Phthalates have been strictly banned in children's products in many countries. However, as a product with a high frequency of daily contact with children, stationery is not strictly regulated for ...phthalates in many countries and the occurrences and risks of phthalates in stationery are rarely reported. In this study, the contents of sixteen types of common phthalates in stationery were determined and the exposure risk of these phthalates to children was also estimated. The total contents of phthalates in all stationery ranged from 5.56 to 3.46 × 105 μg/g, with a median value of 1.48 × 104 μg/g. Polyvinyl chloride (PVC) desk mats (DMs) contained the highest contents of phthalates among all types of stationery. Percutaneous absorption and hand-to-mouth ingestion levels of phthalates for school-age children from the DMs were 2.03 × 10−5 - 10.14 μg/kg-Bw/day and 2.14 × 10−5 - 10.67 μg/kg-Bw/day, respectively. Di-2-ethylhexyl phthalate (DEHP) had the highest proportion, detection rate, and exposure level among all measured phthalates. Our study revealed that phthalates in PVC stationery, especially classroom DMs, at both contents and exposure risks, were higher than those in many other children's plastic products. It was necessary to strengthen the management of plastic stationery from the perspective of materials and phthalates addition.
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•High levels of phthalates have been found in stationery for children in China.•The highest phthalate content was found in PVC desk mats.•DEHP predominated among the detected phthalates.•Percutaneous exposure of DEHP from desk mats contributed greatly to the daily exposure dose for school-age children.
The sports industry is an important component of social life and the national economy. With the advent of the era of big data, promoting the decision-making and scientific construction of the sports ...and cultural goods industry is conducive to the transformation and upgrading of the sports industry. In view of the shortcomings of the current sports stationery industry consumption data system, this paper combines
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-means spatial clustering, fusion decision tree, naive Bayes, and other data mining algorithms and data warehouse technologies to the sports stationery industry. The consumption data system is the research object, and the analysis of geospatial feature clustering, customer segmentation, and consumption preference prediction of sports stationery industry consumption is carried out. The data mining–based sports cultural product industry data fusion system model is constructed, and the architecture, technology path, and function realization of the model are clarified. The actual case analysis and performance test results show that the realized sports cultural goods consumption data fusion system can provide a scientific reference model and basis for the modern sports stationery industry to use data mining and other new technologies to establish a decision-making information system.
This paper is devoted to fourth order compact schemes and fast algorithms for solving stationary Stokes equations with different boundary conditions numerically. One of the main ideas is to decouple ...the Stokes equations into three Poisson equations for the pressure and the velocity via the pressure Poisson equation (PPE). The augmented strategy is utilized to provide numerical boundary conditions for the pressure. Different velocity boundary conditions require different interpolation strategies for the augmented methods. The augmented variable is solved by the GMRES method. A new simple and efficient preconditioning strategy has also been developed to accelerate the convergence of the GMRES iteration. Numerical examples presented in this paper confirmed the designed convergence order and the efficiency of the new methods.
•An augmented fourth-order approach is proposed to solve Stokes equations with various boundary conditions.•A new and efficient preconditioning strategy is developed for solving the Schur complement system in the GMRES iteration.•Non-trivial numerical examples are presented to confirm the effectiveness of the proposed method.
This paper reports the non-targeted analysis of unknown volatile components in scented stationery based on headspace gas chromatography-Orbitrap high-resolution mass spectrometry. The volatiles ...released from the samples (22 scented erasers and 17 scented pens) under specific headspace conditions were analyzed. A qualitative analysis of unknown substances was carried out according to four identification steps (step 1: comprehensive score and retention index, step 2: identification of molecular ion peaks by chemical ionization, step 3: fragment ion detail comparison for distinguishing isomers, step 4: verification by chemical standards). A total of 101 volatile substances were identified in the scented erasers, and 86 volatile substances were identified in the scented pens. The identified substances were divided into eight categories. Aliphatic hydrocarbons, aromatic hydrocarbons, esters, and alcohols were the top four groups of substances identified in scented erasers and pens. The identified substances were further filtered and screened according to their detection rate, toxicity, and response intensity. Finally, 14 high-risk volatile chemicals in scented stationery were listed. This study can be used as a reference for identifying unknown substances and as a guide for monitoring volatile chemicals in products and assessing their possible risks to consumers.
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•This study explored the unknown volatile components in scented stationery.•Non-targeted analysis method was developed with GC-Orbitrap HRMS.•A qualitative analysis was carried out according to four identification steps.•14 high-risk volatile substances in scented stationery were listed.•The method could be used to identify potential risk and promote safer products.
Recently, as a potential source of stationery products, bamboo has been continuously excavated for its commercial value in sustainable development. The research on the design of the bamboo pen ...holder, based on the concept of sustainable design, is not only a symbol of Chinese culture but also a reflection of perceptual factors underlying college students’ preferences. This study aims at user-centered product design by integrating Design Thinking (DT) and Kansei Engineering (KE). We proposed the KE–DT framework which allows designers to coordinate the user’s feelings as design elements. With various college student questionnaires, expert interviews, and cluster analysis, 7 Kansei words were selected to describe the sentimental value first. Using statistical analysis, the users’ emotional preference for each Kansei word was determined. Finally, the best shape of the pen holder was obtained by Sequential Quadratic Programming (SQP), and the stereoscopic product was displayed. A new round of questionnaire surveys was conducted with the optimized pen container and the previous group. The results indicated that curvature had a significant effect on the preference for bamboo stationery in terms of user and designer cognitive differences. Furthermore, the bamboo pen holder designed by the KE–DT framework proved widely popular.
Inventory management in Office Stationery needs (ATK) is instrumental in supporting administrative activities. Not terinvetaris well, resulting in the use of goods is not optimal and increase ...spending on this ATK. For that required a system that can manage this ATK supplies. so that in the prediction of ATK inventory can coordinate and minimize expenditure of STMIK Hang Tuah Pekanbaru expenditure. The data obtained in this research is ATK At High School of Information and Computer Management (STMIK) Hang Tuah Pekanbaru sourced from Head of Equipment Section such as paper type A4 and F4, Paperclip, Map and Printer Ink. ATK is always experiencing shortage or also excess needs. With the Monte Carlo Method, STMIK Hang Tuah Pekanbaru will be able to determine the Pattern of ATK Supplies requirement in STMIK Hang Tuah Pekanbaru and the method can give a decision in determining the pattern of ATK request that will be requested to the employee. The result of the experiment of this method is to obtain the average number of procurement requests and the average number of procurement. Estimates of the Monte Carlo simulation strategic plan that has been done will yield an estimated information on the average amount of procurement as 16 packs and the estimated average monthly expenditure of Rp 21,333.- With the amount of calculations obtained then the Office Stationery to be purchased can be estimated and inventory can be provided to meet the demand for campus needs in 2018
Dust aerosols play an important role in climate change, however, the annual emissions simulated from dusty weather and dust devils are largely underestimated than observed, possibly due to the lack ...of gust on dust emission contribution under stationary weather conditions. This study estimates the gust emission by the use of 1-year measurements of 10-min wind speed from two field sites in Dunhuang (sandy desert) and Yumen (gravel desert) in northwestern China, and the concurrent estimations of dusty weather and dust devils are examined as well. The results show that: 1) about 25% of gust could contribute to dust emission throughout the year regardless in Dunhuang or Yumen. 2) Three dust processes have diverse occurrence times and intensities, i.e. gust could occur at any time with fiercer fluctuation in dust emission than dust devils and dusty weather which mainly occur between April and September and in spring, respectively. 3) During the non-dusty seasons, both dust devils and gust are prominent with gust overwhelmingly contributing the most, while during the dusty season when three mechanisms co-exists, dusty weather outperforms the others in Dunhuang, but takes a relatively even share of around 33% as the other two in Yumen. 4) On an annual scale, gust is the highest and second-highest contributor to the annual total dust emissions in Yumen and Dunhuang, respectively. This study not only highlights the nonnegligible contributor/mechanism of gust to dust emission, complementing the existing emission mechanisms to form a complete dust emission mechanism system, but also sheds light on a new perspective explaining the largely underestimated dust aerosols that are significant in the assessment of climate effects.
•Significant diurnal, monthly and seasonal variability of gust emission.•Gust emission occurs randomly with the fiercest fluctuations.•Gust emission is overwhelmingly dominant during the non-dusty season.•18.5– 50.4% of annual total dust emission is from gust in sandy deserts and Gobi.•Wind gust is an important and new dust emission mechanism.
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