornet's body are dependent on the extent and nature of hornet activity. Thus, during flight or ventilation activity, the thorax is the warmest part of the body, while the wings, legs, and antennae, as well as the posterior part of the gaster are colder, yet all these body parts are still warmer to varying degrees than the surrounding milieu. Thus, at night, when sentry worker hornets stand guard around the nest entrance and remain practically motionless, the temperature differences between the various body parts are retained unchanged. We conjecture that the described butterfly-shaped lump is a thermoregulatory center (TC), which is neurogenically activated, since the changes occurring in it are rapid, a matter of one to several seconds and do not appear to be directly dependent on the hemolymph supply. The thermoregulatory center keeps a high constant temperature apparently related to hornet activity and the environmental conditions. The temperature cascade is most probably regulated via the tracheal system. Apparently another system activated by a heat pump mechanism keeps the gaster at a lower temperature than the environment.