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In this paper, the theoretical analysis of the position estimation error in position-sensorless operation using pulsating square wave signal injection is presented. The purpose of this paper is to analyze the phenomenon that the position estimation performance varies depending on the injection frequency. Mathematical derivation supported by simulation and experimental results shows that, in no-load condition, the voltage distortion induces position estimation error with 3rd-order harmonics if the frequency of the injected square wave is the same to the switching frequency. While, if the frequency is a half of the switching frequency or heavier load condition in either injection frequency, the effect of nonideal characteristics of inverter disappears and there is no 3rd harmonics in the position estimation error. Therefore, only the effect of cross-coupling inductance is reflected in the estimation error. As the result, the position estimation error appears in the form of 6th-order harmonics due to the spatial harmonics of inductances, and the error is relatively small compared with the switching frequency injection case. The theoretical analysis was verified by simulation and experimental results. [ABSTRACT FROM AUTHOR]

Abstract The common bed bug, Cimex lectularius , possesses a cholinesterase expressed exclusively in the salivary gland (ClSChE). In this study, we investigated the molecular forms, tissue distribution patterns and biochemical properties of ClSChE and showed that ClSChE exists as a soluble monomeric form or a soluble dimeric form connected by a disulfide bridge. Immunohistochemical analysis confirmed that ClSChE was expressed in the epithelial cells of both the salivary gland and the duct. In addition, the secretion of monomeric ClSChE through the proboscis during feeding was confirmed by western blotting using a ClSChE-specific antibody. To predict the role of ClSChE injected into the tissue of an animal host, we analyzed the extent of hydrolysis of acetylcholine (ACh) by ClSChE by ultra-performance liquid chromatography-tandem mass spectrometry. ClSChE binding to ACh was not clearly resolved in the binding assay format used in this study, probably due to the weak but detectable ACh-hydrolytic activity of ClSChE. Nevertheless, kinetic analysis revealed that ClSChE possesses extremely low K m (high affinity to ACh) and V max values. These findings suggest that ClSChE functions virtually as an ACh-sequestering protein by having a very strong affinity to ACh but an extremely long turnover time. Given that ACh regulates a wide variety of host physiologies, we discuss the tentative roles of ClSChE in blood vessel constriction and itch/pain regulation in the host. Graphical abstract Image 1 Highlights • ClSChE is expressed in the epithelial cells of both salivary gland and duct. • Monomeric form of ClSChE is secreted through proboscis during feeding. • UPLC-MS/MS-based kinetic analysis reveals extremely low K m and V max of ClSChE. • ClSChE appears to function virtually as acetylcholine-sequestration protein. • Putative roles of ClSChE in blood feeding are discussed. [ABSTRACT FROM AUTHOR]

In this paper, the characteristics of ripple current of a multimegawatt drive system fed by a pulse-width modulation (PWM) inverter are investigated. Based on the investigation, a novel PWM scheme is devised to reduce the switching loss of the inverter under an identical amount of torque ripple of a motor. The proposed PWM is composed of two parts. The first is minimum torque ripple PWM (MTRPWM), which is optimized in terms of the minimum torque ripple in high modulation index (MI). The second determines the minimum switching frequency while holding the average torque ripple less than the allowable value under various operating conditions. It is termed reduced switching frequency PWM (RSFPWM). Consequently, by simply changing the PWM method from conventional fixed switching frequency continuous PWM to the proposed PWM, MTRPWM and RSFPWM, simulation results show that the switching loss of the inverter driving a 3.5 MW induction motor is reduced to 51.6% while keeping the torque ripple in the allowable boundary, where MI is 1.12. This approach is applied to small-scale experimental sets consisting of an interior permanent magnet synchronous machine (IPMSM) motor-generator set, and an induction machine MG set in an effort to verify the validity and feasibility of the proposed method. Based on these experimental results, the cost indexes of the IPMSM and the induction machine, as defined in this paper, decrease by up to 66% and 77%, respectively, when the proposed method is applied when MI is 1.12 compared with the outcome with the conventional PWM. [ABSTRACT FROM AUTHOR]

To investigate the expression profiles of cellulase genes in termites due to differences in habitat and diet, we collected one species ( Microtermes pakistanicus ) from dry wood, one species ( Macrotermes gilvus ) from rotten damp wood and one species ( Microtermes sp.) from cow dung. Total RNA was extracted from the hind guts containing paunch and from other tissues from each collected species and used for the suppression subtractive hybridization to enrich cellulase genes. The resulting EST libraries were sequenced, the cellulase genes were identified by BLAST search, and their phylogenetic relationships were determined. Depending on habitat and diet, termites exhibited different expression profiles of cellulase genes. Endo- β -1,4-glucanase (glycosyl hydrolase family 9, GHF 9) was the predominant cellulase expressed in M. pakistanicus , which consume dry wood. In contrast, M. gilvus , consuming rotten damp wood, utilized cellobiohydrolase (GHF 7) as the major cellulase. Additionally, β -glucosidase, a cellobiase (GHF 1), was found to be the major cellulase in Microtermes sp., which consume cow dung. Based on these findings and the supposition that raw cellulose materials are likely preprocessed by cellulolytic microorganisms in damp wood and cow dung, we hypothesized that termites consuming these preprocessed cellulose materials (i.e., cellobiase) have adapted to produce more exocellulases than endocellulases. This notion was supported by the fact that endo- β -1,4-glucanase (i.e., endocellulase) was predominantly expressed only in M. pakistanicus , which consume the raw cellulose of dry wood. An analysis of the catalytic domains of the cloned cellulases suggested that these cellulases possess enzymatic activity. [ABSTRACT FROM AUTHOR]

Highlights: [•] Molecular and enzymatic properties of ClAChE1 and ClAChE2 were investigated. [•] Both ClAChE1 and ClAChE2 are mainly distributed in the central nervous system. [•] ClAChE1 showed higher catalytic efficiency toward acetylcholine. [•] ClAChE1 is the more relevant toxicological target for organophosphates and carbamates. [Copyright &y& Elsevier]

Abstract: Genetically modified maize crops expressing Bacillus thuringiensis (Bt) toxins (Bt maize) are increasingly cultivated worldwide, and large amounts of Bt maize have been imported to Korea. Before evaluating the environmental impacts of Bt maize of unknown origin on non-target insects, crystal (Cry) protein types in the imported Bt maize plants were identified. Because Cry1F was found in the tested Bt maize plants, Rhopalosiphum padi, a non-lepidopteran species, was selected as the non-target insect species. Additionally, a widely cultivated domestic maize strain was selected as an alternative control. No difference in survival rate, alata vivipara production, or host preference was observed between R. padi fed on the Bt maize and the control non-Bt maize, indicating that Bt maize plants had no sub-chronic adverse effects on R. padi. The average number of nymphs from Bt maize-fed aphids was 1.73-fold higher than that of non-Bt maize-fed aphids, implying that R. padi population density can increase after several generations in Bt maize fields. An enzyme-linked immunosorbent assay revealed that Cry1F toxin concentrations increased gradually in the body of R. padi when they were fed Bt maize, but that all ingested Cry toxins were excreted within 10days after Bt-fed aphids were transferred to non-Bt maize, suggesting little possibility of Cry toxin exposure via R. padi to the endoparasitoids. However, the possibility still remains that Cry toxins can be transferred to predatory insects in higher trophic levels if they consume Bt maize-fed aphids. [Copyright &y& Elsevier]

Abstract: Large amounts of genetically modified grains producing Bacillus thuringiensis (Bt) toxins have been imported to Korea. Therefore, the establishment of a risk assessment system for evaluating the potential impacts of imported Bt maize on non-target insects is important. Before evaluating the environmental impacts of Bt grains of unknown origin, Cry protein types must first be identified in test Bt grains. Cry toxins of imported Bt maize grains were analyzed by ELISA. Because all tested Bt maize grains contained Cry1A, Tenebrio molitor, a non-lepidopteran species, was selected as the non-target insect species. A domestic maize strain that showed few differences in nutritional composition compared to the Bt maize grain was used as the alternative non-Bt control. Slightly increased survival rate and head capsule width of Bt maize-fed T. molitor were observed, indicating that Bt maize has no sub-chronic adverse effects on T. molitor. An ELISA test revealed that concentrations of Cry1A toxins slowly increased in the body of T. molitor when the insects were fed Bt maize. Such substantial amounts of Cry toxins remaining in the alimentary tract of larvae indicate that Cry toxins can be transferred to the higher trophic level of predatory insects. However, no Cry proteins were detected in the hemolymph of the Bt maize-fed larvae, suggesting that there is little possibility of Cry toxin exposure via T. molitor to the higher endoparasitoids. The risk assessment strategies and protocols established in this study may also be applicable to other imported Bt crops in Korea. [Copyright &y& Elsevier]

Various technologies and standards for the Internet of Things (IoT) have defined the way devices should interact with each other to provide an intelligent IoT service to users in an efficient manner. Although the usability of system interface between the platform and users is one of the key factors for the success of IoT ecosystems, the manner in which IoT platforms should interact with users has not been well studied. Current IoT platforms provide a simple list-based interface to manage devices, which result in the degradation of their usability as the number of devices increases. In this paper, we propose an interactive web-based IoT management system where deep object detection techniques are adopted to facilitate user's device selection and management. The proposed system automatically recognizes the device type from video streams and accordingly generates smart controllers. The users can choose a device by touching an object in the video stream and use a smart controller to control the selected device. Finally, we show the feasibility of the proposed system through the implementation of a prototype which demonstrates a set of user scenarios. [ABSTRACT FROM AUTHOR]