Monooxime‐monocarbamoyl Bispyridinium Xylene‐Linked Reactivators of Acetylcholinesterase—Synthesis,In vitro and Toxicity Evaluation,and Docking Studies

Acetylcholinesterase (AChE) reactivators are crucial antidotes to organophosphate intoxication. A new series of 26 monooxime‐monocarbamoyl xylene‐linked bispyridinium compounds was prepared and tested in vitro, along with known reactivators (pralidoxime, HI‐6, obidoxime, trimedoxime, methoxime, K107, K108 and K203), on a model of tabun‐ and paraoxon‐, methylparaoxon‐ and DFP‐inhibited human erythrocyte AChE. Although their ability to reactivate tabun‐inhibited AChE did not exceed that of the previously known compounds, some newly prepared compounds showed promising reactivation of pesticide‐inhibited AChE. The acute toxicity of the novel compounds was also determined. Docking studies using tabun‐inhibited AChE were performed for three compounds of interest. The structure–activity relationship (SAR) study confirmed the apparent influence of the xylene linkage and carbamoyl moiety on the reactivation ability and toxicity of the agents.     

Fuzzy strategy for failure detection and safety control of complex processes

Fuzzy methodology is applied to develop failure detection and safety control models for processes with ill-known mathematical model and poor accuracy of measurement results of process variables. The models are demonstrated with a hypothetical polymerization process.     

Linguistics and fuzzy models

Classical analytical and/or statistical approaches to analysis of engineering systems have failed when “ill-known” systems have to be studied. There is a certain complexity threshold beyond which it is very difficult to go using conventional mathematical tools. To deal with complex tasks realistically an approach is needed which does not overestimate mathematical formalism. An alternative approach is based on the premise that the key elements in human thinking are not numbers but words. A linguistic quantification is used to specify engineering experience. The linguistic value is transformed into a fuzzy set by a grade of membership. The fuzzy set is a class with the continuous grade of membership. Several algorithms are described which can be used to evaluate the grade of membership for sophisticated fuzzy models (relations).     

Multilevel failure detection system

A fuzy multilevel failure detection system is developed for complex processes with ill-known mathematical model and poor measuring accuracy. The decomposition of the problem is made with the aid of fuzzy switches and diagnostic algorithms which are specified by a set of conditional statements. The diagnosis system is demonstrated by a real low density polyethylene reactor in full detail.     

D-Index: Distance Searching Index for Metric Data Sets

In order to speedup retrieval in large collections of data, index structures partition the data into subsets so that query requests can be evaluated without examining the entire collection. As the complexity of modern data types grows, metric spaces have become a popular paradigm for similarity retrieval. We propose a new index structure, called D-Index, that combines a novel clustering technique and the pivot-based distance searching strategy to speed up execution of similarity range and nearest neighbor queries for large files with objects stored in disk memories. We have qualitatively analyzed D-Index and verified its properties on actual implementation. We have also compared D-Index with other index structures and demonstrated its superiority on several real-life data sets. Contrary to tree organizations, the D-Index structure is suitable for dynamic environments with a high rate of delete/insert operations.     

Control of macrostress σ in reactively sputtered Mo-Al-N films by total gas pressure

This article reports on the effect of the energy delivered to a growing film by bombarding ions and fast neutrals on the macrostress σ and the structure of sputtered films. To demonstrate this effect, we selected Mo-Al-N films with a low (?20 at.%) Al content reactively sputtered using an unbalanced dc magnetron with a target of 100 mm diameter at a high total pressure , low substrate bias and a high substrate ion current density . The main goal of this study was to show the reduction of σ in films sputtered at high pressures of several Pa. Under the conditions given above approximately 4 μm thick Mo-Al-N films with enhanced hardness H≈35 GPa and a very low (?−0.5 GPa) macrostress σ were successfully prepared. This result demonstrates that the enhanced hardness H of Mo-Al-N films is not caused by σ but is due to its nanostructure as shown in the XRD patterns of these films. The Mo-Al-N films with enhanced hardness are composed of a mixture of grains of different crystallographic orientations.     

Numerical investigation of chatter suppression via parametric anti-resonance in a motorized spindle unit during milling

A new concept for increasing process stability during milling processes is presented utilizing a parametric anti-resonance. The beneficial effect is examined by numerical calculations in the time domain for an example spindle which is supported conventionally by ball bearings and is equipped with an additional active magnetic bearing that enables the realization of a deliberate parametric excitation. In the present study the stiffness of this active support bearing is changed periodically with time. The parametric excitation is tuned to a parametric anti-resonance which triggers the transfer of vibration energy between the vibration modes of the underlying system without this additional time-periodicity. It is highlighted how vibration energy is transferred from the first bending mode of the rotor, which is the most critical one by means of regenerative chatter, to a mode with higher damping in order to increase the effective damping of the entire spindle drive unit.