Design, construction, and analysis of a continuous-temperature infrared calibrator for temperature measurement using an infrared scanner

A continuous-temperature infrared calibrator is designed and constructed for providing reference video signals in temperature measurement using an infrared scanner. The calibrator can be controlled for a wide range of temperature settings and to present a continuous span of reference signals for calibration purposes. Both analytical and experimental methods are used to evaluate the performance of the calibrator. Results show that the calibrator has a normal total emissivity of at least 0.984, which is about 1% lower than the predicted value. Methods to improve the emissivity of the calibrator are also discussed. The paper provides for analytical equations useful for parameters estimation in the future design of the calibrator.     

The study of cost-tolerance model by incorporating process capability index into product lifecycle cost

To reduce the cost of manufacturing systems, many studies of cost minimization have been performed. Since tolerance design significantly affects the manufacturers’ cost, the optimization of cost-tolerance allocation will be an important issue for reducing these costs. Costs incurred in a product life-cycle include manufacturing cost and quality loss. However, most cost-tolerance optimization models frequently ignore the concept of quality loss and may not lead to an accurate analysis of the tolerance. Until now, process capability analysis has been the tool used to evaluate the adequacy of a production tool in meeting a quality target. Hence, the concept of process capability analysis should be included into the cost-tolerance optimization model. In this study, a flexible cost-tolerance optimization model will be constructed by integrating the process capability index into the product life-cycle cost function. The constructed cost-tolerance optimization model simultaneously considers the manufacturing cost of the components, the process capability of the manufacturing operations, and the quality loss of products. The decision-maker can apply the proposed cost-tolerance optimization model to determine a reasonable tolerance with minimum total cost including consideration of the process capability .     

Note: Development of a high resolution six-degrees-of-freedom optical vibrometer for precision stage

A high resolution six degrees of freedom (6-DOF) optical vibrometer is proposed. 6-DOF vibrations can be simultaneously measured using the proposed optical vibrometer, which reduces measurement time and number. The performance of the proposed vibrometer is verified by experiments. The results show that the accuracy of the proposed optical vibrometer is ±30 nm∕200 nm and ±0.04 arcsec∕0.1 arcsec at 1000 Hz.     

The effect of tenocyte/hyaluronic acid therapy on the early recovery of healing Achilles tendon in rats

The aim of this study was to explore the potential for a better recovery outcome for the Achilles tendon at an early healing stage when a mixed biomaterial-tenocyte injection is used. The experimental animals underwent single limb Achilles tendon transection followed by suturing repair. A solution of either hyaluronic acid with or without tenocytes or normal saline was randomly chosen to be injected around the injury site after surgery. To obtain the comprehensive recovery condition of the rats on different management protocols, the animals were evaluated histologically, mechanically, and functionally. A significant difference in the recovery condition was found in the injured tendon injected with the hyaluronic acid solution with tenocytes compared with the other groups. Tendon stiffness and the locomotion abilities of the rats with healing Achilles tendons were improved in the hyaluronic acid with tenocyte transplantation group. The acceleration of the inflammatory phase in rats with the hyaluronic acid with tenocyte injections might be the major reason for the better functional outcomes.     

Characterization of conduction in PZT thin films produced by laser ablation deposition

Abstract

Both direct current (d.c.) and alternating current (a.c.) conductivity measurements were undertaken on lead zirconate titanate (PZT) films synthesized by laser ablation deposition. Direct current (I) displayed an initial time dependence of the form I ∝ t^?γ (γ ∝ 0.5–1.0). The possible reasons for this time dependence are discussed. At lower temperatures, the a.c. electrical conductivity shows a frequency dependence of the form σ ∝ ω′ which is explained as electrical charge hopping. At higher temperatures, the d.c. component of electrical conductivity becomes dominant, and is accompanied by a strong low frequency dispersion of the dielectric constant. The results are compared to published data on conductivity in SrTiO₃, and discussed in terms of the latest theories for dielectric response of materials.     

A novel closed‐loop reconfiguration for radial distribution systems with dispersed generation

Abstract

Currently, Tai‐power Company is attempting to change its power distribution systems from radial distribution configurations to closed‐loop configurations in order to enhance the quality of the supply of electricity. Besides, the dispersed generation (DG) should be considered in making the reconfiguration suitable for present circumstances. To form a closed‐loop configuration, a new tie‐line is added in this paper to interconnect two different feeders of the original radial power distribution systems. The multi‐objective is, not only to reduce power transmission loss, but also reduce the cost representative of power distribution reconfiguration. Assuming that the cost representative is a linear function of the system's short‐circuit capacity, line current and bus voltage. The problem solution procedure in this paper is mainly divided into two steps. The first step is to form objective function by determining the weighting factor of each objective term based on the cost‐benefit analysis scheme. Then, the optimum solution is pursued for the objective function by means of refined genetic algorithm (RGA). An example is studied by using the proposed methodology. The results show that the cost‐benefit analysis scheme is verified capable of finding the weighting factors, that the RGA can render stable solutions and that the transmission loss reduction ratio is satisfactory.     

Cellulose nanocrystals and self-assembled nanostructures from cotton, rice straw and grape skin: a source perspective

Cellulose nanocrystals (CNCs) have been derived by sulfuric acid hydrolysis (64–65 wt% H₂SO₄, 10 mL/g cellulose, 45 °C) of pure cellulose isolated from cotton, rice straw and grape skin, producing relatively consistent products in 60, 45 and 30 min, respectively, and generally reflecting the extent of crystallinity and crystallite sizes of these cellulose sources. CNCs in nanorod forms are observed from all three cellulose sources and, in the case of cotton and grape skin, in the presence of more dominant forms of nanoparticles. Cotton CNCs are <10-nm-wide nanorods at up to 40 aspect ratios, whereas rice straw CNCs are flat ribbon cross-sectional shaped in 10:2:1–44:5:1 length/width/thickness ratios, and those from grape skin are abundant nanoparticles but fewer nanorods, all of very different nanoscale dimensions. Freezing (?196 °C) and freeze-drying (?50 °C) of dilute CNC suspensions induce self-assembling of these CNC populations into yet further distinctly different morphologies. Self-assembled cotton CNCs are loosely organized nanorods and nanospheres, whereas grape skin CNCs are mainly nanospheres of 5-nm-sized nanoparticles clusters around nanorod cores. Uniquely, rice straw CNCs assembled anisotropically into ultra-thin non-porous fibers. These source-linked unique CNC geometries and the ability of CNCs to self-assemble into different morphologies present wide ranging dimensions of these renewable cellulose nanomaterial building blocks from by-products of the world largest fiber, cereal and fruit crops.     

Imaging of soft and hard materials using a Boersch phase plate in a transmission electron microscope

Using two levels of electron beam lithography, vapor phase deposition techniques, and FIB etching, we have fabricated an electrostatic Boersch phase plate for contrast enhancement of weak phase objects in a transmission electron microscope. The phase plate has suitable dimensions for the imaging of small biological samples without compromising the high-resolution capabilities of the microscope. A micro-structured electrode allows for phase tuning of the unscattered electron beam, which enables the recording of contrast enhanced in-focus images and in-line holograms. We have demonstrated experimentally that our phase plate improves the contrast of carbon nanotubes while maintaining high-resolution imaging performance, which is demonstrated for the case of an AlGaAs heterostructure. The development opens a new way to study interfaces between soft and hard materials.     

Estimation of Groundwater Aquifer Formation-strength Parameters from Geophysical Well Logs: The Southwestern Coastal Area of Yun-Lin,Taiwan

Abstract

The purpose of this study is to estimate groundwater aquifer formation-strength parameters including shear modulus, bulk modulus, Poisson's ratio, and Young's modulus by using geophysical well logs. A new dispersed-shale index equation was developed by using the natural gamma-ray log and the compensated formation density log to solve a confusing problem of the compaction factor setting in the calculation of sonic porosity for an unconsolidated groundwater aquifer. A useful Poisson's ratio estimation method was employed to estimate groundwater aquifer formation-strength parameters when shear-wave transit time data is lacking in groundwater wells. Hydrogeologic parameters are characterized in estimating formation-strength parameters. Five wells in the southwestern coastal area of Yun-Lin, Taiwan, were logged, and four shallow aquifers were identified from log-derived hydrogeologic characteristics less than 200 m in depth. The formation-strength parameters for aquifers between 310 and 500 m in depth were calculated in two wells because complete formation density and compressional-wave transit time data were available. The results of the aquifer's formation-strength parameters demonstrate that both shear modulus, ranging from 0.15 to 0.42 * 10⁶ psi, and Young's modulus, ranging from 0.40 to 1.07 * 10⁶ psi, increase with depth, whereas bulk compressibility, ranging from 1.2 to 2.6 * 10^?6 psi^?1, decreases with increasing depth.