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.     

Manipulation Complexity of Same-System Runoff Elections

Do runoff elections, using the same voting rule as the initial election but just on the winning candidates, increase or decrease the complexity of manipulation? Does allowing revoting in the runoff increase or decrease the complexity relative to just having a runoff without revoting? For both weighted and unweighted voting, we show that even for election systems with simple winner problems the complexity of manipulation, manipulation with runoffs, and manipulation with revoting runoffs are independent. On the other hand, for some important, well-known election systems we determine what holds for each of these cases. For no such systems do we find runoffs lowering complexity, and for some we find that runoffs raise complexity. Ours is the first paper to show that for natural, unweighted election systems, runoffs can increase the manipulation complexity.     

The complexity of online voter control in sequential elections

Previous work on voter control, which refers to situations where a chair seeks to change the outcome of an election by deleting, adding, or partitioning voters, takes for granted that the chair knows all the voters’ preferences and that all votes are cast simultaneously. However, elections are often held sequentially and the chair thus knows only the previously cast votes and not the future ones, yet needs to decide instantaneously which control action to take. We introduce a framework that models online voter control in sequential elections. We show that the related problems can be much harder than in the standard (non-online) case: For certain election systems, even with efficient winner problems, online control by deleting, adding, or partitioning voters is \(\mathrm {PSPACE}\)-complete, even if there are only two candidates. In addition, we obtain (by a new characterization of coNP in terms of weight-bounded alternating Turing machines) completeness for \({\mathrm {coNP}}\) in the deleting/adding cases with a bounded deletion/addition limit, and we obtain completeness for \({\mathrm {NP}}\) in the partition cases with an additional restriction. We also show that for plurality, online control by deleting or adding voters is in \({\mathrm {P}}\), and for partitioning voters is \({\mathrm {coNP}}\)-hard.     

Regioselective analysis of triacylglycerols by lipase hydrolysis

A modified procedure for the regiospecific analysis of triacylglycerols (TAG) with a 1,3-specific lipase is described. After partial lipase hydrolysis of the triacylglycerol, the released free fatty acids (FFA) and 1,2(2,3)-diacylglycerols (DAG) were isolated by thin-layer chromatography (TLC) and converted to fatty acid methyl esters (FAME). The FAME were analyzed by gas-liquid chromatography (GLC). The 1,3-specific lipases used in this study included supported preparations from strains ofMucor miehei andRhizopus oryzae. The method also was applied to the regiospecific analyses of tung nut and Chinese melon seed oil triacyglycerols, both of which contain high proportions of α-elaeostearic acid. The TAG composition of the oils was substantiated in parallel analysis of the oils by highperformance liquid chromatography with chemical ionization mass spectrometric detection of intact TAG.     

The shield that never was: Societies with single-peaked preferences are more open to manipulation and control

Much work has been devoted, during the past 20 years, to using complexity to protect elections from manipulation and control. Many “complexity shield” results have been obtained—results showing that the attacker’s task can be made NP-hard. Recently there has been much focus on whether such worst-case hardness protections can be bypassed by frequently correct heuristics or by approximations. This paper takes a very different approach: We argue that when electorates follow the canonical political science model of societal preferences the complexity shield never existed in the first place. In particular, we show that for electorates having single-peaked preferences, many existing NP-hardness results on manipulation and control evaporate.     

Evaluation of the compatibility between low pressure melamine (LPM) film printing substrates and inkjet inks

Surface coated wood-based panels play a major role in the forest products industry as materials for construction and furniture elements in numerous interior and exterior applications. Their most important feature besides appropriate mechanical performance and chemical durability is an appealing visual appearance. In this contribution, recent research on the compatibility between two UV-curable inks and different melamine formaldehyde based surface films is presented. The surface texture properties of the printing substrates were investigated by roughness measurements. Substrate surface free energy was measured by contact angle measurements using three different testing liquids covering a wide range of polarities (glycerol, ethylene glycol and diiodomethane). The physical shape of the inkjet ink drops which were placed on the LPM printing substrates was monitored and recorded over time and used as an indicator for the wetting behavior of the tested inks and hence the printability. By combining contact angle and pendant drop measurements the surface tension of the inks was determined. The theoretical findings were confirmed by technological printing tests. To this end, as a hands-on method to establish ink-substrate wetting and compatibility flow coating tests were run and the most suitable ink was selected for printing. The printing results were closely related to the surface properties of the printing substrates.     

Depression, hypomania, and dysfunctional sleep-related cognitions as mediators between stress and insomnia: The best advice is not always found on the pillow!

A cognitive mediation model was examined to find out how stress, depression, and hypomania precipitate the occurrence of dysfunctional sleep-related cognitions, which in turn lead to insomnia. A total of 862 participants (639 women, 223 men; M age: 24.67 years, SD = 5.91) completed a series of self-report questionnaires assessing perceived stress, depression, hypomania, dysfunctional sleep-related cognitions, and insomnia. Compared to men, women reported higher levels of stress, depression, and insomnia. Women also suffered from more dysfunctional sleep-related cognitions. All variables were intercorrelated. Structural equation analyses showed that the relationship between stress and insomnia was largely mediated by dysfunctional sleep-related cognitions. Links between depression and insomnia were found to be weak when controlled for stress and dysfunctional sleep-related cognitions. The findings support a cognitive model of insomnia. Stress must be seen as a precipitating factor in the onset and maintenance of insomnia. Consequently, competencies to deal with dysfunctional sleep-related cognitions should be fostered in stress management programs. In turn, stress management should be a primary focus in the treatment of insomnia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Structural brain correlates of verbal and nonverbal fluency measures in Alzheimer's disease.

This study examined the relationships between regional brain volumes and semantic, phonological, and nonverbal fluency in 32 participants with Alzheimer's disease (AD). Object but not animal semantic fluency correlated with frontal and temporal gray matter volumes. Phonological fluency was not significantly associated with any brain volume examined. Nonverbal fluency was selectively associated with bilateral frontal gray matter volumes. Hippocampal volumes, although markedly reduced in these patients, were not related to any of the fluency measures. Results lend evidence to the importance of the frontal lobes in the directed generation of nonverbal and verbal exemplars by AD patients. Furthermore, both left and right-hemisphere regions contribute to the generation of verbal and nonverbal exemplars. (PsycINFO Database Record (c) 2010 APA, all rights reserved)