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Thermodynamics and kinetic analysis of carbon nanofibers as nanozymes. 碳纳米纤维作为纳米酶的热力学和动力学分析。
IF 4.9 Q1 Engineering Pub Date : 2019-07-16 eCollection Date: 2019-01-01 DOI: 10.2147/NSA.S208310
Maziar Bahreini, Monireh Movahedi, Maryam Peyvandi, Fereshteh Nematollahi, Hessam Sepasi Tehrani

Purpose: Evaluation of structural features, thermodynamics and kinetic properties of carbon nanofibers (CNFs) as artificial nanoscale enzymes (nanozyme).

Methods: Synthesis of CNFs was done using chemical vapor deposition, and transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM) and energy-dispersive x-ray spectroscopy (EDX) were used to provide information on the morphology, elemental monitoring and impurity assay of the CNFs. The thermal features of the CNFs were evaluated using differential thermal analysis (DTA), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) derivative and TGA. The calculated thermo-physical parameters were melting temperature (Tm), weight loss maximum temperature (Tmax ) and enthalpy of fusion (ΔHfusion ). Catalytic activity was assayed by a 4-aminoantypyrine (4-AAP)-H2O2 coupled colorimetric system by UV-visible spectroscopy.

Results: FE-SEM and TEM analysis demonstrated parallel graphitic layers and uniformity of atomic orientation and morphology. The EDX spectra approved carbon element as major signal and presence of partial Ti as impurities of CNFs during CVD process. The DTA thermogram showed the endothermic process had a maximum temperature of 82.27°C at -15.48 mV and that thermal decomposition occurred at about 200°C. The TGA-differential gravimetric analysis thermogram showed that Tmax was 700°C. The DSC heat flow curve showed a melting temperature (Tm) of 254.52°C, ΔHfusion of 3.84 J^.g-1, area under the curve of 58.58 mJ and Te (onset) and Tf (end set) temperatures of 246.60°C and 285.67°C, respectively. The peroxidase activity of the CNFs obeyed the Michaelis-Menten equation with a double-reciprocal curve and the calculated Km, Kcat and Vmax kinetic parameters.

Conclusion: CNFs as peroxidase nanozymes are intrinsically strong and stable nanocatalysts under difficult thermal conditions. The peroxidase activity was demonstrated, making these CNFs candidates for analytical tools under extreme conditions.

目的:评价碳纳米纤维(CNFs)作为人工纳米酶(nanozyme)的结构特征、热力学和动力学性能。方法:采用化学气相沉积和透射电子显微镜(TEM)合成CNFs,利用场发射扫描电子显微镜(FE-SEM)和能谱仪(EDX)对CNFs的形貌、元素监测和杂质分析进行了研究。使用差热分析(DTA)、差示扫描量热法(DSC)、热重分析(TGA)衍生物和TGA对CNFs的热特性进行了评估。计算的热物理参数为熔融温度(Tm)、失重最高温度(Tmax)和熔融焓(ΔHfusion)。采用4-氨基安替吡啉(4-AAP)-H2O2偶联比色体系,用紫外-可见光谱法测定催化活性。结果:FE-SEM和TEM分析表明,石墨层平行,原子取向和形貌均匀。EDX光谱证实碳元素是CVD过程中的主要信号,部分Ti作为CNFs的杂质存在。DTA热谱图显示,吸热过程在-15.48mV时的最高温度为82.27°C,热分解发生在约200°C。TGA差示重量分析热谱图显示Tmax为700°C。DSC热流曲线显示熔融温度(Tm)为254.52°C,ΔHfusion为3.84 J^.g-1,曲线下面积为58.58 mJ,Te(起始)和Tf(终凝)温度分别为246.60°C和285.67°C。CNFs的过氧化物酶活性服从具有双倒数曲线的Michaelis-Menten方程以及计算的Km、Kcat和Vmax动力学参数。结论:CNFs作为过氧化物酶纳米酶,在高温条件下是一种本质上强而稳定的纳米催化剂。过氧化物酶活性得到了证明,使这些CNFs成为极端条件下分析工具的候选者。
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引用次数: 7
Synthesis, characterization, and in vitro evaluation of novel polymer-coated magnetic nanoparticles for controlled delivery of doxorubicin [Retraction]. 新型高分子包裹磁性纳米颗粒的合成、表征和体外评价,用于控制阿霉素的递送[撤回]。
IF 4.9 Q1 Engineering Pub Date : 2019-04-01 eCollection Date: 2019-01-01 DOI: 10.2147/NSA.S207535

[This retracts the article DOI: 10.2147/NSA.S24328.].

[本文撤回文章DOI: 10.2147/NSA.S24328.]。
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引用次数: 2
Fabrication of Polyaniline-Zr(IV) Molybdophosphate as a Nanocomposite and its Potential Applications 聚苯胺-磷酸钼锆纳米复合材料的制备及其应用前景
IF 4.9 Q1 Engineering Pub Date : 2018-12-30 DOI: 10.33425/2639-9466.1008
Bushra R, K. M.A, Sakdapipanich J.T
Electrically conductive composite material PANIZr(IV) molybdophosphate (PZMP) was synthesized, via treatment of Zr(IV) molybdophosphate with PANI(polyaniline) gel. The membrane of this material is fabricated for detection of mercury in waste samples. By using 4-in-line-probe the conducting behaviour of the material was determined, and it was found that conductivity of the nanocomposite lies in the range of semiconductors. The composite showed improved electrochemical properties and outstanding biological activities.
采用聚苯胺凝胶对磷酸钼锆(IV)进行处理,合成了导电复合材料PANIZr(IV)钼磷酸盐(PZMP)。这种材料的膜是用来检测废物样品中的汞的。利用4-in-line探针测定了材料的导电性能,发现纳米复合材料的电导率在半导体范围内。该复合材料具有良好的电化学性能和良好的生物活性。
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引用次数: 3
FEM Analysis for Burring Process of Large Diameter SUS304 Tube 大直径SUS304管毛刺过程有限元分析
IF 4.9 Q1 Engineering Pub Date : 2018-12-30 DOI: 10.33425/2639-9466.1011
J. Ichikawa, S. Nishida, Yuta Kashitani, Kentaro Tsunoda, Yuto Horigome, Naoki Ikeda, Y. Sato
T paper describes a finite element method (FEM) analysis for cold burring process of large diameter SUS304 pipe. The large diameter pipes such as 216.3 mm are used for a plant as a flow channel of gas and liquid. A burring process of pipe is generally for forming the branch. Burring molding is one of the typical molding techniques for branch pipes. The burring process is achieved by drawing of die from prepared hole. And the branch pipes are generally joined by welding. However this process has some problem. First, the burring process is depending on the forming limit of pipe. Second, the wall thickness and strain distribution of formed branch edge is unequal. These problem is caused the pre-hole shape. It generally has difficulty to determine the optimum pre-hole shape. Many try and error is needed. In this study, we proposed that the method of estimation for optimum pre-hole shape of mother pipe by finite element method analysis. The nominal diameter of mother pipe is 200A. And the target nominal diameter of branch pipe is 100A. The diameter is 114.3 mm, and the wall thickness is 3.0 mm. And target burring wall height is 10 mm with uniformly wall height around the edge. The height 10 mm means that is not needed the machining after burring process and is easy to weld to join the branch pipe to mother pipe. Initial pre-hole shape of analysis model is simple circle. After FEM analysis, the height of burring position was measured. Then the diameters of longitudinal direction and circumferential direction was adjusted. After optimum diameter of both direction diameter was determined, the diameter of 45 °direction was analyzed by using point tracking function to estimate of initial optimum diameter. Eventually, the burring formed shape had an uniform 10 mm height. It was clarified that the method of estimation for optimum pre-hole was effective. Junshi Ichikawa et al., Res. Rev. J Mat. Sci. 2018, Volume 6 DOI: 10.4172/2321-6212-C3-020
本文介绍了大直径SUS304管冷刺过程的有限元分析方法。如216.3 mm的大直径管道用于工厂作为气体和液体的流动通道。管道的毛刺加工通常是为了形成分支。毛刺成型是分支管的典型成型工艺之一。毛刺过程是通过从准备好的孔中拉出模具来实现的。支管一般采用焊接连接。然而,这一过程存在一些问题。首先,毛刺过程取决于管材的成形极限。其次,成形分支边缘的壁厚和应变分布不均匀。这些问题都是由孔前形状引起的。一般来说,确定最佳预孔形状比较困难。许多尝试和错误是需要的。在本研究中,我们提出了用有限元法分析估算母管最佳预孔形状的方法。母管公称直径为200A。支管目标公称通径为100A。直径114.3 mm,壁厚3.0 mm。目标毛刺壁高为10mm,边缘壁高均匀。10毫米的高度意味着在毛刺加工后不需要加工,并且易于焊接将支管连接到母管。分析模型的初始预孔形状为简单的圆形。通过有限元分析,测量毛刺位置的高度。然后对纵向和周向直径进行了调整。在确定了两个方向的最优直径后,利用点跟踪函数对45°方向的直径进行分析,估计初始最优直径。最终形成的毛刺形状具有均匀的10mm高度。验证了最佳预孔估算方法的有效性。Junshi Ichikawa等,Res. Rev. J Mat. Sci. 2018, vol . 6 DOI: 10.4172/2321-6212-C3-020
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引用次数: 0
The Effects of Microalloying Elements and Temperaging Treatments Parameters on Nb-V Containing Cast Microalloyed Steels 微合金化元素及回火处理参数对含Nb-V铸造微合金钢的影响
IF 4.9 Q1 Engineering Pub Date : 2018-12-30 DOI: 10.33425/2639-9466.1009
E. F., R. J., Najafidejdehmonfared H
Electrically conductive composite material PANIZr(IV) molybdophosphate (PZMP) was synthesized, via treatment of Zr(IV) molybdophosphate with PANI (polyaniline) gel. The membrane of this material is fabricated for detection of mercury in waste samples. By using 4-in-line-probe the conducting behaviour of the material was determined, and it was found that conductivity of the nanocomposite lies in the range of semiconductors. The composite showed In this study, base composition without alloying elements and three microalloyed steels containing 0.08% wt V, 0.06% wt Nb and 0.06% wt Nb-0.1% wt V in induction furnace, in controlled condition, were casted. Temperaging were carried out on all of specimens for precipitation strengthening. For studying the influence of temperaging time and temperature, specimens with different chemical compositions were temperaged at 400,500,600 and 700 °C for 1,3 and 5 h. All of specimens in as-cast condition were studied using optical microscope and hardness tester. Results showed that as-cast specimens having ferrito-pearlitic microstructures. Nb-bearing specimens shows acicular microstructures. The heat treated samples were studied using Electron Microscope Analysis and hardness tester. Studying of mechanical properties of heat treated specimens, showed that because of precipitation strengthening, hardness of samples increased. By increasing of temperaging temperature in a constant time, hardness has an optimum value. Material To study the effects of microalloying additions and cooling rate on the microstructural and mechanical properties, three heats were produced in the form of 8Cm ×8Cm ×20Cm and 8Cm ×3Cm ×20Cm blocks. The chemical composition of these heats is shown in Table 1. Samle C Mn Si P S V Nb N Base 0.15 1.5 0.3 0.01 0.015 0.01 V 0.15 1.5 0.3 0.01 0.015 0.1 0.01 Nb 0.15 1.5 0.3 0.009 0.011 0.04 0.01 Nb-V 0.15 1.5 0.3 0.009 0.012 0.1 0.04 0.01 Table 1: Chemical compositions of alloys studied (weight %). The alloy designations in Table 1 show the main alloying elements in the heats. The base composition for all heats is 0.15 wt% carbon and 1.5 wt% Mn. Ferroniobium was added to some heats to raise the Nb level to 0.04 wt%. Furthermore, sulfur plus phosphorus levels ranged from 0.02 to 0.035 for all heats. Experimental results To assess the effects of microalloying additions on the mechanical properties, tensile, hardness and Charpy impact tests were conducted for each composition. In order to avoid scattering, three samples were prepared for each test. Optical microscopy and scanning electron microscopy were used for justifying the variation in the mechanical properties. Samples of each heat were optically examined at magnifications ranging from 100 to 1000 times in order to observe major phases and their distributions. Moreover, pearlite volume fraction was determined quantitatively using an image analyzer. Scanning electron microscopy was used for more detailed study of pearlite. Optical microscopy The optical
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引用次数: 1
Horizontal Twin Roll Strip Casting of Aluminum Alloy A7075 A7075铝合金水平双辊带材铸造
IF 4.9 Q1 Engineering Pub Date : 2018-12-30 DOI: 10.33425/2639-9466.1014
Yuta Kashitani, S. Nishida, J. Ichikawa, Kentaro Tsunoda, Yuto Horigome, Y. Nitta, Hideto Harada
Twin roll strip casting of aluminum alloy A7075 using commercial scale machine was operated. Twin roll casting process is able to produce a strip from molten metal directly. Thus this process has a possibility to reduce total cost of sheet making comparing to conventional rolling process. Strip casting process has some disadvantages. Casting speed depends on the material properties. It is difficult to determine the casting conditions. Aluminum alloy A7075 has high tensile strength, and it is known as a material for aerospace application. The sheet is manufactured in small quantities comparing to the other sheet aluminum alloy. It is supposed that the demand of high tensile strength aluminum sheet such as A7075 is going to increase for weight saving of structural material. The aims of this study are to investigate the effect of roll speed on the strip. Strip could not be produced continuously at roll speed of 10 m/min, so the load limit of this experimental apparatus was exceeded. However, a good strip without cracks was produced. Continuous strip was produced at a roll speed of 20 m/min. The strip was consisted of a mat part and a metallic luster part. However, cracks were observed in the white mat part of the board. Continuous strip was produced at a roll speed of 30 m/min. However, rolling cracks were observed at the edges of the strip. It is necessary to control the solidification distance by installing the nozzle.
对A7075铝合金双辊带坯连铸进行了试验研究。双辊连铸工艺能够直接从熔融金属中生产带钢。因此,与传统的轧制工艺相比,该工艺有可能降低板材制造的总成本。带钢连铸工艺有一些缺点。铸造速度取决于材料的性能。铸造条件很难确定。铝合金A7075具有较高的抗拉强度,被誉为航空航天应用的材料。与其他铝合金板材相比,这种板材的生产数量很少。预计由于结构材料的轻量化,对A7075等高抗拉强度铝板的需求将会增加。本研究的目的是探讨轧辊速度对带钢的影响。在10 m/min的轧制速度下不能连续生产带材,超过了本实验装置的负荷极限。但是,生产出了无裂纹的良好带钢。以20 m/min的辊速生产连续带材。这条由一个垫子部分和一个金属光泽部分组成。然而,在板的白色垫部分观察到裂纹。以30 m/min的辊速生产连续带材。但在带钢边缘出现了轧制裂纹。需要通过安装喷嘴来控制凝固距离。
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引用次数: 1
Cold Plastic Forming of ABS Plastic Pipe ABS塑料管的冷塑性成形
IF 4.9 Q1 Engineering Pub Date : 2018-12-30 DOI: 10.33425/2639-9466.1012
Kentaro Tsunoda, S. Nishida, J. Ichikawa, Yuta Kashitani, Yuto Horigome, Naoki Ikeda, Hideto Harada, Nobuyuki Kamei
This paper describes about cold plastic forming of ABS plastic pipe. Experiment and Finite element method (FEM) analysis of pipe expansion process were operated. The application of ABS plastic pipe for air conditioner is under consideration instead of metal pipe in Japan because of weight saving of air conditioner for lowering the gravity point against earthquake. The parts of ABS plastic pipe is generally produced by injection molding. The processes need the cooling time, and it takes much time. In addition, expensive mold die is needed for each application. Thus, cold plastic forming of ABS plastic pipe was proposed. The cold plastic forming of ABS plastic pipe chosen for this study is hardly studied by other authors. Product ability of cold plastic forming is higher than the injection molding or hot working. And the punch and die shape is simple comparing to these process. In this study, pipe expansion process was operated. The ABS plastic pipe has a 10 mm diameter and 8mm inner diameter and 1 mm thickness. At first, true stress and true strain curves at any strain rate were measured by ring compression test. Obtained flow stresses was used to FEM analysis. Experimental device for pipe expansion process was made by Dip Inc.. Objective inner diameter was 10 mm. FEM analysis was operated to clarify the deformation behavior such as load-stroke diagram. It was possible to produce the expanded ABS pipe. The whitening of worked pipe and strain recovery was observed. Analysis result was indicated the good agreement comparing to experimental result in load-stroke diagram.
介绍了ABS塑料管的冷塑性成形工艺。对管道膨胀过程进行了实验和有限元分析。日本正在考虑用ABS塑料管代替金属管用于空调,因为空调可以减轻重量,降低地震重力点。ABS塑料管的零件一般采用注射成型的方式生产。这个过程需要冷却时间,而且需要很长时间。此外,每种应用都需要昂贵的模具。为此,提出了ABS塑料管的冷塑性成形方法。本研究选用的ABS塑料管的冷塑性成形技术是其他作者很少研究的。冷塑性成形的产品性能高于注塑或热加工。与这些工艺相比,冲模形状简单。本研究采用管道膨胀工艺。ABS塑料管直径10mm,内径8mm,厚度1mm。首先,通过环压缩试验测量任意应变速率下的真应力和真应变曲线。将得到的流变应力用于有限元分析。管道膨胀过程实验装置由Dip公司研制。物镜内径10 mm。通过有限元分析,明确了载荷-行程图等变形行为。生产膨胀ABS管是可能的。观察了加工管的白化和应变恢复情况。载荷-行程图的分析结果与实验结果吻合较好。
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引用次数: 0
Smart Materials and Structures: State of the Art and Applications 智能材料与结构:技术现状与应用
IF 4.9 Q1 Engineering Pub Date : 2018-10-31 DOI: 10.21767/2471-9838.100034
N. Ghareeb, M. Farhat
Abstract The world of materials is an exciting and challenging field of research since it has always played a dominant role in the evolution of human civilization. The demands from aerospace, defence, automotive and industrial branches on more advanced and innovative materials has led to the development of a new generation of materials with much better performance and capabilities than the existing conventional structural and functional materials. As a result, the era of smart materials has started. Smart materials can change their physical properties in response to a specific stimulus input. However, there is still a blurry image over the types and potential applications of smart materials. The objective of this paper is to define the field of smart materials and structures, together with its current status and potential benefits. However, more focus will be devoted to piezoelectric materials and results are presented and discussed. Finally, and in order to demonstrate the characteristics of one class of smart materials, two numerical examples are proposed and results are presented.
材料世界是一个令人兴奋和具有挑战性的研究领域,因为它一直在人类文明的进化中起着主导作用。航空航天、国防、汽车和工业部门对更先进和创新材料的需求导致了新一代材料的发展,这些材料的性能和能力远远优于现有的传统结构和功能材料。因此,智能材料的时代已经开始。智能材料可以根据特定的刺激输入改变其物理特性。然而,人们对智能材料的类型和潜在应用仍有一个模糊的认识。本文的目的是定义智能材料和结构领域,以及它的现状和潜在的好处。然而,更多的焦点将放在压电材料和结果提出和讨论。最后,为了说明一类智能材料的特性,给出了两个数值算例并给出了结果。
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引用次数: 6
Chemical Bonding Character of Love Herbal Medicine: A Prominent Medicine Candidate for Preventing HIV Virus 爱情草药的化学键特性:预防HIV病毒的重要候选药物
IF 4.9 Q1 Engineering Pub Date : 2018-06-30 DOI: 10.33425/2639-9466.1003
Arend L. Mapanawang, Hendry. I. Elim
Anti-oxidant with a very high concentration of IC50 = 6.54 ng/ml extracted from zingiberaceae fruit (Halmahera Golobe) had made this local fruit a very good candidate for improving human health. Based on this finding, a medicine named as love herbal had been fabricated with a multitasking healing in human body problems. In order to analyze the physical working system of this medicine, one investigated the optical properties of it by using chemical bonding spectroscopy method. We obtain that such medicine has optical uniqueness behaviors contributed by 4 main types of chemical bonds named as N-H (Bending) at 1562 cm-1, C=C at 1697 cm-1, C C at 2070 cm-1, and C-H at 3013 cm-1 which might be closely in conjunction with multitasking healing of human body problems, for example in improving antibody protection of human body from cancer deceases, viruses problems, and the health of heart and liver. Such finding was then tested for handling HIV virus as a result with a new discovery that such virus can be reduced dramatically from ~8 million virus to be just about ~8000 virus as the concentration of the medicine increased.
从姜科水果中提取的抗氧化剂浓度极高,IC50 = 6.54 ng/ml,使姜科水果成为改善人体健康的良好选择。基于这一发现,一种名为“爱情草药”的药物被制造出来,具有多任务治疗人体问题的功效。为了分析该药的物理作用体系,采用化学键谱法对其光学性质进行了研究。我们发现这种药物具有光学唯一性行为,这是由4种主要的化学键贡献的,分别是1562 cm-1的N-H(弯曲),1697 cm-1的C=C, 2070 cm-1的C- C和3013 cm-1的C- h,这可能与人体问题的多任务治疗密切相关,例如提高人体对癌症,病毒问题的抗体保护,以及心脏和肝脏的健康。将这一发现用于处理HIV病毒,结果发现,随着药物浓度的增加,HIV病毒可以从800万左右急剧减少到8000左右。
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引用次数: 16
Preparation, Characterization and In-Vivo Antiplasmodial Activity of Magnesium Oxide Nanoparticles on Plasmodium Berghei Infected Mice 氧化镁纳米颗粒制备、表征及对伯氏疟原虫感染小鼠体内抗疟原虫活性研究
IF 4.9 Q1 Engineering Pub Date : 2018-06-30 DOI: 10.33425/2639-9466.1002
Hadiza Am, Taura Dw, B. Muhammad
Magnesium oxide (MgO) nanoparticles were synthesized and assayed for antiplasmodial activity in vivo. MgO nanoparticles were synthesized using sol-gel process and characterized using SEM, FTIR AND UV-VIS spectral study to confirm the formation and size of the nanoparticles. 20% of LD50 value was used to formulate a graded dose of 300, 200 and 100mg/kg. Then 30 mice were group into 5 containing six mice each and were inoculated with 0.2ml of ANKA strain of plasmodium berghei intraperitoneally and were left for the next 7 days before treatment with the graded doses based on their body weight.20/120mg/kg standard dose of Artemether lumefantrine was use as positive control while negative control were given no treatment at all. Data were analyses using mean percentage parasite clearance rate, analysis of variance (ANOVA) and Tukey honestly significant difference test. MgO nanoparticles showed a remarkable clearance rate of 98.8% just after 24hours of administration and at the end of the four day curative model all the parasites were cleared from the blood. There was statistically significant difference between groups as determine by oneway ANOVA F (3,16) =24.30,p=3.36E-06. This clearly showed that MgO nanoparticles are superior in the clearance of the ANKA strain of plasmodium berghei in infected mice.
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引用次数: 0
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Nanotechnology, Science and Applications
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