Aluminum Rods Research Articles

Fiber Optic Displacement Sensor for Temperature Measurement

A simple design of a temperature sensor is proposed and demonstrated using a fiber optic displacement sensor based on an intensity modulation technique. The proposed sensor uses a plastic optical fiber (POF)-based coupler as a probe in conjunction with a flat surface aluminum rod as a target. The aluminum rod is placed within the linear range of the sensor's displacement curve, which is from 0 to 1400 μm. The sensor is capable of measuring the temperature of an aluminum rod ranging from 42°C to 90°C with a measured sensitivity of 0.0044 mV/°C, with a linearity of more than 98% and a resolution of 2.4°C. The proposed sensor also shows a high degree of stability and good repeatability. The simplicity of design, accuracy, flexible dynamic range, and the low cost of fabrication are favorable attributes of the sensor and beneficial for real-field applications.

Producing ultrafine-grained aluminum rods by cyclic forward-backward extrusion: Study the microstructures and mechanical properties

A cyclic forward-backward extrusion (CFBE) process was used as a severe plastic deformation (SPD) technique to produce ultrafine-grained aluminum rods. Yield strength and tensile strength of the specimens increased by increasing the number of CFBE cycles, while elongation to break decreased due to an increase in the grain refinement and microhardness. According to transmission electron microscopy (TEM) and electron backscatter diffraction (EBSD) results, the average grain size was reduced from 120μm to 315nm after only 3cycles of CFBE.

Equal Channel Angular Pressing of Cu-Al Bimetallic Rod

Coextrusion and corolling are the major processes to produce bimetallic rods, tubes and wires, the objective being to perform clad metals, bimetallic joints or seals. The aim of the present work is to produce bimetallic rods showing an ultrafine grained microstructure with enhanced properties. Bimetallic Cu-Al rods were deformed by equal channel angular pressing (ECAP) in order to study their microstructure. ECAP is an interesting process for producing bulk materials with refined microstructure and, consequently, changes in physical, chemical and mechanical properties can be observed. Higher shear strength and dimensional stability are among the advantages of this process. A comparative experimental study of pure commercial copper with cylindrical inner aluminium rods of different diameters processed by one-pass equal channel angular pressing has been carried out. The ECAP die used in this research was a 90º 2-channels intersecting angle. Electron backscattered (EBSD) and X-ray diffraction techniques were used for microstructure characterization (deformation, grain fragmentation and microstrain evaluation) at the interfaces and away from them. It was found that the microstructure in the ECAP deformed Cu-Al bimetallic rods was influenced by the dimensions of the aluminium inner rod. In fact, the microstructure appeared to be much more elongated and refined in the samples containing smaller diameter aluminium rods.

Formation of Composite Surface during Friction Surfacing of Steel with Aluminium

Commercial pure aluminium was deposited on medium carbon steel using friction surfacing route. An aluminium rod was used as the consumable tool. Normal load and tool rotation speed were the variables. Under certain combinations of load and speed the deposition was continuous and uniform. The deposit consisted of Al embedded with fine particles of iron. The interface between substrate material and deposited material was smooth and relatively small. A mechanism is discussed for formation of a composite surface on the steel substrate.

J024011 羽ばたき飛行ロボットの弾性翼の空気力学的デザイン

Research and development of Micro air vehicles (MAVs) with a maximal dimension less than 15 cm have been a very hot topic in the last decade. MAVs are desired to be capable of performing missions such as environmental monitoring, surveillance, and assessment in dangerous environments. Currently most Bio-inspired MAVs have four wings, while many insects and birds can fly by two wings. In this study, especially focusing on the wing structure and in-flight deformation of flapping wings, we evaluated the aerodynamic performance of single flapping wing which has a semi-elliptic planform and is made of a polyethylene film, a carbon rod at leading edge and aluminum rod at wing base. The mean thrust forces by the flapping wings were measured by attaching the wings onto the newly developed measurement system. The aerodynamic performances of the flapping wings in terms of flexible wing kinematics and vortex structures and their relationship with aerodynamic force generation were further investigated by combining the reconstruction of three-dimensional wing kinematics and the computational fluid dynamic (CFD) method. The flexible wing kinematics, and the force generation by flexible flapping wings accordingly, was found to be strongly affected by the flapping frequency, wing beat amplitude and wing structure which suggest that the optimum wing structure for flapping MAV is dependent on the wing kinematics at wing base.

Quantitative imaging of freezing at the millimeter scale using neutron radiography

Freezing of fluids in capillary structures affects systems that range from soils to the polymer membranes that are used in fuel cells. Neutron radiography can be used to image phase change within otherwise opaque structures and previous studies have shown the capability of quantitative imaging of freezing at ∼3mm scale. In this study, a 1.6mm diameter water column within an aluminum rod was imaged using neutron radiography and fluid density information was extracted. A ray-tracing flux model was developed in order to correct for the effects of beam divergence on the acquired images. The model produced image intensity maps that fit experimental data with R2 values of 0.98. Density measurements for water and ice within the capillary were found to be 1.00±0.03 and 0.93±0.03g/cm3, respectively, which are within 1% of published density values for both phases.

Rational technology for the deoxidation and out-of-furnace treatment of low-silicon steel

A rational technology is proposed for the deoxidation of low-silicon steel. It includes preliminary deoxidation by ferrosilicomanganese in metal tapping from a steel-melting unit and the introduction of aluminum ingots and aluminum rods during out-of-furnace treatment. As a result, the contamination of rolled roll sheets by nonmetallic inclusions decreases and the metal yield increases.

The Evolving Structure of Plasma Formed From the Surface of Aluminum Rods Driven to Megaampere Current

Plasma formation from thick Al rods ohmically heated during the diffusion of pulsed multimegagauss magnetic field is examined experimentally. Rods in the <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Z</i> -pinch configuration are driven to 1.0-MA peak current. The evolution of the resultant surface plasma is complex yet highly reproducible. Surface plasmas first form at discrete hot spots. As the pulsed current grows, plasma filaments form, first along the current, and then transverse to it. As the plasma temperature rises, emissions become increasingly uniform until instabilities grow and modulate the surface.

Evaluating the Risk of Eye Injuries: Intraocular Pressure During High Speed Projectile Impacts

Purpose: To evaluate the risk of eye injuries by determining intraocular pressure during high speed projectile impacts.Methods: A pneumatic cannon was used to impact eyes with a variety of projectiles at multiple velocities. Intraocular pressure was measured with a small pressure sensor inserted through the optic nerve. A total of 36 tests were performed on 12 porcine eyes with a range of velocities between 6.2 m/s and 66.5 m/s. Projectiles selected for the test series included a 6.35 mm diameter metal ball, a 9.25 mm diameter aluminum rod, and an 11.16 mm diameter aluminum rod. Experiments were designed with velocities in the range of projectile consumer products such as toy guns.Results: A range of intraocular pressures ranged between 2017 mmHg to 26426 mmHg (39 psi–511 psi). Four of the 36 impacts resulted in globe rupture.Conclusions: Intraocular pressures dramatically above normal physiological pressure were observed for high speed projectile impacts. These pressure data provide critical insight to chronic ocular injuries and long-term complications such as glaucoma and cataracts.

MRI study of cryoinjury infarction in pig hearts: i. Effects of intrapericardial delivery of bFGF/VEGF embedded in alginate beads

The aim of the study was the testing of sustained intrapericardial delivery of vascular growth factors (GFs) from alginate beads on cryoinjury size and perfusion. In domestic pigs (15-20 kg, n = 21), the left ventricular (LV) anterolateral wall of exposed hearts was cryoinjured using an aluminum rod (25 mm o.d.) cooled in liquid nitrogen. Alginate beads (d = 3.2 ± 0.2 mm), containing human recombinant basic fibroblast GF (bFGF, 50 µg) and vascular endothelial GF (VEGF, 50 µg) + heparin (50 µg) or heparin alone (Con, n = 5), were sutured to the cryoinjured epicardium (GF, n = 5; Con, n = 3 ) or pericardium (GF, n = 3; Con, n = 2), or no beads were implanted (n = 4). Four pigs were sham-operated. Cine and T(1) -weighted MRI was performed in vivo at ~2.5 h and 1, 2, 3 and 4 weeks after injury in a 3T imager. A double bolus of GdDTPA was injected (0.05 and 0.15 mmol/kg) and first-pass and late enhancement kinetics were monitored. After 4-week cryoinjury, following the injection of 5 x 10(6) 15-µm NIR fluorescent microspheres (FMS, 645/680 nm), hearts were sliced and examined with fluorescence imaging. Triphenyltetrazolium chloride (TTC) staining was used to determine infarct areas. Epicardial GF-containing beads were encapsulated within the hypointense 3-4-week infarct tissue. This tissue had a 75% higher LV thickening index, a lower distribution volume for GdDTPA (0.44 ± 0.12 vs 0.68 ± 0.05, p = 0.02), and 25% faster first-pass Gd kinetics relative to control infarctions. TTC staining revealed TTC-positive islands in the core of treated infarcts, which showed higher FMS fluorescence relative to surrounding infarct tissue (0.64 ± 0.14 vs. 0.31 ± 0.14; p < 0.0001) and to control infarcts (0.37 ± 0.09, p < 0.05). GF-beads attached to the pericardium were not effective. We conclude that sustained intrapericardial release of bFGF + VEGF from alginate beads attached to the epicardium facilitated vascular growth in the cryoinjured area.

Experimental validation of control rod related perturbations of moderator regions in an SCWR-like fuel lattice

Two different types of perturbations of an SCWR-like fuel lattice have been investigated experimentally in the central test zone of the PROTEUS zero-power research reactor at the Paul Scherrer Institute in Switzerland. In each case, a campaign of high-resolution gamma-ray spectroscopy measurements was carried out on 34 fuel pins of the test lattice. In the first case, the test lattice was perturbed by inserting aluminum rods into the four central moderator regions, while in the second case, the perturbation was affected using steel absorber rods (instead of aluminum). The derived reaction rates are the capture rate in 238U ( C 8) and the total fission rate ( F tot), as also the reaction rate ratio C 8/ F tot. Each of these has been mapped on the lattice and compared to calculated results from whole-reactor Monte Carlo simulations with MCNPX. Excellent agreement has been obtained, for both perturbed lattices, between the calculated and experimental distributions of C 8, F tot and C 8/ F tot. Considering that control rods in an SCWR assembly are foreseen to be inserted into the central moderator regions, these results may be considered as generic validation of Monte Carlo simulations for the two different types of lattice perturbations which inserted control rods imply, viz. moderator displacement and strong neutron absorption. In a second step, calculated C 8, F tot and C 8/ F tot distributions for the two perturbed lattices (as well as for the unperturbed lattice) have been compared, at assembly level, between MCNPX and the deterministic LWR lattice code CASMO-4E. In the case of the unperturbed lattice, as well as for the lattice with steel rods, the agreement between the codes is found to be within ∼1% for all pins and each reaction rate. However, for the lattice with aluminum rods, i.e. the case with mainly just moderator displacement involved, CASMO overestimates the reaction rates in the vicinity of the perturbations by up to 2–3%, when employing the standard input options. The reason for this discrepancy has been found to be the leakage treatment, which uses the fundamental-mode buckling applied in a homogenized sense across the lattice. In this way, global leakage gradients get averaged out over the entire assembly. The optional input card BZ2 for CASMO resolves this problem, and the codes then agree within 1% even for the aluminum case.

Interfacial Microstructure and Bonding Strength of Copper Cladding Aluminum Rods Fabricated by Horizontal Core-Filling Continuous Casting

Copper cladding aluminum (CCA) rods with a diameter of 30 mm and a sheath thickness of 3 mm were fabricated by horizontal core-filling continuous casting (HCFC) technology. The microstructure and morphology, distribution of chemical components, and phase composition of the interface between Cu and Al were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), and energy dispersive spectrometer (EDS). The formation mechanism of the interface and the effects of key processing parameters, e.g., aluminum casting temperature, secondary cooling intensity, and mean withdrawing speed on the interfacial microstructure and bonding strength were investigated. The results show that the CCA rod has a multilayered interface, which is composed of three sublayers—sublayer I is Cu9Al4 layer, sublayer II is CuAl2 layer, and sublayer III is composed of α-Al/CuAl2 pseudo eutectic. The thickness of sublayer III, which occupies 92 to 99 pct of the total thickness of the interface, is much larger than the thicknesses of sublayers I and II. However, the interfacial bonding strength is dominated by the thicknesses of sublayers I and II; i.e., the bonding strength decreases with the rise of the thicknesses of sublayers I and II. When raising the aluminum casting temperature, the total thickness of the interface increases while the thicknesses of sublayers I and II decrease and the bonding strength increases. Either augmenting the secondary cooling intensity or increasing the mean withdrawing speed results in the decrease in both total thickness of the interface and the thicknesses of sublayers I and II, and an increase in the interfacial bonding strength. The CCA rod with the largest interfacial bonding strength of 67.9 ± 0.5 MPa was fabricated under such processing parameters as copper casting temperature 1503 K (1230 °C), aluminum casting temperature 1063 K (790 °C), primary cooling water flux 600 L/h, secondary cooling water flux 700 L/h, and mean withdrawing speed 87 mm/min. The total thickness of the interface of the CCA rod fabricated under the preceding processing parameters is about 75 μm, while the thicknesses of sublayers I and II are about 1.1 and 0.1 μm, respectively.

Controlled round-window stimulation in human temporal bones yielding reproducible and functionally relevant stapedial responses

Stimulation of the round window (RW) has gained increasing clinical importance. Clinical, as well as human temporal bone and in-vivo animal studies show considerable variability. The influence of RW stimulation on the cochlea remains unclear. We designed a human temporal-bone study with controlled direct mechanical stimulation of the RW membrane to identify conditions for successful RW stimulation. Eight human temporal bones were stimulated on the RW by piezoelectric stack actuators with cylindrical aluminium rods of diameter 0.5 mm and with either flat or 30° inclined top surface. Using a dedicated two-stage positioning protocol for the actuator, we achieved highly reproducible measurements of the stimulus vibration at the RW and of the resultant vibration of the stapes footplate. The reverse transmission, characterized by the displacement ratio of the stapes-footplate relative to the actuator tip on the RW membrane, yielded an average displacement ratio of 0.089 up to 1.2 kHz when the actuator was coupled without angular misalignment to the RW membrane. The results suggest that 90-μm pretension of the RW membrane is essential for optimum and reproducible RW stimulation. The displacements are shown to be roughly consistent with the equal-volume displacement hypothesis under specific assumptions about the displacement mode of the RW membrane. It is further suggested that the large inter-patient variability in the effectiveness of RW stimulation might be due primarily to the success of coupling, rather than to the variability of functionally relevant anatomical parameters.

MRI studies of cryoinjury infarction in pig hearts: ii. Effects of intrapericardial delivery of adipose‐derived stem cells (ADSC) embedded in agarose gel

The purpose was to assess effects of intrapericardially deposited adipose-derived stem cells (ADSC) as a source of angiogenic factors on cryoinjury infarction. To enhance this effect and reduce incorporation of ADSC into tissue, the cells were immobilized in agarose gel patches transplanted onto cryoinjured epicardium. In domestic pigs (15-20 kg) the left ventricular (LV) anterior wall of exposed hearts was cryoinjured using aluminum rod (Φ=25 mm) cooled in liquid nitrogen. Sterilized circular patches made of agarose gel were placed in a nylon bag and sutured to cryoinjured epicardium. In 4 pigs, the patches contained 650,000 human ADSCs; in control animals patches were cell-free (n=2) or no patches were implanted (n=2). Cine and T(1)-weighted MRI was performed in vivo weekly (4 weeks) after injury using a 3 T imager. Following baseline imaging, a double bolus of gadopentate dimeglumine was injected (GdDTPA, 0.05 and 0.15 mmol/kg) and serial short axis images were acquired. In the 4-week ADSC-treated group, 2 pigs were assessed using GdDTPA and 2 pigs were assessed using MnCl(2) (70 micromol/kg/14 min). In all pigs, 5 × 10(6) NIR fluorescent microspheres (15 µm FMS, 645/680 nm) were injected into the hearts, which were excised, sliced and examined with fluorescence imaging for FMS content. Triphenyltetrazolium chloride (TTC) staining was used to determine necrotic areas. Four-week infarction areas were hypokinetic and appeared hyperintensive on Gd-enhanced MR images, hypointensive on Mn-enhanced images, and were TTC-negative. First-pass Gd enhancement kinetics was faster in the infarct area of ADSC-treated hearts: 152 ± 89 vs 54 ± 5.3% of normal in control (p = 0.03). Accordingly, FMS fluorescence was much higher in the treated infarcts (144 ± 59% of remote, n = 4) relative to control hearts (58 ± 13%, n = 4), which correlated with 3 times higher microvascular density in treated hearts. LV wall thickening was partially restored by ADSC treatment. ADSC-containing patches attached to cryoinjured epicardium greatly improved perfusion and microvascular density of scar tissue.

SU-E-T-100: Measurement of a Cobalt-60 Teletherapy Irradiator Spectrum Using a Compton Spectrometer

Purpose: To characterize the photon spectrum from a Theratronics T1000 cobalt-60 teletherapy unit using Compton spectrometry and compare to primary beam measurement and Monte Carlo (MC) simulation. Methods: A well-shielded high-purity germanium detector was used to measure the photon spectrum scattered at 22.5 and 70 degrees from the central axis of a 10cm×10cm beam of a cobalt-60 teletherapy unit. The central-axis photons were scattered using an aluminum rod (6mm diameter) positioned 100cm from the source, and the scattered photons were admitted to the detector through a 30cm-long collimating aperture (2mm diameter). The measured Compton-scattered spectra were corrected for detector response, determined using a model of the measurement apparatus in the MCNP5 MC code, and Compton relations (energy-angle and Klein-Nishina) to determine the central-axis spectrum at 100cm from the source. The primary photon spectrum was measured with the collimating aperture aligned to the central axis and corrected for detector response. A MC model of the cobalt-60 unit was developed in MCNP5 and used to generate the central-axis spectrum for a 10cmx10cm field. Results: The primary photon peaks from the cobalt-60 source were appropriately shifted to lower energies in the Compton-scattered spectra. The resolution of the shifted peaks degraded with increasing scattering angle. The corrected scattered spectra compared well with the primary measurement and MC simulation for peak position, but disagreed in the lower-energy continuum where source and collimator scatter are present. Differences are likely due to resolution loss with scattering and incomplete measurement correction. Conclusions: The spectrum from a cobalt-60 teletherapy unit was measured using Compton spectrometry. This spectrum was compared to direct measurement and MC simulation of the unit. Results indicate that small scattering angles should be used with this measurement technique and that further work is required to reconcile differences between measurements and simulations for source and collimator scatter.

The Continuous Casting Technology of the Aluminum Rod Assigned for the Wire for Electrical Purposes

New technologies of the production of the aluminium charge assigned for drawing, including the tests on the process of continuous casting (CC). This type of technology, which includes the casting of copper and zinc, is widely spread in the world (trademarks: Upcast, Rautomead and Vertic). Yet, there is a lack of experience in the production and reproduction of the cast wires made of aluminium and its alloys assigned for electrical purposes. That is why the authors of the work aimed at investigating the casting process of the aluminium wires obtained with the technology of continuous casting.

Radial Force Measurements in Carotid Stents: Influence of Stent Design and Length of the Lesion

Purpose To assess the differences in radial force of carotid stents and whether the length of the lesion influences the measurements. Materials and Methods Different models of tapered stents of similar size (length, 30 mm) were used. The tapered nitinol Acculink, Protégé, and Cristallo Ideale carotid artery stents and the straight, braided Elgiloy carotid Wallstent were compared. A measurement device consisting of three film loops along the stent body connected to aluminium rods with copper strain gauges was developed. Five stents of each type were deployed within 3-mm stenoses in simulated long (26 mm) and short (8 mm) stenoses. Results In the short stenosis simulation, the greatest radial force was seen in the Protégé stent, at 3.14 N ± 0.45, followed by the Cristallo Ideale stent (1.73 N ± 0.51), Acculink (1.16 N ± 0.21), and Wallstent (0.84 N ± 0.10; P < .001). In the long stenosis simulation, peak radial force again was highest in the Protégé stent (1.67 N ± 0.37), but the Acculink stent was second (0.95 N ± 0.12) and the Wallstent third (0.80 N ± 0.06). The Cristallo Ideale stent, in contrast to the short stenosis simulation, produced the least radial force (0.44 N ± 0.13) in the long stenosis simulation ( P = .001). Conclusions Radial forces exerted by carotid stents vary significantly among stent designs. Differences between stent types are dependent on the length of the stenosis. An understanding of radial force is necessary for a well-considered choice of stent type in each individual patient.

Mitigation of nonthermal plasma production to measure the pulsed magnetic field threshold for the thermal formation of plasma from thick aluminum surfaces a)

Untangling the roles of different plasma formation mechanisms in high-current electrical discharges requires controlling each mechanism and isolating its effects. Recent experiments use this method to find that thermal formation of plasma occurs from 6061-alloy Al conductors by ohmic heating when the surface field reaches a magnetic field threshold of 2.2 MG (independently of ∂B/∂t ranging from 30 to 80 MG/μs) [T. J. Awe et al., Phys. Rev. Lett. 104, 035001 (2010)]. The experiments pulse 1.0 MA peak current on the surface of thick (∼1.0 mm diameter) aluminum rods in 100 ns. Strong electric fields are necessarily introduced, and precursor plasma may form (e.g., from arcing electrical contacts). To ensure plasma formation is predominantly thermal, a systematic study of multiple combinations of high-current electrodes and central-rod profiles was completed. Data from multiple diagnostics show that the time and location of plasma formation strongly correlate with the hardware combination used. An extensive dataset (greater than 100 shots) enabled numerous hypotheses to be tested regarding plasma formation mechanisms. For hardware with compressed, large-diameter current joints, plasma formation is a predominantly thermal process driven by ohmic heating.

Selection of soldering temperature for ultrasonic-assisted soldering of 5056 aluminum alloy using Zn–Al system solders

The conditions for sound butt-joints of 5056 aluminum alloy containing 4.6 mass% Mg using Zn– xAl ( x = 5, 13, and 38 mass%) solder at the relevant temperatures were investigated. Each solder foil was inserted between faying surfaces of 5056 aluminum rods. Ultrasonic vibration at a frequency of 19 kHz was applied to the faying surfaces through an aluminum substrate at soldering temperatures for 4 s in air. The strength of obtained solder joints was measured by tensile tests. The microstructure in the solder layer after the soldering process was evaluated with an SEM-EDX. The results of tensile tests revealed that joints soldered under the liquidus temperature of Zn–Al solders showed higher strength than joints soldered over the liquidus temperature. In the joints soldered over the solder liquidus temperature, the joint strength decreased with an increase in soldering temperature. It was caused by the formation of MgZn 2 in the solder layer due to dissolution of 5056-Al into the solder liquid during the soldering process. On the other hand, ultrasonic-assisted soldering under the solder liquidus temperature suppressed dissolution of 5056-Al and improved the joint strength by reducing the formation of MgZn 2.

Magnitude Verses Offset Study with EM Transmitter in Different Resistive Medium

Seabed Logging (SBL) is new technique to detect hydrocarbon reservoir under the sea bed. EM transmitter is used to transmit low frequency electromagnetic signals into the subsurface layers of the sea bed to detect different resistive layers. However, detection of resistivity contrast in different resistive layers for a deep target is still a challenge in SBL. Due to economical point of view a scaled tank with a scale factor of 2000 was built to study the resistivity contrast. In the scale tank experiment aluminium rod EM transmitter of length 50 cm is towed at 35 cm height from the bottom of the tank. Three receivers are placed at 25 cm from the bottom of the tank. A series of experiments were conducted with different resistive mediums such as (tap water, salt water and salt water with oil packets). The oil packets were placed at certain positions in the water tank. The electromagnetic field responses from different resistive layers were recorded by the receivers. Different response in the magnitude of magnetic field was observed by different resistive medium. It was also observed that the magnetic field strength had increased 50% for salt water and 150% for oil which clearly shows the resistivity contrast. Our preliminary results have shown that high resistive layers in a conductive medium can be detected by using the experimental set up. © 2011 Asian Network for Scientific Information.