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This article proposes an inverted U-curve theory to represent the changes in transit-induced gentrification with increases in mass rapid transit (MRT) station density over time. A forty-year experi...

Despite the increasing attention paid to metro-induced gentrification, the literature must still present evidence of whether the practice is accompanied by household displacement. Accordingly, this research explored whether proximity to metro stations is associated with the displacement of lower-income households (LHs) by higher-income households (HHs). The study areas comprised two gentrifiable neighborhoods in Taipei City, Taiwan, including a metro station area and a comparison area (being far from metro stations) with a similar socioeconomic context. The detailed and longitudinal records of household income tax in the study areas between 2001 and 2016 were collected and analyzed through survival analyses. Empirical results suggested that household displacements are associated with metro stations. Specifically, LHs in the metro station area had higher survival risks and lower survival years than HHs in the metro station area and LHs in the comparison area. The findings broaden our understanding of metro-induced household displacement and suggest that geographical exclusion of the economically disadvantaged groups from mass rapid transit services has occurred.

This article presents a transnational comparison study to clarify the difference in the associations of built environment with public bike usage in three cities in eastern Asia. This study sampled passengers entering or leaving metro stations in seven neighborhoods in Beijing, Taipei, and Tokyo for home-based work trips. Their mode choices of connecting travels between trip origins/destinations and metro stations were analyzed using logit and latent class models . Empirical evidence reveals that the associations of built environments with public bike usage of the study cities rarely accord with one other. Results are unable to support that empirical knowledge on the association of built environment with public bike usage is transferable among transnational cities despite their geographical and cultural proximity. Collecting local empirical knowledge on travel behavior is critical for developing bike-friendly built environments for a city.

This work demonstrated a novel amperometric method to measure the concentration of histamine directly without using any enzymatic reaction or a complicated derivation scheme. Based on the strong chelating property between histamine and cupric (II) ions, cupric oxide would be dissolved by the histamine and a cupric-histamine complex would be formed on the electrode surface, subsequently, an oxidative current resulted from the regeneration of the surface cupric oxide was used to reflect the concentration of the histamine in the sample. Under the optimal conditions with operating potential at 200 mV in a 100 mM phosphate buffer, pH 10.0, containing 50 mM acetate, a suitable dynamic range of histamine from 1 to 750 μM with a sensitivity of 15 nA/μM (R = 0.999) and a detection limit of 0.33 μM was achieved on a typical FIA system. Subsequently, the performance of this scheme was integrated with high-performance liquid chromatography as an electrochemical detector. In optimal conditions, the linear range is estimated from 10 to 2500 μM (0.5–125 nmol per injection), which is an adequate range for the determination of the freshness quality of a seafood. Finally, the feasibility of this scheme in real sample application was demonstrated by evaluating the histamine level in a fresh saury fish and a defrost one, respectively.

Improving PCM endurance is a fundamental issue when it is considered as an alternative to replace DRAM as main memory. Memory-based wear leveling (WL) is an effective way to improve PCM endurance, but its major challenge is how to efficiently determine the appropriate memory pages for allocation or swapping. In this article, we present a constant-cost WL design that is compatible with existing memory management. Two implementations, namely bucket-based and array-based WL, with constant-time (or nearly zero) search cost are proposed to be integrated into the OS layer and the hardware layer, respectively, as well as to trade between time and space complexity. The results of experiments conducted based on an implementation in Android, as well as simulations with popular benchmarks, to evaluate the effectiveness of the proposed design are very encouraging.

This work described a novel method to evaluate the electroosmotic flow (EOF) without using any complicated electric profile or physical modification of the running buffer. In a typical off- channel based microfludic device, it is found the carbon ink based decoupler electrode maintains its reduction capability after the electric field is turned off, this phenomenon makes it continually converts the dissolved oxygen into hydrogen peroxide. Since the electric field is isolated before the decoupler electrode, this in-situ generated sample plug is delivered to pass through the detector with an equal velocity to the EOF in the next run. Therefore, the velocity of EOF can be easily estimated based on the migration time and the distance between the decoupler and the working electrode. Subsequently, the application of simultaneous evaluation of the velocity of EOF and the electrophoretic property of several analytes, including catechol, 2-aminophenol, dopamine and hydrogen peroxide have been also demonstrated in this method, respectively.

In this work, we have developed a simple and reliable cobalt oxide (Co3O4) based amperometric sensor for the determination of NADH. A sheet shape Co3O4 nanooxide was synthesized by the CTAB assisted hydrothermal technique and was characterized by SEM and XPS. Owing to the redox property of Co3O4, the operating potential of NADH can be significantly reduced from 0.7down to 0.1 V. Compared to a commercial Co3O4 nanoparticle modified electrode, this nanosheet form cobalt oxide possesses a rapid background subsiding characteristic and a low residual current. This scheme was conducted on a flow injection system with a constant operating potential of 0.1 V (vs. Ag/AgCl, 3 M) in a 0.2 M phosphate buffer at pH 6.0. A suitable linear range from 10 to 100 μM (R=0.999) with a detection limit of 4.25 μM (S/N=3) was obtained. The RSD for 20 successive measurements of 75 μM NADH is only 1.4%, which indicates a high stability and no contamination during NADH oxidation. This scheme did not suffer from conventional antioxidants, including dopamine, uric acid, epinephrine, serotonin, histamine, and 4-acetaminophen, except ascorbic acid. Thus, an ascorbate oxidase was introduced to remove the ascorbic acid before the sample was injected into the flow injection analysis system. After this simple pretreatment, the influence of ascorbic acid was eliminated, successfully.

Changes in indium tin oxide (ITO) film surface during electrochemical treatment in oxalic acid, tartaric acid, and citric acid were investigated. Controlling the voltage applied on ITO film allows the formation of a passive layer, effectively protecting the film surface. X-ray photoelectron spectrometry showed that the passive layer composition was predominantly SnO2 in tartaric acid, while a composite of tin oxide and tin carboxylate in citric or oxalic acid. Even though the passive films on ITO surface generated in these organic acids, the indium or tin could complex with the organic acid anions, enhancing the dissolution of ITO films. The experimental results show that the interaction between the dissolution and passivation could assist to planarize the ITO surface. We found that the optimal treatment at 0.5 V in 3 wt.% tartaric acid could provide the ITO surface with root-mean-squared roughness less than 1.0 nm, due to the weak complexing characteristics of tartaric acid.

Samples of airborne and surface-bound microbial contamination were taken in two intensive care units of a large-scale medical center. Microbial analyses included total bacterial and fungal loads, as well as the four bacterial species of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Acinetobacter baumannii. Among the 114 surface samples taken from seven designated surface locations of room and equipment for each patient, P. aeruginosa was the most frequently detected (19.3%) and most abundant (mean count: 4.18 cfu/plate) bacterium, whereas the respirator represented the most heavily contaminated surface location in both total pathogenic bacteria colony counts (272 cfu) and frequency of positive detection (38.2%). P. aeruginosa also represented the most frequently detected (39.1%, n = 46) and abundant (11.52 ± 17.16 cfu/m^3) bacterium in the air samples (n = 46), and was the only bacterium exhibiting a positive correlation of the mean counts between air and surface samples. The data analysis results further suggested a higher value of relative risk among the infected patients in the presence of the pathogens as compared to those in the absence of them, although the evidence of a of correlation for the individual bacterial species between the environmental samples and infected patients was inconclusive. This study also found that the mean airborne counts and the detection frequencies of these bacteria after patient visitation periods were higher than those before visitation, and that the installation of local air ionizers did not lead to any discernible differences in total bacterial and fungal concentrations.

This project demonstrates a novel amperometric method to measure the concentration of nabam through a process of potential assisted surface oxide on the copper based electrode. Based on the strong cuprous ion chelating capability of nabam, the cuprous oxide layer is dissolved away from the electrode surface. A subsequent oxidative current induced from regeneration of the oxide layer was used to reflect the concentration of the nabam. Under a set of optimal conditions with operating potential at −125 mV in the 50 mM phosphate buffer, pH 5.75, a suitable dynamic range of nabam from 0.2 μM to 10 μM (or 0.051–2.56 ppm) was achieved, which meets the requirement of the Joint FAO/WHO Meeting on Pesticide Residues. This method is free from the environmental interferences. However, most of all metal ions show a negative deviation due to the formation of other metal–nabam complexes. Here, a simple cation exchange column was used to release the chelated nabam molecule. Finally, two successful real applications were demonstrated by using a standard addition procedure after this cation exchange pretreatment.

A facile synthesis method has been developed for preparing porous hexadecyltrimethylammonium-coated Pt–Ag nanosponges using ascorbic acid. As determined via electron diffraction and mapping element measurements, the nanosponges feature fcc and mixed-alloy structures. The nanosponges were successfully deposited on the sidewalls of sodium dodecyl sulfate-micelle-functionalized herringbone graphite nanofibers (Pt–Ag/GN) using an electrostatic attraction. Further, as supported by in situ analyses, the mass activity and electrochemical kinetics of the Pt–Ag/GN nanocomposite toward the electrocatalysis of the oxygen reduction reaction (ORR) were studied. The results demonstrate that the mass activity of Pt–Ag/GN is 5.59 × 10 −3 mA μg pt −1 and greater than 3.91 × 10 −3 mA μg pt −1 , the commercial Pt/C (at −0.15 V vs. Ag/AgCl). The numbers of ORR transfer electrons on the new composites reached 3.44 (at −0.15 V vs. Ag/AgCl), which shows that the ORR occurred quickly.

A novel structure-specific electrochemical sensing scheme to monitor analyte, independent of its oxidation potential, is described. Molecules with multidentate chelating sites that can form stable five- or six-membered ring complexes with cupric ions are appropriate for this approach. In the copper-based electrode, potential-accelerating complex formation behavior is observed, and an apparent oxidation current is induced to regenerate the oxide layer until reaching its maximum steady state. In this unique electroanalytical method, a suitable potential is utilized to increase the coordination number of the metal electrode surface rather than direct oxidation of the analyte. The experimental results show that the signal sensitivity depends primarily on the pK a of the chelating sites and the solution pH. Several aliphatic amines were studied with this simple approach, and the detection limits for spermidine (SPD; 0.19 μM) and spermine (SPM; 0.14 μM) at a low oxidation potential (0.25 V vs. Ag/AgCl) were obtained. A higher operating potential was used to improve the sensitivity for putrescine (PUT) and cadaverine (CAD). The detection limit was improved to 0.05, 0.06, 0.11 and 0.27 μM for SPD, SPM, PUT and CAD, respectively, without surface fouling (less than 3% with RSD). The feasibility of its clinical application is demonstrated by integrating this sensor with high-performance liquid chromatography (HPLC).

New determination scheme of p-aminophenol by using MnO2 as a preoxidant is demonstrated in this work. In the flow injection system, the p-aminophenol is oxidized to quinoneimine by MnO2 at up-stream, which can be detected at a suitable reductive potential. After optimization, the linear range of PAP is started from 1 μM to 30 μM (R2=0.999), the estimated detection limit (S/N=3) is 0.28 μM. Two real samples are studied and excellent recoveries are achieved by using standard addition method.

Time-reversal mirror (TRM) was recently developed for underwater communication system application. This technique has been introduced as an approach to compensate for signal distortion due to multiple path effect in ocean waveguide. TRM is used in this paper for sending a message signal in ocean waveguide, received at time-reversal-array (TRA), and retransmitted to the dynamic ocean environment with an internal solitary wave. The focal structures obtained from different simulating cases are used for bidirectional transmission expediency, and the TRA is used as the relay-line or trunked radio. Ocean waveguide characteristic effects on acoustical properties are also shown in this paper, and focal structure in different ocean environments is analyzed to provide an optimal approach to underwater communication systems and for physical insight's interests.

This paper presents the Statistical Analysis of Passive Sonar Performance Prediction in Littoral Environments. Passive sonar performance and acoustic prediction mainly refer to the detection range. The inputs for estimating the sonar detection range include the Figure of Merit (FOM), Transmission Loss (TL), and Ambient Noise (NL) of the operation region. These inputs are directly related to the ocean environment; hence, the detection range is, too. A littoral environment is highly variable both in time and space. This paper proposes a methodology for analyzing the statistical properties of the detection range from measurements of ocean water column properties. It is found that the detection range of the southwestern region of Taiwan in the summer is 13.8km with 5.9km as the standard deviation and in the winter is 37.8km with 33.6km as the standard deviation.

Liquid crystal (LC) cells with photopolymers usually exhibit a fast response time but inevitably present decreased optical transmittance and lower contrast ratio due to incomplete dark states. In this study, we show that this issue can be improved when photopolymerization at low temperature is considered. Comparing performance with the 4 wt% RM257-doped fringe-field switching (FFS) LC cell photopolymerized at room temperature, the 1.4 wt% RM257-doped FFS LC cell photopolymerized at low temperature (273 K) shows better contrast ratio and lower operating voltage. In addition, the electrostriction effect can be also reduced in LC cells with lower RM257-doped concentration. As a result, the 1.4 wt% RM257-doped FFS cell shows a response time as fast as that in the 4 wt% RM257-doped FFS cell. Meanwhile, the average response time for gray-to-gray switching of the optimal FFS cell is 4.9 ms.

In this approach, a novel method to fabricate an integrated amperometric platform used in off-channel electrophoresis has been introduced. A simple screen printed protocol combining a wet etching procedure was used to define the pattern on a glass substrate, and whole electrodes were constructed by filling the conductive carbon ink into the etched cavities. A simple Teflon tape was used to align this platform with the micro-channel, and the variation of reassembling of this device can be down to 2.2% without the assistance of microscope. This device was characterized by dopamine (DA) and catechol (CA), and the width of half peak is around 4 s, even a 100 μm double T shape injection design and a 550 μm working electrode were used in this work. Under the optimum condition, this device possesses a low background with a noise level of 1.4 pA (peak to peak). The linear range for DA and CA are 0.1–100 μM ( R = 0.998) and 0.2–200 μM ( R = 0.996) with a theoretical plate number of 1.57 × 10 4 and 3.46 × 10 4 (plate/m), respectively.

Iminodiacetic acid (IDA) and octyl moieties were covalently bound on nonporous particles, which were prepared from dispersion polymerization of methyl methacrylate and glycidyl methacrylate. After being charged with copper ions, the IDA-bound particles could specifically adsorb deoxyribonuclease I (DNase I) through the affinity interaction between protein and immobilized metal ion. A mixed-ligand (metal-chelate and octyl-bound) support was obtained after hydrophobic (octyl) groups were also introduced to the particle surface. The affinity adsorption of DNase I on the copper-IDA chelate was influenced by interaction between the protein and the bound octyl group. Both the affinity and the hydrophobic interactions could be well described by the Langmuir isotherms. The equilibrium adsorption constants were estimated separately to be 0.96 and 0.50 liter g(-1) for affinity and hydrophobic bindings, respectively. For binding on mixed-ligand support, the adsorption constant was 0.45 liter g(-1). It was evident that both affinity and hydrophobic interactions are involved in the adsorption of proteins onto mixed-ligand particles. Desorption of the inactive proteins from the support was possible by increasing the hydrophobicity of the solution. Copyright 2001 Academic Press.

Financial statements of all listed and over the counter (OTC) companies collected by stock exchange represent valuable big open data. Therefore, automatic processing and analyzing such big data would create tremendous added value economically. In this paper, we design and implement a cloud service for evaluating company's financial health using XBRL-based financial statements collected by Taiwan Stock Exchange Corporation (TWSE). The XBRL-based financial statements are parsed and stored as key-value pairs into MongoDB, which is a kind of NoSQL database. The proposed system is designed using three-tier architecture for flexibility and maintainability. It also provides user-friendly interface with various charts. The proposed system indeed demonstrates powerful benefits of implementing interactive data using XBRL for financial disclosure documents in big data era.

Particles of methyl methacrylate (MMA) and glycidyl methacrylate (GMA) copolymer having narrow size distributions were prepared by the method of dispersion polymerization. Results from the analysis of particle porosity and the correlation of specific surface area with the reciprocal of particle diameter suggest that the prepared particles were nonporous. The particle size was found to decrease from 4.2 to 2.1 μm with increasing the mass ratio of GMA/MMA from 0.1 to 0.75. Polymer particles having an average diameter falling in this range are suitable for being employed as the stationary phase in protein chromatography. The decrease in particle size when GMA was present could be due to the increase in adsorption rate of poly(vinyl pyrrolidone). The oligomer chains that were rich in GMA were more active for adsorbing and grafting PVP, compared with the moiety of MMA. An increase in the GMA/MMA ratio also leaded to a decrease in epoxy-group density on the particle surface, since the reactivity of GMA was greater than that of MMA. Results of this work suggest that the influence of GMA/MMA mass ratio on the particle size and surface functionality of the nonporous particles was very significant. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1457–1463, 1999

This article described a novel amperometry which can be used for determination of purine derivatives including uric acid, xanthine, hypoxanthine, guanine, and adenine without surface contamination. By applying a constant potential of −0.125 V (vs. Ag/AgCl) in a flow injection system, the chelating capability of these purine derivatives converts the cuprous oxide layer into a soluble complex. This behavior would dissolve the passive oxide layer and expose the bottom copper layer to the solution, subsequently; an oxidation current which attributed to the regeneration of the original cuprous oxide layer is used to reflect the concentration of these purine derivatives. In a 50 mM phosphate buffer, pH 7.0, this approach provides a high sensitivity with LOQ of sub-micro molar level of five purines and high stability with a RSD of 2.5% for 10 μM xanthine ( N = 12). This method does not suffer from most biological species including ascorbic acid, acetaminophen, creatine, dopamine, sarcosine, ammonium ion, chloride ion, and urea at equal or higher than its physiological concentration.

In this work, we have developed a simple and reliable cobalt oxide (Co₃O₄) based amperometric sensor for the determination of NADH. A sheet shape Co₃O₄ nanooxide was synthesized by the CTAB assisted hydrothermal technique and was characterized by SEM and XPS. Owing to the redox property of Co₃O₄, the operating potential of NADH can be significantly reduced from 0.7 down to 0.1 V. Compared to a commercial Co₃O₄ nanoparticle modified electrode, this nanosheet form cobalt oxide possesses a rapid background subsiding characteristic and a low residual current. This scheme was conducted on a flow injection system with a constant operating potential of 0.1 V (vs. Ag/AgCl, 3 M) in a 0.2 M phosphate buffer at pH 6.0. A suitable linear range from 10 to 100 μM (R=0.999) with a detection limit of 4.25 μM (S/N=3) was obtained. The RSD for 20 successive measurements of 75 μM NADH is only 1.4%, which indicates a high stability and no contamination during NADH oxidation. This scheme did not suffer from conventional antioxidants, including dopamine, uric acid, epinephrine, serotonin, histamine, and 4-acetaminophen, except ascorbic acid. Thus, an ascorbate oxidase was introduced to remove the ascorbic acid before the sample was injected into the flow injection analysis system. After this simple pretreatment, the influence of ascorbic acid was eliminated, successfully.

In this work, a highly structural dependent amperometric scheme was proposed for the determination of creatinine without enzymatic assistance. The principle of this novel method is based upon the formation of a soluble copper-creatinine complex on the copper electrode surface. Subsequently, an oxidative current from the regeneration of the surface oxide layer is monitored and it is proportional to the concentration of the creatinine. This scheme can be conducted at potential of -0.1 V (vs. Ag/AgCl, 3 M) in phosphate buffer (pH 7). A typical calibration plot from 25 μg/dL to 1.5 mg/dL (R(2)=0.997) with a detection limit of 6.8 μg/dL (S/N=3) is achieved. The relative standard deviation of 21 successive injections of 0.2 mg/dL creatinine is 0.018. Under the optimal conditions, the frequently encountered biological interferences at physiological or higher concentration were investigated. Only uric acid revealed an obvious interference (298.1%). However, a Nafion(®) coated copper plating electrode shows a successful decrement of the interference of the uric acid with slightly decreased sensitivity of creatinine. The feasibility of this scheme for further clinical application is demonstrated by both HPLC and FIA to evaluate the creatinine concentration in a urine sample.

The on-chip Transient Voltage Suppressor (TVS) embedded in the silicon based transceiver IC has been proposed in this paper by using 0.8 μm Bipolar-CMOS-DMOS (BCD) process. The structure of the on-chip TVS is a high voltage Dual Silicon-Controlled-Rectifier (DSCR) with ±19V of high holding voltage (Vh) under the evaluation of 100ns pulse width of the Transmission Line Pulsing (TLP) system. The holding current (Ih) of the on-chip TVS is so high that can pass ±200mA latchup testing. Therefore, the on-chip TVS can be safely applied to protect the ±12V of signal level for RS232. The RS232 transceiver IC with on-chip TVS has been evaluated to pass the IEC61000-4-2 contact ±12kV stress without any hard damages and latchup issue. Moreover, the RS232 transceiver IC also has been verified to well protect the system over the IEC61000-4-2 contact ±20kV stress (CLASS B) in the smart scanner and notebook application

Nonporous particles of microsize were prepared by the dispersion polymerization of styrene and glycidyl methacrylate and chemically modified to introduce amino groups on the surface by grafting with either hexamethylenediamine or N-methyl-1,3-propanediamine. Aminated particles were then coupled with phosphorylated single-stranded polynucleotides at the 5′-end through covalent linkages. The affinity columns packed with these prepared polynucleotide-immobilized particles effectively retained single-stranded DNA, which could base-pair with the immobilized sequence. Bound DNAs could be eluted to yield a sharp peak by using an aqueous solution of 0.4 M NaOH. The nonspecific adsorption due to the electrostatic interaction between the polynucleotide and the residual amino groups on the particle surface via the amination with hexamethylenediamine was significant and could only be reduced by using a high salt (NaCl) concentration. A higher salt concentration in the elution solution could result in a portion of complementary polynucleotide eluted in the nonretained fraction. However, the nonspecific adsorption of polynucleotides was insignificant in the column packed with DNA-immobilized particles prepared via amination using N-methyl-1,3-propanediamine. The column was effective for microanalysis of sequence-specific DNA.

Affinity chromatography on non-porous particles of microsize is particularly useful for the rapid analysis and micropreparative separation of proteins. The elution behavior of proteins in an affinity column packed with non-porous copolymerized particles of styrene, methyl methacrylate and glycidyl methacrylate was investigated both theoretically and experimentally, using the lysozyme-Cibacron Blue 3G-A affinity system. Equations used to predict the elution profiles, resulting from the elution by increasing the ionic strength (NaCl concentration) in the mobile phase, were obtained. The maximum adsorbate concentration, desorption rate constant and equilibrium constant under elution conditions were determined by matching experimental data with predicted elution profiles. Based on the parameters determined at a flow-rate of 0.5 ml/min and with 1 M NaCl in the elution buffer, the model equations could predict the elution profiles for other experimental runs, where different flow-rates and sodium chloride concentrations were used. Both the experimental and predicted results revealed that the affinity interaction kinetics are not significantly influenced by the flow-rate and, hence, the film mass transfer. To elute bound lysozyme from immobilized dye ligand, a higher value of the ionic strength leads to a faster elution and a sharper elution peak. The influence of elution conditions on the kinetic and thermodynamic parameters and, consequently, on the elution peak profiles was evaluated. The model equations can also predict the behavior of protein elution from an affinity column by changing the pH of the mobile phase, according to a previous study.