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In the recent years, the development of wind turbines has been so hectic in Taiwan. The design of the turbine blades directly impacts power effectiveness. In this study, the effects of manufacturing parameters and environmental factors on the mechanical properties of carbon fiber/epoxy composites that are used in turbine blades are discussed. Parameters of the manufacturing process affect the mechanical properties. Carbon composites made by a different numbers of layers are tested on various aspects of performance such as mechanical strength and corrosion resistance.
This study investigated the flow bifurcations of flows driven by a pressure gradient in a rectangular curved tube. When fluid flows within a curved tube, due to the centrifugal effect, secondary vortices can be induced in the cross section of the tube. The secondary flow states are dependent on the magnitude of the pressure gradient (q) and the aspect ratio (γ). In this study, the continuation method was applied to investigate the flow bifurcations in a curved tube with increasing pressure gradient (1 < q < 6000) and aspect ratio (0.9 < γ < 1.4).
The bifurcation diagrams are composed of solution branches, which are linked by limiting points or bifurcation points. The flow states in a solution branch belong to the same group. The ranges of the flow states and the relationship between the states can also be derived from the bifurcation diagrams. In this study, two types of bifurcation were found, one in the range of 0.9 < γ < 1.17, and another in the range of 1.18 < γ < 1.4. The ranges of stable flow solutions and the distributions of limit and bifurcation points in both pressure gradient and aspect ratio are derived in this study.
Prior to integrated circuit (IC) packaging, die performance must be verified using probe cards to screen for defective products. With the decrease in IC line width, the dimensions of the pads used for performance verification and the spacing between adjacent pads have also decreased. However, when the pad pitch is reduced to less than 30 μm, commonly used probe cards will face manufacturing problems in miniaturization. To resolve probe card manufacturing problems caused by the miniaturization of IC components, the use of an anisotropic conductive film (ACF) in probe cards was proposed in this study. Theoretical calculations and experimental testing of this probe structure were conducted to demonstrate the feasibility of this concept.
In theoretical calculations, composite material and buckling theory were utilized to evaluate the buckling behavior of the ACF. In experimental testing, photolithography and electroplating techniques were used to control the line width and spacing intervals of the micron-scale metal wires in the ACF. After the ACF was fabricated, the mechanical properties of the ACF during wafer testing were assessed. Theoretical analyses and experimental testing verified that ACFs can potentially be applied to the performance verification of IC products. In the ACF structure, multiple probes came into contact with each pad. Therefore, ACFs can potentially be applied to the performance verification of IC components with pad diameters of less than 20 μm. The results of this study directly benefit the miniaturization of ICs.
In recent years, compact camera modules (CCMs) have been widely used in consumer electrical and electronic products. CCMs with low cost specially are necessary for portable devices. Therefore, the present group recently developed a miniaturized open-loop controlled camera module with low cost for cellphone applications, in which the Lorentz force is balanced by a magnetic restoring force. To enhance the performance of the camera module, this article reports a pattern structure to modify the linearity of the magnetic restoring force. We fabricated a CCM prototype with the dimensions of 8.5 mm × 8.5 mm × 5 mm and demonstrated the usefulness of the pattern structure with the CCM prototype. Its potential applications are foreseeable in portable devices, such as cellphones, web cameras, personal digital assistants and other commercial electronics.
The aim of the study was to evaluate the comparative risk of self-harm associated with the use of different antidepressants.
A cohort study was conducted using data from Taiwan's National Health Insurance Research Database from 2001 to 2012. A total of 751 606 new antidepressant users with depressive disorders were included. The study outcome was hospitalization due to self-harm (International Classification of Diseases, Ninth Revision, Clinical Modification codes: E950–E958 and E980–E988). Cox proportional hazards models with stratification of the propensity score deciles were used to estimate the hazard ratios of self-harm hospitalization during the first year following the initiation of antidepressant treatment.
There were 1038 hospitalization episodes due to self-harm that occurred during the follow-up of 149 796 person-years, with an overall incidence rate of 6.9 [95% confidence interval (CI) 6.5–7.4] per 1000. Compared with fluoxetine, the risk of self-harm hospitalization was higher for maprotiline [adjusted hazard ratio (aHR) = 3.00, 95% CI 1.40–6.45], milnacipran (aHR = 2.34, 95% CI 1.24–4.43) and mirtazapine (aHR = 1.40, 95% CI 1.06–1.86), lower for bupropion (aHR = 0.51, 95% CI 0.30–0.86), and similar level of risk was found for other selective serotonin reuptake inhibitors (citalopram, escitalopram, fluvoxamine, paroxetine and sertraline).
The risk of self-harm may vary across different antidepressant drugs. It would be of importance to conduct further research to investigate the influence of antidepressant use on self-harm behaviors.
EVA foams, like all other polymers, also exhibit strain-rate effects and hysteresis. However, currently available approaches for predicting the mechanical response of polymeric foam subjected to an arbitrarily imposed loading history and strain-rate effect are highly limited. Especially, the strain rates in the intermediate rate domain (between 100 and 102 s–1) are extremely difficult to study. The use of data generated through the drop tower technique for implementation in constitutive equations or numerical models has not been considered in past studies. In this study, an experiment including a quasi-static compression test and drop impact tests with a high speed camera was conducted. An inverse analysis technique combined with a finite element model for material parameter identification was developed to determine the stress–strain behavior of foam at different specific strain rates. It was used in this study to simulate multiple loading and unloading cycles on foam specimens, and the results were compared with experimental measurements.
The effects of various parameters, such as thermal properties of substrates, thermal interface materials (TIMs) and heat sinks on the thermal performance of the light emitting diode (LED) light bars and backlight module are investigated experimentally and numerically in terms of junction temperature (Tj) and thermal resistances from junction to air (Rj-a). The results show that the measured Rj-a of the light bars by powering-on five LEDs in the test is different from one by powering-on only one LED, resulting from the extra heat coming from the adjacent LED packages affecting the Tj for the case of powering-on five LEDs. For the modules, Rj-a is significantly reduced by using the heat sinks for all backlight modules, and aluminum and iron heat sinks do not show any obvious difference in heat dissipation along with any substrates and TIMs. Furthermore, both experimental and simulation results show that the thermal conductivity of the substrates are more important and dominant than TIM and heat sink for the Rj-a of the backlight modules concerned, and also demonstrate that the thermal field for the local model can represent the one in full-scale backlight module.
Voice restoration after laryngopharyngectomy can be achieved with an autologous ileocolic flap. We have observed that the length of the flap influences vocal outcome. This investigation aimed to evaluate the association between ileocolic flap length and vocal quality after laryngopharyngectomy.
The charts of patients who underwent voice rehabilitation with an ileocolic flap after laryngopharyngectomy between 1 January 2011 and 30 December 2012 were abstracted. The length of ileum segment in the ileocolic flap was stratified, and voice outcome was evaluated three months post-operatively, while adjusting for confounding variables.
There was a significant association between flap length and loudness, maximum phonation time and sound pressure level (p < 0.05). All three parameters were best in the 10 cm length group.
Voice rehabilitation after laryngopharyngectomy is possible with an ileocolic flap. The optimal ileocolic flap contains a 10 cm ileum segment. Complications are frequent but amenable to revision surgery.
Through silicon via (TSV) is the critical structure for three dimensional (3D) integration, which provides vertical interconnection between stacking dies. In TSV structure, large coefficient differences of thermal expansion exist between silicon substrate, dielectric material, and filled metal. Due to the large thermal mismatch, the high thermal stress occurring at the interface of different materials would result in delamination. Therefore, thermal-mechanical reliability is a key issue for 3D integration. In this study, we investigated the thermal-mechanical stress distribution of TSV under the condition of the accelerated thermal cycling loading by finite element analysis based on a 3D model of TSV structure. Due to the thermal expansion, that the TSV structure squeezed the surface area between TSVs at a high temperature resulted in compressive stresses at the surface area between TSVs. Therefore, a proper distance between the stress-sensitive device and the TSV should be kept. The stress analysis shows that the maximum thermal stress occurs in the outside region of TSV interface and in the annular region of TSV at a high temperature and at a low temperature, respectively. This study helps to obtain a clear thermal stress distribution of TSV and possible failure regions can be determined.
An uneven neurocognitive profile is a hallmark of autism spectrum disorder (ASD). Studies focusing on the visual memory performance in ASD have shown controversial results. We investigated visual memory and sustained attention in youths with ASD and typically developing (TD) youths.
We recruited 143 pairs of youths with ASD (males 93.7%; mean age 13.1, s.d. 3.5 years) and age- and sex-matched TD youths. The ASD group consisted of 67 youths with autistic disorder (autism) and 76 with Asperger's disorder (AS) based on the DSM-IV criteria. They were assessed using the Cambridge Neuropsychological Test Automated Battery involving the visual memory [spatial recognition memory (SRM), delayed matching to sample (DMS), paired associates learning (PAL)] and sustained attention (rapid visual information processing; RVP).
Youths with ASD performed significantly worse than TD youths on most of the tasks; the significance disappeared in the superior intelligence quotient (IQ) subgroup. The response latency on the tasks did not differ between the ASD and TD groups. Age had significant main effects on SRM, DMS, RVP and part of PAL tasks and had an interaction with diagnosis in DMS and RVP performance. There was no significant difference between autism and AS on visual tasks.
Our findings implied that youths with ASD had a wide range of visual memory and sustained attention impairment that was moderated by age and IQ, which supports temporal and frontal lobe dysfunction in ASD. The lack of difference between autism and AS implies that visual memory and sustained attention cannot distinguish these two ASD subtypes, which supports DSM-5 ASD criteria.
Singularity-free workspace is a very important criterion for the design of manipulators, especially for parallel manipulators which are well known for their limited workspace and complex singularities. This paper studies geometric parameters and dexterity measures that affect the size of a singularity-free joint space and proposes methods for the development of 6-DOF Stewart–Gough parallel manipulators that have better singularity-free joint space. With a local dexterity measure as the objective function, a systematic method is employed to search for the design with a maximal singularity-free joint space. The related workspaces are also investigated. It is shown that the workspace is not proportional to the size of the joint space and that manipulators with a larger singularity-free workspace usually have relatively poor dexterity.
In this study, the fictitious time integration method (FTIM) is applied to investigate wave propagation over an arbitrary bathymetry with measured uncertainty. The FTIM is used to convert the higher-order elliptic mild-slope equation (EMSE) into a FTIM like EMSE (FTIMEMSE). It has the advantage to describe wave transformation from deep water to shallow water region in a large coastal area with numerical efficiency. The validity of the noise resistance for the measured uncertainty of the bathymetry is also studied. In addition, typical examples for waves propagating over an elliptic shoal rest on a horizontal and sloping bottom is presented. It is concluded that the FTIM is robust in the numerical stability and capable of against the noise of the measurement.
We investigated lactate dehydrogenase isoenzyme patterns in the cyst fluid of auricular pseudocysts and autogenous blood, to assist the diagnosis of auricular pseudocyst.
Twenty patients with auricular pseudocysts participated in this study conducted in Kaohsiung Medical University Hospital between February 2007 and June 2010. Patterns of lactate dehydrogenase in cyst fluid and autogenous blood were analysed.
Levels of lactate dehydrogenase 1 and 2 were lower in auricular pseudocysts than in autogenous blood, whereas levels of lactate dehydrogenase 4 and 5 were higher; this difference was statistically significant (p < 0.001).
Lactate dehydrogenase isoenzyme patterns in auricular pseudocyst fluid indicated higher percentage distributions of lactate dehydrogenase 4 and 5 and lower percentage distributions of lactate dehydrogenase 1 and 2. An effective laboratory method of evaluating the different lactate dehydrogenase isoenzyme components was developed; this method may improve the accuracy of auricular pseudocyst diagnosis.
In clinical practice, cam-out failure at the recess-screwdriver interfaces may occur when tightening or removing a bone screw. For titanium-based periarticular fixation, the literature reports have revealed that cold welding at the plate-screw interfaces makes the screw recess especially prone to cam-out failure during screw removal. In this study, the effects of the four recess shapes (cross, hexagon, star, and crest), three torque value (0.8, 1.0, and 1.2N-m), and the three interfacial misfits (0.00, 0.05, and 0.10mm) on the cam-out failure were numerically evaluated. The free-rotation angle, torque-recess angle, slippage-resisting length, and interfacial stress distribution were defined and chosen as comparison indices for the twelve recess-misfit variations. The results revealed that the interfacial slippage, torque transfer, and stress distribution are highly related to both recess shape and interfacial misfit. The stresses of all recesses and screwdrivers consistently initiate at the contact sites. However, the recess profile significantly affects the stress propagation. The stress patterns of the recess and screwdriver are quite different between the cross-star and hexagon-crest groups. The cross-star group is superior to the hexagon-crest group in terms of the torque-recess angle and slippage-resisting length over. This makes the recess of the cross-star group less stressed than its counterpart. However, the volumes of the cross and the star screwdriver are more highly stressed than the hexagon due to the irregular shape and the thinner flange, respectively. The greater torque and misfit increase the performance difference between the four recess designs. In conclusion, the geometry of the cross and star groups provide the better performance of the screw recess in terms of torque-transferring efficiency and slippage-resisting ability. If the screwdriver material is properly strengthened and the stress-concentrating corners are modified, the cross and star groups would be the optimal designs that protects and extends the lifetime of both recess and reused screwdriver.
In this study, a novel procedure has been developed for predicting the notched strengths of composite plates each with a center hole. In this approach, the stress distribution of a composite plate with a center hole is first obtained by a finite element analysis, in which the experimental notched strength is applied at the boundary of the finite element model. Secondly, the point stress criterion (PSC) is used to find the characteristic length for each plate with different size of hole by an interpolation of the finite element analysis results. The characteristic length is then expressed as an empirical function of the hole size as well as the width of the plate. Finally, the notched strengths of composite plates are predicted based on the empirical function and the finite element analysis results incorporated with the principle of superposition in elasticity. For validation, three different cases from the literatures are adopted for comparison. It is shown that the predicted notched strengths by this new methodology agree well with both the experimental results and the results from analytical solutions based PSC.
This study performs parametric analyses on the displacement ductility capacity of a fixed-head reinforced concrete pile in homogeneous clay, considering the spread of plasticity in the pile. The parametric study regards the pile as a limited ductility structure, which conditionally allows the pile to have inelastic response during large loading. The variables considered include the pile section parameters and p-y model parameters. A large number of pushover analyses are conducted to examine the displacement ductility capacity of the pile. The results show that the plastic hinging will occur at the pile head region for a fixed-head pile, and the displacement ductility capacity of the pile is mainly influenced by the over-strength ratio of the pile section. Furthermore, the second plastic region may occur in ground when the axial force is in high tension. Based on the design concept of limited ductility structures, the high tensile force in pile should be avoided in pile design. A quantitative relationship between the displacement ductility capacity and over-strength ratio is suggested for engineering applications.
We investigated gustatory changes in patients with chronic otitis media, before and after middle-ear surgery.
This prospective study included 38 patients with unilateral chronic otitis media. We used taste testing solutions to evaluate each patient's taste function. Intra-operative assessments of the chorda tympani nerve were also compared and analysed.
Patients with chronic otitis media had significantly worse ipsilateral perception of sour, bitter and salty tastes. In patients with good intra-operative preservation of the chorda tympani nerve, there was significant improvement in gustatory function one month post-operatively, compared with the pre-operative baseline. In patients who sustained intra-operative chorda tympani nerve injury, one month post-operative gustatory function was the same as the pre-operative baseline.
Middle-ear surgery for chronic otitis media not only treats the ear but also improves gustatory function in the majority of patients. In patients with intra-operative injury to the chorda tympani nerve, post-operative taste decline is only temporary.
We report production of a self-injected, collimated (8 mrad divergence), 600 pC bunch of electrons with energies up to 350 MeV from a petawatt laser-driven plasma accelerator in a plasma of electron density ne = 1017 cm−3, an order of magnitude lower than previous self-injected laser-plasma accelerators. The energy of the focused drive laser pulse (150 J, 150 fs) was distributed over several hot spots. Simulations show that these hot spots remained independent over a 5 cm interaction length, and produced weakly nonlinear plasma wakes without bubble formation capable of accelerating pre-heated (~1 MeV) plasma electrons up to the observed energies. The required pre-heating is attributed tentatively to pre-pulse interactions with the plasma.
Rose geranium (Pelargonium graveolens, Geraniaceae) has anti-cancer and anti-inflammatory properties, and promotes wound healing. Similarly, Ganoderma tsugae (Ganodermataceae), Codonopsis pilosula (Campanulaceae) and Angelica sinensis (Apiaceae) are traditional Chinese herbs associated with immunomodulatory functions. In the present study, a randomised, double-blind, placebo-controlled study was conducted to examine whether the Chinese medicinal herb complex, RG-CMH, which represents a mixture of rose geranium and extracts of G. tsugae, C. pilosula and A. sinensis, can improve the immune cell count of cancer patients receiving chemotherapy and/or radiotherapy to prevent leucopenia and immune impairment that usually occurs during cancer therapy. A total of fifty-eight breast cancer patients who received chemotherapy or radiotherapy were enrolled. Immune cell levels in patient serum were determined before, and following, 6 weeks of cancer treatment for patients receiving either an RG-CMH or a placebo. Administration of RG-CMH was associated with a significant reduction in levels of leucocytes from 31·5 % for the placebo group to 13·4 % for the RG-CMH group. Similarly, levels of neutrophils significantly decreased from 35·6 % for the placebo group to 11·0 % for the RG-CMH group. RG-CMH intervention was also associated with a decrease in levels of T cells, helper T cells, cytotoxic T cells and natural killer cells compared with the placebo group. However, these differences between the two groups were not statistically significant. In conclusion, administration of RG-CMH to patients receiving chemotherapy/radiotherapy may have the capacity to delay, or ease, the reduction in levels of leucocytes and neutrophils that are experienced by patients during cancer treatment.