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Materials (Basel, Switzerland) Feb 2023A Helmholtz resonator (HR) with an embedded aperture is an effective acoustic metamaterial for noise reduction in the low-frequency range. Its sound absorption property...
A Helmholtz resonator (HR) with an embedded aperture is an effective acoustic metamaterial for noise reduction in the low-frequency range. Its sound absorption property is significantly affected by the aperture shape. Sound absorption properties of HRs with the embedded aperture for various tangent sectional shapes were studied by a two-dimensional acoustic finite element simulation. The sequence of resonance frequency from low to high was olive, common trapeziform, reverse trapeziform, dumbbell and rectangle. Meanwhile, those HRs for various cross-sectional shapes were investigated by a three-dimensional acoustic finite element simulation. The sequence of resonance frequency from low to high were round, regular hexagon, square, regular triangle and regular pentagon. Moreover, the reason for these phenomena was analyzed by the distributions of sound pressure, acoustic velocity and temperature. Furthermore, on the basement of the optimum tangent and cross-sectional shape, the sound absorption property of parallel-connection Helmholtz resonators was optimized. The experimental sample with optimal parameters was fabricated, and its average sound absorption coefficient reached 0.7821 in 500-820 Hz with a limited thickness of 30 mm. The research achievements proved the significance of aperture shape, which provided guidance for the development of sound absorbers in the low-frequency range.
PubMed: 36837229
DOI: 10.3390/ma16041597 -
Foods (Basel, Switzerland) Feb 2023Patulin (PAT) is a toxic secondary metabolite produced by sp. and sp., which acts as a contaminant of most apples and their products. The internationally recognized...
Patulin (PAT) is a toxic secondary metabolite produced by sp. and sp., which acts as a contaminant of most apples and their products. The internationally recognized HACCP system is selected as the theoretical basis to more effectively reduce the PAT in apple juice concentrate (AJC). Through field investigation of apple juice concentrate (AJC) production enterprises, we collected 117 samples from 13 steps of AJC production, including whole apple, apple pulp, and apple juice. PAT contents were analyzed via high-performance liquid chromatography (HPLC) and compared with samples from the different production processes. The result demonstrated that the PAT content was significantly ( < 0.05) influenced by five processes, receipt of raw apples, sorting of raw apples, adsorption step, pasteurization, and aseptic filling. These processes were determined as the CCPs. Monitoring systems for maintaining CCPs within acceptable limits were established, and corrective actions were proposed in case a CCP was surpassed. Based on the above-identified CCPs, critical limits, and control methods (corrective actions), a HACCP plan related to the production process of AJC was established. This study provided important guidance for juice manufacturers wishing to effectively control the PAT content in their products.
PubMed: 36832860
DOI: 10.3390/foods12040786 -
Heliyon Feb 202321st Century Learning shifts the learning paradigm to change the way of learning and teaching. Organizing education containing three aspects of work readiness...
21st Century Learning shifts the learning paradigm to change the way of learning and teaching. Organizing education containing three aspects of work readiness (knowledge, attitudes, and skills) is challenging for educators. Many educators only use the explanation method in vocational guidance, and do not fully use the demonstration method of learning machining practices related to how to work, how to behave in the workplace, and how to comply with regulations in the workplace, this causes many graduates who only have minimal competence, so they are not according to industry standards. This study aims to determine the effect of integrated vocational guidance on student work readiness in Vocational High Schools. This research is quasi-experimental research with a quantitative approach. The experimental design used was a pretest-posttest non-equivalent control group design. This study used a control group with an explanation method and an experimental group with a demonstration method. In the explanation method in this study, the teacher explains how the machine works verbally, while in the demonstration method, the teacher demonstrates how the machine works and operates it, followed by student activities practising it again in the machine laboratory. The population of this study were students of the Mechanical Engineering Expertise Program. Data collection is done by observation and tests. Observations were used to collect data on technical skills and work attitudes. The test is used to collect data on aspects of basic knowledge. The results showed that: (1) The value of work readiness (knowledge, attitudes, skills) using the explanation method based on the Minimum Completeness Criteria (MCC); (2) The value of work readiness (knowledge, attitudes, skills) with the demonstration method above the MCC. This research has practical implications for vocational teachers who provide vocational guidance services with demonstration methods to students, especially the latest technological advances for learning, such as the use of the internet, digital technology, VR/AR, etc.
PubMed: 36814606
DOI: 10.1016/j.heliyon.2023.e13333 -
Frontiers in Pediatrics 2022While the association between father absence and youth hostility has been well-documented among depressed youths, there is a lack of research on the potential mechanism...
BACKGROUND
While the association between father absence and youth hostility has been well-documented among depressed youths, there is a lack of research on the potential mechanism underlying such an association. This study aimed to test a serial mediation model of self-esteem and frustration tolerance on the link between father absence and youth hostility.
METHODS
A total of 137 Chinese youths with major depressive disorder were recruited from Wuhan Mental Health Center. They completed a survey including the Father Absence Questionnaire to measure father absence, the Chinese Hostility Inventory (CHI) to measure hostility, the Psychological Endurance Questionnaire to measure frustration tolerance, and the Self-esteem Scale (SES) to measure self-esteem. A series of multiple linear regression models were employed to assess the associations among father absence, self-esteem, frustration tolerance, and hostility.
RESULTS
Although father absence was modestly associated with hostility ( = 0.30, < 0.001), subsequent serial mediation analysis showed that father absence was not directly related to hostility (= 0.06, = 0.29) when self-esteem and frustration tolerance were included in the model. High levels of father absence had an adverse effect on levels of self-esteem, which decreased levels of frustration tolerance, and thus higher levels of hostility among depressed youths. The indirect effects of father absence on hostility through self-esteem, frustration tolerance, as well as through self-esteem and frustration tolerance serially accounted for 28%, 24%, and 24% of the total effect, respectively.
CONCLUSION
Our study tested a serial mediation model of self-esteem and frustration tolerance as mediators between father absence and hostility among depressed youths. The findings strengthened our understanding of the potential mechanism underlying the association between self-esteem and frustration tolerance, which may provide useful guidance for future intervention programs.
PubMed: 36776682
DOI: 10.3389/fped.2022.711241 -
Frontiers in Public Health 2022The outbreak and spread of the pandemics have been an issue of critical concern globally, posing a significant threat to the health sector globally. This study aimed to...
INTRODUCTION
The outbreak and spread of the pandemics have been an issue of critical concern globally, posing a significant threat to the health sector globally. This study aimed to examine the basic knowledge and attitudes toward the recommended protective measures at different times, respond to the COVID-19 pandemic, and provide recommendations for developing targeted strategies and measures for preventing and controlling public health emergencies.
METHODS
The study used self-filled questionnaires to examine the public's knowledge, attitudes, and practices on COVID-19 at two different period, from 20 to 31 March 2020 (the beginning period) and 22-27 April 2022 (the regular epidemic prevention and control period). Descriptive and quantitative analyses were used for statistical analysis.
RESULTS AND DISCUSSION
The survey collected 2375 valid questionnaires. A comparison of the two periods reveals that as the epidemic continued over a long period, the level of knowledge, attitudes toward preventive measures, risk perceptions, and adoption behavior of the respondents at the beginning of the epidemic were significantly higher than during the regular epidemic prevention and control period. With the upsurge in the spread of the epidemic, the public needs a multi-channel, targeted, and all-round guidance and information on prevention and control of the COVID-19, and internalizes knowledge into individual's behavior of actively responding to diseases.When the epidemic lasts for a long time, the relevant agencies should strengthen their monitoring role to promote public compliance with the recommended measures.
Topics: Humans; COVID-19; SARS-CoV-2; Pandemics; Surveys and Questionnaires; Health Knowledge, Attitudes, Practice
PubMed: 36743164
DOI: 10.3389/fpubh.2022.1063384 -
Frontiers in Nutrition 2022The production of the large yellow croaker has seasonal and regional characteristics, which is typically preserved on ice, possibly leading to its deterioration in a...
INTRODUCTION
The production of the large yellow croaker has seasonal and regional characteristics, which is typically preserved on ice, possibly leading to its deterioration in a short time. Therefore, in this study, we focused on the effect of temperature fluctuation on the quality changes of the large yellow croaker during frozen storage.
METHODS
In this experiment, the large yellow croaker was soaked in a low-salt solution, and physical and chemical properties, water-holding capacity, color, and protein characteristics of the muscle were investigated after repeated freeze-thaw (F-T) cycles and frozen storage.
RESULTS AND DISCUSSION
The results show the deterioration of muscle quality of large yellow croaker after low-salt treatment was lower than that of the salt-free soaking group. The salting treatment significantly ( < 0.05) enhanced the yield of large yellow croaker, which was 24.3% greater than the salt-free soaking group after 6 weeks of frozen storage. The microstructure of the salted muscle was more stable and maintained its cellular structure after F-T cycles and frozen storage. The b* value of the salt-free soaking group increased from b* value of the low-salt soaking group decreased from acceptable range. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis indicates the content of 17 kDa peptide decreased in the low-salt soaking group, and the peptides at 21 and 24 kDa increased during frozen storage. The results of the present study provide guidance for the optimal processing, transport, and storage of large yellow croaker, but the effect of salting on lipid oxidation and protein oxidation requires further study.
PubMed: 36704793
DOI: 10.3389/fnut.2022.1103838 -
International Journal of Environmental... Jan 2023COVID-19 accelerated the growth of the digital economy and digital transformation across the globe. Meanwhile, it also created a higher demand for productivity in the...
COVID-19 accelerated the growth of the digital economy and digital transformation across the globe. Meanwhile, it also created a higher demand for productivity in the real economy. Hence, the correlation between the digital economy and green productivity is worth studying as COVID-19 prevention becomes the norm. The digital economy overcomes the limitations imposed by traditional factors of production on economic growth and empowers innovative R&D and resource allocation in all aspects. This study delved into the digital economy by focusing on its green value at different levels of development. The study gathered the green-productivity indices and the principal components of the digital economy for each prefecture-level city in China from 2011 to 2019 and meticulously portrayed their trends in spatial and temporal figures. Meanwhile, regression models were used to verify the mechanism through which digital-economy development influences the changes in green productivity. The results showed that: (1) a higher level of digital economy helps to increase urban green total-factor productivity (GTFP) and that the conclusions of this paper still held after potential endogeneity problems were solved through the instrumental-variables approach; (2) the digital economy will drive an increase in urban GTFP by upgrading firms' production technologies and that digital-economy development encourages green patent applications from firms; and (3) as the digital economy develops, it will also drive urban GTFP increases by removing polluting enterprises from the market and that the higher the level of digital-economy development, the greater the number and probability of polluting enterprises exiting the market. In view of this study's results, the government should increase the importance of the digital economy, strengthen the role of the digital economy in promoting urban green development, and provide more guidance on regional green development with the help of the digital economy.
Topics: Humans; Cities; COVID-19; Economic Development; Resource Allocation; China; Efficiency
PubMed: 36674198
DOI: 10.3390/ijerph20021442 -
BMC Medical Education Jan 2023To investigate the influence of group counselling on the career planning and career maturity of male nursing students.
OBJECTIVE
To investigate the influence of group counselling on the career planning and career maturity of male nursing students.
METHOD
Sixty male nursing students were randomly selected from a specific-level first-class hospital in Hunan Province from July to August 2020 by using the convenience sampling method and were subsequently divided into the control group and the experimental group using the random number table method. The control group received routine pre-job training, including aspects concerning the hospital profile, nurse etiquette, nursing core systems, professional ethics, nursing emergency treatment and career prospects and planning. In the experimental group, career planning group counselling was added after the regular pre-service training (once a week) with each session lasting 2 h for a total of six training sessions. At six weeks and three months after the intervention, the career status evaluation scale and the college students' career maturity scale were used to compare the career planning and career maturity status of the two groups of male nursing students.
RESULTS
After six weeks and three months of intervention, all the dimensions and total scores of both the career status evaluation scale and the career maturity scale in the experimental group were superior to those in the control group with statistically significant differences (all P < 0.05). The repeated measures of variance analysis indicated that the differences in the total score for career planning and the four dimensions in terms of intergroup effect, time effect and interaction effect between the two groups were statistically significant (P < 0.05). The intergroup effect, time effect and interaction effect of the total score for vocational maturity, career goal, career confidence, career value, career freedom and career reference of the two groups were statistically significant (P < 0.05), while the time effect of the relative dependency dimension was also statistically significant (P < 0.05).
CONCLUSION
Group counselling can significantly improve the career planning and career maturity status of male nursing students and has a certain long-term effect.
Topics: Humans; Male; Career Choice; Counseling; Education, Nursing, Baccalaureate; Students, Nursing
PubMed: 36650532
DOI: 10.1186/s12909-022-03981-9 -
International Journal of Environmental... Dec 2022This study identifies if there are differences in the personality scores of professionals with varying degrees of congruence, considering each dimension of the RIASEC...
This study identifies if there are differences in the personality scores of professionals with varying degrees of congruence, considering each dimension of the RIASEC model. Method: A cross-sectional survey study. Participants responded to three measures: Vocational Interests Scale (VIS); Occupational Classification Inventory (OCI-R) for estimating congruence; and The Next Big Five Inventory (BFI-2) for estimating personality. Results: Congruence was associated with at least one personality dimension in the Realistic, Investigative, Artistic, and Conventional types. In addition, we identified significant differences between the personality scores of professionals according to the degree of congruence in the Realistic, Investigative, Artistic, and Enterprising types.
Topics: Humans; Cross-Sectional Studies; Working Conditions; Career Choice; Vocational Guidance; Personality
PubMed: 36613040
DOI: 10.3390/ijerph20010719 -
Materials (Basel, Switzerland) Dec 2022In concrete structures, replacing conventional steel bars with high-strength steel reinforcement (HSSR) can effectively save the use of materials. However, the...
In concrete structures, replacing conventional steel bars with high-strength steel reinforcement (HSSR) can effectively save the use of materials. However, the deformation properties and strength dispersion of HSSR are different from those of conventional steel reinforcement, which restricts or conservatively uses them in practical applications. For example, the partial safety factor of HRB500 grade steel bars (the yield strength is 500 MPa) in guideline GB50010-2010 is larger than that of conventional steel bars, and there is no relevant guidance for HRB600 grade steel bars (the yield strength is 600 MPa). Based on this, this paper will propose the limit state design method of high-strength steel reinforced concrete beam (HSSRCB) based on reliability analysis, which is convenient for the popularization and use of HSSR. Firstly, the flexural performance test of HSSRCBs was introduced, and the flexural capacity of HSSRCB was analyzed based on the existing prediction model. Second, a sectional numerical analysis model was established, where the section was discretized into several points, and then the curvature was gradually increased to obtain the corresponding bending moment through integration. A large number of samples were calculated to obtain statistical characteristics of the error of prediction model. Then, the limit state functions were established for two kinds of format, including partial safety factor format (PSSF) and resistance reduction factor format (RRFF), respectively, and the reliability of HSSRCBs was analyzed based on Monte Carlo simulation. Finally, the recommended values of partial safety factor of material and reduction factor of bearing capacity were proposed, in which the design strength of HRB500 and HRB600 reinforcement was 454 MPa and 545 MPa for PSSF, respectively, and the resistance reduction factor for the flexural capacity of HSSRCB was 0.8 and 0.75 for RRFF, respectively.
PubMed: 36556805
DOI: 10.3390/ma15248999