The growing popularity of microcontroller-based prototyping boards in many engineering and science applications has greatly increased the demand of mechatronic skills in the technical job market. The need to keep up w...
详细信息
The growing popularity of microcontroller-based prototyping boards in many engineering and science applications has greatly increased the demand of mechatronic skills in the technical job market. The need to keep up with this new tend, combined with the proven effectiveness of integrating theoretical learning with hands-on, project-based activities has driven the development of new educational standards and curricula pivoting on the use of microcontroller-based prototyping boards. However, the most common Integrated Development Environments (IDE) used to simplify program development lack the intuitiveness and post-processing capabilities needed in an instructional environment. This paper presents an approach aimed at overcoming these obstacles. It provides a unique and comprehensive framework for programming Arduino boards through the c/c++ interpreter ch. It extends the authors' previous work on the topic by integrating a Graphical User Interface (GUI) and a library of functions, and by improving the serial communication protocol. The paper also shows how the toolkit can be easily integrated with other features and toolkits available in ch such as plotting and line-by-line debugging to create comprehensive projects tailored for K-14 students at different levels. The concepts presented in this work are applied to programming Arduino boards but provide a general basis upon which similar frameworks can be implemented for other boards or in other programming languages.
Backgroud Recent studies have demonstrated that cystatin c is a valuable risk marker for cardiovascular disease morbidity and ***,we hypothesized that the pre-ablation cystatin c level was associated with post-ablatio...
详细信息
Backgroud Recent studies have demonstrated that cystatin c is a valuable risk marker for cardiovascular disease morbidity and ***,we hypothesized that the pre-ablation cystatin c level was associated with post-ablation atrial fibrillation(AF)*** 207 patients were enrolled and completed in this prospective observational *** with AF scheduled for receive radiofrequency catheter ablation(RFcA)therapy were screened for the *** ablation therapy,electrocardiogram,24 h holter monitor,transesophageal echocardiography,serum cystatin c,high-sensitivity c-reactive protein,creatinine levels,and routine blood examinations were *** ablation,patients were followed up every week for the first month,and then at 2,3,6,9,and 12 ***,patients came back to out-patient clinic every six months *** or 24 h holter monitor were repeated if the patient experienced palpitations or every six *** recurrence was defined as atrial flbrillation/atrial flutter or atrial tachycardia lasting≥30 seconds within three months after *** compared to patients with no AF recurrence,patients with recurrence had longer AF history(P=0.007),more early recurrence(P=0.000),a larger left atrium(P=0.004),and higher pre-ablation cystatin c levels(P=0.000).Multivariate regression analysis revealed that cystatin c and left atria(LA)diameter were risk factors for AF *** adjusting for LA diameter,the risk of AF recurrence increased 30%with every milligram cystatin c elevation(95%cI:1.117-1.523).conclusions Pre-ablation cystatin c levels were associated with AF recurrence after RFcA therapy,an optimal cut-off value of 1.190 mg/L(sensitivity=0.576;specificity=0.851).
Needled composites have stronger interlaminar properties compared to two-dimensional fiber composite structures due to the introduction of z-directional fibers in the fiber composite layup. An effective multi-scale fi...
详细信息
Needled composites have stronger interlaminar properties compared to two-dimensional fiber composite structures due to the introduction of z-directional fibers in the fiber composite layup. An effective multi-scale finite element model is developed in this paper for the complex structure of needle-punched composites. Three scales, namely fRVE, pRVE, and lRVE, are modeled from the fiber scale, the delamination scale, and the laminate scale. using ABAQUS, periodic boundary conditions are applied to the RVEs at different scales to obtain the effective mechanical properties of various RVEs. Meanwhile, the effect of needling density on the needled composites is predicted by applying the above multi-scale model. The increase of needling density can enhance the out-of-plane effective mechanical properties of the composites, but it also weakens the in-plane effective mechanical properties. The maximum error of the elastic modulus calculation is 17.68% with that of the reference, thus verifying the rationality of the multi-scale model.
Rational utilization of biomass waste in creating new clean energy such as lithium-ion batteries is conducive to alleviating the energy crisis and boosting environmental protection. Herein, using peanut shells as the ...
详细信息
Rational utilization of biomass waste in creating new clean energy such as lithium-ion batteries is conducive to alleviating the energy crisis and boosting environmental protection. Herein, using peanut shells as the carbon source, a MnO/ccomposite material was successfully prepared through an eco-environmental and facile approach based on hydrothermal treatment and pyrolysis. The resultant MnO/ccomposite material demonstrated a hierarchical porous structure and MnO particles with irregular morphology were embedded in the pores. When used in a lithium-ion battery, the material exhibited much better lithium storage properties than those for pristine MnO and peanut shell-derived carbon. In 0.0-3.0 V, the composite material can supply an initial specificcapacity of 1169.5 mA h g(-1), with a capacity retention ratio of 84.9 % after 200 electrochemical cycles. Even at 2400 mA g(-1), the material can still offer a discharge capacity of 532.3 mA h g(-1), manifesting an outstanding rate performance. The enhanced lithium storage properties of the composite material are attributed to the support of the porous carbon matrix derived from peanut shells, which are not only conducive to improving conductivity but also capable of buffering the volume expansion/shrinkage caused by lithiation/delithiation during charge/discharge processes.
The Li4Ti5O12/ccomposites were synthesized by one-step solid-phase reaction using metatitanic acid, lithium carbonate and sucrose as raw materials. The effects of the molar ratio of lithium to titanium, calcining tem...
详细信息
The Li4Ti5O12/ccomposites were synthesized by one-step solid-phase reaction using metatitanic acid, lithium carbonate and sucrose as raw materials. The effects of the molar ratio of lithium to titanium, calcining temperature, calcination time, and sucrose content on the structure of Li4Ti5O12/ccomposites were studied. XRD, SEM, TEM and electrochemical performance tests were used to characterize the results. The results showed that n(Li):n(Ti) = 0.85, calcination temperature was 750 degrees c, calcination time was 6 h, and the sucrose addition amount was 30% of the total mass of raw materials. Under the conditions, the pure Li4Ti5O12/ccomposites can be synthesized. The particles are uniform, the particle size is 0.1-1 mu m, and the carbon envelopment is better. The specificcapacity is up to 163.94 mAh/g at 0.1 c rate, and the theoretical specificcapacity is 175 mAh/g very close.
To investigate the ablation mechanism of the mullite modified c/c-Sic-Hfccomposites prepared by precursor infiltration pyrolysis, a 60 s single ablation and 30 s x 3 cyclic ablations were carried out at heat fluxes o...
详细信息
To investigate the ablation mechanism of the mullite modified c/c-Sic-Hfccomposites prepared by precursor infiltration pyrolysis, a 60 s single ablation and 30 s x 3 cyclic ablations were carried out at heat fluxes of 2.38 and 4.18 MW/m2, respectively. Results showed that the ablation temperatures played a vital role in the ablation process. Under the lower heat flux condition, the single ablation behavior was mainly influenced by the escape of gaseous oxidation products and slight airflow erosion, while cyclic ablation was influenced primarily by the stresses induced by crystallization transformation during the heating-cooling process. Under the higher heat flux condition, HfSiO4 was gradually generated at the interface between HfO2 and SiO2, which stabilized the crystallization of HfO2. The ablation behavior under higher heat flux was mainly influenced by thermal-induced stresses and mechanical forces of high-velocity airflow.
A facile way of synthesizing LiFePO4/c with high tap density was introduced. LiFePO4/ccomposites were synthesized by a combination of wet ball milling, spray drying, and carbothermal reduction technology using inexpe...
详细信息
A facile way of synthesizing LiFePO4/c with high tap density was introduced. LiFePO4/ccomposites were synthesized by a combination of wet ball milling, spray drying, and carbothermal reduction technology using inexpensive FePO4. The effect of sphericity of secondary microsphere on electrochemical properties and tap density of LiFePO4/ccomposite was systematically investigated. The sphericity of the secondary microsphere is controlled by particle size of primary particle with varying the ball grinding time. The composites were characterized in detail by X-ray diffraction (XRD), scanning electron microscopy (SEM), and tap density testing. The particle size of primary particle can effectively influence the sphericity of the secondary microsphere, and consequently change the electrochemical properties and tap density of LiFePO4/c. The optimum LiFePO4/c with high tap density of 1.68 g cm(-3) contains 2.1 wt% carbon and shows an excellent rate capability and cycle performance, with the initial discharge capacities of 164.0, 159.6, 154.9, 148.3, and 138.3 mAh g(-1) at 0.2 c, 0.5 c, 1 c, 2 c, and 5 c. The good electrochemical properties are attributed to the smaller particle, uniform primary particle size distribution, and the uniform carbon coating. The high tap density of LiFePO4/ccomposite is attributed to the better sphericity of secondary microsphere. With the primary particle size decreasing, the secondary microsphere sphericity is better.
Magnetometers based on superconducting quantum interference devices (SQUIDs), fabricated from thin films of YBa2cu3O7-x and operated in liquid nitrogen at 77K, have achieved a magnetic field noise below 10 fT Hz(-1/2)...
详细信息
Magnetometers based on superconducting quantum interference devices (SQUIDs), fabricated from thin films of YBa2cu3O7-x and operated in liquid nitrogen at 77K, have achieved a magnetic field noise below 10 fT Hz(-1/2). These devices are now sufficiently sensitive for use in an intriguing variety of applications, including geophysics, magnetocardiology, nondestructive evaluation of metal structures, and scanning SQUID microscopes.
The synthesis of cuO/c nanocomposites was fabricated using an uncomplicated and eco-friendly method by cyperus rotundus (c. rotundus) leaf extract. The formation of nanocomposites and their size were optimized with va...
详细信息
The synthesis of cuO/c nanocomposites was fabricated using an uncomplicated and eco-friendly method by cyperus rotundus (c. rotundus) leaf extract. The formation of nanocomposites and their size were optimized with various factors, such as operational parameters, viz. exposure time, temperature, and concentration of the precursor, by response surface methodology (RSM). The effects of the synthesis of cuO/c nanocomposite samples and their characterization by various analytical techniques such as UV, XRD, XPS, EDX, SEM, and TEM have been reviewed and confirmed. The XRD patterns revealed that the biosynthesized cuO/c sample exhibited a monoclinic and crystalline structure. Moreover, the elements available in nanocomposites were determined as cu 2p, O 1 s, and c1s using XPS analysis. The TEM pictures reveal the morphology of the nanocomposites as spherical in form, with an average size of 30 nm. Additionally, synthesized cuO/c nanocomposites were examined for toxic effects on the mortality of two-winged insect larvae, and they were absolutely found to be extremely active and considerably kill larvae. The molecular docking study found that the nanocomposites were able to bind to the target protein with high affinity, which suggests that they are likely to be effective larvicidal agents. Our existing analysis findings can open up a replacement void for the larvicidal analysis exploiting biosynthesized nanocomposites.
Thermal silazane cleavage of dichloroboryldisilylamines (SiclmMe3-m)N(SiMe3)(Bcl2) (1: m?=?1;2: m?=?2) at 196 degrees c leads to the borazine derivates [(SiclmMe3-m)NB(clnMe1-n)]3 (3: m?=?1, n?=?0.185;4: m?=?2, n?=?0....
详细信息
Thermal silazane cleavage of dichloroboryldisilylamines (SiclmMe3-m)N(SiMe3)(Bcl2) (1: m?=?1;2: m?=?2) at 196 degrees c leads to the borazine derivates [(SiclmMe3-m)NB(clnMe1-n)]3 (3: m?=?1, n?=?0.185;4: m?=?2, n?=?0.111) characterized by NMR and IR spectroscopy and mass spectrometry. Single-crystal X-ray diffraction structure analyses reveal (BN)3 units with unusual twisted boat conformations in both compounds. Additionally, more detailed studies are done to clear up the function of the by-products (SiclmMe3-m)N(SiclMe2)(BclMe) formed during the cyclization step leading to asymmetrically boron substituted borazine derivatives. The single-source precursors 3 and 4 were cross-linked with methylamine producing polymers 3P and 4P, which were transformed into black amorphous materials with ceramic yields of 20.8 % and 50.3 %, respectively. ceramic 4c (Si1.00B0.98?N2.55?c1.37O0.05) was further investigated by 11B and 29Si magic angle spinning (MAS) NMR spectroscopy. A combined study of high-temperature TG analyses and X-ray powder diffraction analyses confirms the thermal stability of 4c up to 1670 degrees c. copyright (c) 2012 John Wiley & Sons, Ltd.
暂无评论