Textiles screen-printed with photochromic ethyl cellulose-spirooxazine composite nanoparticles

Photochromic compounds change colour on exposure to light, while the reversion may be attributable either to radiation or may be thermal. The use of photochromism on fabrics can provide new opportunities to develop smart textiles; for example, sensors and active protective clothes. Ethyl cellulose-1,3-dihydro-1,3,3,4,5 (and 1,3,3,5,6) -pentamethyl-spiro-[2H-indole-2,3′-(3H)naphtha(2,1-b)(1,4)oxazine] composites were prepared by an oil-in-water emulsion, solvent evaporation method in order to form easily suspendable and fatigue-resistant photochromic nanoparticles in screen-printing paste. Their size was well below 1 μm and did not change substantially over a wide range of dye concentrations. After screen-printing, a homogenous photochromic layer was built on a cotton substrate surface, which represented substantial blue colour development in CIELab colour space measurements because of ultraviolet light, even at a dye concentration of 0.045% w/w. The addition of a photodegradation inhibitor, Tinuvin 144, further increased the coloration of the printed fabric

The optical effect of thermal expansion over excessed injection molded lens arrays in modern LED outdoor luminaires

For the rapid development observable in solid state lighting technology, both in favor of the better lighting performance achievable and the advantage in upkeep, changing the conventional installations to LED luminaires is often considerable in the modern roadway lighting practice. By these modernization investments the sales volume is usually high for lower additional expenses and a quicker RoI; thus the replacement products are generally cost sensitive. As the global market price of Aluminum increases on a long term trend, while the cost of the task efficient luminous power became very desirable with Light Emitting Diode; a high level of integration and compactness is demanded by such luminaire designs. This approach raises complex technical challenges, as the thermal expansion difference between the lens array and the Insulated Metal Substrate (IMS) Printed Circuit Board can lead to major deviation in the light distribution over the rated ambient temperature range. Having a robust design is a key aspect in providing a reliable, safe lighting design for any application of a global product

Technological solutions to compensate humanmeteorological measurement errors with measuring human activity and movement

To enhance the objectivity of humanmeteorological measurements, various instrumental measurements are required. These equipments are suitable to explore the desired relationships, only if those are able to record simultaneously the individual's physiological and micro-environmental parameters and their transients. It is also important to possibly filter or measure the disturbances effecting our measurements in order to compensate errors in our results. In our case this factor is the physical activity of the individual, which has effect on physiological parameters, therefore we have to register its value in function of time. The following paper deals with technical and theoretical questions of measuring this factor and summarizes the ascertainment we collected during the experiments. The topic is an integral part of teh PhD research Á. Pintér behooves at Budapest University of Technology and Economics

Time Domain Analysis and Spectral Methods for Determining Rotational Speed of Rotary Machines

Accurate estimation of rotational speed of rotary machines has usually high priority in technical applications. This information should be calculated for many diagnostic algorithms, control or regulation processes. Incorrectly estimated values could occur serious disturbances in the operation of machines. Additional instrumentation often may be obstructed due to lack of space, but the construct of the machine may also affect the accuracy of measurement. In such cases, vibration diagnostic tools can be the disposal of difficulty. Mounting an acceleration sensor onto the outer surface of the measured device is not a major challenge. In most cases using time, frequency or quefrency domain analysis, it is possible to estimate the rotational speed of the analysed rotary machine. The calculated spectra and cepstra can help to determine the rotational speed more easily and more accurate than the time domain methods. This paper presents the comparison of these methods in terms of their usability and rotational speed estimation accuracy. A possible error of traditional optical measurement due to misalignment and benefits of the other methods are illustrated in this article via measured data series of a Brushless DC (BLDC) motor driven system

Technological considerations in measuring weather derived epileptic seizures of dogs

As in every technical discipline, the objective, reproducible instrumental measurements are indispensable. It is no different at investigating the effect of weather on living organism. The parallel measurement of the atmospheric environment and the physiological parameters is novel and individual, as well as the investigation of epileptic seizures depending on weather situations. Several questions came up in connection with our equipment designed for studying dogs epileptic phenomenon, such as fixing, water resistant,- and robust implementation, the problem of data storage, measurement schedule or the power supply for instance. Keeping these in mind during the development process we got an apparatus, which since is an integral part of our further researches

Measurement of color defective and normal color vision subjects´ color and luminance contrast threshold functions on CRT

To perform a more complete diagnosis on the effect of color vision deficiency on visual performance we measured luminance and color contrast threshold functions. Measurements were carried out on CRT for a range of spatial frequencies on color deficient and normal color vision individuals. Luminance and color contrast threshold is a measure of the recognition limits of low luminance and color contrast patterns. Both of them are function of the image features and spatial frequency. In our test patterns of stripes with a sinusoidal luminance profile were displayed on the monitor. The subject´s task was to detect the presence and orientation of these gratings. In the study 6 normal and 6 anomalous trichromats were measured. In the case of color contrast threshold measurement it is essential to apply colors with identical luminance sensation, otherwise the test person might be able to differentiate between the presented colors not based on hue but based on luminance. The increasing accessibility of computers and color monitors provides a platform for color vision tests based on brightness sensation correction. In our experiment we define the subject´s relative luminance sensation stimulated by the primary colors of the monitor with the method of direct heterochromatic photometry. Although, there were no significant differences in luminance contrast threshold between normal color vision and color deficient subjects, we found significant reduction in red-green color contrast threshold at all color defectives. The results prove the assumption that color deficiency has a negative effect on noticing details in color environment

Hybrid spectral speed determination method for rotary machines

Accurate rotational speed determination for rotary machines tends to be allocated high priority in technical applications. In some cases, it is not easy to measure shaft speed directly. Vibration diagnostic tools can offer an alternative solution to the problem posed by direct rotational speed measurement. Using calculated spectra and cepstra can help to determine the rotational speed easily and accurately. This paper examines the comparison of the spectrum and cepstrum based methods in terms of their applicable ranges and rotational speed estimation accuracy. Most papers which present similar comparisons state that the speed of rotary machines can be determined better with cepstrum calculation. However, this argument does not entirely stand up to scrutiny. This paper explains how to calculate the possible speed estimation error which arises out of the resolution of the discrete output data produced by the methodologies. The novel hybrid speed estimation logic uses these equations to decide which method results in the most accurate output. Numerous vibration measurements were made to test the usability of this hybrid method. It was successfully tested on electromotive drive trains, as well as spark- and compression-ignition internal combustion engines with different cylinder numbers and arrangements

Time Domain Analysis and Spectral Methods for Determining Rotational Speed of Rotary Machines

Accurate estimation of rotational speed of rotary machines has usually high priority in technical applications. This information should be calculated for many diagnostic algorithms, control or regulation processes. Incorrectly estimated values could occur serious disturbances in the operation of machines. Additional instrumentation often may be obstructed due to lack of space, but the construct of the machine may also affect the accuracy of measurement. In such cases, vibration diagnostic tools can be the disposal of difficulty. Mounting an acceleration sensor onto the outer surface of the measured device is not a major challenge. In most cases using time, frequency or quefrency domain analysis, it is possible to estimate the rotational speed of the analysed rotary machine. The calculated spectra and cepstra can help to determine the rotational speed more easily and more accurate than the time domain methods. This paper presents the comparison of these methods in terms of their usability and rotational speed estimation accuracy. A possible error of traditional optical measurement due to misalignment and benefits of the other methods are illustrated in this article via measured data series of a Brushless DC (BLDC) motor driven system

Internet based light quality measurement

The goal of this project was to implement a device, which can measure the illuminance and the correlated color temperature (CCT) of a light source and also works as a webserver. The analyzation of light sources is very important in our everyday life. With the use of a webserver the measured values are easily accessible and the calculation methods can be changed without any changes on the hardware. It also provides a solution to store and analyze the results without further human interaction. Therefore the device is capable of collecting and analyzing a large amount of data. For these criterions we chose a PIC microcontroller, an Ethernet chip and two different sensors. One of the sensors is an RGB sensor and the other one is a LUX sensor. Both of the sensors are using photodiodes to sense the different attributions of a light source. Through this article we show the basic theory behind the project, the implementation and calibration of the device; then the results of the measurements and finally we mention some possibilities for future improvements

Technological solutions to compensate humanmeteorological measurement errors with measuring human activity and movement

To enhance the objectivity of humanmeteorological measurements, various instrumental measurements are required. These equipments are suitable to explore the desired relationships, only if those are able to record simultaneously the individual's physiological and micro-environmental parameters and their transients. It is also important to possibly filter or measure the disturbances effecting our measurements in order to compensate errors in our results. In our case this factor is the physical activity of the individual, which has effect on physiological parameters, therefore we have to register its value in function of time. The following paper deals with technical and theoretical questions of measuring this factor and summarizes the ascertainment we collected during the experiments. The topic is an integral part of teh PhD research Á. Pintér behooves at Budapest University of Technology and Economics