Introduction of methyl groups to acetate substituted chain of (Z)-5-decenyl acetate,a pheromone component of turnip moth,agrotis segetum: synthesis,single-sensillum recordings,and structure-activity relationships

Methyl-substituted analogs of (Z)-5-decenyl acetate, a pheromone component of the turnip moth,Agrotis segetum, have been synthesized and studied by electrophysiological single-sensillum recordings and molecular mechanics calculations [MM2(85)]. The analogs are monomethyl substituted in the 2, 3, 4, and 5 positions and geminally dimethyl substituted in the 2, 3, and 4 positions. The methyl groups have been employed as space probes to study the degree of steric complementarity between the acetate-substituted alkyl chain of the pheromone component and its receptor. The electrophysiological activities, interpreted in terms of a receptor interaction model, indicate significant steric repulsive interactions between the introduced methyl groups and the receptor. This implies a high degree of complementarity between the acetate-substituted alkyl chain of the natural pheromone component and its receptor.Schiff., Lepidoptera: Noctuidae.     

Determination of the vapor pressures of moth sex pheromone components by a gas chromatographic method

The vapor pressures of decyl acetate, five decenyl acetate isomers, (Z)-7-dodecenyl acetate, and (Z)-9-tetradecenyl acetate have been determined at three to six temperatures in the interval 25–45 °C by a gas Chromatographic method suitable for accurate measurements of the low vapor pressures of moth sex pheromone components at biologically relevant temperatures. The vapor pressure values at 30.5 °C are 3.80 Pa for decyl acetate, 4.08–5.40 Pa for the decenyl acetate isomers, 0.562 Pa for (Z)-7-dodecenyl acetate, and 0.094 Pa for (Z)-9-tetradecenyl acetate. The vapor pressures of the decenyl acetates show a small but significant dependence on the double bond position. Four of the compounds in this study, 10Ac,Z5–10Ac,Z7–12Ac, andZ9–14Ac have recently been identified as sex pheromone components of the turnip moth,Agrotis segetum. Large differences between the mole percentages of the component as found in liquid extracts of female abdominal tips and the corresponding mole percentages in the vapor phase are predicted.     

Resource pooling for frameless network architecture with adaptive resource allocation

The system capacity for future mobile communication needs to be increased to fulfill the emerging requirements of mobile services and innumerable applications. The cellular topology has for long been regarded as the most promising way to provide the required increase in capacity. However with the emerging densification of cell deployments, the traditional cellular structure limits the efficiency of the resource, and the coordination between different types of base stations is more complicated and entails heavy cost. Consequently, this study proposes frameless network architecture (FNA) to release the cell boundaries, enabling the topology needed to implement the FNA resource allocation strategy. This strategy is based on resource pooling incorporating a new resource dimension-antenna/antenna array. Within this architecture, an adaptive resource allocation method based on genetic algorithm is proposed to find the optimal solution for the multi-dimensional resource allocation problem. Maximum throughput and proportional fair resource allocation criteria are considered. The simulation results show that the proposed architecture and resource allocation method can achieve performance gains for both criteria with a relatively low complexity compared to existing schemes.     

Gradiometric micro-SQUID susceptometer for scanning measurements of mesoscopic samples

We have fabricated and characterized micro-SQUID susceptometers for use in low-temperature scanning probe microscopy systems. The design features the following: a 4.6 mum diameter pickup loop; an integrated field coil to apply a local field to the sample; an additional counterwound pickup-loop/field-coil pair to cancel the background signal from the applied field in the absence of the sample; modulation coils to allow setting the SQUID at its optimum bias point (independent of the applied field), and shielding and symmetry that minimizes coupling of magnetic fields into the leads and body of the SQUID. We use a SQUID series array preamplifier to obtain a system bandwidth of 1 MHz. The flux noise at 125 mK is approximately 0.25 mu Phi 0/ sqrt Hz above 10 kHz, with a value of 2.5 mu Phi 0/ sqrt Hz at 10 Hz. The nominal sensitivity to electron spins located at the center of the pickup loop is approximately 200 muB/ sqrt Hz above 10 kHz, in the white-noise frequency region.     

Combining an Angle Criterion with Voxelization and the Flying Voxel Method in Reconstructing Building Models from LiDAR Data

Abstract: Traditional documentation capabilities of laser scanning technology can be further exploited for urban modeling through the transformation of resulting point clouds into solid models compatible for computational analysis. This article introduces such a technique through the combination of an angle criterion and voxelization. As part of that, a k‐nearest neighbor (kNN) searching algorithm is implemented using a predefined number of kNN points combined with a maximum radius of the neighborhood, something not previously implemented. From this sample, points are categorized as boundary or interior points based on an angle criterion. Façade features are determined based on underlying vertical and horizontal grid voxels of the feature boundaries by a grid clustering technique. The complete building model involving all full voxels is generated by employing the Flying Voxel method to relabel voxels that are inside openings or outside the façade as empty voxels. Experimental results on three different buildings, using four distinct sampling densities showed successful detection of all openings, reconstruction of all building façades, and automatic filling of all improper holes. The maximum nodal displacement divergence was 1.6% compared to manually generated meshes from measured drawings. This fully automated approach rivals processing times of other techniques with the distinct advantage of extracting more boundary points, especially in less dense data sets (<175 points/m²), which may enable its more rapid exploitation of aerial laser scanning data and ultimately preclude needing a priori knowledge.     

Acceleration of Anti‐Markovnikov Hydroamination in the Synthesis of an Active Pharmaceutical Ingredient

Slow chemical reactions are a big challenge in the modern pharmaceutical industry. Their accelerations together with the introduction of continuous manufacturing modes are major drivers for future development. One example reaction is hydroamination, a reaction between unsaturated hydrocarbons and amines. Such a reaction type is the main focus of this work. More precisely, the anti‐Markovnikov hydroamination reaction between cis/trans 9H‐thioxanthene‐2‐chloro‐9‐(2‐propenylidene)‐(9CI) and 1‐(2‐hydroxyethyl)piperazine (HEP) is investigated in detail. It has been traditionally performed in toluene with a huge excess of HEP and reaction times of up to 24 h. Acceleration of the reaction from 24 down to 4 h is achieved by switching from batch operation mode in toluene to either solvent‐free batch mode or microwave‐assisted hydroamination with tetrahydrofuran as a solvent.     

Reasoning Processes in Propositional Logic

We conducted a computer-based psychological experiment in which a random mix of 40 tautologies and 40 non-tautologies were presented to the participants, who were asked to determine which ones of the formulas were tautologies. The participants were eight university students in computer science who had received tuition in propositional logic. The formulas appeared one by one, a time-limit of 45 s applied to each formula and no aids were allowed. For each formula we recorded the proportion of the participants who classified the formula correctly before timeout (accuracy) and the mean response time among those participants (latency). We propose a new proof formalism for modeling propositional reasoning with bounded cognitive resources. It models declarative memory, visual memory, working memory, and procedural memory according to the memory model of Atkinson and Shiffrin and reasoning processes according to the model of Newell and Simon. We also define two particular proof systems, T and NT, for showing propositional formulas to be tautologies and non-tautologies, respectively. The accuracy was found to be higher for non-tautologies than for tautologies (p < .0001). For tautologies the correlation between latency and minimum proof length in T was .89 and for non-tautologies the correlation between latency and minimum proof length in NT was .87.     

Round‐robin prediction of the fatigue limit of a ring of spheroidal graphite cast iron

A round‐robin investigation has been performed, where stress analysts from eight different organisations carried out a total of 11 predictions of the expected fatigue limit of a diametrically loaded cast ring subjected to fluctuating tensile or compressive loading. Whereas geometry, load parameters, and type and quality of material (spheroidal graphite cast iron EN‐GJS‐600‐3) had been prescribed, the participants were free to use computational tools and models, and fatigue assessment models and data of their own choice. The objectives of the investigation were to compare the 11 predictions (i) among themselves, and (ii) with a posteriori experimental fatigue limits determined by means of stair‐case testing. The fatigue limit predictions showed coefficients of variation of as large as 25%. Even for a group of analysts from a single organisation, the coefficients variation were around 15%. Fatigue tests gave mean fatigue limits 60% (tensile loading) and 30% (compressive loading) above the a priori predictions. Possible reasons for the large deviations between single predictions and for their conservatism have been proposed. It seems that design engineers (i) make use of the available room for interpretation of models and data, and (ii) have an unconscious tendency to make conservative assumptions. Only if models and data for fatigue assessment are prescribed in great detail, can the ‘scatter’ among fatigue limit predictions be expected to decrease below 15–25%. Improved ‘absolute’ predictions would require more accurate fatigue data.