Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 8 de 8
Filter
Add more filters










Database
Language
Publication year range
1.
Nanomaterials (Basel) ; 13(3)2023 Feb 02.
Article in English | MEDLINE | ID: mdl-36770557

ABSTRACT

It is shown in this paper that a polymer, MA-PEG 1000-DGEBA (MP1D), exhibits antireflection, substrate-dependent photoluminescence (SDP), wide band-gap, and photoconduction characterization. MP1D was synthesized from maleic anhydride, polyethylene glycol 1000, and bisphenol-A diglycidyl ether. Self-assembled nanoparticles embedded in MP1D film and ranging from 2.5 to 31.6 nm are observed, which could be expected as scatterers to enhance light trapping and extraction. The size of the nanoparticle increases with the concentration of the MP1D solution. Besides solution concentration, the nanoparticle dimension could be modified by the chain length of polyethylene glycol in the polymer synthesis. The effects of solution concentration, annealing temperature, annealing period, and substrate on the photoluminescence (PL) of MP1D films are examined. Increasing solution concentration increases PL intensity. However, aggregation-caused quenching is explicit as the solution concentration exceeds 100 mM. PL intensity increases with annealing temperature, which could be attributed to crystallinity improvement. PL intensity increases with increasing the annealing period from 0.5 to 2 h. Nonetheless, as the annealing period exceeds 2 h, PL quenching is emerging, which could be due to aggregation. It is expected that MP1D could be a promising candidate for host materials and MP1D film could play a multifunctional role (antireflective and light-trapping functions) in optoelectronics.

2.
Sensors (Basel) ; 22(3)2022 Feb 07.
Article in English | MEDLINE | ID: mdl-35161989

ABSTRACT

This paper explores poly-silicon-germanium (poly-SiGe) avalanche photo-sensors (APSs) involving a device of heterojunction structures. A low pressure chemical vapor deposition (LPCVD) technique was used to deposit epitaxial poly-SiGe thin films. The thin films were subjected to annealing after the deposition. Our research shows that the most optimal thin films can be obtained at 800 °C for 30 min annealing in the hydrogen atmosphere. Under a 3-µW/cm2 incident light (with a wavelength of 550 nm) and up to 27-V biased voltage, the APS with a n+-n-p-p+ alloy/SiO2/Si-substrate structure using the better annealed poly-SiGe film process showed improved performance by nearly 70%, 96% in responsivity, and 85% in quantum efficiency, when compared to the non-annealed APS. The optimal avalanche multiplication factor curve of the APS developed under the exponent of n = 3 condition can be improved with an increase in uniformity corresponding to the APS-junction voltage. This finding is promising and can be adopted in future photo-sensing and optical communication applications.

3.
Polymers (Basel) ; 13(23)2021 Dec 02.
Article in English | MEDLINE | ID: mdl-34883732

ABSTRACT

In this paper, it is reported that a metal-free and non-conjugated polymer, MA-PEG 8000-BADGE (MP8B), exhibits an antireflective property and substrate-dependent photoluminescence (SDP). MP8B was constructed from maleic anhydride, poly(ethylene glycol) and bisphenol-A diglycidyl ether. Self-assembled nanoparticles are found in MP8B and can prospectively act as scattering centers to improve light trapping and extraction. MP8B films prepared from MP8B solutions have been characterized by photoluminescence (PL), atomic force microscopy (AFM), tunnelling electron microscope (TEM), reflectance, transmittance, and UV-Vis absorption spectrum. MP8B films can suppress light reflection and enhance light transmission. The PL spectrum of MP8B film on ITO peaks at approximately 538 nm, spanning from 450 to 660 nm at a concentration of 25 mM. Meanwhile, the effects of concentration and substrate on the PL of MP8B films are also investigated in this study. Surface roughness becomes larger with concentration. A red shift of the PL spectrum is observed as solution concentration increases. Meanwhile, aggregation-caused quenching (ACQ) is insignificant. Moreover, the PL spectra of MP8B films show a substrate-dependent phenomenon due to dielectric screening. The optical band-gap energy of MP8B is approximately 4.05 eV. It is concluded that MP8B is a promising candidate for a host material, and its film can be utilized as a multifunctional layer (i.e., antireflective and light-scattering functions) for optoelectronic applications.

4.
Article in English | MEDLINE | ID: mdl-30513932

ABSTRACT

To determine the relationships between exposure to environmental contaminants in water and chronic kidney disease (CKD), we investigated the associations of 61 water attributes with the prevalence of CKD and End-Stage Renal Disease (ESRD) using data from 2005 to 2011 from all 22 counties and cities in the main island of Taiwan. We acquired patient information from the Taiwan Longitudinal Health Insurance Database to calculate the age-standardized CKD and ESRD prevalence rates and linked the patients' residences to the water quality monitoring data, which were sampled periodically for a total of over 45,000 observations obtained from the Taiwan Environmental Water Quality Information Database. The association analysis adjusting for gender, age, and annual effects showed that the zinc (Zn), ammonia, chemical oxygen demand (COD), and dissolved oxygen in rivers were weakly correlated with CKD (τ = 0.268/0.250/0.238/-0.267, p = 6.01×10-6/2.52×10-5/6.05×10-5/3.30×10-5, respectively), but none for ESRD. The importances of Zn and COD in rivers were also demonstrated in a CKD regression model. Moreover, an unusually high CKD prevalence was related to arsenic contamination in groundwater. A further prospective cohort study would improve our understanding of what level of environmental water with risky properties could affect the development of CKD.


Subject(s)
Renal Insufficiency, Chronic/epidemiology , Water Quality , Adolescent , Adult , Biological Oxygen Demand Analysis , Databases, Factual , Female , Humans , Kidney Failure, Chronic/epidemiology , Male , Middle Aged , Prevalence , Taiwan/epidemiology , Water Pollutants, Chemical/analysis , Young Adult
5.
Sensors (Basel) ; 18(8)2018 Jul 24.
Article in English | MEDLINE | ID: mdl-30042339

ABSTRACT

Recently, an upsurge of deep learning has provided a new direction for the field of computer vision and visual tracking. However, expensive offline training time and the large number of images required by deep learning have greatly hindered progress. This paper aims to further improve the computational performance of CNT which is reported to deliver 5 fps performance in visual tracking, we propose a method called Fast-CNT which differs from CNT in three aspects: firstly, an adaptive k value (rather than a constant 100) is determined for an input video; secondly, background filters used in CNT are omitted in this work to save computation time without affecting performance; thirdly, SURF feature points are used in conjunction with the particle filter to address the drift problem in CNT. Extensive experimental results on land and undersea video sequences show that Fast-CNT outperforms CNT by 2~10 times in terms of computational efficiency.

7.
Acta Paediatr Taiwan ; 46(5): 318-20, 2005.
Article in English | MEDLINE | ID: mdl-16640010

ABSTRACT

This is a case of an 11-year-old boy who developed septic arthritis of the right knee after a stabbing injury by a toothpick. Arthroscopic debridement of the distal femur and arthrotomy with synovectomy were performed at two hospitals. Cultures from both yielded Eikenella corrodens, an organism that may be normally found in oral secretions. The boy was given treatment with intravenous ceftriaxone after surgery and discharged home without complications. E. corrodens is part of the normal human oropharyngeal flora. It has been reported as the cause of infections at many sites, which are largely due to contamination with oral secretions. A penetrating injury with an object contaminated with oral bacterial flora should lead clinicians to consider this organism as a potential pathogen.


Subject(s)
Arthritis, Infectious/etiology , Eikenella corrodens/isolation & purification , Gram-Negative Bacterial Infections/etiology , Knee Injuries/complications , Knee Joint , Wounds, Stab/complications , Child , Humans , Male
8.
Inorg Chem ; 36(9): 1955-1960, 1997 Apr 23.
Article in English | MEDLINE | ID: mdl-11669803

ABSTRACT

As part of our ongoing study of different substituents of Al(2)N(2) ring systems, the synthesis, structural characterization, and spectroscopic studies on several amido derivatives of four-coordinated aluminum are described. The compounds Al(2)(NEt(2))(2)(N(i)Pr(2))(2)Cl(2), 1, Al(2)((N(i)Pr(2))(4)Cl(2), 2, Al((N(i)Pr(2))(3), 3, Al(NEt(2))(3), 4, {Al(N(i)PrH)(3)}(3), 5, Al(2)(NEt(2))(2)(N(i)Pr(2))(2)H(2), 6, and AlCl(3)(N(i)PrH(2))(2){Al(NH(3))(NH(2))[Al(N(i)PrH)(N(i)Pr)Cl](2)}(2), 7, were synthesized by substitution reactions and characterized by mass spectra, IR spectra, elemental analysis, and (1)H, (13)C, and (27)Al NMR data. The structures of three compounds, viz., 1, 6, and 7, have been determined by single-crystal X-ray diffraction analysis. Crystal data with Mo Kalpha (1 and 7, lambda = 0.710 73 Å) or Cu Kalpha (6, lambda = 1.541 78 Å) radiation: (1) Al(2)N(4)C(20)H(48)Cl(2), a = 7.747(2) Å, b = 9.648(2) Å, c = 10.110(3) Å, alpha = 102.91(2) degrees, beta = 83.54(2) degrees, gamma = 110.19(2) degrees, triclinic, space group P&onemacr;, Z = 1, R = 0.053 for 1789 (I > 3sigma(I)) reflections; (6) Al(2)N(4)C(20)H(50), a = 15.088(2) Å, b = 14.506(3) Å, c = 12.439(3) Å, orthorhombic, space group Cmca (No. 64), Z = 4, R = 0.045 for 701 (I > 3sigma(I)) reflections; (7) Al(7)N(14)C(30)H(86)Cl(7), a = 29.914(9) Å, b = 10.197(3) Å, c = 20.525(5) Å, beta = 90.99(4) degrees, monoclinic, space group C2/c, Z = 4, R = 0.042 for 2472 (I > 2sigma(I)) reflections.

SELECTION OF CITATIONS
SEARCH DETAIL
...