Search

Coastal Escherichia coli (E. coli) significantly influence ocean safety and public health, thus requiring an effective E. coli pollution monitoring. However conventional detection relying on manual field sampling is time-consuming. Here, this study established an E. coli estimation model based on thermal remote sensing of unmanned aerial vehicles (UAV). This model was developed against one-year comprehensive field work in a representative sandy beach and further validated against 50 beaches in Hong Kong to evaluate its applicability. The estimated E. coli concentrations were in a reliable agreement with direct measurements. For this model, this study deployed the radon-222 (

Fecal pollution poses a global threat to environmental safety and ecosystem, but the mechanism of microbial transport and occurrence in the beach groundwater system is still poorly explored. Here, we leveraged one-year field data of Escherichia coli (E. coli) and radon-222 (

Although submarine groundwater discharge (SGD) comprises an insignificant proportion of the global hydrologic cycle, it contributes significantly to chemical fluxes into the coastal waters due to concentrated constituents in coastal groundwater. Large nutrient loadings derived from SGD can lead to a series of environmental and ecological problems such as algal blooms, resulting in water discoloration, severe dissolved oxygen depletion, and eventually beach closures and massive fish kills. Previous studies have demonstrated the relationship between algal blooms and SGD obtained from direct measurement with seepage meters or from geo-tracer (i.e., radon and radium) based models; these traditional methods are time-consuming, laborious and point monitoring, and can hardly achieve a high spatiotemporal resolution SGD estimation, which is vital in revealing the effects of SGD to algal blooms over a long period. Alternatively, remote sensing methods for high spatiotemporal resolution SGD localization and quantification are applicable and effective. The temperature difference or anomaly between groundwater and coastal water extracted from satellite thermal images can be used as the indicator to localize and detect SGD especially its fresh component (or fresh SGD). In this study, multi-year (2005, 2011 and 2018) radon samples in Tolo Harbour were used to train regression models between in-situ radon (Rn) activity and the temperature anomaly by Landsat satellite thermal images. The models were used to estimate two-decade variations of fresh SGD in Tolo Harbour. The synergistic analysis between the time series of fresh SGD derived from regression models and high spatiotemporal resolution ecological metrics (chlorophyll-a, algal cell counts, and E.coli) leads to the findings that the increase of the fresh SGD associated with high nutrient concentrations is witnessed 10–20 days before the observations of algal bloom events. This study makes the first attempt to demonstrate the strong relation between the SGD and algal blooms over a vicennial span, and also provides a cost effective and robust technique to estimate SGD on a bay scale.

The explosive growth of phytoplankton under favorable conditions in subtropical coastal waters can lead to water discolouration and massive fish kills. Traditional water quality monitoring relies on manual field sampling and laboratory analysis of chlorophyll-a (Chl-a) concentration, which is resources intensive and time consuming. The cloudy weather of Hong Kong also precludes using satellite images for algal blooms monitoring. This study for the first time demonstrates the use of an Unmanned Aerial Vehicle (UAVs) to quantitatively map surface water Chl-a distribution in coastal waters from a low altitude. An estimation model for Chl-a concentration from visible images taken by a digital camera on a UAV has been developed and validated against one-year field data. The cost-effective and robust technology is able to map the spatial and temporal variations of Chl-a concentration during an algal bloom. The proposed method offers a useful complement to traditional field monitoring for fisheries management.

In Recent year, the traditional Si and wide band-gap power semiconductor devices, particularly Si MOSFET, Si IGBT, SiC MOSFET and GaN E-HEMT have gained considerable attention in several industrial applications such as the hybrid electric vehicle, the internet data center and aero-space applications. Attachment of power semiconductor devices to an insulated metal carrier substrate is essential for providing electrical and structural connections as well as a heat dissipation path. The die attach materials play a vital role in ensuring the system performance and reliability. In this study, the key technologies including multi-chip Cu paste sintering and panel level packaging have been developed. With an optimized process condition, a voidless die attaching joint was gained, and the die shear strength was as high as 70 MPa as sintering. Furthermore, the reduction of thermal resistance was measured by using Cu sintering, and the electrical performance of the newly developed Synchronous Rectifier was fully reported in this study.

Debris flow is a serious disaster which always leads to huge damages in Taiwan. After typhoon or downpour, the fluid pressure and the impact of the huge rocks and floating woods brought by debris flow may contribute to structural damage of bridges, or damage the bridge base which is attributed to the washout of the riverbed. These phenomena would seriously influence works concerning shelter-seeking and damage-relieving. Case studies in this research consist of two phase. For the first phase, data of debris flow cases such as typhoon and rainfall information Kaohsiung Baolai No.2 Bridge in Taiwan as case in 100/200 years return flood peak flow. Numerical simulation was performed using SMS-2D, result were presented in the main deep trough and area. For the second phase, this study designed a checking evaluation procedure of concrete cracking failure of foundation of bridge by using mathematic algorithm. This author certainly expects this procedure could be a further reference for pier and foundation of the bridge design.

Taiwan shaped to the narrow island, whose topography and climatic factors affecting the subject, river current is swift and steep riverbed erosion phenomenon is quite serious, this study Kaohsiung Baolai No.2 Bridge in southern Taiwan as an example and SMS-2D numerical model to simulate flow field during severe typhoon, and thereby calculate the scour depth around pipes by high sand silting, the riverbed elevation change after typhoon can be accurately simulated and provides references of related projects.

The carrier mobility of pentacene OTFT is enhanced by annealing its gate dielectric (SiO 2 ) in NH 3 . The device has a field-effect mobility of 0.53 cm 2 /V s, with on/off current ratio of 10 6 , and subthreshold slope of 2.4 V per decade. When compared with the control sample with N 2 -annealed SiO 2 as gate dielectric, the mobility of the proposed pentacene OTFT is increased by over 50%. AFM micrographs show that the higher mobility should be due to the smoother gate-dielectric surface passivated by the NH 3 annealing, and also larger pentacene grains grown on the smoother gate-dielectric surface.

Carbon-doped SiO 2 (SiOC), a low dielectric constant (low- k ) material was integrated with copper to fabricate Cu–SiOC single damascene test structures. Dielectric leakage between metal lines was assessed by voltage ramp method. This work is to investigate the effect of voltage ramp ( V ramp ) rate on the dielectric breakdown and leakage mechanism of Cu–SiOC interconnects with different metal widths and spaces. Breakdown field ( ξ BD ) was found to increase as the ramp rate was increased; median charge to breakdown ( Q BD ) decreased as the ramp rate was increased. At any given ramp rate Q BD was almost constant for different interline spaces, and this was correlated; this median Q BD was found to be linear with that obtained from time-dependent dielectric breakdown (TDDB) tests. This provides the possibility of using accelerated ramp results to predict the long-term reliability; hence, Q BD from V ramp can be used as a failure criterion to assess dielectric reliability.

The relative biological effectiveness (RBE) of high-energy protons has been well investigated, but estimates of RBE for lower-energy (40MeV) protons are scarce. In the present work, measurements were made of the lineal energy spectra using a home-made miniature tissue-equivalent proportional counter for 15 and 30MeV protons from the TR 30/15 cyclotron. Monte Carlo simulations were made for the same spectra using the FLUKA code. These spectra were coupled to several biological models to evaluate the RBE for various biological endpoints.

Introduction Epidepride is a compound with an affinity in picomolar range for D 2 /D 3 receptors. The aim of this work was designed to investigate the diagnostic possibility of [ 123 I]epidepride imaging platform for risperidone-treatment chronic MK-801-induced rat schizophrenia model. Methods Rats received repeated administration of MK-801 (dissolved in saline, i.p., 0.3mg/kg/day) or saline for 4weeks. After 1-week administration of MK-801, rats in MK-801+risperidone group received risperidone (0.5mg/kg/day) intraperitoneally 15min prior to MK-801 administration for the rest of 3-week treatment. We obtained serial [ 123 I]epidepride neuroimages from nanoSPECT/CT and evaluated the alteration of specific binding in striatum and midbrain. Results Risperidone reversed chronic MK-801-induced decrease in social interaction duration. IHC and ELISA analysis showed consistent results that chronic MK-801 treatment significantly decreased striatal and midbrain D 2 R expression but repeated risperidone administration reversed the effect of MK-801 treatment. In addition, [ 123 I]epidepride nanoSPECT/CT neuroimaging revealed that low specific [ 123 I]epidepride binding ratios caused by MK-801 in striatum and midbrain were statistically alleviated after 1- and 2-week risperidone administration, respectively. Conclusions We established a rat schizophrenia model by chronic MK-801 administration for 4weeks. [ 123 I]Epidepride nanoSPECT neuroimaging can trace the progressive alteration of D 2 R expression in striatum and midbrain caused by long-lasting MK-801 treatment. Besides diagnosing illness stage of disease, [ 123 I]epidepride can be a useful tool to evaluate therapeutic effects of antipsychotic drug in chronic MK-801-induced rat schizophrenia model.

Myopic crescent, refractive error and axial length were previously investigated in Hong Kong Chinese subjects. The myopic crescent was found to correlate with axial length and myopic refraction. In this study, three groups of Hong Kong Chinese with different degrees of myopia were assessed for optic disc ovalness, refractive error and axial length. The axial length was significantly correlated with the degree of myopia, indicating that the myopia was axial in nature. The regression line shows that 0.44 mm of axial elongation would give about one dioptre of increase in myopia. The elliptical ratio of the optic disc was defined as the maximal disc diameter divided by the minimal disc diameter. All three groups showed an oval disc with vertical axis greater and an increased ovalness for the high myopic group with an elliptical ratio from 1.11 in low myopia to 1.29 in high myopia. There is a small amount (about four degrees) of temporal rotation of this vertical oval orientation, which is independent of the amount of myopia. This result shows an association between axial elongation of the globe and optic disc ovalness, in addition to the previously described temporal myopic crescent. Therefore, in myopic subjects, a vertically oval disc may be associated with a myopic refraction rather than glaucoma.

(LR x Sm 1 − x ) 2 (Fe 1 − y Co y ) 17 alloys (LRLa, Ce; x  0, 0.1, 0.3, 0.5, 0.8, and 1; y = 0, 0.2) were prepared by are melting, homogenization and pulverizing. A single-phase Th 2 Zn 17 -type structure is sustained for the whole range of x for Ce, but only for x y = 0, 0.2). The alloys were then nitrogenated under flowing nitrogen to give (LR x Sm 1 − x ) 2 (Fe 1 − y Co y ) 17 N 2 − δ (δ = ± 0.1) alloys. These were pulverized again and mixed with 16.7 wt.% Zn powder, after which they were die pressed then sintered at 450 °C. The bonded magnets have a remanence of 4.9–5.6 kG (at about 80% of true density), a coercivity of 2.8–3.9 kOe and a ( BH ) max value of 3.3–3.5 MG Oe, depending on LR and x , but are independent of y . Low density, and uneven and low nitrogen content are the main reasons for unsound magnetic properties. There is much room for improvement in the magnetic properties, by optimizing the nitrogenation and densification. The La- or Ce-substituted Sm 2 (Fe,Co) 17 N 2 − δ alloys show potential in applications as low price resin-bonded magnets.

The addition of 2 at.% Cr or W into a sintered (Nd,Dy)-Fe,Co)-B alloy is very effective in improving room temperature coercivity and thermal stability. The W-containing alloy shows twice the coercivity value of that of W-free alloy at temperatures higher than 100 degrees C. Both W and Cr alloying greatly improve the high temperature stability. There exists a WFeB precipitate phase in the W-containing alloy. The WFeB phase is platelet with its long axis parallel to the c-axis of the 2-14-1 phase. The domain wall pinning at the precipitate phase, as evidenced by the Lorentz microscopy, is the cause of enhanced coercivity of this alloy, particularly at high temperatures. >

The magnetic properties of hydrogenated or/and nitrogenated SmFe/sub 3/ alloys are studied. It is found that SmFe/sub 3/ can be readily hydrogenated while not nitrogenated. There are two hydrogenation temperatures, that at 195 degrees C corresponding to the formation of SmFe/sub 3/H/sub x/ and that at 450 degrees C corresponding to decrepitation of SmFe/sub 3/ phase forming SmH and alpha -Fe, respectively. The SmFe/sub 3/H/sub 1.34/ has the highest saturation magnetization of all, while anisotropy field decreases due to hydrogenation. The difficulty in nitrogenation is attributed to kinetic reasons of the formation of SmN compound, around 20 nm in size, on the surface or grain boundary of the powder, retarding further diffusion of nitrogen into the matrix. >

Keratoconus is a condition in which the cornea assumes a complex irregular curvature caused by central corneal thinning. The abnormal topography of the cornea in combination with central corneal scarring results in an impaired visual acuity. Even in mild cases spectacles do not correct vision adequately. The use of hard contact lenses with a spherical geometry in the past has already given a marked therapeutic improvement. The use of these lenses however, is complicated by hypoxia and mechanical trauma of the cornea. These complications could theoretically be avoided by fitting elliptical lenses with a high oxygen transmission. To investigate this hypothesis we compared low oxygen-permeable spherical lenses with high oxygen-permeable elliptical contact lenses in a group of twenty patients with mild keratoconus. Our results showed both a marked subjective and objective visual improvement after fitting elliptical lenses with a low incidence of complications.

The activity of phosphoenolpyruvate (PEP) carboxylase in preparations obtained by lysis of spheroplasts of three species of blue-green algae was found to be 1.5- to 5-fold higher at 20°C than that of RuDP carboxylase. This level of enzyme activity suggests that these algae may have the ability to fix carbon dioxide by a C4 pathway.

A microcomputer is used to control a dual-channel, sine-wave generator as the excitation to both the left and right ears in experimental subjects, and for on-line measurement of the neuronal spike counts. The effects of varying the walking pattern and phase angle between the two channels can be investigated. After normalisation of spike counts, the result can be displayed as a 3-D plot on a CRT or an x-y plotter. The system is useful for general steady state and transient binaural measurement

At the onset of our first field trials of tra­ choma vaccine in Taiwan in 1959, some prevalence data were available on trachoma infection in entering primary school chil­ dren. Later the World Health Organization performed an island-wide prevalence sur­ vey. We undertook to obtain incidence data in order to assist us in the understand­ ing of the natural history of trachoma on Taiwan and in the evaluation of trachoma vaccine and drug treatment studies.

SummaryField trials of experimental egg-grown trachoma virus vaccine have been carried out in preschool-aged children in 2 rural areas on Taiwan. Four hundred and five children randomly divided between a placebo and trachoma vaccine groups have been followed for 2 1/2 years during which 4 injections of vaccine have been given. Eighteen per cent of the placebo group have converted to trachoma compared to 8% of those receiving vaccine. An average of 2.98 months of trachoma have been observed in the placebo group compared to 1.22 months in the vaccine group. Both these measures suggested that the vaccine was approximately 60% effective in reducing trachoma. A third study in an urban area with 89 children showed similar vaccine effectiveness.