Parametric surface and properties defined on parallelogrammic domain

AbstractSimilar to the essential components of many mechanical systems, the geometrical properties of the teeth of spiral bevel gears greatly influence the kinematic and dynamic behaviors of mechanical systems. Logarithmic spiral bevel gears show a unique advantage in transmission due to their constant spiral angle property. However, a mathematical model suitable for accurate digital modeling, differential geometrical characteristics, and related contact analysis methods for tooth surfaces have not been deeply investigated, since such gears are not convenient in traditional cutting manufacturing in the gear industry. Accurate mathematical modeling of the tooth surface geometry for logarithmic spiral bevel gears is developed in this study, based on the basic gearing kinematics and spherical involute geometry along with the tangent planes geometry; actually, the tooth surface is a parametric surface defined on a parallelogrammic domain. Equivalence proof of the tooth surface geometry is then given in order to greatly simplify the mathematical model. As major factors affecting the lubrication, surface fatigue, contact stress, wear, and manufacturability of gear teeth, the differential geometrical characteristics of the tooth surface are summarized using classical fundamental forms. By using the geometrical properties mentioned, manufactura-bility (and its limitation in logarithmic spiral bevel gears) is analyzed using precision forging and multi-axis freeform milling, rather than classical cradle-type machine tool based milling or hobbing. Geometry and manufacturability analysis results show that logarithmic spiral gears have many application advantages, but many urgent issues such as contact tooth analysis for precision plastic forming and multi-axis freeform milling also need to be solved in a further study

Topic-based integrator matching for pull request

Pull Request (PR) is the main method for code contributions from the external contributors in GitHub. PR review is an essential part of open source software developments to maintain the quality of software. Matching a new PR for an appropriate integrator will make the PR reviewing more effective. However, PR and integrator matching are now organized manually in GitHub. To make this process more efficient, we propose a Topic-based Integrator Matching Algorithm (TIMA) to predict highly relevant collaborators(the core developers) as the integrator to incoming PRs . TIMA takes full advantage of the textual semantics of PRs. To define the relationships between topics and collaborators, TIMA builds a relation matrix about topic and collaborators. According to the relevance between topics and collaborators, TIMA matches the suitable collaborators as the PR integrator

Chitosan-Templated Bio-coloration of Cotton Fabrics via Laccase-Catalyzed Polymerization of Hydroquinone

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.There is an increasing interest in the development of enzymatic coloration of textile fabrics as an alternative to conventional textile dyeing processes, which is successful for dyeing protein fibers. However, unmodified cotton fabrics are difficult to be dyed through enzyme catalysis due to the lack of affinity of biosynthesized dyes to cotton fibers. In order to improve the enzyme‐catalyzed dyeability of cotton fibers, chitosan was used to coat cotton fabrics as template. A novel and facile bio‐coloration technique using laccase catalysis of hydroquinone was developed to dye chitosan‐templated cotton fabrics. The polymerization of hydroquinone with the template of chitosan under the laccase catalysis was monitored by ultraviolet‐vis spectrophotometer on the absorbance of reaction solution. A significant peak of UV‐vis spectrum at 246 nm corresponding to large conjugated structures appeared and increased with increasing the duration of enzymatic catalysis. The effect of different treatment conditions on the laccase‐catalyzed dyeing of cotton fabric was investigated to determine their optimal parameters of laccase‐catalyzed coloration. Fourier‐transform infrared spectroscopy spectra demonstrated the formation of H‐bond and Schiff base reaction between chitosan and polymerized hydroquinone. Scanning electron microscopy indicated that the surface of dyed cotton fiber was much rougher than that of the control sample. Moreover, X‐ray photoelectron spectroscopy also revealed the existence of the chitosan/polymerized hydroquinone complex and polymerized hydroquinone on the dyed cotton fibers. This chitosan‐templated approach offers possibility for biological dyeing coloration of cotton fabrics and other cellulosic materials

Enzymatic coloration and finishing of wool with laccase and polyethylenimine

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Enzymes have been widely used in the textile wet processing. The precise reaction specificity of an enzyme has been utilised for specific or targeted textile finishing without causing undesirable fibre damage. Laccases are important enzymes for their application in textile processing due to their great versatility and capability of catalysing the oxidation of a broad range of substrates. The investigation of laccase-catalysed coloration towards either wool or polyethylenimine was carried out. It is understood that amino groups from wool and polyethylenimine are involved in the formation of polymeric colour during laccase catalysation of catechin and gallic acid. The colour depth and shrink-resistance of wool can be improved significantly by incorporating a multi-primary amine compound, such as polyethylenimine, and a crosslinking agent, such as glycerol diglycidyl ether, in the enzymatic coloration process of wool. This demonstrated the potential to achieve combined coloration and shrink-resistant finishing for wool fabrics

Enzymatic thiol-ene click reaction: an eco-friendly approach for MPEGMA-grafted modification of wool fibers

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.The thiol–ene click reaction has been commonly used for the modification of many materials due to its high efficiency, high selectivity, and reliability. To further promote the sustainable technology for the modification of keratin-based materials, enzymatic biotechnology and thiol–ene click chemistry was integrated for the first time for grafting modification of wool fibers with methoxy polyethylene glycol methacrylate (MPEGMA). Wool fibers were reduced to create thiol groups and then grafted with MPEGMA through a horseradish peroxidase (HRP)-mediated thiol–ene click reaction. In order to understand the grafting mechanism of MPEGMA on wool, l-cysteine was used as a model compound for the thiol group of the reduced wool in the current research. The structures of MPEGMA reacted with l-cysteine and grafted on wool fabrics were investigated by FTIR, MALDI-TOF, Raman spectra, and XPS. The surface morphology, wettability, moisture penetrability, and regain of modified wool fibers were also assessed. The results showed that l-cysteine reacted with MPEGMA through the thiol–ene click reaction. The MPEGMA-grafted wool fabric had good surface wettability, and its moisture penetrability and regain were also improved when compared with untreated wool fabric. The HRP-initiated thiol–ene grafting reaction not only encouraged green and sustainable click chemistry but also provide an alternative eco-friendly approach for modification and functionalization of keratin and keratin-containing materials

APOA-I: a possible novel biomarker for metabolic side effects in first episode schizophrenia

The purpose of this study was to investigate the change in plasma protein expression in first episode schizophrenia after an 8-week treatment with risperidone, and to explore potential biomarkers for metabolic side effects associated with risperidone treatment. Eighty first-episode schizophrenia patientswere enrolled in the study. Fifteen of the 80 patients were randomly selected to undergo proteomic analysis. Plasma proteins were obtained before and after the 8-week risperidone treatment, and measured using two-dimensional gel electrophoresis (2-DE), Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry(MALDI-TOF/TOF) and peptide mass fingerprinting.Proteins with the highest fold changes after risperidone treatment were then measured for all 80 patients using enzyme linked immunosorbent assay (ELISA). The relationship between changes in plasma protein levels and changes in metabolic parameters after risperidone treatment was examined. In 15 randomly selected patients, approximately 1,500 protein spots were detected in each gel by 2-DE. Of those proteins, 22 spots showed significant difference in abundance after risperidone treatment (p\u27s \u3c 0.05). After MALDI-TOF peptide mass fingerprinting, apolipoprotein A-I (APOA-I) and Guanine Nucleotide Binding Protein, Alpha Stimulating (GNAS), were found to have the highest fold changes.The content of APOA-I was significantly increased, and the content of GNAS was significantly decreased after risperidone treatment (p\u27s\u3c0.05). The analysis in the entire study sample showed similar findings in changes of APOA-I and GNAS after risperidone treatment. Further analysis showed significant relationships between changesin APOA-1 and changes in triglyceride, total cholesterol, and body mass index after controlling for age, gender and family history of diabetes. Similar analysis showed a trend positive relationship between changes in GNAS and changes in BMI. Using proteomic analysis, the study suggested that APOA-I might be a novel biomarkers related to metabolic side effects in first episode schizophrenia treated with risperidone