Search results for: Hsiao-Lan Wang
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1352

Search results for: Hsiao-Lan Wang

122 Consumer Over-Indebtedness in Germany: An Investigation of Key Determinants

Authors: Xiaojing Wang, Ann-Marie Ward, Tony Wall

Abstract:

The problem of over-indebtedness has increased since deregulation of the banking industry in the 1980s, and now it has become a major problem for most countries in Europe, including Germany. Consumer debt issues have attracted not only the attention of academics but also government and debt counselling institutions. Overall, this research aims to contribute to the knowledge gap regarding the causes of consumer over-indebtedness in Germany and to develop predictive models for assessing consumer over-indebtedness risk at consumer level. The situation of consumer over-indebtedness is serious in Germany. The relatively high level of social welfare support in Germany suggests that consumer debt problems are caused by other factors, other than just over-spending and income volatility. Prior literature suggests that the overall stability of the economy and level of welfare support for individuals from the structural environment contributes to consumers’ debt problems. In terms of cultural influence, the conspicuous consumption theory in consumer behaviour suggests that consumers would spend more than their means to be seen as similar profiles to consumers in a higher socio-economic class. This results in consumers taking on more debt than they can afford, and eventually becoming over-indebted. Studies have also shown that financial literacy is negatively related to consumer over-indebtedness risk. Whilst prior literature has examined structural and cultural influences respectively, no study has taken a collective approach. To address this gap, a model is developed to investigate the association between consumer over-indebtedness and proxies for influences from the structural and cultural environment based on the above theories. The model also controls for consumer demographic characteristics identified as being of influence in prior literature, such as gender and age, and adverse shocks, such as divorce or bereavement in the household. Benefiting from SOEP regional data, this study is able to conduct quantitative empirical analysis to test both structural and cultural influences at a localised level. Using German Socio-Economic Panel (SOEP) study data from 2006 to 2016, this study finds that social benefits, financial literacy and the existence of conspicuous consumption all contribute to being over-indebted. Generally speaking, the risk of becoming over-indebted is high when consumers are in a low-welfare community, have little awareness of their own financial situation and always over-spend. In order to tackle the problem of over-indebtedness, countermeasures can be taken, for example, increasing consumers’ financial awareness, and the level of welfare support. By analysing causes of consumer over-indebtedness in Germany, this study also provides new insights on the nature and underlying causes of consumer debt issues in Europe.

Keywords: consumer, debt, financial literacy, socio-economic

Procedia PDF Downloads 211
121 Evaluating the Service Quality and Customers’ Satisfaction for Lihpaoland in Taiwan

Authors: Wan-Yu Liu, Tiffany April Lin, Yu-Chieh Tang, Yi-Lin Wang, Chieh-Hui Li

Abstract:

As the national income in Taiwan has been raised, the life style of the public has also been changed, so that the tourism industry gradually moves from a service industry to an experience economy. The Lihpaoland is one of the most popular theme parks in Taiwan. However, the related works on performance of service quality of the park have been lacking since its re-operation in 2012. Therefore, this study investigates the quality of software/hardware facilities and services of the Lihpaoland, and aims to achieve the following three goals: 1) analyzing how various sample data of tourists leads to different results for service quality of LihpaoLand; 2) analyzing how tourists respond to the service tangibility, service reliability, service responsiveness, service guarantee, and service empathy of LihpaoLand; 3) according to the theoretical and empirical results, proposing how to improve the overall facilities and services of LihpaoLand, and hoping to provide suggestions to the LihpaoLand or other related businesses to make decision. The survey was conducted on the tourists to the LihpaoLand using convenience sampling, and 400 questionnaires were collected successfully. Analysis results show that tourists paid much attention to maintenance of amusement facilities and safety of the park, and were satisfied with them, which are great advantages of the park. However, transportation around the LihpaoLand was inadequate, and the price of the Fullon hotel (which is the hotel closest to the LihpaoLand) were not accepted by tourists – more promotion events are recommended. Additionally, the shows are not diversified, and should be improved with the highest priority. Tourists did not pay attention to service personnel’s clothing and the ticket price, but they were not satisfied with them. Hence, this study recommends to design more distinctive costumes and conduct ticket promotions. Accordingly, the suggestions made in this study for LihpaoLand are stated as follows: 1) Diversified amusement facilities should be provided to satisfy the needs at different ages. 2) Cheep but tasty catering and more distinctive souvenirs should be offered. 3) Diversified propaganda schemes should be strengthened to increase number of tourists. 4) Quality and professional of the service staff should be enhanced to acquire public praise and tourists revisiting. 5) Ticket promotions in peak seasons, low seasons, and special events should be conducted. 6) Proper traffic flows should be planned and combined with technologies to reduce waiting time of tourists. 7) The features of theme landscape in LihpaoLand should be strengthened to increase willingness of the tourists with special preferences to visit the park. 8) Ticket discounts or premier points card promotions should be adopted to reward the tourists with high loyalty.

Keywords: service quality, customers’ satisfaction, theme park, Taiwan

Procedia PDF Downloads 471
120 Spatial Distribution and Cluster Analysis of Sexual Risk Behaviors and STIs Reported by Chinese Adults in Guangzhou, China: A Representative Population-Based Study

Authors: Fangjing Zhou, Wen Chen, Brian J. Hall, Yu Wang, Carl Latkin, Li Ling, Joseph D. Tucker

Abstract:

Background: Economic and social reforms designed to open China to the world has been successful, but also appear to have rapidly laid the foundation for the reemergence of STIs since 1980s. Changes in sexual behaviors, relationships, and norms among Chinese contributed to the STIs epidemic. As the massive population moved during the last 30 years, early coital debut, multiple sexual partnerships, and unprotected sex have increased within the general population. Our objectives were to assess associations between residences location, sexual risk behaviors and sexually transmitted infections (STIs) among adults living in Guangzhou, China. Methods: Stratified cluster sampling followed a two-step process was used to select populations aged 18-59 years in Guangzhou, China. Spatial methods including Geographic Information Systems (GIS) were utilized to identify 1400 coordinates with latitude and longitude. Face-to-face household interviews were conducted to collect self-report data on sexual risk behaviors and diagnosed STIs. Kulldorff’s spatial scan statistic was implemented to identify and detect spatial distribution and clusters of sexual risk behaviors and STIs. The presence and location of statistically significant clusters were mapped in the study areas using ArcGIS software. Results: In this study, 1215 of 1400 households attempted surveys, with 368 refusals, resulting in a sample of 751 completed surveys. The prevalence of self-reported sexual risk behaviors was between 5.1% and 50.0%. The self-reported lifetime prevalence of diagnosed STIs was 7.06%. Anal intercourse clustered in an area located along the border within the rural-urban continuum (p=0.001). High rate clusters for alcohol or other drugs using before sex (p=0.008) and migrants who lived in Guangzhou less than one year (p=0.007) overlapped this cluster. Excess cases for sex without a condom (p=0.031) overlapped the cluster for college students (p<0.001). Conclusions: Short-term migrants and college students reported greater sexual risk behaviors. Programs to increase safer sex within these communities to reduce the risk of STIs are warranted in Guangzhou. Spatial analysis identified geographical clusters of sexual risk behaviors, which is critical for optimizing surveillance and targeting control measures for these locations in the future.

Keywords: cluster analysis, migrant, sexual risk behaviors, spatial distribution

Procedia PDF Downloads 340
119 Implicit U-Net Enhanced Fourier Neural Operator for Long-Term Dynamics Prediction in Turbulence

Authors: Zhijie Li, Wenhui Peng, Zelong Yuan, Jianchun Wang

Abstract:

Turbulence is a complex phenomenon that plays a crucial role in various fields, such as engineering, atmospheric science, and fluid dynamics. Predicting and understanding its behavior over long time scales have been challenging tasks. Traditional methods, such as large-eddy simulation (LES), have provided valuable insights but are computationally expensive. In the past few years, machine learning methods have experienced rapid development, leading to significant improvements in computational speed. However, ensuring stable and accurate long-term predictions remains a challenging task for these methods. In this study, we introduce the implicit U-net enhanced Fourier neural operator (IU-FNO) as a solution for stable and efficient long-term predictions of the nonlinear dynamics in three-dimensional (3D) turbulence. The IU-FNO model combines implicit re-current Fourier layers to deepen the network and incorporates the U-Net architecture to accurately capture small-scale flow structures. We evaluate the performance of the IU-FNO model through extensive large-eddy simulations of three types of 3D turbulence: forced homogeneous isotropic turbulence (HIT), temporally evolving turbulent mixing layer, and decaying homogeneous isotropic turbulence. The results demonstrate that the IU-FNO model outperforms other FNO-based models, including vanilla FNO, implicit FNO (IFNO), and U-net enhanced FNO (U-FNO), as well as the dynamic Smagorinsky model (DSM), in predicting various turbulence statistics. Specifically, the IU-FNO model exhibits improved accuracy in predicting the velocity spectrum, probability density functions (PDFs) of vorticity and velocity increments, and instantaneous spatial structures of the flow field. Furthermore, the IU-FNO model addresses the stability issues encountered in long-term predictions, which were limitations of previous FNO models. In addition to its superior performance, the IU-FNO model offers faster computational speed compared to traditional large-eddy simulations using the DSM model. It also demonstrates generalization capabilities to higher Taylor-Reynolds numbers and unseen flow regimes, such as decaying turbulence. Overall, the IU-FNO model presents a promising approach for long-term dynamics prediction in 3D turbulence, providing improved accuracy, stability, and computational efficiency compared to existing methods.

Keywords: data-driven, Fourier neural operator, large eddy simulation, fluid dynamics

Procedia PDF Downloads 74
118 Numerical Simulation of Waves Interaction with a Free Floating Body by MPS Method

Authors: Guoyu Wang, Meilian Zhang, Chunhui LI, Bing Ren

Abstract:

In recent decades, a variety of floating structures have played a crucial role in ocean and marine engineering, such as ships, offshore platforms, floating breakwaters, fish farms, floating airports, etc. It is common for floating structures to suffer from loadings under waves, and the responses of the structures mounted in marine environments have a significant relation to the wave impacts. The interaction between surface waves and floating structures is one of the important issues in ship or marine structure design to increase performance and efficiency. With the progress of computational fluid dynamics, a number of numerical models based on the NS equations in the time domain have been developed to explore the above problem, such as the finite difference method or the finite volume method. Those traditional numerical simulation techniques for moving bodies are grid-based, which may encounter some difficulties when treating a large free surface deformation and a moving boundary. In these models, the moving structures in a Lagrangian formulation need to be appropriately described in grids, and the special treatment of the moving boundary is inevitable. Nevertheless, in the mesh-based models, the movement of the grid near the structure or the communication between the moving Lagrangian structure and Eulerian meshes will increase the algorithm complexity. Fortunately, these challenges can be avoided by the meshless particle methods. In the present study, a moving particle semi-implicit model is explored for the numerical simulation of fluid–structure interaction with surface flows, especially for coupling of fluid and moving rigid body. The equivalent momentum transfer method is proposed and derived for the coupling of fluid and rigid moving body. The structure is discretized into a group of solid particles, which are assumed as fluid particles involved in solving the NS equation altogether with the surrounding fluid particles. The momentum conservation is ensured by the transfer from those fluid particles to the corresponding solid particles. Then, the position of the solid particles is updated to keep the initial shape of the structure. Using the proposed method, the motions of a free-floating body in regular waves are numerically studied. The wave surface evaluation and the dynamic response of the floating body are presented. There is good agreement when the numerical results, such as the sway, heave, and roll of the floating body, are compared with the experimental and other numerical data. It is demonstrated that the presented MPS model is effective for the numerical simulation of fluid-structure interaction.

Keywords: floating body, fluid structure interaction, MPS, particle method, waves

Procedia PDF Downloads 75
117 Molecular Dynamics Study of Ferrocene in Low and Room Temperatures

Authors: Feng Wang, Vladislav Vasilyev

Abstract:

Ferrocene (Fe(C5H5)2, i.e., di-cyclopentadienyle iron (FeCp2) or Fc) is a unique example of ‘wrong but seminal’ in chemistry history. It has significant applications in a number of areas such as homogeneous catalysis, polymer chemistry, molecular sensing, and nonlinear optical materials. However, the ‘molecular carousel’ has been a ‘notoriously difficult example’ and subject to long debate for its conformation and properties. Ferrocene is a dynamic molecule. As a result, understanding of the dynamical properties of ferrocene is very important to understand the conformational properties of Fc. In the present study, molecular dynamic (MD) simulations are performed. In the simulation, we use 5 geometrical parameters to define the overall conformation of Fc and all the rest is a thermal noise. The five parameters are defined as: three parameters d---the distance between two Cp planes, α and δ to define the relative positions of the Cp planes, in which α is the angle of the Cp tilt and δ the angle the two Cp plane rotation like a carousel. Two parameters to position the Fe atom between two Cps, i.e., d1 for Fe-Cp1 and d2 for Fe-Cp2 distances. Our preliminary MD simulation discovered the five parameters behave differently. Distances of Fe to the Cp planes show that they are independent, practically identical without correlation. The relative position of two Cp rings, α, indicates that the two Cp planes are most likely not in a parallel position, rather, they tilt in a small angle α≠ 0°. The mean plane dihedral angle δ ≠ 0°. Moreover, δ is neither 0° nor 36°, indicating under those conditions, Fc is neither in a perfect eclipsed structure nor a perfect staggered structure. The simulations show that when the temperature is above 80K, the conformers are virtually in free rotations, A very interesting result from the MD simulation is the five C-Fe bond distances from the same Cp ring. They are surprisingly not identical but in three groups of 2, 2 and 1. We describe the pentagon formed by five carbon atoms as ‘turtle swimming’ for the motion of the Cp rings of Fc as shown in their dynamical animation video. The Fe- C(1) and Fe-C(2) which are identical as ‘the turtle back legs’, Fe-C(3) and Fe-C(4) which are also identical as turtle front paws’, and Fe-C(5) ---’the turtle head’. Such as ‘turtle swimming’ analog may be able to explain the single substituted derivatives of Fc. Again, the mean Fe-C distance obtained from MD simulation is larger than the quantum mechanically calculated Fe-C distances for eclipsed and staggered Fc, with larger deviation with respect to the eclipsed Fc than the staggered Fc. The same trend is obtained for the five Fe-C-H angles from same Cp ring of Fc. The simulated mean IR spectrum at 7K shows split spectral peaks at approximately 470 cm-1 and 488 cm-1, in excellent agreement with quantum mechanically calculated gas phase IR spectrum for eclipsed Fc. As the temperature increases over 80K, the clearly splitting IR spectrum become a very board single peak. Preliminary MD results will be presented.

Keywords: ferrocene conformation, molecular dynamics simulation, conformer orientation, eclipsed and staggered ferrocene

Procedia PDF Downloads 218
116 Analyzing the Relationship between Physical Fitness and Academic Achievement in Chinese High School Students

Authors: Juan Li, Hui Tian, Min Wang

Abstract:

In China, under the considerable pressure of 'Gaokao' –the highly competitive college entrance examination, high school teachers and parents often worry that doing physical activity would take away the students’ precious study time and may have a negative impact on the academic grades. There was a tendency to achieve high academic scores at the cost of physical exercise. Therefore, the purpose of this study was to examine the relationship between the physical fitness and academic achievement of Chinese high school students. The participants were 968 grade one (N=457) and grade two students (N=511) with an average age of 16 years from three high schools of different levels in Beijing, China. 479 were boys, and 489 were girls. One of the schools is a top high school in China, another is a key high school in Beijing, and the other is an ordinary high school. All analyses were weighted using SAS 9.4 to ensure the representatives of the sample. The weights were based on 12 strata of schools, sex, and grades. Physical fitness data were collected using the scores of the National Physical Fitness Test, which is an annual official test administered by the Ministry of Education in China. It includes 50m run, sits and reach test, standing long jump, 1000m run (for boys), 800m run (for girls), pull-ups for 1 minute (for boys), and bent-knee sit-ups for 1 minute (for girls). The test is an overall evaluation of the students’ physical health on the major indexes of strength, endurance, flexibility, and cardiorespiratory function. Academic scores were obtained from the three schools with the students’ consent. The statistical analysis was conducted with SPSS 24. Independent-Samples T-test was used to examine the gender group differences. Spearman’s Rho bivariate correlation was adopted to test for associations between physical test results and academic performance. Statistical significance was set at p<.05. The study found that girls obtained higher fitness scores than boys (p=.000). The girls’ physical fitness test scores were positively associated with the total academic grades (rs=.103, p=.029), English (rs=.096, p=.042), physics (rs=.202, p=.000) and chemistry scores (rs=.131, p=.009). No significant relationship was observed in boys. Cardiorespiratory fitness had a positive association with physics (rs=.196, p=.000) and biology scores (rs=.168, p=.023) in girls, and with English score in boys (rs=.104, p=.029). A possible explanation for the greater association between physical fitness and academic achievement in girls rather than boys was that girls showed stronger motivation in achieving high scores in whether academic tests or fitness tests. More driven by the test results, girls probably tended to invest more time and energy in training for the fitness test. Higher fitness levels were associated with an academic benefit among girls generally in Chinese high schools. Therefore, physical fitness needs to be given greater emphasis among Chinese adolescents and gender differences need to be taken into consideration.

Keywords: physical fitness; adolescents; academic achievement; high school

Procedia PDF Downloads 132
115 Fuzzy Optimization for Identifying Anticancer Targets in Genome-Scale Metabolic Models of Colon Cancer

Authors: Feng-Sheng Wang, Chao-Ting Cheng

Abstract:

Developing a drug from conception to launch is costly and time-consuming. Computer-aided methods can reduce research costs and accelerate the development process during the early drug discovery and development stages. This study developed a fuzzy multi-objective hierarchical optimization framework for identifying potential anticancer targets in a metabolic model. First, RNA-seq expression data of colorectal cancer samples and their healthy counterparts were used to reconstruct tissue-specific genome-scale metabolic models. The aim of the optimization framework was to identify anticancer targets that lead to cancer cell death and evaluate metabolic flux perturbations in normal cells that have been caused by cancer treatment. Four objectives were established in the optimization framework to evaluate the mortality of cancer cells for treatment and to minimize side effects causing toxicity-induced tumorigenesis on normal cells and smaller metabolic perturbations. Through fuzzy set theory, a multiobjective optimization problem was converted into a trilevel maximizing decision-making (MDM) problem. The applied nested hybrid differential evolution was applied to solve the trilevel MDM problem using two nutrient media to identify anticancer targets in the genome-scale metabolic model of colorectal cancer, respectively. Using Dulbecco’s Modified Eagle Medium (DMEM), the computational results reveal that the identified anticancer targets were mostly involved in cholesterol biosynthesis, pyrimidine and purine metabolisms, glycerophospholipid biosynthetic pathway and sphingolipid pathway. However, using Ham’s medium, the genes involved in cholesterol biosynthesis were unidentifiable. A comparison of the uptake reactions for the DMEM and Ham’s medium revealed that no cholesterol uptake reaction was included in DMEM. Two additional media, i.e., a cholesterol uptake reaction was included in DMEM and excluded in HAM, were respectively used to investigate the relationship of tumor cell growth with nutrient components and anticancer target genes. The genes involved in the cholesterol biosynthesis were also revealed to be determinable if a cholesterol uptake reaction was not induced when the cells were in the culture medium. However, the genes involved in cholesterol biosynthesis became unidentifiable if such a reaction was induced.

Keywords: Cancer metabolism, genome-scale metabolic model, constraint-based model, multilevel optimization, fuzzy optimization, hybrid differential evolution

Procedia PDF Downloads 80
114 Epidemiology of Gestational Choriocarcinoma: A Systematic Review

Authors: Farah Amalina Mohamed Affandi, Redhwan Ahmad Al-Naggar, Seok Mui Wang, Thanikasalam Kathiresan

Abstract:

Gestational choriocarcinoma is a condition in which there is an abnormal growth or a tumor inside the women’s uterus after conception. It is a type of gestational trophoblastic disease which is relatively rare and malignant. The current epidemiological data of this disease are inadequate. The purposes of this study are to examine the epidemiology of choriocarcinoma and their risk factors based on all available population-based and hospital-based data of the disease. In this study, we searched The MEDLINE and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases using the keywords ‘choriocarcinoma’, ‘gestational’, ‘gestational choriocarcinoma’ and ‘epidemiology’. We included only human studies published in English between 1995 and 2015 to ensure up to date evidence. Case studies, case reports, animal studies, letters to the editor, news, and review articles were excluded. Retrieved articles were screened in three phases. In the first phase, any articles that did not match the inclusion criteria based solely on titles were excluded. In the second phase, the abstracts of remaining articles were screened thoroughly; any articles that did not meet our inclusion criteria were excluded. In the final phase, full texts of the remaining articles were read and assessed to exclude articles that did not meet the inclusion criteria or any articles that fulfilled the exclusion criteria. Duplicates articles were also removed. Systematic reviews and meta-analysis were excluded. Extracted data were summarized in table and figures descriptively. The reference lists of included studies were thoroughly reviewed in search for other relevant studies. A total of ten studies met all the selection criteria. Nine were retrospective studies and one was cohort study. Total numbers of 4563 cases of choriocarcinoma were reviewed from several countries which are Korea, Japan, South Africa, USA, New Mexico, Finland, Turkey, China, Brazil and The Netherlands. Different studies included different range of age with their mean age of 28.5 to 30.0 years. All studies investigated on the disease’s incidence rate, only two studies examined on the risk factors or associations of the disease. Approximately 20% of the studies showed a reduction in the incidence of choriocarcinoma while the other 80% showed inconsistencies in rate. Associations of age, fertility age, occupations and socio-demographic with the status remains unclear. There is limited information on the epidemiological aspects of gestational choriocarcinoma. The observed results indicated there was a decrease in the incidence rate of gestational choriocarcinoma globally. These could be due to the reduction in the incidence of molar pregnancy and the efficacy of the treatment, mainly by chemotherapy.

Keywords: epidemiology, gestational choriocarcinoma, incidence, prevalence, risk factor

Procedia PDF Downloads 330
113 Microwave Dielectric Constant Measurements of Titanium Dioxide Using Five Mixture Equations

Authors: Jyh Sheen, Yong-Lin Wang

Abstract:

This research dedicates to find a different measurement procedure of microwave dielectric properties of ceramic materials with high dielectric constants. For the composite of ceramic dispersed in the polymer matrix, the dielectric constants of the composites with different concentrations can be obtained by various mixture equations. The other development of mixture rule is to calculate the permittivity of ceramic from measurements on composite. To do this, the analysis method and theoretical accuracy on six basic mixture laws derived from three basic particle shapes of ceramic fillers have been reported for dielectric constants of ceramic less than 40 at microwave frequency. Similar researches have been done for other well-known mixture rules. They have shown that both the physical curve matching with experimental results and low potential theory error are important to promote the calculation accuracy. Recently, a modified of mixture equation for high dielectric constant ceramics at microwave frequency has also been presented for strontium titanate (SrTiO3) which was selected from five more well known mixing rules and has shown a good accuracy for high dielectric constant measurements. However, it is still not clear the accuracy of this modified equation for other high dielectric constant materials. Therefore, the five more well known mixing rules are selected again to understand their application to other high dielectric constant ceramics. The other high dielectric constant ceramic, TiO2 with dielectric constant 100, was then chosen for this research. Their theoretical error equations are derived. In addition to the theoretical research, experimental measurements are always required. Titanium dioxide is an interesting ceramic for microwave applications. In this research, its powder is adopted as the filler material and polyethylene powder is like the matrix material. The dielectric constants of those ceramic-polyethylene composites with various compositions were measured at 10 GHz. The theoretical curves of the five published mixture equations are shown together with the measured results to understand the curve matching condition of each rule. Finally, based on the experimental observation and theoretical analysis, one of the five rules was selected and modified to a new powder mixture equation. This modified rule has show very good curve matching with the measurement data and low theoretical error. We can then calculate the dielectric constant of pure filler medium (titanium dioxide) by those mixing equations from the measured dielectric constants of composites. The accuracy on the estimating dielectric constant of pure ceramic by various mixture rules will be compared. This modified mixture rule has also shown good measurement accuracy on the dielectric constant of titanium dioxide ceramic. This study can be applied to the microwave dielectric properties measurements of other high dielectric constant ceramic materials in the future.

Keywords: microwave measurement, dielectric constant, mixture rules, composites

Procedia PDF Downloads 367
112 Applying Big Data Analysis to Efficiently Exploit the Vast Unconventional Tight Oil Reserves

Authors: Shengnan Chen, Shuhua Wang

Abstract:

Successful production of hydrocarbon from unconventional tight oil reserves has changed the energy landscape in North America. The oil contained within these reservoirs typically will not flow to the wellbore at economic rates without assistance from advanced horizontal well and multi-stage hydraulic fracturing. Efficient and economic development of these reserves is a priority of society, government, and industry, especially under the current low oil prices. Meanwhile, society needs technological and process innovations to enhance oil recovery while concurrently reducing environmental impacts. Recently, big data analysis and artificial intelligence become very popular, developing data-driven insights for better designs and decisions in various engineering disciplines. However, the application of data mining in petroleum engineering is still in its infancy. The objective of this research aims to apply intelligent data analysis and data-driven models to exploit unconventional oil reserves both efficiently and economically. More specifically, a comprehensive database including the reservoir geological data, reservoir geophysical data, well completion data and production data for thousands of wells is firstly established to discover the valuable insights and knowledge related to tight oil reserves development. Several data analysis methods are introduced to analysis such a huge dataset. For example, K-means clustering is used to partition all observations into clusters; principle component analysis is applied to emphasize the variation and bring out strong patterns in the dataset, making the big data easy to explore and visualize; exploratory factor analysis (EFA) is used to identify the complex interrelationships between well completion data and well production data. Different data mining techniques, such as artificial neural network, fuzzy logic, and machine learning technique are then summarized, and appropriate ones are selected to analyze the database based on the prediction accuracy, model robustness, and reproducibility. Advanced knowledge and patterned are finally recognized and integrated into a modified self-adaptive differential evolution optimization workflow to enhance the oil recovery and maximize the net present value (NPV) of the unconventional oil resources. This research will advance the knowledge in the development of unconventional oil reserves and bridge the gap between the big data and performance optimizations in these formations. The newly developed data-driven optimization workflow is a powerful approach to guide field operation, which leads to better designs, higher oil recovery and economic return of future wells in the unconventional oil reserves.

Keywords: big data, artificial intelligence, enhance oil recovery, unconventional oil reserves

Procedia PDF Downloads 283
111 Tracing the Developmental Repertoire of the Progressive: Evidence from L2 Construction Learning

Authors: Tianqi Wu, Min Wang

Abstract:

Research investigating language acquisition from a constructionist perspective has demonstrated that language is learned as constructions at various linguistic levels, which is related to factors of frequency, semantic prototypicality, and form-meaning contingency. However, previous research on construction learning tended to focus on clause-level constructions such as verb argument constructions but few attempts were made to study morpheme-level constructions such as the progressive construction, which is regarded as a source of acquisition problems for English learners from diverse L1 backgrounds, especially for those whose L1 do not have an equivalent construction such as German and Chinese. To trace the developmental trajectory of Chinese EFL learners’ use of the progressive with respect to verb frequency, verb-progressive contingency, and verbal prototypicality and generality, a learner corpus consisting of three sub-corpora representing three different English proficiency levels was extracted from the Chinese Learners of English Corpora (CLEC). As the reference point, a native speakers’ corpus extracted from the Louvain Corpus of Native English Essays was also established. All the texts were annotated with C7 tagset by part-of-speech tagging software. After annotation all valid progressive hits were retrieved with AntConc 3.4.3 followed by a manual check. Frequency-related data showed that from the lowest to the highest proficiency level, (1) the type token ratio increased steadily from 23.5% to 35.6%, getting closer to 36.4% in the native speakers’ corpus, indicating a wider use of verbs in the progressive; (2) the normalized entropy value rose from 0.776 to 0.876, working towards the target score of 0.886 in native speakers’ corpus, revealing that upper-intermediate learners exhibited a more even distribution and more productive use of verbs in the progressive; (3) activity verbs (i.e., verbs with prototypical progressive meanings like running and singing) dropped from 59% to 34% but non-prototypical verbs such as state verbs (e.g., being and living) and achievement verbs (e.g., dying and finishing) were increasingly used in the progressive. Apart from raw frequency analyses, collostructional analyses were conducted to quantify verb-progressive contingency and to determine what verbs were distinctively associated with the progressive construction. Results were in line with raw frequency findings, which showed that contingency between the progressive and non-prototypical verbs represented by light verbs (e.g., going, doing, making, and coming) increased as English proficiency proceeded. These findings altogether suggested that beginning Chinese EFL learners were less productive in using the progressive construction: they were constrained by a small set of verbs which had concrete and typical progressive meanings (e.g., the activity verbs). But with English proficiency increasing, their use of the progressive began to spread to marginal members such as the light verbs.

Keywords: Construction learning, Corpus-based, Progressives, Prototype

Procedia PDF Downloads 128
110 Efficacy and Safety of Computerized Cognitive Training Combined with SSRIs for Treating Cognitive Impairment Among Patients with Late-Life Depression: A 12-Week, Randomized Controlled Study

Authors: Xiao Wang, Qinge Zhang

Abstract:

Background: This randomized, open-label study examined the therapeutic effects of computerized cognitive training (CCT) combined with selective serotonin reuptake inhibitors (SSRIs) on cognitive impairment among patients with late-life depression (LLD). Method: Study data were collected from May 5, 2021, to April 21, 2023. Outpatients who met diagnostic criteria for major depressive disorder according to the fifth revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria (i.e., a total score on the 17-item Hamilton Depression Rating Scale (HAMD-17) ≥ 18 and a total score on the Montreal Cognitive Assessment scale (MOCA) <26) were randomly assigned to receive up to 12 weeks of CCT and SSRIs treatment (n=57) or SSRIs and Control treatment (n=61). The primary outcome was the change in Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog) scores from baseline to week 12 between the two groups. The secondary outcomes included changes in the HAMD-17 score, Hamilton Anxiety Scale (HAMA) score and Neuropsychiatric Inventory (NPI) score. Mixed model repeated measures (MMRM) analysis was performed on modified intention-to-treat (mITT) and completer populations. Results: The full analysis set (FAS) included 118 patients (CCT and SSRIs group, n=57; SSRIs and Control group, n =61). Over the 12-week study period, the reduction in the ADAS-cog total score was significant (P < 0.001) in both groups, while MMRM analysis revealed a significantly greater reduction in cognitive function (ADAS-cog total scores) from baseline to posttreatment in the CCT and SSRIs group than in the SSRI and Control group [(F (1,115) =13.65, least-squares mean difference [95% CI]: −2.77 [−3.73, −1.81], p<0.001)]. There were significantly greater improvements in depression symptoms (measured by the HAMD-17) in the CCT and SSRIs group than in the control group [MMRM, estimated mean difference (SE) between groups −3.59 [−5.02, −2.15], p < 0.001]. The least-squares mean changes in the HAMA scores and NPI scores between baseline and week 8 were greater in the CCT and SSRIs group than in the control group (all P < 0.05). There was no significant difference between groups on response rates and remission rates by using the last-observation-carried-forward (LOCF) method (all P > 0.05). The most frequent adverse events (AEs) in both groups were dry mouth, somnolence, and constipation. There was no significant difference in the incidence of adverse events between the two groups. Conclusions: CCT combined with SSRIs was efficacious and well tolerated in LLD patients with cognitive impairment.

Keywords: late-life depression, cognitive function, computerized cognitive training, SSRIs

Procedia PDF Downloads 50
109 An Empirical Analysis on the Evolution Characteristics and Textual Content of Campus Football Policy in China

Authors: Shangjun Zou, Zhiyuan Wang, Songhui You

Abstract:

Introduction In recent years, the Chinese government has issued several policies to promote the institutional reform and innovation of the development of campus football, but many problems have been exposed in the process of policy implementation. Therefore, this paper attempts to conduct an empirical analysis of the campus football policy texts to reveal the dynamic development of the microsystem in the process of policy evolution. Methods The selected policy contents are coded by constructing a two-dimensional analysis framework of campus football policy tool-policy objective. Specifically, the X dimension consists of three oriented policy tools: environment, supply and demand, while the Y dimension is divided into six aspects of policy objectives, including institution, competition, player teaching, coach training, resource guarantee and popularization. And the distribution differences of textual analysis units on X and Y dimensions are tested by using SPSS22.0 so as to evaluate the characteristics and development trend of campus football policy on respective subjects. Results 1) In the policy evolution process of campus football stepping into the 2.0 Era, there were no significant differences in the frequency distribution of policy tools(p=0.582) and policy objectives(p=0.603). The collaborative governance of multiple participants has become the primary trend, and the guiding role of Chinese Football Association has gradually become prominent. 2) There were significant differences in the distribution of policy tools before the evolution at a 95% confidence level(p=0.041). With environmental tools always maintaining the dominant position, the overall synergy of policy tools increased slightly. 3) There were significant differences in the distribution of policy objectives after the evolution at a 90% confidence level(p=0.069). The competition system of policy objective has not received enough attention while the construction of institution and resource guarantee system has been strengthened. Conclusion The upgraded version of campus football should adhere to the education concept of health first, promote the coordinated development of youth cultural learning and football skills, and strive to achieve more solid popularization, more scientific institution, more comprehensive resource guarantee and adequate integration. At the same time, it is necessary to strengthen the collaborative allocation of policy tools and reasonable planning of policy objectives so as to promote the high quality and sustainable development of campus football in the New Era. Endnote The policy texts selected in this paper are “Implementation Opinions on Accelerating the Development of Youth Campus Football” and “Action Plans for the Construction of Eight Systems of National Youth Campus Football”, which were promulgated on August 13, 2015 and September 25, 2020 respectively.

Keywords: campus football, content analysis, evolution characteristics, policy objective, policy tool

Procedia PDF Downloads 189
108 A Narrative Inquiry of Identity Formation of Chinese Fashion Designers

Authors: Lily Ye

Abstract:

The contemporary fashion industry has witnessed the global rise of Chinese fashion designers. China plays more and more important role in this sector globally. One of the key debates in contemporary time is the conception of Chinese fashion. A close look at previous discussions on Chinese fashion reveals that most of them are explored through the lens of cultural knowledge and assumptions, using the dichotomous models of East and West. The results of these studies generate an essentialist and orientalist notion of Chinoiserie and Chinese fashion, which sees individual designers from China as undifferential collective members marked by a unique and fixed set of cultural scripts. This study challenges this essentialist conceptualization and brings fresh insights to the discussion of Chinese fashion identity against the backdrop of globalisation. Different from a culturalist approach to researching Chinese fashion, this paper presents an alternative position to address the research agenda through the mobilisation of Giddens’ (1991) theory of reflexive identity formation, privileging individuals’ agency and reflexivity. This approach to the discussion of identity formation not only challenges the traditional view seeing identity as the distinctive and essential characteristics belonging to any given individual or shared by all members of a particular social category or group but highlights fashion designers’ strategic agency and their role as fashion activist. This study draws evidence from a textual analysis of published stories of a group of established Chinese designers such as Guo Pei, Huishan Zhang, Masha Ma, Uma Wang, and Ma Ke. In line with Giddens’ concept of 'reflexive project of the self', this study uses a narrative methodology. Narratives are verbal accounts or stories relating to experiences of Chinese fashion designers. This approach offers the fashion designers a chance to 'speak' for themselves and show the depths and complexities of their experiences. It also emphasises the nuances of identity formation in fashion designers, whose experiences cannot be captured in neat typologies. Thematic analysis (Braun and Clarke, 2006) is adopted to identify and investigate common themes across the whole dataset. At the centre of the analysis is individuals’ self-articulation of their perceptions, experiences and themselves in relation to culture, fashion and identity. The finding indicates that identity is constructed around anchors such as agency, cultural hybridity, reflexivity and sustainability rather than traditional collective categories such as culture and ethnicity. Thus, the old East-West dichotomy is broken down, and essentialised social categories are challenged by the multiplicity and fragmentation of self and cultural hybridity created within designers’ 'small narratives'.

Keywords: Chinoiserie, fashion identity, fashion activism, narrative inquiry

Procedia PDF Downloads 293
107 Exploring the Correlation between Population Distribution and Urban Heat Island under Urban Data: Taking Shenzhen Urban Heat Island as an Example

Authors: Wang Yang

Abstract:

Shenzhen is a modern city of China's reform and opening-up policy, the development of urban morphology has been established on the administration of the Chinese government. This city`s planning paradigm is primarily affected by the spatial structure and human behavior. The subjective urban agglomeration center is divided into several groups and centers. In comparisons of this effect, the city development law has better to be neglected. With the continuous development of the internet, extensive data technology has been introduced in China. Data mining and data analysis has become important tools in municipal research. Data mining has been utilized to improve data cleaning such as receiving business data, traffic data and population data. Prior to data mining, government data were collected by traditional means, then were analyzed using city-relationship research, delaying the timeliness of urban development, especially for the contemporary city. Data update speed is very fast and based on the Internet. The city's point of interest (POI) in the excavation serves as data source affecting the city design, while satellite remote sensing is used as a reference object, city analysis is conducted in both directions, the administrative paradigm of government is broken and urban research is restored. Therefore, the use of data mining in urban analysis is very important. The satellite remote sensing data of the Shenzhen city in July 2018 were measured by the satellite Modis sensor and can be utilized to perform land surface temperature inversion, and analyze city heat island distribution of Shenzhen. This article acquired and classified the data from Shenzhen by using Data crawler technology. Data of Shenzhen heat island and interest points were simulated and analyzed in the GIS platform to discover the main features of functional equivalent distribution influence. Shenzhen is located in the east-west area of China. The city’s main streets are also determined according to the direction of city development. Therefore, it is determined that the functional area of the city is also distributed in the east-west direction. The urban heat island can express the heat map according to the functional urban area. Regional POI has correspondence. The research result clearly explains that the distribution of the urban heat island and the distribution of urban POIs are one-to-one correspondence. Urban heat island is primarily influenced by the properties of the underlying surface, avoiding the impact of urban climate. Using urban POIs as analysis object, the distribution of municipal POIs and population aggregation are closely connected, so that the distribution of the population corresponded with the distribution of the urban heat island.

Keywords: POI, satellite remote sensing, the population distribution, urban heat island thermal map

Procedia PDF Downloads 104
106 A Comparison of qCON/qNOX to the Bispectral Index as Indices of Antinociception in Surgical Patients Undergoing General Anesthesia with Laryngeal Mask Airway

Authors: Roya Yumul, Ofelia Loani Elvir-Lazo, Sevan Komshian, Ruby Wang, Jun Tang

Abstract:

BACKGROUND: An objective means for monitoring the anti-nociceptive effects of perioperative medications has long been desired as a way to provide anesthesiologists information regarding a patient’s level of antinociception and preclude any untoward autonomic responses and reflexive muscular movements from painful stimuli intraoperatively. To this end, electroencephalogram (EEG) based tools including BIS and qCON were designed to provide information about the depth of sedation while qNOX was produced to inform on the degree of antinociception. The goal of this study was to compare the reliability of qCON/qNOX to BIS as specific indicators of response to nociceptive stimulation. METHODS: Sixty-two patients undergoing general anesthesia with LMA were included in this study. Institutional Review Board (IRB) approval was obtained, and informed consent was acquired prior to patient enrollment. Inclusion criteria included American Society of Anesthesiologists (ASA) class I-III, 18 to 80 years of age, and either gender. Exclusion criteria included the inability to consent. Withdrawal criteria included conversion to the endotracheal tube and EEG malfunction. BIS and qCON/qNOX electrodes were simultaneously placed on all patients prior to induction of anesthesia and were monitored throughout the case, along with other perioperative data, including patient response to noxious stimuli. All intraoperative decisions were made by the primary anesthesiologist without influence from qCON/qNOX. Student’s t-distribution, prediction probability (PK), and ANOVA were used to statistically compare the relative ability to detect nociceptive stimuli for each index. Twenty patients were included for the preliminary analysis. RESULTS: A comparison of overall intraoperative BIS, qCON and qNOX indices demonstrated no significant difference between the three measures (N=62, p> 0.05). Meanwhile, index values for qNOX (62±18) were significantly higher than those for BIS (46±14) and qCON (54±19) immediately preceding patient responses to nociceptive stimulation in a preliminary analysis (N=20, * p= 0.0408). Notably, certain hemodynamic measurements demonstrated a significant increase in response to painful stimuli (MAP increased from 74 ±13 mm Hg at baseline to 84 ± 18 mm Hg during noxious stimuli [p= 0.032] and HR from 76 ± 12 BPM at baseline to 80 ± 13 BPM during noxious stimuli [p=0.078] respectively). CONCLUSION: In this observational study, BIS and qCON/qNOX provided comparable information on patients’ level of sedation throughout the course of an anesthetic. Meanwhile, increases in qNOX values demonstrated a superior correlation to an imminent response to stimulation relative to all other indices

Keywords: antinociception, BIS, general anesthesia, LMA, qCON/qNOX

Procedia PDF Downloads 137
105 Mechanism Design and Dynamic Analysis of Active Independent Front Steering System

Authors: Cheng-Chi Yu, Yu-Shiue Wang, Kei-Lin Kuo

Abstract:

Active Independent Front Steering system is a steering system which can according to vehicle driving situation adjusts the relation of steering angle between inner wheel and outer wheel. In low-speed cornering, AIFS sets the steering angles of inner and outer wheel into Ackerman steering geometry to make vehicle has less cornering radius. Besides, AIFS changes the steering geometry to parallel or even anti-Ackerman steering geometry to keep vehicle stability in high-speed cornering. Therefore, based on the analysis of the vehicle steering behavior from different steering geometries, this study develops a new screw type of active independent front steering system to make vehicles best cornering performance at any speeds. The screw type of active independent front steering system keeps the pinion and separates the rack into main rack and second rack. Two racks connect by a screw. Extra screw rotated motion powered by assistant motor through coupler makes second rack move relative to main rack, which can adjust both steering ratio and steering geometry. First of all, this study distinguishes the steering geometry by using Ackerman percentage and utilizes the software of ADAMS/Car to construct diverse steering geometry models. The different steering geometries are compared at low-speed and high-speed cornering, and then control strategies of the active independent front steering systems could be formulated. Secondly, this study applies closed loop equation to analyze tire steering angles and carries out optimization calculations to make the steering geometry from traditional rack and pinion steering system near to Ackerman steering geometry. Steering characteristics of the optimum steering mechanism and motion characteristics of vehicle installed the steering mechanism are verified by ADAMS/Car models of front suspension and full vehicle respectively. By adding dual auxiliary rack and dual motor to the optimum steering mechanism, the active independent front steering system could be developed to achieve the functions of variable steering ratio and variable steering geometry. At last, this study uses ADAMS/Car and Matlab/Simulink to co-simulate the cornering motion of vehicles confirms the vehicle installed the Active Independent Front Steering (AIFS) system has better handling performance than that with Active Independent Steering (AFS) system or with Electric Power Steering (EPS) system. At low-speed cornering, the vehicles with AIFS system and with AFS system have better maneuverability, less cornering radius, than the traditional vehicle with EPS system because that AIFS and AFS systems both provide function of variable steering ratio. However, there is a slight penalty in the motor(s) power consumption. In addition, because of the capability of variable steering geometry, the vehicle with AIFS system has better high-speed cornering stability, trajectory keeping, and even less motor(s) power consumption than that with EPS system and also with AFS system.

Keywords: active front steering system, active independent front steering system, steering geometry, steering ratio

Procedia PDF Downloads 188
104 Using the Micro Computed Tomography to Study the Corrosion Behavior of Magnesium Alloy at Different pH Values

Authors: Chia-Jung Chang, Sheng-Che Chen, Ming-Long Yeh, Chih-Wei Wang, Chih-Han Chang

Abstract:

Introduction and Motivation: In recent years, magnesium alloy is used to be a kind of medical biodegradable materials. Magnesium is an essential element in the body and is efficiently excreted by the kidneys. Furthermore, the mechanical properties of magnesium alloy is closest to human bone. However, in some cases magnesium alloy corrodes so quickly that it would release hydrogen on surface of implant. The other product is hydroxide ion, it can significantly increase the local pH value. The above situations may have adverse effects on local cell functions. On the other hand, nowadays magnesium alloy corrode too fast to maintain the function of implant until the healing of tissue. Therefore, much recent research about magnesium alloy has focused on controlling the corrosion rate. The in vitro corrosion behavior of magnesium alloys is affected by many factors, and pH value is one of factors. In this study, we will study on the influence of pH value on the corrosion behavior of magnesium alloy by the Micro-CT (micro computed tomography) and other instruments.Material and methods: In the first step, we make some guiding plates for specimens of magnesium alloy AZ91 by Rapid Prototyping. The guiding plates are able to be a standard for the degradation of specimen, so that we can use it to make sure the position of specimens in the CT image. We can also simplify the conditions of degradation by the guiding plates.In the next step, we prepare the solution with different pH value. And then we put the specimens into the solution to start the corrosion test. The CT image, surface photographs and weigh are measured on every twelve hours. Results: In the primary results of the test, we make sure that CT image can be a way to quantify the corrosion behavior of magnesium alloy. Moreover we can observe the phenomenon that corrosion always start from some erosion point. It’s possibly based on some defect like dislocations and the voids with high strain energy in the materials. We will deal with the raw data into Mass Loss (ML) and corrosion rate by CT image, surface photographs and weigh in the near future. Having a simple prediction, the pH value and degradation rate will be negatively correlated. And we want to find out the equation of the pH value and corrosion rate. We also have a simple test to simulate the change of the pH value in the local region. In this test the pH value will rise to 10 in a short time. Conclusion: As a biodegradable implant for the area with stagnating body fluid flow in the human body, magnesium alloy can cause the increase of local pH values and release the hydrogen. Those may damage the human cell. The purpose of this study is finding out the equation of the pH value and corrosion rate. After that we will try to find the ways to overcome the limitations of medical magnesium alloy.

Keywords: magnesium alloy, biodegradable materials, corrosion, micro-CT

Procedia PDF Downloads 457
103 Telepsychiatry for Asian Americans

Authors: Jami Wang, Brian Kao, Davin Agustines

Abstract:

COVID-19 highlighted the active discrimination against the Asian American population easily seen through media, social tension, and increased crimes against the specific population. It is well known that long-term racism can also have a large impact on both emotional and psychological well-being. However, the healthcare disparity during this time also revealed how the Asian American community lacked the research data, political support, and medical infrastructure for this particular population. During a time when Asian American fear for safety with decreasing mental health, telepsychiatry is particularly promising. COVID-19 demonstrated how well psychiatry could integrate with telemedicine, with psychiatry being the second most utilized telemedicine visits. However, the Asian American community did not utilize the telepsychiatry resources as much as other groups. Because of this, we wanted to understand why the patient population who was affected the most by COVID-19 mentally did not seek out care. To do this, we decided to study the top top telepsychiatry platforms. The current top telepsychiatry companies in the United States include Teladoc and BetterHelp. In the Teladoc mental health sector, they only had 4 available languages (English, Spanish, French, and Danis,) with none of them being an Asian language. In a similar manner, Teladoc’s top competitor in the telepsychiatry space, BetterHelp, only listed a total of 3 Asian languages, including Mandarin, Japanese, and Malaysian. However, this is still a short list considering they have over 20 languages available. The shortage of available physicians that speak multiple languages is concerning, as it could be difficult for the Asian American community to relate with. There are limited mental health resources that cater to their likely cultural needs, further exacerbating the structural racism and institutional barriers to appropriate care. It is important to note that these companies do provide interpreters to comply with the nondiscrimination and language assistance federal law. However, interactions with an interpreter are not only more time-consuming but also less personal than talking directly with a physician. Psychiatry is the field that emphasizes interpersonal relationships. The trust between a physician and the patient is critical in developing patient rapport to guide in better understanding the clinical picture and treating the patient appropriately. The language barrier creates an additional barrier between the physician and patient. Because Asian Americans are one of the largest growing patient population bases, these telehealth companies have much to gain by catering to the Asian American market. Without providing adequate access to bilingual and bicultural physicians, the current system will only further exacerbate the growing disparity. The healthcare community and telehealth companies need to recognize that the Asian American population is a severely underserved population in mental health and has much to gain from telepsychiatry. The lack of language is one of many reasons why there is a disparity for Asian Americans in the mental health space.

Keywords: telemedicine, psychiatry, Asian American, disparity

Procedia PDF Downloads 105
102 Reading as Moral Afternoon Tea: An Empirical Study on the Compensation Effect between Literary Novel Reading and Readers’ Moral Motivation

Authors: Chong Jiang, Liang Zhao, Hua Jian, Xiaoguang Wang

Abstract:

The belief that there is a strong relationship between reading narrative and morality has generally become the basic assumption of scholars, philosophers, critics, and cultural critics. The virtuality constructed by literary novels inspires readers to regard the narrative as a thinking experiment, creating the distance between readers and events so that they can freely and morally experience the positions of different roles. Therefore, the virtual narrative combined with literary characteristics is always considered as a "moral laboratory." Well-established findings revealed that people show less lying and deceptive behaviors in the morning than in the afternoon, called the morning morality effect. As a limited self-regulation resource, morality will be constantly depleted with the change of time rhythm under the influence of the morning morality effect. It can also be compensated and restored in various ways, such as eating, sleeping, etc. As a common form of entertainment in modern society, literary novel reading gives people more virtual experience and emotional catharsis, just as a relaxing afternoon tea that helps people break away from fast-paced work, restore physical strength, and relieve stress in a short period of leisure. In this paper, inspired by the compensation control theory, we wonder whether reading literary novels in the digital environment could replenish a kind of spiritual energy for self-regulation to compensate for people's moral loss in the afternoon. Based on this assumption, we leverage the social annotation text content generated by readers in digital reading to represent the readers' reading attention. We then recognized the semantics and calculated the readers' moral motivation expressed in the annotations and investigated the fine-grained dynamics of the moral motivation changing in each time slot within 24 hours of a day. Comprehensively comparing the division of different time intervals, sufficient experiments showed that the moral motivation reflected in the annotations in the afternoon is significantly higher than that in the morning. The results robustly verified the hypothesis that reading compensates for moral motivation, which we called the moral afternoon tea effect. Moreover, we quantitatively identified that such moral compensation can last until 14:00 in the afternoon and 21:00 in the evening. In addition, it is interesting to find that the division of time intervals of different units impacts the identification of moral rhythms. Dividing the time intervals by four-hour time slot brings more insights of moral rhythms compared with that of three-hour and six-hour time slot.

Keywords: digital reading, social annotation, moral motivation, morning morality effect, control compensation

Procedia PDF Downloads 149
101 Studying Second Language Learners' Language Behavior from Conversation Analysis Perspective

Authors: Yanyan Wang

Abstract:

This paper on second language teaching and learning uses conversation analysis (CA) approach and focuses on how second language learners of Chinese do repair when making clarification requests. In order to demonstrate their behavior in interaction, a comparison was made to study the differences between native speakers of Chinese with non-native speakers of Chinese. The significance of the research is to make second language teachers and learners aware of repair and how to seek clarification. Utilizing the methodology of CA, the research involved two sets of naturally occurring recordings, one of native speaker students and the other of non-native speaker students. Both sets of recording were telephone talks between students and teachers. There were 50 native speaker students and 50 non-native speaker students. From multiple listening to the recordings, the parts with repairs for clarification were selected for analysis which included the moments in the talk when students had problems in understanding or hearing the speaker and had to seek clarification. For example, ‘Sorry, I do not understand ‘and ‘Can you repeat the question? ‘were the parts as repair to make clarification requests. In the data, there were 43 such cases from native speaker students and 88 cases from non-native speaker students. The non-native speaker students were more likely to use repair to seek clarification. Analysis on how the students make clarification requests during their conversation was carried out by investigating how the students initiated problems and how the teachers repaired the problems. In CA term, it is called other-initiated self-repair (OISR), which refers to student-initiated teacher-repair in this research. The findings show that, in initiating repair, native speaker students pay more attention to mutual understanding (inter-subjectivity) while non-native speaker students, due to their lack of language proficiency, pay more attention to their status of knowledge (epistemic) switch. There are three major differences: 1, native Chinese students more often initiate closed-class OISR (seeking specific information in the request) such as repeating a word or phrases from the previous turn while non-native students more frequently initiate open-class OISR (not specifying clarification) such as ‘sorry, I don’t understand ‘. 2, native speakers’ clarification requests are treated by the teacher as understanding of the content while non-native learners’ clarification requests are treated by teacher as language proficiency problem. 3, native speakers don’t see repair as knowledge issue and there is no third position in the repair sequences to close repair while non-native learners take repair sequence as a time to adjust their knowledge. There is clear closing third position token such as ‘oh ‘ to close repair sequence so that the topic can go back. In conclusion, this paper uses conversation analysis approach to compare differences between native Chinese speakers and non-native Chinese learners in their ways of conducting repair when making clarification requests. The findings are useful in future Chinese language teaching and learning, especially in teaching pragmatics such as requests.

Keywords: conversation analysis (CA), clarification request, second language (L2), teaching implication

Procedia PDF Downloads 256
100 Effects of the Natural Compound on SARS-CoV-2 Spike Protein-Mediated Metabolic Alteration in THP-1 Cells Explored by the ¹H-NMR-Based Metabolomics Approach

Authors: Gyaltsen Dakpa, K. J. Senthil Kumar, Nai-Wen Tsao, Sheng-Yang Wang

Abstract:

Context: Coronavirus disease 2019 (COVID-19) is a severe respiratory illness caused by the SARS-CoV-2 virus. One of the hallmarks of COVID-19 is a change in metabolism, which can lead to increased severity and mortality. The mechanism of SARS-CoV-2-mediated perturbations of metabolic pathways has yet to be fully understood. Research Aim: This study aimed to investigate the metabolic alteration caused by SARS-CoV-2 spike protein in Phorbol 12-myristate 13-acetate (PMA)-induced human monocytes (THP-1) and to examine the regulatory effect of natural compounds like Antcins A on SARS-CoV-2 spike protein-induced metabolic alteration. Methodology: The study used a combination of proton nuclear magnetic resonance (1H-NMR) and MetaboAnalyst 5.0 software. THP-1 cells were treated with SARS-CoV-2 spike protein or control, and the metabolomic profiles of the cells were compared. Antcin A was also added to the cells to assess its regulatory effect on SARS-CoV-2 spike protein-induced metabolic alteration. Findings: The study results showed that treatment with SARS-CoV-2 spike protein significantly altered the metabolomic profiles of THP-1 cells. Eight metabolites, including glycerol-phosphocholine, glycine, canadine, sarcosine, phosphoenolpyruvic acid, glutamine, glutamate, and N, N-dimethylglycine, were significantly different between control and spike-protein treatment groups. Antcin A significantly reversed the changes in these metabolites. In addition, treatment with antacid A significantly inhibited SARS-CoV-2 spike protein-mediated up-regulation of TLR-4 and ACE2 receptors. Theoretical Importance The findings of this study suggest that SARS-CoV-2 spike protein can cause significant metabolic alterations in THP-1 cells. Antcin A, a natural compound, has the potential to reverse these metabolic alterations and may be a potential candidate for developing preventive or therapeutic agents for COVID-19. Data Collection: The data for this study was collected from THP-1 cells that were treated with SARS-CoV-2 spike protein or a control. The metabolomic profiles of the cells were then compared using 1H-NMR and MetaboAnalyst 5.0 software. Analysis Procedures: The metabolomic profiles of the THP-1 cells were analyzed using 1H-NMR and MetaboAnalyst 5.0 software. The software was used to identify and quantify the cells' metabolites and compare the control and spike-protein treatment groups. Questions Addressed: The question addressed by this study was whether SARS-CoV-2 spike protein could cause metabolic alterations in THP-1 cells and whether Antcin A can reverse these alterations. Conclusion: The findings of this study suggest that SARS-CoV-2 spike protein can cause significant metabolic alterations in THP-1 cells. Antcin A, a natural compound, has the potential to reverse these metabolic alterations and may be a potential candidate for developing preventive or therapeutic agents for COVID-19.

Keywords: SARS-CoV-2-spike, ¹H-NMR, metabolomics, antcin-A, taiwanofungus camphoratus

Procedia PDF Downloads 71
99 Methylphenidate Use by Canadian Children and Adolescents and the Associated Adverse Reactions

Authors: Ming-Dong Wang, Abigail F. Ruby, Michelle E. Ross

Abstract:

Methylphenidate is a first-line treatment drug for attention deficit hyperactivity disorder (ADHD), a common mental health disorder in children and adolescents. Over the last several decades, the rate of children and adolescents using ADHD medication has been increasing in many countries. A recent study found that the prevalence of ADHD medication use among children aged 3-18 years increased in 13 different world regions between 2001 and 2015, where the absolute increase ranged from 0.02 to 0.26% per year. The goal of this study was to examine the use of methylphenidate in Canadian children and its associated adverse reactions. Methylphenidate use information among young Canadians aged 0-14 years was extracted from IQVIA data on prescriptions dispensed by pharmacies between April 2014 and June 2020. The adverse reaction information associated with methylphenidate use was extracted from the Canada Vigilance database for the same time period. Methylphenidate use trends were analyzed based on sex, age group (0-4 years, 5-9 years, and 10-14 years), and geographical location (province). The common classes of adverse reactions associated with methylphenidate use were sorted, and the relative risks associated with methylphenidate use as compared with two second-line amphetamine medications for ADHD were estimated. This study revealed that among Canadians aged 0-14 years, every 100 people used about 25 prescriptions (or 23,000 mg) of methylphenidate per year during the study period, and the use increased with time. Boys used almost three times more methylphenidate than girls. The amount of drug used was inversely associated with age: Canadians aged 10-14 years used nearly three times as many drugs compared to those aged 5-9 years. Seasonal methylphenidate use patterns were apparent among young Canadians, but the seasonal trends differed among the three age groups. Methylphenidate use varied from region to region, and the highest methylphenidate use was observed in Quebec, where the use of methylphenidate was at least double that of any other province. During the study period, Health Canada received 304 adverse reaction reports associated with the use of methylphenidate for Canadians aged 0-14 years. The number of adverse reaction reports received for boys was 3.5 times higher than that for girls. The three most common adverse reaction classes were psychiatric disorders, nervous system disorders and injury, poisoning procedural complications. The number one commonly reported adverse reaction for boys was aggression (11.2%), while for girls, it was a tremor (9.6%). The safety profile in terms of adverse reaction classes associated with methylphenidate use was similar to that of the selected control products. Methylphenidate is a commonly used pharmaceutical product in young Canadians, particularly in the province of Quebec. Boys used approximately three times more of this product as compared to girls. Future investigation is needed to determine what factors are associated with the observed geographic variations in Canada.

Keywords: adverse reaction risk, methylphenidate, prescription trend, use variation

Procedia PDF Downloads 160
98 Current Status and Influencing Factors of Transition Status of Newly Graduated Nurses in China: A Multi-center Cross-sectional Study

Authors: Jia Wang, Wanting Zhang, Yutong Xv, Zihan Guo, Weiguang Ma

Abstract:

Background: Before becoming qualified nurses, newly graduated nurses(NGNs) must experience a painful transition period, even transition shocks. Transition shocks are public health issues. To address the transition issue of NGNs, many programs or interventions have been developed and implemented. However, there are no studies to understand and assess the transition state of newly graduated nurses from work to life, from external abilities to internal emotions. Aims: Assess the transition status of newly graduated nurses in China. Identify the factors influencing the transition status of newly graduated nurses. Methods: The multi-center cross-sectional study design was adopted. From May 2022 to June 2023, 1261 newly graduated nurse in hospitals were surveyed online with the the Demographic Questionnaire and Transition Status Scale for Newly Graduated Nurses. SPSS 26.0 were used for data input and statistical analysis. Statistic description were adopted to evaluate the demographic characteristics and transition status of NGNs. Independent-samples T-test, Analysis of Variance and Multiple regression analysis was used to explore the influencing factors of transition status. Results: The total average score of Transition Status Scale for Newly Graduated Nurses was 4.00(SD = 0.61). Among the various dimensions of Transition Status, the highest dimension was competence for nursing work, while the lowest dimension was balance between work and life. The results showed factors influencing the transition status of NGNs include taught by senior nurses, night shift status, internship department, attribute of working hospital, province of work and residence, educational background, reasons for choosing nursing, types of hospital, and monthly income. Conclusion: At present, the transition status score of new nurses in China is relatively high, and NGNs are more likely to agree with their own transition status, especially the dimension of competence for nursing work. However, they have a poor level of excess in terms of life-work balance. Nursing managers should reasonably arrange the working hours of NGNs, promote their work-life balance, increase the salary and reward mechanism of NGNs, arrange experienced nursing mentors to teach, optimize the level of hospitals, provide suitable positions for NGNs with different educational backgrounds, pay attention to the culture shock of NGNs from other provinces, etc. Optimize human resource management by intervening in these factors that affect the transition of new nurses and promote a better transition of new nurses.

Keywords: newly graduated nurse, transition, humanistic car, nursing management, nursing practice education

Procedia PDF Downloads 85
97 Winter Wheat Yield Forecasting Using Sentinel-2 Imagery at the Early Stages

Authors: Chunhua Liao, Jinfei Wang, Bo Shan, Yang Song, Yongjun He, Taifeng Dong

Abstract:

Winter wheat is one of the main crops in Canada. Forecasting of within-field variability of yield in winter wheat at the early stages is essential for precision farming. However, the crop yield modelling based on high spatial resolution satellite data is generally affected by the lack of continuous satellite observations, resulting in reducing the generalization ability of the models and increasing the difficulty of crop yield forecasting at the early stages. In this study, the correlations between Sentinel-2 data (vegetation indices and reflectance) and yield data collected by combine harvester were investigated and a generalized multivariate linear regression (MLR) model was built and tested with data acquired in different years. It was found that the four-band reflectance (blue, green, red, near-infrared) performed better than their vegetation indices (NDVI, EVI, WDRVI and OSAVI) in wheat yield prediction. The optimum phenological stage for wheat yield prediction with highest accuracy was at the growing stages from the end of the flowering to the beginning of the filling stage. The best MLR model was therefore built to predict wheat yield before harvest using Sentinel-2 data acquired at the end of the flowering stage. Further, to improve the ability of the yield prediction at the early stages, three simple unsupervised domain adaptation (DA) methods were adopted to transform the reflectance data at the early stages to the optimum phenological stage. The winter wheat yield prediction using multiple vegetation indices showed higher accuracy than using single vegetation index. The optimum stage for winter wheat yield forecasting varied with different fields when using vegetation indices, while it was consistent when using multispectral reflectance and the optimum stage for winter wheat yield prediction was at the end of flowering stage. The average testing RMSE of the MLR model at the end of the flowering stage was 604.48 kg/ha. Near the booting stage, the average testing RMSE of yield prediction using the best MLR was reduced to 799.18 kg/ha when applying the mean matching domain adaptation approach to transform the data to the target domain (at the end of the flowering) compared to that using the original data based on the models developed at the booting stage directly (“MLR at the early stage”) (RMSE =1140.64 kg/ha). This study demonstrated that the simple mean matching (MM) performed better than other DA methods and it was found that “DA then MLR at the optimum stage” performed better than “MLR directly at the early stages” for winter wheat yield forecasting at the early stages. The results indicated that the DA had a great potential in near real-time crop yield forecasting at the early stages. This study indicated that the simple domain adaptation methods had a great potential in crop yield prediction at the early stages using remote sensing data.

Keywords: wheat yield prediction, domain adaptation, Sentinel-2, within-field scale

Procedia PDF Downloads 64
96 Biomechanical Evaluation for Minimally Invasive Lumbar Decompression: Unilateral Versus Bilateral Approaches

Authors: Yi-Hung Ho, Chih-Wei Wang, Chih-Hsien Chen, Chih-Han Chang

Abstract:

Unilateral laminotomy and bilateral laminotomies were successful decompressions methods for managing spinal stenosis that numerous studies have reported. Thus, unilateral laminotomy was rated technically much more demanding than bilateral laminotomies, whereas the bilateral laminotomies were associated with a positive benefit to reduce more complications. There were including incidental durotomy, increased radicular deficit, and epidural hematoma. However, no relative biomechanical analysis for evaluating spinal instability treated with unilateral and bilateral laminotomies. Therefore, the purpose of this study was to compare the outcomes of different decompressions methods by experimental and finite element analysis. Three porcine lumbar spines were biomechanically evaluated for their range of motion, and the results were compared following unilateral or bilateral laminotomies. The experimental protocol included flexion and extension in the following procedures: intact, unilateral, and bilateral laminotomies (L2–L5). The specimens in this study were tested in flexion (8 Nm) and extension (6 Nm) of pure moment. Spinal segment kinematic data was captured by using the motion tracking system. A 3D finite element lumbar spine model (L1-S1) containing vertebral body, discs, and ligaments were constructed. This model was used to simulate the situation of treating unilateral and bilateral laminotomies at L3-L4 and L4-L5. The bottom surface of S1 vertebral body was fully geometrically constrained in this study. A 10 Nm pure moment also applied on the top surface of L1 vertebral body to drive lumbar doing different motion, such as flexion and extension. The experimental results showed that in the flexion, the ROMs (±standard deviation) of L3–L4 were 1.35±0.23, 1.34±0.67, and 1.66±0.07 degrees of the intact, unilateral, and bilateral laminotomies, respectively. The ROMs of L4–L5 were 4.35±0.29, 4.06±0.87, and 4.2±0.32 degrees, respectively. No statistical significance was observed in these three groups (P>0.05). In the extension, the ROMs of L3–L4 were 0.89±0.16, 1.69±0.08, and 1.73±0.13 degrees, respectively. In the L4-L5, the ROMs were 1.4±0.12, 2.44±0.26, and 2.5±0.29 degrees, respectively. Significant differences were observed among all trials, except between the unilateral and bilateral laminotomy groups. At the simulation results portion, the similar results were discovered with the experiment. No significant differences were found at L4-L5 both flexion and extension in each group. Only 0.02 and 0.04 degrees variation were observed during flexion and extension between the unilateral and bilateral laminotomy groups. In conclusions, the present results by finite element analysis and experimental reveal that no significant differences were observed during flexion and extension between unilateral and bilateral laminotomies in short-term follow-up. From a biomechanical point of view, bilateral laminotomies seem to exhibit a similar stability as unilateral laminotomy. In clinical practice, the bilateral laminotomies are likely to reduce technical difficulties and prevent perioperative complications; this study proved this benefit through biomechanical analysis. The results may provide some recommendations for surgeons to make the final decision.

Keywords: unilateral laminotomy, bilateral laminotomies, spinal stenosis, finite element analysis

Procedia PDF Downloads 399
95 An Exploration of Possible Impact of Drumming on Mental Health in a Hospital Setting

Authors: Zhao Luqian, Wang Yafei

Abstract:

Participation in music activities is beneficial for enhancing wellbeing, especially for aged people (Creech, 2013). Looking at percussion group in particular, it can facilitate a sense of belonging, relaxation, energy, and productivity, learning, enhanced mood, humanising, seems of accomplishment, escape from trauma, and emotional expression (Newman, 2015). In health literatures, group drumming is effective in reducing stress and improving multiple domains of social-motional behaviors (Ho et al., 2011; Maschi et al., 2010) because it offers a creative and mutual learning space that allows patients to establish a positive peer interaction (Mungas et al., 2014; Perkins, 2016). However, very few studies have investigated the effect of group drumming from the aspect of patients’ needs. Therefore, this study focuses on the discussion of patients' specific needs within mental health and explores how group percussion may meet their needs. Seligman’s (2011) five core elements of mental health were applied as patients’ needs in this study: (1) Positive emotions; (2) Engagement; (3) Relationships; (4) Meaning and (5) Accomplishment. 12 participants aged 57- 80 years were interviewed individually. The researcher also had observation in four drumming groups simultaneously. The results reveal that group drumming could improve participants’ mental wellbeing. First, it created a therapeutic health care environment extending beyond the elimination of boredom, and patients could focus on positive emotions during the session of group drumming. Secondly, it was effective in satisfying patients’ level of engagement. Thirdly, this study found that joining a percussion group would require patients to work on skills such as turn-taking and sharing. This equal relationship is helpful for releasing patients’ negative mood and thus forming tighter relationships between and among them. Fourthly, group drumming was found to meet patients’ meaning needs through offering them a place of belonging and a place for sharing. Its leaner-oriented approach engaged patients by a sense of belonging, accepting, connecting, and ownership. Finally, group drumming could meet patients’ needs for accomplishment through the learning process. The inclusive learning process, which indicates there is no right or wrong throughout the process, allowed patients to make their own decisions. In conclusion, it is difficult for patients to achieve positive emotions, engagement, relationships, meanings, and accomplishments in a hospital setting. Drumming can be practiced for enhancement in terms of reducing patients’ negative emotions and improving their experiences in a hospital through enriched social interaction and sense of accomplishment. Also, it can help patients to enhance social skills in a controlled environment.

Keywords: group drumming, hospital, mental health, music psychology

Procedia PDF Downloads 90
94 Kinematical Analysis of Tai Chi Chuan Players during Gait and Balance Test and Implication in Rehabilitation Exercise

Authors: Bijad Alqahtani, Graham Arnold, Weijie Wang

Abstract:

Background—Tai Chi Chuan (TCC) is a type of traditional Chinese martial art and is considered a benefiting physical fitness. Advanced techniques of motion analysis have been routinely used in the clinical assessment. However, so far, little research has been done on the biomechanical assessment of TCC players in terms of gait and balance using motion analysis. Objectives—The aim of this study was to investigate whether TCC improves the lower limb conditions and balance ability using the state of the art motion analysis technologies, i.e. motion capture system, electromyography and force platform. Methods—Twenty TCC (9 male, 11 female) with age between (42-77) years old and weight (56.2-119 Kg), and eighteen Non-TCC participants (7 male, 11 female), weight (50-110 Kg) with age (43- 78) years old at the matched age as a control group were recruited in this study. Their gait and balance were collected using Vicon Nexus® to obtain the gait parameters, and kinematic parameters of hip, knee, and ankle joints in three planes of both limbs. Participants stood on force platforms to perform a single leg balance test. Then, they were asked to walk along a 10 m walkway at their comfortable speed. Participants performed 5 trials of single-leg balance for the dominant side. Also, the participants performed 3 trials of four square step balance and 10 trials of walking. From the recorded trials, three good ones were analyzed using the Vicon Plug-in-Gait model to obtain gait parameters, e.g. walking speed, cadence, stride length, and joint parameters, e.g. joint angle, force, moments, etc. Result— The temporal-spatial variables of TCC subjects were compared with the Non-TCC subjects, it was found that there was a significant difference (p < 0.05) between the groups. Moreover, it was observed that participants of TCC have significant differences in ankle, hip, and knee joints’ kinematics in the sagittal, coronal, and transverse planes such as ankle angle (19.90±19.54 deg) for TCC while (15.34±6.50 deg) for Non-TCC, and knee angle (14.96±6.40 deg) for TCC while (17.63±5.79 deg) for Non-TCC in the transverse plane. Also, the result showed that there was a significant difference between groups in the single-leg balance test, e.g. maintaining single leg stance time in the TCC participants showed longer duration (20.85±10.53 s) in compared to Non-TCC people group (13.39±8.78 s). While the result showed that there was no significant difference between groups in the four square step balance. Conclusion—Our result showed that there are significant differences between Tai Chi Chuan and Non-Tai Chi Chuan participants in the various aspects of gait analysis and balance test, as a consequence of these findings some of biomechanical parameters such as joints kinematics, gait parameters and single leg stance balance test, the Tai Chi Chuan could improve the lower limb conditions and could reduce a risk of fall for the elderly with ageing.

Keywords: gait analysis, kinematics, single leg stance, Tai Chi Chuan

Procedia PDF Downloads 127
93 The Effect of Metal-Organic Framework Pore Size to Hydrogen Generation of Ammonia Borane via Nanoconfinement

Authors: Jing-Yang Chung, Chi-Wei Liao, Jing Li, Bor Kae Chang, Cheng-Yu Wang

Abstract:

Chemical hydride ammonia borane (AB, NH3BH3) draws attentions to hydrogen energy researches for its high theoretical gravimetrical capacity (19.6 wt%). Nevertheless, the elevated AB decomposition temperatures (Td) and unwanted byproducts are main hurdles in practical application. It was reported that the byproducts and Td can be reduced with nanoconfinement technique, in which AB molecules are confined in porous materials, such as porous carbon, zeolite, metal-organic frameworks (MOFs), etc. Although nanoconfinement empirically shows effectiveness on hydrogen generation temperature reduction in AB, the theoretical mechanism is debatable. Low Td was reported in AB@IRMOF-1 (Zn4O(BDC)3, BDC = benzenedicarboxylate), where Zn atoms form closed metal clusters secondary building unit (SBU) with no exposed active sites. Other than nanosized hydride, it was also observed that catalyst addition facilitates AB decomposition in the composite of Li-catalyzed carbon CMK-3, MOF JUC-32-Y with exposed Y3+, etc. It is believed that nanosized AB is critical for lowering Td, while active sites eliminate byproducts. Nonetheless, some researchers claimed that it is the catalytic sites that are the critical factor to reduce Td, instead of the hydride size. The group physically ground AB with ZIF-8 (zeolitic imidazolate frameworks, (Zn(2-methylimidazolate)2)), and found similar reduced Td phenomenon, even though AB molecules were not ‘confined’ or forming nanoparticles by physical hand grinding. It shows the catalytic reaction, not nanoconfinement, leads to AB dehydrogenation promotion. In this research, we explored the possible criteria of hydrogen production temperature from nanoconfined AB in MOFs with different pore sizes and active sites. MOFs with metal SBU such as Zn (IRMOF), Zr (UiO), and Al (MIL-53), accompanying with various organic ligands (BDC and BPDC; BPDC = biphenyldicarboxylate) were modified with AB. Excess MOFs were used for AB size constrained in micropores estimated by revisiting Horvath-Kawazoe model. AB dissolved in methanol was added to MOFs crystalline with MOF pore volume to AB ratio 4:1, and the slurry was dried under vacuum to collect AB@MOF powders. With TPD-MS (temperature programmed desorption with mass spectroscopy), we observed Td was reduced with smaller MOF pores. For example, it was reduced from 100°C to 64°C when MOF micropore ~1 nm, while ~90°C with pore size up to 5 nm. The behavior of Td as a function of AB crystalline radius obeys thermodynamics when the Gibbs free energy of AB decomposition is zero, and no obvious correlation with metal type was observed. In conclusion, we discovered Td of AB is proportional to the reciprocal of MOF pore size, possibly stronger than the effect of active sites.

Keywords: ammonia borane, chemical hydride, metal-organic framework, nanoconfinement

Procedia PDF Downloads 186