Auxiliary Compound Research Articles

Master and Auxiliary Compound Control for Multi-Channel Confluent Water Supply Switching Control Based on Variable Universe Fuzzy PID

During the multi-channel confluent water supply process, the pressure control of the main pipe is often held back by such problems as non-linearity, hysteresis and parameter uncertainty, its own unique load dynamic changes, channel switching disturbance and other system characteristics caused by the actual working conditions. Moreover, pressure fluctuations in the main pipe will lead to a reduction in the service life of fire-fighting equipment, an increase in the failure rate, and even an interruption of the fire-fighting water supply. Therefore, a master and auxiliary control strategy is proposed to stabilize the pressure change in the process of multi-channel concentrated water supply switching, by using variable universe fuzzy proportional integral derivative (PID) control as the main controller on the main pipe and traditional PID control as the subsidiary controller on the channel. The control strategy is verified by the co-simulation platforms of LabVIEW and AMESim. Simulation results show that the variable universe fuzzy PID control and the master and auxiliary compound control based on the variable universe fuzzy PID control have advantages in step response, tracking response and anti-interference, respectively. The parameters obtained in the co-simulation are used in the experimental system. The experimental results show that the maximum deviation rate of main pipe pressure can be reduced by about 10% compared with other control methods under different loads. In conclusion, the proposed control strategy has strong anti-interference ability, fast dynamic response speed, high stability and good peak shaving effect.

Characterization of the Site-Specific Acid-Base Equilibria of 3-Nitrotyrosine.

The complete macro- and microequilibrium analyses of 3-nitrotyrosine, a biomarker of oxidative stress damage, are presented for the first time. The protonation macroconstants were determined by 1 H-NMR-pH titration, while microconstants were elucidated by a combination of deductive and NMR methods, in which properties of the methyl ester derivative as an auxiliary compound were also studied. Combination of the NMR-pH characterization of the title and auxiliary compounds and the pair-interactivity parameters of 3-iodotyrosine provided the sufficient system to evaluate all the microconstants. NMR-pH profiles, macroscopic and microscopic protonation schemes, and species-specific distribution diagrams are included. The phenolate basicity of 3-nitrotyrosine is 500 times below that of tyrosine, and it is even lower than that of 3-iodotyrosine. This phenomenon can be explained by the stronger electron withdrawing and the negative mesomeric effect of the nitro group. Based on our results, 89 % of the phenolic OH groups are deprotonated in 3-NT molecules at the pH of the blood plasma.

Hydroxyphosphinylacetic acid as a chiral auxiliary compound

The aim of the presented research was to check whether 2-hydroxy-2-(ethoxyphenylphosphinyl)acetic acid is a versatile chiral phosphonic auxiliary (readily seen in 31P NMR). The preliminary studies indicate that this compound may be used as chiral derivatizing agents for amines and alcohols, since the separation of selected examples of diastereomeric alcohols and amines in 31P NMR spectra was found to be satisfactory. The preliminary research about using this compound as a CSA are also promising.

A bivariate risk model with mutual deficit coverage

We consider a bivariate Cramér–Lundberg-type risk reserve process with the special feature that each insurance company agrees to cover the deficit of the other. It is assumed that the capital transfers between the companies are instantaneous and incur a certain proportional cost, and that ruin occurs when neither company can cover the deficit of the other. We study the survival probability as a function of initial capitals and express its bivariate transform through two univariate boundary transforms, where one of the initial capitals is fixed at 0. We identify these boundary transforms in the case when claims arriving at each company form two independent processes. The expressions are in terms of Wiener–Hopf factors associated to two auxiliary compound Poisson processes. The case of non-mutual agreement is also considered. The proposed model shares some features of a contingent surplus note instrument and may be of interest in the context of crisis management.

Potential role of the cardiovascular non-antibiotic (helper compound) amlodipine in the treatment of microbial infections: scope and hope for the future

The appearance of multiresistant bacterial strains coupled with the globally ongoing problem of infectious diseases point to the imperative need for novel and affordable antimicrobial drugs. The antibacterial potential of cardiovascular non-antibiotics such as amlodipine (AML), dobutamine, lacidipine, nifedipine and oxyfedrine has been reported previously. Of these drugs, AML proved to have the most significant antibacterial activity against Gram-positive and Gram-negative bacteria. Time–kill curve studies indicate that this Ca 2+ channel blocker exhibits bactericidal activity against Listeria monocytogenes and Staphylococcus aureus. AML could protect against murine listeriosis and salmonellosis at doses ranging within its maximum recommended human or non-toxic ex vivo dose. AML acts as a ‘helper compound’ in synergistic combination with streptomycin against several Gram-positive and Gram-negative bacterial strains in vitro as well as in the murine salmonellosis model in vivo. The present review focuses on the possible use of cardiovascular non-antibiotics such as AML as auxiliary compound targets for synergistic combinations in infections and hypertension conditions, rationalised on the basis of the activities of the compounds.

1-[(4S)-4-Benzyl-2-thioxo-1,3-thiazolidin-3-yl]propan-1-one

The analysis of the title chiral auxiliary compound, C13H15NOS2, has enabled the determination of the absolute configuration at the benzyl-bearing ring C atom as S. In the crystal structure, mol­ecules aggregate into helical chains along the b axis via C—H⋯O contacts.

On Approximating the Individual Risk Model

Error bounds are developed for Kornya-Presman–type approximations to the individual risk model. In particular, error bounds are given for the compound Poisson approximation, with the Poisson parameter equal to the expected number of claims. The approximations considered are a modification by Hipp of an approximation originally developed by Kornya, as well as Kornya’s original approximation. The error bounds are similar in concept to Hipp’s original error bounds using concentration–functions, as refined by Čekanavičius, Roos, and others. Computation of the bounds, however, is considerably simplified. In particular, concentration function type bounds called width-norm bounds are calculated directly from the values of the approximation, avoiding completely the need for calculating a special auxiliary compound Poisson distribution. Two examples are given. Depending on the portfolio parameters, the width-norm error bounds may or may not be sharper than the Hipp-Roos error bounds. In any event, it is recommended that the simpler widthnorm calculation, possibly together with an increase in the order of the approximation, be considered in practical applications if the goal is to achieve a specified accuracy with the least amount of computation. For large portfolios, where the maximum claim on any one policy is relatively small compared to the expected aggregate claims, the width-norm error bounds compare quite favorably with error bounds developed by De Pril and by Dhaene.

Durability of high performance color hardener

The properties of high performance color hardener (HPCH) and the mechanism were studied. HPCH is a composite system, which is composed of cementitious and auxiliary cementing materials, composite additives, abrasion resistance component (aggregate) and pigment. The porosity and pore structure of the material are obviously improved due to the activation, filling and adsorption of auxiliary cementing materials, thus resulting in a great increase of binding capacity for ions in HPCH and the obstacles of ion migrating. The density of material structure, bonding capacity of cementitious material to the abrasion-resisting component and the corrosion resistance are greatly and effectively improved by adding the auxiliary cementing materials and compound additives. According to the tests of dry shrinkage, sulphate resistance, chloride permeability and Ca(OH)2 content distribution, the property superiority of HPCH is analyzed. The mechanism of materials modification of HPCH is explained from the microscopic point of view by testing the pore structure and pore distribution via the mercury intrusion pressure method.

Internal Lipid Wool Structure Modification Due to a Nonionic Auxiliary Used in Dyeing at Low Temperatures

An analytical and microscopical study of wool fibers differently treated with a non-ionic dye auxiliary product such as Baylan NT elucidates the action mechanism of this compound in low temperature dyeing of wool. Lipids are extracted from wool samples previously treated with Baylan NT, and the compounds are analyzed quantitatively with thin layer chromatography coupled to a flame ionization detection system. Previous solubilization of free fatty acids by the Baylan treatment is considered to be the main cause of some changes in the lipid morphological structure, resulting in the release of ceramides in subsequent solvent extraction. These are found in a significantly higher amount in the extract of the wool treated with the auxiliary compound. Furthermore, the microscopical study shows higher penetration of the fluorescent dye in wool fibers treated with the auxiliary compound, thereby confirming the importance of cell membrane complex modification in the improving the dyeing characteristics of wool and permitting dyeing at low temperatures.

Chemoselective preparation of ketones by the grignard reaction of N‐acylpyrazoles

AbstractN‐Acylpyrazoles afford chemoselectively the corresponding ketones in good yields by the use of equimolar amounts of Grignard reagent. In the case of an optically active N‐acylpyrazole, optical asymmetry was retained in comparable optical yield. Ketone formation by the Grignard reactions can be regarded as an important functionalization in a synthetic loop using pyrazoles as the auxiliary compound.

Multiple auxiliary compound driver loudspeaker system

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ChemInform Abstract: Stereoselective N‐Acylation of a New Chiral Auxiliary Compound: 3‐ Phenyl‐l‐menthopyrazole.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Stereoselective N-acylation of a new chiral auxiliary compound; 3-phenyl- l-menthopyrazole

As a new chiral auxiliary compound having a pyrazole ring system, the synthetic utility of (4R,7S)-3-phenyl-4-methyl-7-isopropyl-4,5,6,7-tetrahydroindazole (3-phenyl- l-menthopyrazole), which was prepared from l-menthone, was discussed.

Sterically hindered N-aryl pyrroles: chromatographic separation of enantiomers and barriers to racemization

The novel N-aryl-2,5-dimethylpyrrole-3-carbaldehydes (1)–(7) have been synthesized by condensation of hexane-2,5-dione with the appropriate aniline and subsequent Vilsmeier–Haack formylation of the pyrrole ring. Diastereoisomeric association complexes of these racemic pyrroles were studied by 1H n.m.r. spectroscopy chemical shifts and the splittings induced by the optically active auxiliary compound (+)-Eu(hfbc)3. Separation of the enantiomers of (6) was achieved by liquid chromatography on triacetylcellulose. The barrier to partial rotation about the C–N bond in (6) was determined and their lower limits in (2) and (4) were estimated by variable temperature 1H n.m.r. spectroscopy.

Application of NMR spectroscopy of chiral association complexes. 12—rate determination of an intramolecular motion in a free molecule by means of dynamic NMR measurements in the presence of an auxiliary compound

AbstractThe rate constants of intramolecular processes can sometimes be measured only in the presence of optically active auxiliary compounds. The problem of obtaining the rate for the free molecule was solved by linear extrapolation of rate constant from the complexed to the uncomplexed molecule (LERCUM). This method is developed theoretically and checked experimentally. 2‐Bromo‐2‐methyl‐1‐(3‐bromo‐2‐methoxy‐4,5,6‐trimethylphenyl)‐1‐propanone has the advantage that rotation about its carhonyl‐to‐aryl bond can be measured both in the presence of (+)−2,2,2‐trifluoro‐1‐phenylethanol as well as in the absence of an auxiliary compound. The novel method of extrapolation is confirmed by the agreement between both results.

Preparative separations and racemizations of enantiomeric diaziridines

Preparative separations or enrichments of enantiomers of diaziridines 1, 2, and 5 were achieved by liquid chromatography on triacetylcellulose, (+)- 1 and (+)- 2 being isolated almost pure (Table 1). Enantiomeric purities were determined by 1H NMR in the presence of the optically active auxiliary compound (+)-Eu(hfbc) 3. The barriers to nitrogen inversion in 1 and 4 were determined and its lower limit in the nitrogen unsubstituted diaziridine 3 was estimated.

Applications of NMR spectroscopy of chiral association complexes 5. Stereodynamics and diastereotopism in chiral 1,3‐dienes \documentclass{article}\pagestyle{empty}\begin{document}${\rm HOCMe}_{\rm 2} \rlap{--} ({\rm CCl =\!= CCl\rlap{--})}_{\rm 2} {\rm X}$\end{document}

AbstractThe barriers to partial rotation around the central single bond in chiral dienes \documentclass{article}\pagestyle{empty}\begin{document}${\rm HOCMe}_{\rm 2} \rlap{--} ({\rm CCl =\!= CCl\rlap{--})}_{\rm 2} {\rm X}$\end{document} have been determined by coalescence of either 1H NMR signals (X = CH2OCH3) or 13C NMR signals (X = H). In the presence of the optically active shift reagent (+) − Eu(hfbc)3 all 1H signals were split at temperatures where the interconversion of enantiomers is slow. The temperature dependence of these spectra also yielded free activation enthalpies for the enantiomerizations which were in agreement with the ones obtained without Eu(hfbc)3. The assignment of the four methyl resonances appearing in the presence of (+) − Eu(hfbc)3 at low temperature was possible by gradually increasing the rate of enantiomerization or gradually replacing the optically active auxiliary compound by the racemic one.

Enantioselective Synthesis of Homoallyl Alcohols via Chiral Allylboronic Esters

Optically active homoallyl alcohols of type (2) are preparable in good yields by an enantioselective synthesis. endo-Phenyl-exo,exo -glycol, which affords the ester (1) with boranes B(CH2CR2CH2)3, serves as (regenerable) chiral auxiliary compound.

A liquid-scintillation method for determining tritium in the tissues of animals dosed with tritium-labelled vitamin A

A liquid-scintillation counting method is described for determining tritium as tritium-labeled vitamin A in suspensions of tissue, blood, and feces. Some problems of the method are examined, such as the influence on the measurements of the composition of the scintillator and the auxiliary compound, anhydrous sodium sulfate. The use of an internal standard is described, and the range of error and evaluation of the results are discussed. Finally, the procedure is described in detail and results are reported that show good agreement between this method and the conventional method for determining vitamin A. (auth)