scholarly journals Oxadiazole Based Polyether as Sensitive Films for Ratiometric Optical Temperature Detection

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
H. C. Neitzert ◽  
S. Cuccurullo ◽  
S. Concilio ◽  
P. Iannelli

A new type of polymer, based on the oxadiazole group, has been tested as indicator material for a ratiometric photoluminescence and optical reflection based temperature sensor in the temperature range between 30°C and 60°C. Thin films of the new polymer have been deposited by spin-coating on a glass substrate, excited by means of a low-cost near UV-LED. The optical spectrum, as detected by a fiber-based PC-card optical spectrometer, consisted of the reflection peak at the excitation wavelength and two distinct photoluminescence peaks at 430 nm and 480 nm, both in the blue spectral region. The peak amplitudes of all three spectral peaks depend linearly on the exciting light intensity. Changing the sample temperature, all peak amplitude values decrease monotonously with increasing temperature. By using a ratiometric approach, it has been found that the ratio between the two photoluminescence peaks was almost constant with temperature, while the ratio between the main photoluminescence peak at 430 nm and the reflection peak around 380 nm scaled nicely with the ambient temperature. Therefore, it has been proposed to use the latter criterion and a simple polynomial fit to the temperature versus peak amplitude relation.

Author(s):  
Shih-Ming Wang ◽  
Chih-Peng Yang ◽  
Zhe-Zhi Ye ◽  
Chuntai Yen

The products of 3C, bioscience, medical industry, and aerospace industry are becoming smaller and smaller. The components of the products are made of various materials with complex 3D shapes requiring high accuracy in their dimensions and contours. An accurate micro-/meso-scale CNC machine tool is an essential part of this technology. A new type of CNC micro machine tool with a toggle-like mechanism having the characteristics of low-cost and fine-resolution was developed. With geometric reduction principle, the machine can provide finer feed resolution and better positioning accuracy without using high-end driving components and controller. The kinematics model and characteristics of the machine were derived and analyzed. Modal analysis and dynamic compliance analysis were employed to design a light-weight structure with good stiffness. The accuracy calibration results showed the machine can reach a positioning accuracy of 500 nm. Prototype of the machine was built, and furthermore some micro machining examples were demonstrated in this paper.


Author(s):  
Peter N Dudley ◽  
Sara N John ◽  
Miles E Daniels ◽  
Eric M. Danner

In North America, impassable, man-made barriers block access to salmonid spawning habitat and require costly restoration efforts in the remaining habitats. Evaluating restored spawning habitat quality requires information on salmon water velocity and depth preferences, which may vary in relation to other variables (e.g. water temperature). We demonstrate a generalizable, low cost method to gather and analyze this data by combining aerial redd surveys of winter-run Chinook salmon (Oncorhynchus tshawytscha), 2D hydraulic modeling, and generalized linear models to calculate spawning resource selection functions (RSFs). Our method permits the examination of interactions between environmental variables on habitat selection, which are frequently treated as independent. Our methods resulted in a RSF that shows interactions between both velocity and depth preference with changing temperature. Preferred depth increased and preferred velocity decreased with increasing temperature. Spawning RSFs for environmental variables may change as other environmental conditions (i.e. water temperature) change, thus it is importance to account for potential interactions when using or producing RSFs.


1996 ◽  
Vol 445 ◽  
Author(s):  
W. Kowbel ◽  
V. Chellappa ◽  
J.C. Withers

AbstractRapid advances in high power electronics packaging require the development of new heat sink materials. Advanced composites designed to provide thermal expansion control as well as improved thermal conductivity have the potential to provide benefits in the removal of excess heat from electronic devices. Carbon-carbon (C-C) composits are under consideration for several military and space electronic applications including SEM-E electronic boxes. The high cost of C-C composits has greatly hindered their wide spread commercialization. A new manufacturing process has been developed to produce high thermal conductivity (over 400 W/mK) C-C composites at greatly reduced cost (less than $50/lb). This new material has potential applications as both a heat sink and a substrate. Dielectric coatings such as A1N and diamond were applied to this new type of heat sink material. Processing, as well as mechanical and thermal properties of this new class of heat sink material will be presented.


2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Xiaoxia Liu ◽  
Miaomiao Tian ◽  
Wenmei Gao ◽  
Jinzhong Zhao

An efficient, sensitive, and low-cost method has been developed for turn-on fluorescence sensing of dopamine (DA). The method relies on the rapid reaction of DA and 3-Hydroxyphenylboronic acid (3-HPBA) via specific recognition between boronic acids and cis-diol of DA in alkaline solution. The reaction product shows an excitation wavelength of 417 nm and the maximum emission peak at 470 nm. The proposed method allows the determination of DA in the range of 50 nM–25 μM, and the whole detection can be completed within 5 minutes. Furthermore, the presented approach has good selectivity and has been successfully applied to DA sensing in human serum samples, showing great potential in clinical diagnosis.


Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1873
Author(s):  
Petronela Pascariu ◽  
Niculae Olaru ◽  
Aurelian Rotaru ◽  
Anton Airinei

A new type of material based on carbon/ZnO nanostructures that possesses both adsorption and photocatalytic properties was obtained in three stages: cellulose acetate butyrate (CAB) microfiber mats prepared by the electrospinning method, ZnO nanostructures growth by dipping and hydrothermal methods, and finally thermal calcination at 600 °C in N2 for 30 min. X-ray diffraction (XRD) confirmed the structural characteristics. It was found that ZnO possesses a hexagonal wurtzite crystalline structure. The ZnO nanocrystals with star-like and nanorod shapes were evidenced by scanning electron microscopy (SEM) measurements. A significant decrease in Eg value was found for carbon/ZnO hybrid materials (2.51 eV) as compared to ZnO nanostructures (3.21 eV). The photocatalytic activity was evaluated by studying the degradation of three dyes, Methylene Blue (MB), Rhodamine B (RhB) and Congo Red (CR) under visible-light irradiation. Therefore, the maximum color removal efficiency (both adsorption and photocatalytic processes) was: 97.97% of MB (C0 = 10 mg/L), 98.34% of RhB (C0 = 5 mg/L), and 91.93% of CR (C0 = 10 mg/L). Moreover, the value of the rate constant (k) was found to be 0.29 × 10−2 min−1. The novelty of this study relies on obtaining new photocatalysts based on carbon/ZnO using cheap and accessible raw materials, and low-cost preparation techniques.


2016 ◽  
Vol 847 ◽  
pp. 72-77
Author(s):  
Yu Xuan Liang ◽  
Peng Peng Bai ◽  
Shu Qi Zheng

Pyrite (FeS2) is an important semiconductor material which shows various excellent optical and electrical properties and extensive applied prospect as a new-type, photoelectrical functional materials. In this study, a low cost and efficient simple hydrothermal two-step synthetic method was given to obtain FeS2 microspheres with 2-3 μm in diameter. The obtained products were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and ultraviolet and visible spectrophotometer (UV-Vis). XRD showed that the synthetic sample consisted of two crystal structures of FeS2, pyrite and marcasite. SEM observation indicated that FeS2 microspheres were well crystallized and had good uniformity. UV-Vis spectrum had a strong optical absorption in the region of 200-400 nm wave length. The reaction temperature had an impact on the size of FeS2 microspheres. A possible mechanism for the size of the FeS2 microspheres generated at high temperature is smaller than that at low temperature is discussed.


2012 ◽  
Vol 512-515 ◽  
pp. 431-434 ◽  
Author(s):  
Wei Liu ◽  
Zhi Peng Xie ◽  
Li Li Zhang ◽  
Xian Feng Yang

In this study, low-cost kerosene with low toxicity was used as organic solvent to research the solvent debinding behavior of ceramic compact produced by injection molding. The Influences of time, temperature and solid loading on the debinding rate were investigated, the mechanism of which was also discussed. The results show that: The debinding rate increased with increasing temperature and decreased with extended time; Diffusion is the controlling factor at the initial stage and temperature was the main factor influencing the reaction rate; Dissolution is the controlling factor and concentration difference was the main factor at the later stage; The higher the solid loading of green body, the slower the debinding rate and the lower the final proportion of binder removal.


2020 ◽  
Vol 4 (10) ◽  
pp. 5313-5326 ◽  
Author(s):  
S. Rajkumar ◽  
E. Elanthamilan ◽  
J. Princy Merlin ◽  
I. Jenisha Daisy Priscillal ◽  
I. Sharmila Lydia

The as-synthesized CuCo2O4/PANI nanocomposite has emerged as a new type of electrode material for energy storage applications due to its low cost and sustainable and high electrochemical performance.


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