Photoelectric Technology Research Articles

Effect of support treatment on electrical properties of heterojunctions n-TiO2/p-Si

Recently, metal oxides with semiconducting properties, such as titanium dioxide ( ТіО 2 ), have been widely used in various devices, especially in the photoelectric technology for various purposes. At the same time, the interest to the semiconductor heterojunctions is steadily growing due to their advantages in comparison with homojunctions. Nowadays the heterojunctions are widely used in electronics, lasers and photogalvanization. The article studies the electrical properties of the anisotype heterojunctions n-ТiО 2 /p-Si obtained by applying thin-film TiO 2 on the etched and polished polycrystalline Si supports. Since the electrical characteristics of the components of the heterojunctions and metallurgical boundary affect significantly the performance of the semiconductor devices based on the heterojunctions, such studies are important for the further development of the devices based on the heterojunctions n-ТiО 2 /p-Si for electronics and solar energy. The dependence of the height of the potential barrier and the subsequent resistance on the method of processing of the silicon supports was studied. It was determined that the tunneling is a dominant mechanism of current transport through the heterostructures under different conditions of the Si surface processing

Design and Experimental Analysis of Novel Refractometer Based on Photoelectric Sensor Technology

A novel refractometer based on photoelectric sensor technology and differential method is proposed. Sensing principle and mathematical model are introduced; structure and key parameters of sensing probe are designed through detail calculation. Theoretical solution shows resolution reaches order of 10-5. Preliminary experiments verify the feasibility of the design, experimental results show stability error better than ±1.02×10-4, error caused by temperature is 6.65×10-6/°C.

Research and Application of Energy-Saving Design Technologies in Science Center Building

According to the target of a science center building, some energy-saving technologies and relevant principles phases in architectural planning and design phase, architectural design and construction phase, and so on. With the requirements of energy-saving technologies and an environmental protection technology, some successful experience of Guangdong science center which named as the largest science center building of current China discussed. As a result, the energy-saving science center building design methods came into being, which includes natural ventilation techniques of central yard, optimization technology of enclosed structure, photoelectric curtain wall technology and solar power and so on.

Study on the Control Technology of Piezoelectric Transducer Assembly

The author analyzes the problems existing in the traditional assembly system and puts forward a new method based on the motor control. This paper introduces the design and development of the automatic assembly system of ultrasonic cleaning transducer. In the system we use photoelectric isolation technology to solve the problems that driving circuit interference control chip while using a chip control many motors and this simplify the assembly system structure, reduce the cost of the assembly system and improve the assembly system automation and precision.

Design of a Tele-Operation Robot Based on Video Communication

For some circumstances, it would be extremely dangerous to use direct human labor and then robots are often required to complete those tasks in this kind of environments. Unfortunately, computer control and intelligence are not sufficiently developed to permit the robots to fulfill these advanced technical tasks only by their own initiative. Tele-operation robot may be a good way for this problem. Robots will fulfill the given task at the real environment to avoid the possible harm to people and engineers will give out the proper instructions to robot in tele-operation mode. A type of manipulation robot will be introduced and key technologies will also be explained. It synthetically adopts wireless network video technology, photoelectric sensor technology and wireless Bluetooth technology. By this method, the operator can obtain even more information of the working environment, and the robot will also complete the dangerous task more effectively.

An experimental study of the correlation for predicting the frost height in applying the photoelectric technology

It is found that the photoelectric technology is suitable for the accurate measurement of the frost height. The objectives of this paper are to experimentally investigate the correspondence between the output signal of the photoelectric sensor and the frost height, and then develop a generalized correlation to predict the frost height directly and accurately. The experiments are conducted in a wide range of operating conditions for air temperature 17.7 °C–27.2 °C, relative humidity 21.6% RH to 64.9% RH, air velocity 0.5 m/s to 4.5 m/s and cold surface temperature −10.5 °C to −6.5 °C. Based on 21 groups of experiments with total 600 data, a linear correlation with a relative deviation of ±10% is setup. Further validation of this correlation is conducted by comparing the predicted results with 4 additional experiments, and approximately 95% of the predicted frost heights are consistent with the measured data within a relative deviation of ±10%. These results indicate that the photoelectric technology can predict the frost height directly. The application of the proposed correlation to provide defrost control strategy is also discussed in this paper.

A Pervasive System for Nuclear Medicine Department

Pervasive Computing technologies can be successfully adopted in designing smart and enhanced healthcare services and applications. Within a typical healthcare institution, one particular facility which can greatly benefit from pervasive technologies is the Nuclear Medicine Department, where nuclear medicine diagnostic tests like PET scan and nuclear scintigraphy are routinely carried out involving the use of radioactive substances. This paper presents a pervasive healthcare system which is intended to support clinicians in handling nuclear medicine test sessions within an appropriate, safety-aware context. The proposed system also includes features to easily interoperate with heterogeneous software and databases already present in traditional hospitals. Its design lies on a methodology which integrates RFID and photoelectric sensor technologies. An experimental prototype has been implemented and tested showing the feasibility of the system in a real healthcare facility.

400 years of astrometry: from Tycho Brahe to Hipparcos

Galileo Galilei’s use of the newly invented telescope for astronomical observation resulted immediately in epochal discoveries about the physical nature of celestial bodies, but the advantage for astrometry came much later. The quadrant and sextant were pre-telescopic instruments for measurement of large angles between stars, improved by Tycho Brahe in the years 1570–1590. Fitted with telescopic sights after 1660, such instruments were quite successful, especially in the hands of John Flamsteed. The meridian circle was a new type of astrometric instrument, already invented and used by Ole Romer in about 1705, but it took a hundred years before it could fully take over. The centuries-long evolution of techniques is reviewed, including the use of photoelectric astrometry and space technology in the first astrometry satellite, Hipparcos, launched by ESA in 1989. Hipparcos made accurate measurement of large angles a million times more efficiently than could be done in about 1950 from the ground, and it will soon be followed by Gaia which is expected to be another one million times more efficient for optical astrometry.

An analysis of the feasibility and characteristics of photoelectric technique applied in defrost-control

An innovative photoelectric technology is presented in this paper for detecting frost in the field of defrost-control of refrigerator or freezer applications. Experiments were conducted with a small-scale laboratory test section under natural convection conditions. Two agreeable properties of the new technology, “on–off” and “linear”, have been demonstrated by the experiments. The first property provides an effective judgment of the defrost-control strategy while the second one is suitable for developing an accurate measurement of the frost height. The characteristics (electric current, environment temperature, metal surface temperature, light intensity and sensor location) that affect the properties were investigated for the development of this technology.

A Relative Time Analysis of the Performance of Residential Smoke Detection Technologies

A statistical study was conducted to compare the performance of different residential smoke detector technologies when exposed to different fire types. In order to facilitate comparisons between different fire and smoke growth rates, a non-dimensional smoke detector activation relative time was employed. Data from four major experimental studies was analyzed utilizing the relative time approach. The Common Language Effect Size, a measure of the probability that a particular detector technology will be the first to detect a fire of a particular type, was used to assess detector performance. The analysis confirmed previous results that ionization detectors, on average, respond faster to flaming fires, and that photoelectric detectors, on average, respond faster to smoldering fires. More importantly, this study also determined that the responses of ionization, photoelectric, and combination technologies are statistically equivalent for any given future residential fire That is, it cannot be determined with confidence which detector technology will alarm first to the next fire. Additionally, the analysis found that this statistical equivalence between detector technologies has not changed in the last 35 years despite increased fire growth rates associated with changes in furniture materials over that same time span.

The case for non‐contact

In many instances measurement equipment which makes contact with the media or product provides inaccurate results owing to corrosion, mechanical damage or a build‐up of the monitored production on the sensor. In view of the possible deleterious effects it is better to operate a non‐contact method of monitoring, especially in the food and pharmaceutical industries. This produces greater reliability coupled with lower maintenance. The infinite possibilities of non‐contact options require expertise in inductive, capacitative, photoelectric, infrared and ultrasonic measurement and control technology.