Search results for: Rebecca Zeng

Authors: Linlin Wang, Guangdong Bian, Jifeng Shen, Jingzhu Zeng

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Zinc-aluminum alloys have been applied as alternatives to bronze, aluminum alloys, and cast iron due to their distinguishing features such as high as-cast strength, excellent bearing properties, as well as low energy requirements for melting. In this study, oxide coatings were produced on ZA27 zinc-aluminum alloy by a plasma electrolytic oxidation (PEO) method. Three coatings were deposited by using three various electrolytes, i.e. silicate, aluminate and aluminate/borate composite solutions. The current density is set at 0.1A/cm2, deposition time is 40 mins for all the deposition processes. The surface morphology and phase structure of the three coatings were characterized by scanning electron microscopy （SEM） and X-ray diffraction (XRD). Pin-on-disc sliding wear tests were conducted to test the tribological properties of coatings. The results indicated that the coating produced using the aluminate/borate composite electrolyte had the highest deposition rate and best wear resistance among the three coatings.

Keywords: oxide coating, PEO, tribological properties, ZA27

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Authors: Irene Ludji

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This article discusses the relevance of the sanctuary movement in relation to the idea of solidarity understood through the lens of ethics. There are three parts of this article. First is the investigation on the background of sanctuary movements in the U.S., the UK, and Canada. The repeated theme behind sanctuary movements includes practicing religious traditions, protecting vulnerable life, and challenging the unjust law. Second is the examination of the ethics of solidarity using Thomas D. Williams, who claims it as the extension of responsible love based on respect towards human dignity, and Rebecca Todd Peters, who claims the ethics of solidarity as the transformative ethic rooted in social justice. Third is the analysis of the connection between the central theme of sanctuary movements and the ethics of solidarity. This article concludes that sanctuary movement is indeed a solidarity movement that remains relevant in our world today because the acknowledgment of human dignity, as the basis for solidarity, is vital in transforming an unjust social system that creates the need for a sanctuary in the first place.

Keywords: sanctuary movement, solidarity, ethics, U.S., UK, canada

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Authors: Huiwu Yu, Xiangyou Li, Xiaoyan Zeng

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Porous spheres have been widely used in many fields due to their attractive features. In this work, an approach for fabricating porous spheres of nanoparticles was presented, in which the nanoparticles were welded together to form micro spheres by simply irradiating the nanoparticles in liquid medium by a picosecond laser. As an example, anatase titanium dioxide was chosen as a typical material on account of its metastability. The structure and morphologies of the products were characterised by X-ray diffraction (XRD), scanning electron microscope (SEM), Raman, and high-resolution transmission electron microscopy (HRTEM), respectively. The results showed that, anatase titanium dioxide micro spheres (2-10 μm) with macroporous (10-100 nm) were prepared from nano-anatase titanium dioxide nanoparticles (10-100 nm). The formation process of polycrystalline anatase titanium dioxide microspheres was investigated with different liquid mediums and the input laser fluences. Thus, this facile laser irradiation approach might provide a way for the fabrication of porous microspheres without phase-transition.

Keywords: titanium dioxide, porous microspheres, picosecond laser, nano-welding

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Authors: Ji Chen, Chunhui Zhang, Fanming Zeng, Lei Zhang, Ying Li, Wei Zhang

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Based on the synthetic principle of force, a pre-compressed nonlinear isolator with quasi-zero-stiffness (QZS) is developed for shock isolation of ship equipment. The proposed isolator consists of a vertical spring with positive stiffness and several lateral springs with negative stiffness. An analytical expression of vertical stiffness of the nonlinear isolator is derived and numerical simulation on the effect of the geometric design parameters is carried out. Besides, a pre-compressed QZS shock isolation system model is established. The stiffness characteristic of the system is studied and the effects of excitation amplitude and friction damping on shock isolation performance are discussed respectively. The research results show that in comparison with linear shock isolation system, the pre-compressed QZS shock isolation system could realize constant-force or approximately constant-force function and perform better anti-impact performance.

Keywords: quasi-zero-stiffness, constant-force, pre-compressed, large deformation, shock isolation, friction damping

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Authors: Michael Koblischka, Anjela Koblischka-Veneva, XianLin Zeng, Essia Hannachi, Yassine Slimani

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Superconducting foams of YBa2Cu3O7 (abbreviated Y-123) were produced using the infiltration growth (IG) technique from Y2BaCuO5 (Y-211) foams. The samples were investigated by SEM (scanning electron microscopy) and electrical resistivity measurements. SEM observations indicated the specific microstructure of the foam struts with numerous tiny Y-211 particles (50-100 nm diameter) embedded in channel-like structures between the Y-123 grains. The investigation of the excess conductivity of different prepared composites was analyzed using Aslamazov-Larkin (AL) model. The investigated samples comprised of five distinct fluctuation regimes, namely short-wave (SWF), one-dimensional (1D), two-dimensional (2D), three-dimensional (3D), and critical (CR) fluctuations regimes. The coherence length along the c-axis at zero-temperature (ξc(0)), lower and upper critical magnetic fields (Bc1 and Bc2), critical current density (Jc) and numerous other superconducting parameters were estimated from the data. The analysis reveals that the presence of the tiny Y-211 particles alters the excess conductivity and the fluctuation behavior observed in standard YBCO samples.

Keywords: Excess conductivity, Foam, Microstructure, Superconductor YBa2Cu3Oy

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Authors: Youhang Zhou, Weimin Zeng, Qi Xie

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Abstract: In order to solve the wear recognition problem of the machine tool guide surface, a new machine tool guide surface recognition method based on the radar-graph barycentre feature is presented in this paper. Firstly, the gray mean value, skewness, projection variance, flat degrees and kurtosis features of the guide surface image data are defined as primary characteristics. Secondly, data Visualization technology based on radar graph is used. The visual barycentre graphical feature is demonstrated based on the radar plot of multi-dimensional data. Thirdly, a classifier based on the support vector machine technology is used, the radar-graph barycentre feature and wear original feature are put into the classifier separately for classification and comparative analysis of classification and experiment results. The calculation and experimental results show that the method based on the radar-graph barycentre feature can detect the guide surface effectively.

Keywords: guide surface, wear defects, feature extraction, data visualization

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Authors: Yan Zeng, Li Tao, Liujun Han, Tianye Zhang, Yongan Yu, Kaijun Ma, Long Chen

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Mechanical asphyxia is one of the main cause of death; however, death by mechanical asphyxia may be difficult to prove in court, particularly in cases in which corpses exhibit no obvious signs of asphyxia. To identify a credible biomarker of asphyxia, we first examined the expression levels of all the mRNAs in human cardiac tissue specimens subjected to mechanical asphyxia and compared these expression levels with those of the corresponding mRNAs in specimens subjected to craniocerebral injury. A total of 119 differentially expressed mRNAs were selected and the expression levels of these mRNAs were examined in 44 human cardiac tissue specimens subjected to mechanical asphyxia, craniocerebral injury, hemorrhagic shock and other causes of death. We found that DUSP1 and KCNJ2 were up-regulated in tissue specimens of mechanical asphyxia compared with control tissues, with no significant correlation between age, environmental temperature and PMI, indicating that DUSP1 and KCNJ2 may associate with mechanical asphyxia-induced death and can thus serve as useful biomarkers of death by mechanical asphyxia.

Keywords: mechanical asphyxia, biomarkers, DUSP1, KCNJ2, cardiac tissue

Procedia PDF Downloads 267

Authors: Rebecca Rumbul

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The operation of the state can often appear opaque to citizens wishing to access official information, who have to negotiate a path through numerous levels of bureaucracy rationalized through institutional policy to acquire what information they want. Even where individual states have 'Right to Information' legislation guaranteeing citizen access to information, public sector conformity to such laws vary between states and between state organizations. In response to such difficulties in bringing citizens and information together, many NGO's around the world have begun designing and hosting digital portals to facilitate the requesting and receiving of official information. How then, are these 'civic technology' tools affecting the behavior of the state? Are they increasing the transparency of the state? This study looked at 5 Right to Information civic technology sites in Chile, Uruguay, Ukraine, Hungary and the UK, and found that such sites were providing a useful platform to publish official information, but that states were still reluctant to comply with all requests. It concludes that civic technology can be an important tool in increasing the transparency of the state, but that the state must have an institutional commitment to information rights for this to be fully effective.

Keywords: digital, ICT, transparency, civic technology

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Authors: Rubaiyea Uddin, Rebecca Taylor, Emily Levesque

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The hippocampus, located in the limbic system, is most commonly known for its role in memory and spatial navigation (as cited in Brain Reward and Pathways). It maintains an especially important role in specifically episodic and declarative memory. The hippocampus has also recently been linked to dopamine, the reward pathway’s primary neurotransmitter. Since research has found that dopamine also contributes to memory consolidation and hippocampal plasticity, this neurotransmitter is potentially responsible for contributing to the hippocampus’s role in memory formation. In this experiment we tested to see the effect of tactile cues on spatial navigation for eight different mice. We used a radial arm that had one designated “reward” arm containing sucrose. The presence or absence of bedding was our tactile cue. We attempted to see if the memory of that cue would enhance the mice’s memory of having received the reward in that arm. The results from our study showed there was no significant response from the use of tactile cues on spatial navigation on our 129 mice. Tactile cues therefore do not influence spatial navigation.

Keywords: mice, radial arm maze, memory, spatial navigation, tactile cues, hippocampus, reward, sensory skills, Alzheimer's, neuro-degenerative diseases

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Authors: Katie Jerram, Jacqui Nevols, Rebecca Howes, Hayley Richardson, Debbie Suso, Thomas Batten, Reny Mathai

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Pyomyositis is an uncommon acute purulent skeletal muscle infection, usually caused by Staphylococcus aureus, occurring either spontaneously or following local trauma. Immunocompromise is a risk factor. It presents with pyrexia, pain, and tenderness of the affected muscle, which may have a firm ‘woody’ feel. Management usually involves surgery and prolonged courses of antibiotics, but alongside these active treatments, palliation of symptoms such as pain is also a priority. A short case series of diabetic inpatients under the care of the Renal Medicine team with pyomyositis is presented, demonstrating that Hospital Palliative Care Teams may be well placed to provide symptom management advice by working jointly with the patient’s medical or surgical team. A review of the literature on the management of pain in pyomyositis is also presented, and there was no clear consensus on the best strategy. It may be that a combination of analgesics and adjuncts is the most effective strategy, perhaps combined with the holistic approach used within palliative care.

Keywords: pyomyositis, pain, palliation, analgesia

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Authors: Chin-Yuan Hsieh, Wei-Chun Lu, Yu-Hong Zeng

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The situation of a group of fish die is frequently found due to the fish disease caused by the deterioration of aquaculture water quality. The toxic ammonia is produced by animals as a byproduct of protein. The system is designed by the smart sensor technology and developed by the mathematical model to monitor the water parameters 24 hours a day and predict the relationship among twelve water quality parameters for monitoring the water quality in aquaculture. All data measured are stored in cloud server. In productive ponds, the daytime pH may be high enough to be lethal to the fish. The sudden change of the aquaculture conditions often results in the increase of PH value of water, lack of oxygen dissolving content, water quality deterioration and yield reduction. From the real measurement, the system can send the message to user’s smartphone successfully on the bad conditions of water quality. From the data comparisons between measurement and model simulation in fish aquaculture site, the difference of parameters is less than 2% and the correlation coefficient is at least 98.34%. The solubility rate of oxygen decreases exponentially with the elevation of water temperature. The correlation coefficient is 98.98%.

Keywords: aquaculture, sensor, ammonia, dissolved oxygen

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Authors: Cheng Zeng, Xia Luo

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Passenger organization has always been an essential part of China's metro operation and management. Facing the massive passenger flow, stations need to improve their intelligence and automation degree by an appropriate integrated system. Based on the existing integrated supervisory control system (ISCS) and simulation software (Anylogic), this paper designs an intelligent passenger organization system (IPOS) for metro stations. Its primary function includes passenger information acquisition, data processing and computing, visualization management, decision recommendations, and decision response based on interlocking equipment. For this purpose, the logical structure and intelligent algorithms employed are particularly devised. Besides, the structure diagram of information acquisition and application module, the application of Anylogic, the case library's function process are all given by this research. Based on the secondary development of Anylogic and existing technologies like video recognition, the IPOS is supposed to improve the response speed and address capacity in the face of emergent passenger flow of metro stations.

Keywords: anylogic software, decision-making support system, intellectualization, ISCS, passenger organization

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Authors: Tao Yin, Zeqiang Zhang, Wei Liang, Yanqing Zeng, Yu Zhang

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To accelerate the remanufacturing process of electronic waste products, this study designs a partial disassembly line with the multi-robotic station to effectively dispose of excessive wastes. The multi-robotic partial disassembly line is a technical upgrade to the existing manual disassembly line. Balancing optimization can make the disassembly line smoother and more efficient. For partial disassembly line balancing with the multi-robotic station (PDLBMRS), a mixed-integer programming model (MIPM) considering the robotic efficiency differences is established to minimize cycle time, energy consumption and hazard index and to calculate their optimal global values. Besides, an enhanced NSGA-II algorithm (HNSGA-II) is proposed to optimize PDLBMRS efficiently. Finally, MIPM and HNSGA-II are applied to an actual mixed disassembly case of two types of computers, the comparison of the results solved by GUROBI and HNSGA-II verifies the correctness of the model and excellent performance of the algorithm, and the obtained Pareto solution set provides multiple options for decision-makers.

Keywords: waste disposal, disassembly line balancing, multi-robot station, robotic efficiency difference, HNSGA-II

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Authors: Kim Quy Le, Duan Fei, Jia Wei Chew, Jun Zeng, Maria Fabiola Leyva

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In line with the sustainable development goal, molded fiber products play important roles in reducing plastic-based packaging. To fabricate molded fiber products, besides using conventional meshing tools, 3D printing is employed to manufacture the molded fiber screen. 3D printing technique allows printing molded fiber screens with complex geometry, flexible in pore size and shape. The 3D printed molded fiber screens are in the progress of investigation to improve the de-watering efficiency, fiber collection, mechanical strength, etc. In addition, the fiber distribution on the screen is also necessary to access the quality of the screen. Besides using experimental methods to capture the fiber distribution on screen, simulation also offers using tools to access the uniformity of fiber. In this study, the fiber was simulated using the multi-sphere model to simulate the fibers. The interaction of the fibers was able to mimic by employing the discrete element method. The fiber distribution was captured and compared to the experiment. The simulation results were able to reveal the fiber deposition layer upon layer and explain the formation of uneven thickness on the tilted area of molded fiber screen.

Keywords: 3D printing, multi-jet fusion, molded fiber screen, discrete element method

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Authors: Zhang Tianci, Ding Meng, Zuo Hongfu, Zeng Lina, Sun Zejun

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Automation of airport operations can greatly improve ground movement efficiency. In this paper, we study the speed profile design problem for advanced airport ground movement control and guidance. The problem is constrained by the surface four-dimensional trajectory generated in taxi planning. A decomposed approach of two stages is presented to solve this problem efficiently. In the first stage, speeds are allocated at control points which ensure smooth speed profiles can be found later. In the second stage, detailed speed profiles of each taxi interval are generated according to the allocated control point speeds with the objective of minimizing the overall fuel consumption. We present a swarm intelligence based algorithm for the first-stage problem and a discrete variable driven enumeration method for the second-stage problem since it only has a small set of discrete variables. Experimental results demonstrate the presented methodology performs well on real world speed profile design problems.

Keywords: airport ground movement, fuel consumption, particle swarm optimization, smoothness, speed profile design

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Authors: Tobias Stephan Kaeding, Rebecca Schwarz, Momme Kück, Lothar Stein

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Introduction: The goal of this randomized and controlled study is to examine whether whole-body vibration (WBV) training is able to reduce self-reported physical disability in office employees with chronic low-back pain. Materials and methods: 41 subjects (68.3% female/mean age 45.5 ± 9.1 years/mean BMI 26.6 ± 5.2) were randomly allocated to an intervention group (INT (n= 21)) or a control group (CON (n=20). The INT participated in WBV training 2.5 times per week for 3 months. The primary outcome was the change in the Roland and Morris disability questionnaire (RMQ) score over the study period. In addition, secondary outcomes included changes in the Oswestry Disability Index (ODI). Results: The compliance with the intervention in the INT reached a mean of 81.1% ± 31.2% with no long-lasting unwanted side effects. We found significant positive effects of 3 months of WBV training in the INT compared to the CON regarding the RMQ (p=0.027) and the ODI (p=0.002). Conclusions: WBV training seems to be an effective, safe and suitable intervention for the reduction of the self-reported physical disability in seated working employees with chronic low-back pain.

Keywords: back pain, exercise, occupational health management, vibration training

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Authors: Radhika S. Oke, Rebecca S. Thombre

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Medicinal plants and herbs have a great history of their utility as remedy for treatment of variety of ailments. Secondary metabolites present in these plants are responsible for their medicinal activity. In the present investigation, phytochemical screening of aqueous and alcoholic leaf extract of Anethum graveolens L. was performed. Total phenolic content and total antioxidant activity of the extracts was quantitatively estimated by Folin-Ciocalteau method and DPPH (1, 1-Diphenyl-2-picryl hydrazyl) method respectively. Qualitative tests suggested that Alkaloids, tannins and phenolic compounds were present in all the extracts of the plant. Aqueous extracts was found to have more phytochemicals as compared to alcoholic extracts. Extract of Anethum graveolens L. was found to contain good amount phenolics and exhibited antioxidant activity. The extracts also demonstrated potent antimicrobial activity against selected gram positive and negative bacteria. The study revealed the potential application of Anethum graveolens L. (Dill) in medicine and health.

Keywords: Anethum graveolens L., antioxidant, antimicrobial activity, medicine and health

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Authors: Cam Minh Tri Tien, Richard Fenrich, Tristan Shelley, Nam Mai-Duy, Allan Malano, Xuesen Zeng

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Since additive manufacturing is a layer-by-layer deposition approach, good bonding quality between adjacent layers is critically important to achieve optimal mechanical performance, including applications in pressure vessels. The need to enhance the strength of printed products, especially in the build direction where layup gaps and voids exist between the printed layers, has garnered significant attention. The proposed research will focus on improving the current Fused Deposition Modelling (FDM) process to produce polymers reinforced with chopped fibers, utilizing a controlled heat zone to enhance the adhesion between printed layers. Energy will be applied to both printed and printing layers to improve the bonding strength between adjacent layers. Through the enhanced FDM process, the mechanical performance of composite parts will experience a substantial improvement, particularly in the build direction, as compared to current FDM methods. A combination of experimental, numerical, and analytical methods will be employed to demonstrate the enhanced performance of heat-controlled 3D printed parts.

Keywords: 3D Printing, pressure vessels, interlayer bonding, controlled heat

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Authors: Joseph Ignagni, Rebecca Deen

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This paper analyzes the extent to which the U.S. Supreme Court votes to support the position of the United States in cases where the government is a party to the litigation. This study considers the relationship between the Solicitor General’s Office and the U.S. Supreme Court. The Solicitor General has the unique position of being the representative of the Executive Branch and the U.S. government before the Supreme Court. While a great deal of research has looked at the Solicitor General’s success as a “friend of the court,” far less has considered this relationship when the U.S. is a direct party in the litigation. This paper investigates the success rate of the Solicitor General’s Office in these cases. We find that there is considerable variation in the U.S. government’s success rate before the Court depending on the issue, Supreme Court leadership, the ideological direction of the Court and whether the U.S. approached the Court as a petitioner or respondent. We conduct our analysis on the Court’s decisions from 1953-2009. This study adds to our understanding of checks and balances, separation of powers, and inter-institutional relationships between the branches of the federal government of the United States.

Keywords: U.S. president, solicitor general, U.S. Supreme Court, separation of power, checks and balances

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Authors: P. S. Jagadeesh Kumar, Tracy Lin Huan, Rebecca K. Rossi, Yanmin Yuan, Xianpei Li

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The fiscal growth of any country hinges on the prudent administration of water resources. The river Yamuna and Ganga are measured as the life line of India as it affords the needs for life to endure. Earth observation over remote sensing images permits the precise description and identification of ingredients on the superficial from space and airborne platforms. Multiple and heterogeneous image sources are accessible for the same geographical section; multispectral, hyperspectral, radar, multitemporal, and multiangular images. In this paper, a taxonomical learning of the fluvial geomorphological features of river Yamuna and Ganga over doon valley using color fusion of multispectral remote sensing images was performed. Experimental results exhibited that the segmentation based colorization technique stranded on pattern recognition, and color mapping fashioned more colorful and truthful colorized images for geomorphological feature extraction.

Keywords: color fusion, geomorphology, fluvial processes, multispectral images, pattern recognition

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Authors: Rebecca Owusu Coffie, Atakelty Hailu

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Variants of production frontier models have emerged, however, only a limited number of them are applied in empirical research. Hence the effects of these alternative frontier models are not well understood, particularly within sub-Saharan Africa. In this paper, we apply recent advances in the production frontier to examine levels of technical efficiency and efficiency drivers. Specifically, we compare the heteroscedastic parametric and the semiparametric stochastic smooth coefficient (SPSC) models. Using rice production data from Ghana, our empirical estimates reveal that alternative specification of efficiency estimators results in either downward or upward bias in the technical efficiency estimates. Methodologically, we find that the SPSC model is more suitable and generates high-efficiency estimates. Within the parametric framework, we find that parameterization of both the mean and variance of the pre-truncated function is the best model. For the drivers of technical efficiency, we observed that longer farm distances increase inefficiency through a reduction in labor productivity. High soil quality, however, increases productivity through increased land productivity.

Keywords: pre-truncated, rice production, smooth coefficient, technical efficiency

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Authors: Liuhui Zhu, Peng Zeng

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The rural revitalization strategy means to take the country and the city on the same level, and achieve urban-rural integration and comprehensive development of rural areas. Beijing-Tianjin-Hebei rural areas have always been the weak links in the region, with prominently uneven development between urban and rural areas. The rural areas need to join the overall regional synergy. Based on the analysis of the characteristics and problems of rural development in the region from the perspective of production-living-ecology space, the paper proposes the township as the basic unit for rural revitalization according to the overall requirements of the rural revitalization strategy. The basic unit helps to realize resource arrangement, functional organization, and collaborative governance organized by the production-living-ecology spatial network. The paper summarizes the planning strategies for the basic unit. Through spatial cognition and spatial reconstruction, the three space is networked through the base, nodes, and connections to improve the comprehensive value of rural areas and achieve the multiple goals of rural revitalization.

Keywords: rural revitalization, Beijing-Tianjin-Hebei region, township level, production-living-ecology spatial network

Procedia PDF Downloads 172

Authors: Pawasuth Saengdee, Chamras Promptmas, Ting Zeng, Silke Leimkühler, Ulla Wollenberger

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Sulfite has been used as a versatile preservative to limit the microbial growth and to control the taste in some food and beverage. However, it has been reported to cause a wide spectrum of severe adverse reactions. Therefore, it is important to determine the amount of sulfite in food and beverage to ensure consumer safety. An efficient electrocatalytic biosensor for sulfite detection was developed by immobilizing of human sulfite oxidase (hSO) on 3-aminoproplytriethoxysilane (APTES) modified indium tin oxide (ITO) electrode. Cyclic voltammetry was employed to investigate the electrochemical characteristics of the hSO modified ITO electrode for various pretreatment and binding conditions. Amperometry was also utilized to demonstrate the current responses of the sulfite sensor toward sodium sulfite in an aqueous solution at a potential of 0 V (vs. Ag/AgCl 1 M KCl). The proposed sulfite sensor has a linear range between 0.5 to 2 mM with a correlation coefficient 0.972. Then, the additional polymer layer of PVA was introduced to extend the linear range of sulfite sensor and protect the enzyme. The linear range of sulfite sensor with 5% coverage increases from 2.8 to 20 mM at a correlation coefficient of 0.983. In addition, the stability of sulfite sensor with 5% PVA coverage increases until 14 days when kept in 0.5 mM Tris-buffer, pH 7.0 at 4 8C. Therefore, this sensor could be applied for the detection of sulfite in the real sample, especially in food and beverage.

Keywords: sulfite oxidase, bioelectrocatalytsis, indium tin oxide, direct electrochemistry, sulfite sensor

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Authors: Rebecca Thombre, Aishwarya Borate

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Chemical synthesis of nanoparticles produces toxic by-products, as a result of which eco-friendly methods of synthesis are gaining importance. The synthesis of nanoparticles using plant derived extracts is economical, safe and eco-friendly. Biostabilized gold nanoparticles were synthesized using extracts of Garcinia indica. The gold nanoparticles were characterized using UV-Vis spectrophotometry and demonstrated a peak at 527 nm. The presence of plant derived peptides and phytoconstituents was confirmed using the FTIR spectra. TEM analysis revealed formation of gold nanopyramids and nanorods. The SAED analysis confirmed the crystalline nature of nanoparticles. The gold nanoparticles demonstrated antibacterial and antifungal activity against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Aspergillus niger and Pichia pastoris. The cytotoxic activity of gold nanoparticles was studied using HEK, Hela and L929 cancerous cell lines and the apoptosis of cancerous cells were observed using propidium iodide staining. Thus, a simple and eco-friendly method for synthesis of biostabilized gold nanoparticles using fruit extracts of Garcinia indica was developed and the nanoparticles had potent antibacterial, antifungal and anticancer properties.

Keywords: cytotoxic, gold nanoparticles, green synthesis, Garcinia indica, anticancer

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Authors: Xiaolin Zeng, Lei Cheng, Zhirong Li, Xueping Liu

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Aiming at the problem of low accuracy and susceptibility to cultural relic diseases in the generation of high-resolution archaeology drawings by current image generation algorithms, an archaeology drawings generation algorithm based on a conditional generative adversarial network is proposed. An attention mechanism is added into the high-resolution image generation network as the backbone network, which enhances the line feature extraction capability and improves the accuracy of line drawing generation. A dual-branch parallel architecture consisting of two backbone networks is implemented, where the semantic translation branch extracts semantic features from orthophotographs of cultural relics, and the gradient screening branch extracts effective gradient features. Finally, the fusion fine-tuning module combines these two types of features to achieve the generation of high-quality and high-resolution archaeology drawings. Experimental results on the self-constructed archaeology drawings dataset of grotto temple statues show that the proposed algorithm outperforms current mainstream image generation algorithms in terms of pixel accuracy (PA), structural similarity (SSIM), and peak signal-to-noise ratio (PSNR) and can be used to assist in drawing archaeology drawings.

Keywords: archaeology drawings, digital heritage, image generation, deep learning

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Authors: Yan Cheng, Yijun Shao, James Rudolph, Charlene R. Weir, Beth Sahlmann, Qing Zeng-Treitler

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Supervised predictive models require labeled data for training purposes. Complete and accurate labeled data, i.e., a ‘gold standard’, is not always available, and imperfectly labeled data may need to serve as an alternative. An important question is if the accuracy of the labeled data creates a performance ceiling for the trained model. In this study, we trained several models to recognize the presence of delirium in clinical documents using data with annotations that are not completely accurate (i.e., weakly-supervised learning). In the external evaluation, the support vector machine model with a linear kernel performed best, achieving an area under the curve of 89.3% and accuracy of 88%, surpassing the 80% accuracy of the training sample. We then generated a set of simulated data and carried out a series of experiments which demonstrated that models trained on imperfect data can (but do not always) outperform the accuracy of the training data, e.g., the area under the curve for some models is higher than 80% when trained on the data with an error rate of 40%. Our experiments also showed that the error resistance of linear modeling is associated with larger sample size, error type, and linearity of the data (all p-values < 0.001). In conclusion, this study sheds light on the usefulness of imperfect data in clinical research via weakly-supervised learning.

Keywords: weakly-supervised learning, support vector machine, prediction, delirium, simulation

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Authors: Hua-Shan Tai, Yu-Ting Zeng

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In modern and industrial society, enormous amounts of sludge from various of industries are constantly produced; currently, most of the sludge are treated by landfill and incineration. However, both treatments are not ideal because of the limited land for landfill and the secondary pollution caused by incineration. Consequently, treating industrial sludge appropriately has become an urgent issue of environmental protection. In order to solve the problem of the massive sludge, this study uses textile sludge which is the major source of waste sludge in Taiwan as raw material for torrefaction treatments. To investigate the feasibility of producing biofuels from textile sludge by torrefaction, the experiments were conducted with temperatures at 150, 200, 250, 300, and 350°C, with heating rates of 15, 20, 25 and 30°C/min, and with residence time of 30 and 60 minutes. The results revealed that the mass yields after torrefaction were approximately in the range of 54.9 to 93.4%. The energy densification ratios were approximately in the range of 0.84 to 1.10, and the energy yields were approximately in the range of 45.9 to 98.3%. The volumetric densities were approximately in the range of 0.78 to 1.14, and the volumetric energy densities were approximately in the range of 0.65 to 1.18. To sum up, the optimum energy yield (98.3%) can be reached with terminal temperature at 150 °C, heating rate of 20°C/min, and residence time of 30 minutes, and the mass yield, energy densification ratio as well as volumetric energy density were 92.2%, 1.07, and 1.15, respectively. These results indicated that the solid products after torrefaction are easy to preserve, which not only enhance the quality of the product, but also achieve the purpose of developing the material into fuel.

Keywords: biofuel, biomass energy, textile sludge, torrefaction

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Authors: J. Alcisto, M. Papakyriakou, J. Guerra, A. Dominguez, M. Miller, J. Foyos, E. Jones, N. Ula, M. Hahn, L. Zeng, Y. Li, O. S. Es-Said

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Current methods of testing for hydrogen charging are slow and time consuming. The objective of this paper was to determine if hydrogen charging can be detected quantitatively through the use of Charpy Impact (CI) testing. CI is a much faster and simpler process than current methods for detecting hydrogen charging. Steel plates were Electro Discharge Machined (EDM) into ninety-six 4340 steel CI samples and forty-eight tensile bars. All the samples were heat treated at 900°C to austentite and then rapidly quenched in water to form martensite. The samples were tempered at eight different target strengths/target temperatures (145, 160, 170, 180, 190, 205, 220, to 250KSI, thousands of pounds per square inch)/(1100, 1013, 956, 898, 840, 754, 667, 494 degrees Celsius). After a tedious process of grinding and machining v-notches to the Charpy samples, they were divided into four groups. One group was kept as received baseline for comparison while the other three groups were sent to Alcoa (Fasteners) Inc. in Torrance to be cadmium coated. The three groups were coated with three thicknesses (2, 3 and 5 mils). That means that the samples were charged with ascending hydrogen levels. The samples were CI tested and tensile tested, and the data was tabulated and compared to the baseline group of uncharged samples of the same material. The results of this study were successful and indicated that CI testing was able to quantitatively detect hydrogen charging.

Keywords: Charpy impact toughness, hydrogen charging, 4340 steel, Electro Discharge Machined (EDM)

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Authors: Shuo Tian, Xuepiao Bai, Jianqin Shang, Pengtao Gai, Yuansong Zeng

Abstract:

Shot peen forming is an essential forming process for aircraft metal wing panel. With the development of computer simulation technology, scholars have proposed a numerical simulation method of shot peen forming based on stress field. Three shot peen forming indexes of crater diameter, shot speed and surface coverage are required as simulation parameters in the stress field method. It is necessary to establish the relationship between simulation and experimental process parameters in order to simulate the deformation under different shot peen forming parameters. The shot peen forming tests of the 2024-T351 aluminum alloy workpieces were carried out using uniform test design method, and three factors of air pressure, feed rate and shot flow were selected. The second-order response surface model between simulation parameters and uniform test factors was established by stepwise regression method using MATLAB software according to the results. The response surface model was combined with the stress field method to simulate the shot peen forming deformation of the workpiece. Compared with the experimental results, the simulated values were smaller than the corresponding test values, the maximum and average errors were 14.8% and 9%, respectively.

Keywords: shot peen forming, process parameter, response surface model, numerical simulation

Procedia PDF Downloads 57

Authors: Ahmed Al-Mansour, Qiang Zeng

Abstract:

Recycling waste plastics in the form of concrete components, i.e. fine aggregates, has been an attractive topic among the society of civil engineers. Not only does the recycling of plastics reduce the overall cost of concrete production, but it also takes part in solving environmental issues. Nevertheless, the incorporation of recycled plastics into concrete results in an increasing reduction in the mechanical properties of concrete as the percentage of replacement of natural aggregates increases. In order to overcome this reduction, Ethylene-vinyl acetate (EVA) was used as an additive in concrete with recycled plastic aggregates. The aim of this additive is to: 1) increase the interfacial interaction at the interfacial transition zone (ITZ) between plastic pellets and cement matrix, and 2) mitigate the loss in mechanical properties. Three different groups of samples (i.e. cubes and prisms) were tested according to the plastics substituting fine aggregates. 5, 10, and 15% of fine aggregates were substituted for recycled plastic pellets, and 2 – 4% of the cement was substituted for EVA that produces a flexible agent when mixed properly with water. Compressive and tensile strength tests were conducted for the mechanical properties, while SEM and X-CT scan were implemented for further investigation of calcium-silicate-hydrate (C–S–H) formation and ITZ analysis. The optimal amount of plastic particles with EVA is suggested to get the most compact and dense matrix structure according to the results of this study.

Keywords: the durability of concrete, ethylene-vinyl acetate (EVA), interfacial transition zone (ITZ), recycled plastics

Procedia PDF Downloads 159