Search results for: Jing Yang
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 889

Search results for: Jing Yang

649 The Analysis of TRACE/FRAPTRAN in the Fuel Rods of Maanshan PWR for LBLOCA

Authors: J. R. Wang, W. Y. Li, H. T. Lin, J. H. Yang, C. Shih, S. W. Chen

Abstract:

Fuel rod analysis program transient (FRAPTRAN) code was used to study the fuel rod performance during a postulated large break loss of coolant accident (LBLOCA) in Maanshan nuclear power plant (NPP). Previous transient results from thermal hydraulic code, TRACE, with the same LBLOCA scenario, were used as input boundary conditions for FRAPTRAN. The simulation results showed that the peak cladding temperatures and the fuel center line temperatures were all below the 10CFR50.46 LOCA criteria. In addition, the maximum hoop stress was 18 MPa and the oxide thickness was 0.003 mm for the present simulation cases, which are all within the safety operation ranges. The present study confirms that this analysis method, the FRAPTRAN code combined with TRACE, is an appropriate approach to predict the fuel integrity under LBLOCA with operational ECCS.

Keywords: FRAPTRAN, TRACE, LOCA, PWR

Procedia PDF Downloads 487
648 Investigation of Length Effect on Power Conversion Efficiency of Perovskite Solar Cells Composed of ZnO Nanowires

Authors: W. S. Li, S. T. Yang, H. C. Cheng

Abstract:

The power conversion efficiency (PCE) of the perovskite solar cells has been achieved by inserting vertically-aligned ZnO nanowires (NWs) between the cathode and the active layer and shows better solar cells performance. Perovskite solar cells have drawn significant attention due to the superb efficiency and low-cost fabrication process. In this experiment, ZnO nanowires are used as the electron transport layer (ETL) due to its low temperature process. The main idea of this thesis is utilizing the 3D structures of the hydrothermally-grown ZnO nanowires to increase the junction area to improve the photovoltaic performance of the perovskite solar cells. The infiltration and the surface coverage of the perovskite precursor solution changed as tuning the length of the ZnO nanowires. It is revealed that the devices with ZnO nanowires of 150 nm demonstrated the best PCE of 8.46 % under the AM 1.5G illumination (100 mW/cm2).

Keywords: hydrothermally-grown ZnO nanowires, perovskite solar cells, low temperature process, pinholes

Procedia PDF Downloads 288
647 Preparation and Characterization of Organic Silver Precursors for Conductive Ink

Authors: Wendong Yang, Changhai Wang, Valeria Arrighi

Abstract:

Low ink sintering temperature is desired for flexible electronics, as it would widen the application of the ink on temperature-sensitive substrates where the selection of silver precursor is very critical. In this paper, four types of organic silver precursors, silver carbonate, silver oxalate, silver tartrate and silver itaconate, were synthesized using an ion exchange method, firstly. Various characterization methods were employed to investigate their physical phase, chemical composition, morphologies and thermal decomposition behavior. It was found that silver oxalate had the ideal thermal property and showed the lowest decomposition temperature. An ink was then formulated by complexing the as-prepared silver oxalate with ethylenediamine in organic solvents. Results show that a favorable conductive film with a uniform surface structure consisting of silver nanoparticles and few voids could be produced from the ink at a sintering temperature of 150 °C.

Keywords: conductive ink, electrical property, film, organic silver

Procedia PDF Downloads 300
646 Using TRACE and SNAP Codes to Establish the Model of Maanshan PWR for SBO Accident

Authors: B. R. Shen, J. R. Wang, J. H. Yang, S. W. Chen, C. Shih, Y. Chiang, Y. F. Chang, Y. H. Huang

Abstract:

In this research, TRACE code with the interface code-SNAP was used to simulate and analyze the SBO (station blackout) accident which occurred in Maanshan PWR (pressurized water reactor) nuclear power plant (NPP). There are four main steps in this research. First, the SBO accident data of Maanshan NPP were collected. Second, the TRACE/SNAP model of Maanshan NPP was established by using these data. Third, this TRACE/SNAP model was used to perform the simulation and analysis of SBO accident. Finally, the simulation and analysis of SBO with mitigation equipments was performed. The analysis results of TRACE are consistent with the data of Maanshan NPP. The mitigation equipments of Maanshan can maintain the safety of Maanshan in the SBO according to the TRACE predictions.

Keywords: pressurized water reactor (PWR), TRACE, station blackout (SBO), Maanshan

Procedia PDF Downloads 166
645 On Control of Asynchronous Sequential Machines with Switching Capability

Authors: Jung-Min Yang

Abstract:

Corrective control enables us to change the stable state behavior of an asynchronous sequential machine without modifying inner logic of the machine. This paper addresses corrective control for asynchronous machines with switching capability. The considered asynchronous machine consists of a set of different submachines and switches to each machine according to a constant switching sequence. The control goal is to design a corrective controller such that the closed-loop system can match the behavior of a reference model. The reachability of the switched asynchronous machine is described by a logic calculation of the reachability of submachines. The design procedure of the proposed corrective controller is outlined, and the applicability of the proposed scheme is validated in an example.

Keywords: switched asynchronous sequential machines, corrective control, state feedback, switching sequences

Procedia PDF Downloads 424
644 Value Relevance of Accounting Information: Empirical Evidence from China

Authors: Ying Guo, Miaochan Li, David Yang, Xiao-Yan Li

Abstract:

This paper examines the relevance of accounting information to stock prices at different periods using manufacturing companies listed in China’s Growth Enterprise Market (GEM). We find that both the average stock price at fiscal year-end and the average stock price one month after fiscal year-end are more relevant to the accounting information than the closing stock price four months after fiscal year-end. This implies that Chinese stock markets react before the public disclosure of accounting information, which may be due to information leak before official announcements. Our findings confirm that accounting information is relevant to stock prices for Chinese listed manufacturing companies, which is a critical question to answer for investors who have interest in Chinese companies.

Keywords: accounting information, response time, value relevance, stock price

Procedia PDF Downloads 52
643 High Performance Electrocardiogram Steganography Based on Fast Discrete Cosine Transform

Authors: Liang-Ta Cheng, Ching-Yu Yang

Abstract:

Based on fast discrete cosine transform (FDCT), the authors present a high capacity and high perceived quality method for electrocardiogram (ECG) signal. By using a simple adjusting policy to the 1-dimentional (1-D) DCT coefficients, a large volume of secret message can be effectively embedded in an ECG host signal and be successfully extracted at the intended receiver. Simulations confirmed that the resulting perceived quality is good, while the hiding capability of the proposed method significantly outperforms that of existing techniques. In addition, our proposed method has a certain degree of robustness. Since the computational complexity is low, it is feasible for our method being employed in real-time applications.

Keywords: data hiding, ECG steganography, fast discrete cosine transform, 1-D DCT bundle, real-time applications

Procedia PDF Downloads 163
642 Static Output Feedback Control of a Two-Wheeled Inverted Pendulum Using Sliding Mode Technique

Authors: Yankun Yang, Xinggang Yan, Konstantinos Sirlantzis, Gareth Howells

Abstract:

This paper presents a static output feedback sliding mode control method to regulate a two-wheeled inverted pendulum system with considerations of matched and unmatched uncertainties. A sliding surface is designed and the associated sliding motion stability is analysed based on the reduced-order dynamics. A static output sliding mode control law is synthesised to drive the system to the sliding surface and maintain a sliding motion afterwards. The nonlinear bounds on the uncertainties are employed in the stability analysis and control design to improve the robustness. The simulation results demonstrate the effectiveness of the proposed control.

Keywords: two-wheeled inverted pendulum, output feedback sliding mode control, nonlinear systems, robotics

Procedia PDF Downloads 216
641 Fitness Action Recognition Based on MediaPipe

Authors: Zixuan Xu, Yichun Lou, Yang Song, Zihuai Lin

Abstract:

MediaPipe is an open-source machine learning computer vision framework that can be ported into a multi-platform environment, which makes it easier to use it to recognize the human activity. Based on this framework, many human recognition systems have been created, but the fundamental issue is the recognition of human behavior and posture. In this paper, two methods are proposed to recognize human gestures based on MediaPipe, the first one uses the Adaptive Boosting algorithm to recognize a series of fitness gestures, and the second one uses the Fast Dynamic Time Warping algorithm to recognize 413 continuous fitness actions. These two methods are also applicable to any human posture movement recognition.

Keywords: computer vision, MediaPipe, adaptive boosting, fast dynamic time warping

Procedia PDF Downloads 74
640 A Mixing Matrix Estimation Algorithm for Speech Signals under the Under-Determined Blind Source Separation Model

Authors: Jing Wu, Wei Lv, Yibing Li, Yuanfan You

Abstract:

The separation of speech signals has become a research hotspot in the field of signal processing in recent years. It has many applications and influences in teleconferencing, hearing aids, speech recognition of machines and so on. The sounds received are usually noisy. The issue of identifying the sounds of interest and obtaining clear sounds in such an environment becomes a problem worth exploring, that is, the problem of blind source separation. This paper focuses on the under-determined blind source separation (UBSS). Sparse component analysis is generally used for the problem of under-determined blind source separation. The method is mainly divided into two parts. Firstly, the clustering algorithm is used to estimate the mixing matrix according to the observed signals. Then the signal is separated based on the known mixing matrix. In this paper, the problem of mixing matrix estimation is studied. This paper proposes an improved algorithm to estimate the mixing matrix for speech signals in the UBSS model. The traditional potential algorithm is not accurate for the mixing matrix estimation, especially for low signal-to noise ratio (SNR).In response to this problem, this paper considers the idea of an improved potential function method to estimate the mixing matrix. The algorithm not only avoids the inuence of insufficient prior information in traditional clustering algorithm, but also improves the estimation accuracy of mixing matrix. This paper takes the mixing of four speech signals into two channels as an example. The results of simulations show that the approach in this paper not only improves the accuracy of estimation, but also applies to any mixing matrix.

Keywords: DBSCAN, potential function, speech signal, the UBSS model

Procedia PDF Downloads 103
639 PTFE Capillary-Based DNA Amplification within an Oscillatory Thermal Cycling Device

Authors: Jyh J. Chen, Fu H. Yang, Ming H. Liao

Abstract:

This study describes a capillary-based device integrated with the heating and cooling modules for polymerase chain reaction (PCR). The device consists of the reaction polytetrafluoroethylene (PTFE) capillary, the aluminum blocks, and is equipped with two cartridge heaters, a thermoelectric (TE) cooler, a fan, and some thermocouples for temperature control. The cartridge heaters are placed into the heating blocks and maintained at two different temperatures to achieve the denaturation and the extension step. Some thermocouples inserted into the capillary are used to obtain the transient temperature profiles of the reaction sample during thermal cycles. A 483-bp DNA template is amplified successfully in the designed system and the traditional thermal cycler. This work should be interesting to persons involved in the high-temperature based reactions and genomics or cell analysis.

Keywords: polymerase chain reaction, thermal cycles, capillary, TE cooler

Procedia PDF Downloads 419
638 Conscious Capitalism, Conscious Leadership, and Contemplative Management Education: Exploring Pedagogical Implications

Authors: Charlie Yang

Abstract:

The idea that business practitioners urgently need a more holistic and humanistic philosophy about the free market economy has gained some attraction among business practitioners and business professors. Those who have endorsed “conscious capitalism” as an emerging business philosophy also contended that business education should be grounded in a more positive understanding of capitalism, which enables future business leaders to have a greater impact on the world. This study is designed to critically examine the theoretical foundations of conscious capitalism and its practical and pedagogical possibilities as an emerging business movement. Based on the analysis of qualitative data collected through reflective essays written by business students, I will discuss the pedagogical and practical implications for developing conscious leadership in the context of more transformative and contemplative management education.

Keywords: conscious capitalism, conscious leadership, contemplative management education, contemplative pedagogy

Procedia PDF Downloads 36
637 Establishment of a Nomogram Prediction Model for Postpartum Hemorrhage during Vaginal Delivery

Authors: Yinglisong, Jingge Chen, Jingxuan Chen, Yan Wang, Hui Huang, Jing Zhnag, Qianqian Zhang, Zhenzhen Zhang, Ji Zhang

Abstract:

Purpose: The study aims to establish a nomogram prediction model for postpartum hemorrhage (PPH) in vaginal delivery. Patients and Methods: Clinical data were retrospectively collected from vaginal delivery patients admitted to a hospital in Zhengzhou, China, from June 1, 2022 - October 31, 2022. Univariate and multivariate logistic regression were used to filter out independent risk factors. A nomogram model was established for PPH in vaginal delivery based on the risk factors coefficient. Bootstrapping was used for internal validation. To assess discrimination and calibration, receiver operator characteristics (ROC) and calibration curves were generated in the derivation and validation groups. Results: A total of 1340 cases of vaginal delivery were enrolled, with 81 (6.04%) having PPH. Logistic regression indicated that history of uterine surgery, induction of labor, duration of first labor, neonatal weight, WBC value (during the first stage of labor), and cervical lacerations were all independent risk factors of hemorrhage (P <0.05). The area-under-curve (AUC) of ROC curves of the derivation group and the validation group were 0.817 and 0.821, respectively, indicating good discrimination. Two calibration curves showed that nomogram prediction and practical results were highly consistent (P = 0.105, P = 0.113). Conclusion: The developed individualized risk prediction nomogram model can assist midwives in recognizing and diagnosing high-risk groups of PPH and initiating early warning to reduce PPH incidence.

Keywords: vaginal delivery, postpartum hemorrhage, risk factor, nomogram

Procedia PDF Downloads 35
636 Household Choice of Working from Home before and after COVID-19

Authors: Ravipa Rojasavachai, Li Yang

Abstract:

Working from home has become a global phenomenon after the coronavirus outbreak, and most employees have a choice to choose between working from home or the office. In this paper, we examine the demographics and socio-economics factors influencing individuals’ decision to choose working from home rather than the office before and after the coronavirus outbreak based on Australian household data. We find that all factors impact the working from home choice before the coronavirus outbreak, but the number of children turns to an uninfluenced factor on individuals’ choices after the outbreak. We also find that female employees have a higher probability of choosing to work from home after the coronavirus outbreak. This is because they have less concern for their career opportunities and higher wage premium of working from home due to the changing in cultural norms and advanced working from home technologies in companies after the coronavirus outbreak.

Keywords: work from home, telework, remote working, COVID-19, pandemic, wage

Procedia PDF Downloads 64
635 Improved Performance of Cooperative Scheme in the Cellular and Broadcasting System

Authors: Hyun-Jee Yang, Bit-Na Kwon, Yong-Jun Kim, Hyoung-Kyu Song

Abstract:

In the cooperative transmission scheme, both the cellular system and broadcasting system are composed. Two cellular base stations (CBSs) communicating with a user in the cell edge use cooperative transmission scheme in the conventional scheme. In the case that the distance between two CBSs and the user is distant, the conventional scheme does not guarantee the quality of the communication because the channel condition is bad. Therefore, if the distance between CBSs and a user is distant, the performance of the conventional scheme is decreased. Also, the bad channel condition has bad effects on the performance. The proposed scheme uses two relays to communicate well with CBSs when the channel condition between CBSs and the user is poor. Using the relay in the high attenuation environment can obtain both advantages of the high bit error rate (BER) and throughput performance.

Keywords: cooperative communications, diversity gain, OFDM, interworking system

Procedia PDF Downloads 540
634 Tensile Retention Properties of Thermoplastic Starch Based Biocomposites Modified with Glutaraldehyde

Authors: Jen-Taut Yeh, Yuan-jing Hou, Li Cheng, Ya Zhou Wang, Zhi Yu Zhang

Abstract:

Tensile retention properties of bacterial cellulose (BC) reinforced thermoplastic starch (TPS) resins were successfully improved by reacting with glutaraldehyde (GA) in their gelatinization processes. Small amounts of poly (lactic acid) (PLA) were blended with GA modified TPS resins to improve their processability. As evidenced by the newly developed ether (-C-O-C-) stretching bands on FT-IR spectra of TPS100BC0.02GAx series specimens, hydroxyl groups of TPS100BC0.02 resins were successfully reacted with the aldehyde groups of GA molecules during their modification processes. The retention values of tensile strengths (σf) of TPS100BC0.02GAx and (TPS100BC0.02GAx)75PLA25 specimens improved significantly and reached a maximal value as GA contents approached an optimal value at 0.5 part per hundred parts of TPS resin (PHR). By addition of 0.5 PHR GA in biocomposite specimens, the initial tensile strength and elongation at break values of (TPS100BC0.02GA0.5)75PLA25 specimen improved to 24.6 MPa and 5.6%, respectively, which were slightly improved than those of (TPS100BC0.02)75PLA25 specimen. However, the retention values of tensile strengths of (TPS100BC0.02GA0.5)75PLA25 specimen reached around 82.5%, after placing the specimen under 20oC/50% relative humidity for 56 days, which were significantly better than those of the (TPS100BC0.02)75PLA25 specimen. In order to understand these interesting tensile retention properties found for (TPS100BC0.02GAx)75PLA25 specimens. Thermal analyses of initial and aged TPS100BC0.02, TPS100BC0.02GAx and (TPS100BC0.02GAx)75PLA25 specimens were also performed in this investigation. Possible reasons accounting for the significantly improved tensile retention properties of TPS100BC0.02GAx and (TPS100BC0.02GAx)75PLA25 specimens are proposed.

Keywords: biocomposite, strength retention, thermoplastic starch, tensile retention

Procedia PDF Downloads 341
633 Production, Characterization and In vitro Evaluation of [223Ra]RaCl2 Nanomicelles for Targeted Alpha Therapy of Osteosarcoma

Authors: Yang Yang, Luciana Magalhães Rebelo Alencar, Martha Sahylí Ortega Pijeira, Beatriz da Silva Batista, Alefe Roger Silva França, Erick Rafael Dias Rates, Ruana Cardoso Lima, Sara Gemini-Piperni, Ralph Santos-Oliveira

Abstract:

Radium-²²³ dichloride ([²²³Rₐ]RₐCl₂) is an alpha particle-emitting radiopharmaceutical currently approved for the treatment of patients with castration-resistant prostate cancer, symptomatic bone metastases, and no known visceral metastatic disease. [²²³Rₐ]RₐCl₂ is bone-seeking calcium mimetic that bonds into the newly formed bone stroma, especially osteoblastic or sclerotic metastases, killing the tumor cells by inducing DNA breaks in a potent and localized manner. Nonetheless, the successful therapy of osteosarcoma as primary bone tumors is still a challenge. Nanomicelles are colloidal nanosystems widely used in drug development to improve blood circulation time, bioavailability, and specificity of therapeutic agents, among other applications. In addition, the enhanced permeability and retention effect of the nanosystems, and the renal excretion of the nanomicelles reported in most cases so far, are very attractive to achieve selective and increased accumulation in tumor site as well as to increase the safety of [²²³Rₐ]RₐCl₂ in the clinical routine. In the present work, [²²³Rₐ]RₐCl₂ nanomicelles were produced, characterized, in vitro evaluated, and compared with pure [²²³Rₐ]RₐCl2 solution using SAOS2 osteosarcoma cells. The [²²³Rₐ]RₐCl₂ nanomicelles were prepared using the amphiphilic copolymer Pluronic F127. The dynamic light scattering analysis of freshly produced [²²³Rₐ]RₐCl₂ nanomicelles demonstrated a mean size of 129.4 nm with a polydispersity index (PDI) of 0.303. After one week stored in the refrigerator, the mean size of the [²²³Rₐ]RₐCl₂ nanomicelles increased to 169.4 with a PDI of 0.381. Atomic force microscopy analysis of [223Rₐ]RₐCl₂ nanomicelles exhibited spherical structures whose heights reach 1 µm, suggesting the filling of 127-Pluronic nanomicelles with [²²³Rₐ]RₐCl₂. The viability assay with [²²³Rₐ]RₐCl₂ nanomicelles displayed a dose-dependent response as it was observed using pure [²²³Rₐ]RₐCl2. However, at the same dose, [²²³Rₐ]RₐCl₂ nanomicelles were 20% higher efficient in killing SAOS2 cells when compared with pure [²²³Rₐ]RₐCl₂. These findings demonstrated the effectiveness of the nanosystem validating the application of nanotechnology in targeted alpha therapy with [²²³Ra]RₐCl₂. In addition, the [²²³Rₐ]RaCl₂nanomicelles may be decorated and incorporated with a great variety of agents and compounds (e.g., monoclonal antibodies, aptamers, peptides) to overcome the limited use of [²²³Ra]RₐCl₂.

Keywords: nanomicelles, osteosarcoma, radium dichloride, targeted alpha therapy

Procedia PDF Downloads 91
632 Optimization of the Control Scheme for Human Extremity Exoskeleton

Authors: Yang Li, Xiaorong Guan, Cheng Xu

Abstract:

In order to design a suitable control scheme for human extremity exoskeleton, the interaction force control scheme with traditional PI controller was presented, and the simulation study of the electromechanical system of the human extremity exoskeleton was carried out by using a MATLAB/Simulink module. By analyzing the simulation calculation results, it was shown that the traditional PI controller is not very suitable for every movement speed of human body. So, at last the fuzzy self-adaptive PI controller was presented to solve this problem. Eventually, the superiority and feasibility of the fuzzy self-adaptive PI controller was proved by the simulation results and experimental results.

Keywords: human extremity exoskeleton, interaction force control scheme, simulation study, fuzzy self-adaptive pi controller, man-machine coordinated walking, bear payload

Procedia PDF Downloads 330
631 Biotransformation of Monoterpenes by Whole Cells of Eleven Praxelis clematidea-Derived Endophytic Fungi

Authors: Daomao Yang, Qizhi Wang

Abstract:

Monoterpenoids are mainly found in plant essential oils and they are ideal substrates for biotransformation into oxygen-containing derivatives with important commercial value due to their low price and simple structure. In this paper, eleven strains of endophytic fungi from Praxelis clematidea were used as test strains to conduct the whole cell biotransformation of the monoterpenoids: (+)-limonene, (-)-limonene and myrcene. The fungi were inoculated in 50 ml Sabouraud medium and incubated at 30 ℃ with the agitation of 150 r/min for 6 d, and then 0.5% (v/v) substrates were added into the medium and biotransformed for further 3 d. Afterwards the cultures were filtered, and extracted using equal volume of ethyl acetate. The metabolites were analyzed by GC-MS technique with NIST database. The Total Ion Chromatogram of the extractions from the eleven strains showed that the main product of (+)- and (-)-limonene biotransformation was limonene-1,2-diol, while it is limonene and linalool oxide for biotransformation of myrcene. This work will help screen the microorganisms to biotransform the monoterpenes.

Keywords: endophytic fungi, (+)–limonene, (-)–limonene, myrcene

Procedia PDF Downloads 96
630 Simulation and Optimization of an Annular Methanol Reformer

Authors: Shu-Bo Yang, Wei Wu, Yuan-Heng Liu

Abstract:

This research aims to design a heat-exchanger type of methanol reformer coupled with a preheating design in gPROMS® environment. The endothermic methanol steam reforming reaction (MSR) and the exothermic preferential oxidation reaction (PROX) occur in the inner tube and the outer tube of the reformer, respectively. The effective heat transfer manner between the inner and outer tubes is investigated. It is verified that the countercurrent-flow type reformer provides the higher hydrogen yield than the cocurrent-flow type. Since the hot spot temperature appears in the outer tube, an improved scheme is proposed to suppress the hot spot temperature by splitting the excess air flowing into two sites. Finally, an optimization algorithm for maximizing the hydrogen yield is employed to determine optimal operating conditions.

Keywords: methanol reformer, methanol steam reforming, optimization, simulation

Procedia PDF Downloads 304
629 Microfluidic Synthesis of Chlorophyll Extraction–Loaded PCL Composite Microparticles Developed as Health Food

Authors: Ching-Ju Hsiao, Mao-Chen Huang, Pei-Fan Chen, Ruo-Yun Chung, Jiun-Hua Chou, Chih-Hui Yang, Keng-Shiang Huang, Jei-Fu Shaw

Abstract:

Chlorophyll has many benefits for human body. It is known to improve the health of the circulatory, digestive, immune and detoxification systems of the body. However, Chl can’t be preserved at the environment of high temperature and light exposure for a long time due to it is chemical structure is easily degradable. This characteristic causes that human body is difficult to absorb Chl effective components. In order to solve this problem, we utilize polycaprolactone (PCL) polymer encapsulation technology to increase the stability of Chl. In particular, we also established a microfluidic platform provide the control of composite beads diameter. The new composite beads is potential to be a health food. Result show that Chl effective components via the microfludic platform can be encapsulated effectively and still preserve its effective components.

Keywords: chlorophyll, PCL, PVA, microfluidic

Procedia PDF Downloads 520
628 Students' Perception of Using Dental E-Models in an Inquiry-Based Curriculum

Authors: Yanqi Yang, Chongshan Liao, Cheuk Hin Ho, Susan Bridges

Abstract:

Aim: To investigate student’s perceptions of using e-models in an inquiry-based curriculum. Approach: 52 second-year dental students completed a pre- and post-test questionnaire relating to their perceptions of e-models and their use in inquiry-based learning. The pre-test occurred prior to any learning with e-models. The follow-up survey was conducted after one year's experience of using e-models. Results: There was no significant difference between the two sets of questionnaires regarding student’s perceptions of the usefulness of e-models and their willingness to use e-models in future inquiry-based learning. Most of the students preferred using both plaster models and e-models in tandem. Conclusion: Students did not change their attitude towards e-models and most of them agreed or were neutral that e-models are useful in inquiry-based learning. Whilst recognizing the utility of 3D models for learning, student's preference for combining these with solid models has implications for the development of haptic sensibility in an operative discipline.

Keywords: e-models, inquiry-based curriculum, education, questionnaire

Procedia PDF Downloads 396
627 An Atomic Finite Element Model for Mechanical Properties of Graphene Sheets

Authors: Win-Jin Chang, Haw-Long Lee, Yu-Ching Yang

Abstract:

In this study, we use the atomic-scale finite element method to investigate the mechanical behavior of the armchair- and zigzag-structured nanoporous graphene sheets with the clamped-free-free-free boundary condition under tension and shear loadings. The effect of porosity on Young’s modulus and shear modulus of nanoporous graphene sheets is obvious. For the armchair- and zigzag-structured nanoporous graphene sheets, Young’s modulus and shear modulus decreases with increasing porosity. Young’s modulus and shear modulus of zigzag graphene are larger than that of armchair one for the same porosity. The results are useful for application in the design of nanoporous graphene sheets.

Keywords: graphene, nanoporous, Young's modulus, shear modulus

Procedia PDF Downloads 366
626 Continuous Synthesis of Nickel Nanoparticles by Hydrazine Reduction

Authors: Yong-Su Jo, Seung-Min Yang, Seok Hong Min, Tae Kwon Ha

Abstract:

The synthesis of nickel nanoparticles by the reduction of nickel chloride with hydrazine in an aqueous solution. The effect of hydrazine concentration on batch-processed particle characteristics was investigated using Field Emission Scanning Electron Microscopy (FESEM). Both average particle size and geometric standard deviation (GSD) were decreasing with increasing hydrazine concentration. The continuous synthesis of nickel nanoparticles by microemulsion method was also studied using FESEM and X-ray Diffraction (XRD). The average size and geometric standard deviation of continuous-processed particles were 87.4 nm and 1.16, respectively. X-ray diffraction revealed continuous-processed particles were pure nickel crystalline with a face-centered cubic (fcc) structure.

Keywords: nanoparticle, hydrazine reduction, continuous process, microemulsion method

Procedia PDF Downloads 419
625 From “Deafness” to “Aphasia”: A Study of Social Retreat of Families With Hearing-Impaired Children. Interviews with 12 Mothers of Hearing-Impaired Children in Beijing

Authors: Yang Jiayue, Liang Junwen

Abstract:

Case interviews with 12 mothers of hearing-impaired children in Beijing found that families with hard-of-hearing children make all-out efforts for rescue and rehabilitation until they exhaust family resources, they travel to work places, homes, and rehabilitation institutions every day, and social relations gradually shrink inward. In the stigmatized social environment, children with hearing impairment find it difficult to integrate into regular communication and gradually return to a silent world; their parents also suffer from social discrimination and affiliate stigma, and they gradually reduce contact with others. Finally, families with hearing-impaired children become invisible people in society; the "deafness" of children leads families to "loss of voice."

Keywords: family with hearing-impaired children, social retreat, social exclusion, stigma

Procedia PDF Downloads 42
624 Development of Zero-Cement Binder Activated by Carbonation

Authors: Young Cheol Choi, Eun-Jin Moon, Sung-Won Yoo, Sang-Hwa Jung, In-Hwan Yang

Abstract:

Stainless steel slag (STS) is a by-product generated from the stainless steel refining process. The recycling of STS produced in Korea for construction applications is limited due to its poor hydraulic properties. On the other hand, STS has high carbonation reactivity to CO2 as it contains gamma-C2S content. This material is ideal for mineral carbonation which is one of the techniques proposed for carbon emission reduction. The objective of this study is to investigate the feasibility of developing a zero-cement STS binder activated by carbonation as alternative cementitious material. The quantitative analyses for CO2 uptake of STS powder and STS blended cement were investigated using thermogravimetric analysis (TGA), X-ray diffraction (XRD). In addition, the compressive strength and microstructure of STS pastes after CO2 curing were evaluated. Test results showed that STS can be activated by carbonation to gain a sufficient strength as alternative cementitious material.

Keywords: gamma-C2S, CO2 uptake, carbonation, stainless steel slag

Procedia PDF Downloads 438
623 Evaluation of Durability Performance for Bio-Energy Co-Product

Authors: Bo Yang, Hali̇l Ceylan, Ali Ulvi̇ Uzer

Abstract:

This experimental study was performed to investigate the effect of biofuel co-products (BCPs) with sulfur-free lignin addition on the unconsolidated on strength and durability behavior in pavement soil stabilization subjected to freezing–thawing cycles. For strength behavior, a series of unconfined compression tests were conducted. Mass losses were also calculated after freezing–thawing cycles as criteria for durability behavior. To investigate the effect of the biofuel co-products on the durability behavior of the four type’s soils, mass losses were calculated after 12 freezing–thawing cycles. The co-products tested are promising additives for improving durability under freeze-thaw conditions, and each type has specific advantages.

Keywords: durability, mass lose, freezing–thawing test, bio-energy co-product, soil stabilization

Procedia PDF Downloads 337
622 Mathematical Model of a Compound Gear Pump

Authors: Hsueh-Cheng Yang

Abstract:

The generation and design of compound involute spur gearings can be used in gear pump. A compound rack cutter with asymmetric involute teeth is presented for determining the mathematical model of compound gear pumps. This paper covers the following topics: (a) generation and geometry of compound rack cutter is presented and used to generate a compound gear and a compound pinion. (b) Based on the developed compound gears, stress analysis was performed for the symmetric gears and the asymmetric gears. Comparing the results of the stress analysis for the asymmetric involute teeth is superior to the symmetric involute teeth. A numerical example that illustrates the developed compound rack cutter is represented.

Keywords: compound, involute teeth, gear pump, rack cutter

Procedia PDF Downloads 340
621 Removal of Na₂SO₄ by Electro-Confinement on Nanoporous Carbon Membrane

Authors: Jing Ma, Guotong Qin

Abstract:

We reported electro-confinement desalination (ECMD), a desalination method combining electric field effects and confinement effects using nanoporous carbon membranes as electrode. A carbon membrane with average pore size of 8.3 nm was prepared by organic sol-gel method. The precursor of support was prepared by curing porous phenol resin tube. Resorcinol-formaldehyde sol was coated on porous tubular resin support. The membrane was obtained by carbonisation of coated support. A well-combined top layer with the thickness of 35 μm was supported by macroporous support. Measurements of molecular weight cut-off using polyethylene glycol showed the average pore size of 8.3 nm. High salt rejection can be achieved because the water molecules need not overcome high energy barriers in confined space, while huge inherent dehydration energy was required for hydrated ions to enter the nanochannels. Additionally, carbon membrane with additional electric field can be used as an integrated membrane electrode combining the effects of confinement and electric potential gradient. Such membrane electrode can repel co-ions and attract counter-ions using pressure as the driving force for mass transport. When the carbon membrane was set as cathode, the rejection of SO₄²⁻ was 94.89%, while the removal of Na⁺ was less than 20%. We set carbon membrane as anode chamber to treat the effluent water from the cathode chamber. The rejection of SO₄²⁻ and Na⁺ reached to 100% and 88.86%, respectively. ECMD will be a promising energy efficient method for salt rejection.

Keywords: nanoporous carbon membrane, confined effect, electric field, desalination, membrane reactor

Procedia PDF Downloads 101
620 Distributing Complementary Food Supplement - Yingyangbao Reducing the Anemia in Young Children in a County of Sichuan Province after Wenchuan Earthquake

Authors: Lijuan Wang, Junsheng Huo, Jing Sun, Wenxian Li, Jian Huang, Lin Ling, Yiping Zhou, Chengyu Huang, Jifang Hu

Abstract:

Backgrounds and Objective: This study aimed to evaluate the impact of highly nutrient-dense complementary food supplement-Yingyangbao, at the time of 3 months after Wenchuan earthquake, on the anemia of young children in a county in Sichuan province. Methods: The young children aged 6-23 months in the county were fed one sachet Yingyangbao per day. Yingyangbao were distributed for 15 months for free. The children entering 6 months age would be included. The length, weight and hemoglobin of the children aged 6-29 months were assessed at baseline (n=257) and Yingyangbao intervention for 6 (n=218) and 15 months (n=253) by cluster sampling. Growth status has not been described in the paper. The analysis was conducted based on 6-11, 12-17, 18-23 and 24-29 months. Results: It showed that the hemoglobin concentration in each group among the 4 groups increased by 4.9, 6.4, 8.0, 9.5 g/L after 6 months and 12.7, 11.4, 16.7, 15.7 g/L after 15 months compared to the baseline, respectively. The total anemia prevalence in each group was significantly lower after 6 and 15 months than the baseline (P<0.001), except the 6-11 months group after 6 months because of fewer Yingyangbao consumption. Total moderate anemia rate decreased from 18.3% to 5.5% after 6 months, and kept decreasing to 0.8% after another 9 months. The hemoglobin concentration was significantly correlated with the amount of Yingyangbao consumption(P<0.001) The anemia rate was significantly different based on the Yingyangbao compliance (P<0.001). Conclusion: It was concluded that Yingyangbao which contains quality protein, vitamins and micronutrients intervened 15 months could be effective for the improvement of anemia of young children. The study provides the support that the application of the complementary food supplements to reduce the anemia of young children in the emergency of natural disaster.

Keywords: young children, anemia, nutrition intervention, complementary food supplements, Yingyangbao

Procedia PDF Downloads 493