Optimization of the Plate Heat Exchanger Used for Milk Precooling

The article deals with the adjustment of the flow rate of milk and water by a plate heat exchanger, which is used for precooling milk. First, measurements of the parameters of the device in the stable were carried out. Subsequently, the plate heat exchanger was measured in the laboratory. Water at 35 oC was used instead of milk. Different flow ratios of cooling water and cooled water (instead of milk) were set. From the measured values, changes in the temperature of cooled water were calculated depending on its flow rate at a constant ratio of cooling water and cooled water. It was found that in the measured range, there are flow values at which temperature change is maximal. This dependence applies to all selected cooling water and cooled water flow ratios: (0.8, 0.9, 1.0, 1.1, 1.2.). The results show that with the same amount of cooling water, it is possible to achieve greater cooling of milk by 0.7 to 1.6 oC, or to achieve a reduction in water consumption. The device on the farm was modified to allow the flow of milk and cooling water to be changed. The optimal values found were set, and verification measurements were performed. The saving of 4.8% of cooling water was confirmed.O

Characterization of ultra-thin tungsten layers

Atomic force microscopy and surface resistivity measurement were used for characterization of ultra-thin tungsten layers deposited on purified silicon with 200 nm thermic silicon dioxide substrate. Radio-frequency magnetron sputtering was used for tungsten deposition. © Research India Publications

Design of scanning system for mechanoscopic analysis

The work deals with hardware and software proposal of a system suitable for control and visualization of scanning process based on resistivity measurement. Three axis positioning system with conductive contact probe is utilized. The user application was created in MATLAB programming environment. Important part of the design represents the definition of requirements, choice of the appropriate tools, functions and structures needed for reliable realization. Proposed user application allows setting key parameters of the measurement, appropriate method of data acquisition as well as performing online 3D visualization of measured data. The functionality of the application is verified via measurement of a several selected samples. Results of these measurements are also presented

The Innovation of clarinet bell using Bessel functions

Bakalářská práce se věnuje porovnání vlivu klarinetových ozvučníků na jeho výsledné spektrum a směrovou charakteristiku. Porovnává originální ozvučník s vlastními ozvučníky navrženými pomocí Besselových zvukovodů a vyhotovených z ABS plastu. Dále se zabývá principy vzniku tónu a potřebným teoretickým základem.The bachelor's thesis focuses on the comparison of the influence of clarinet bells on its final spectrum and directional characteristics. It compares the original bell with other bells designed using Bessel sound pipes and made of ABS plastic. It also investigates the principles of tone formation and the necessary theoretical basis.

Scanning system for ballistic analysis

This paper presents hardware and software solution of the scanning system designed for ballistic analysis of cartridge cases which were deformed by firing pin after shooting for identification process of firing weapon. The system is based on resistivity measurement between the scanning tip and a sample and three axis servomotor positioning controlled by application created in MATLAB programming environment. Output of the application is matrix of coordinates for 3D visualization of deformed cartridges for firearm identification process. Measured example results are included. © Springer International Publishing Switzerland 2016

Quality control in microelectronics using scanning probe microscopy

In this paper, atomic force microscopy and its variation scanning microwave microscopy were used for the characterization of microelectronics (PNP bipolar transistors on a chip and epitaxial layers with different properties on a silicon substrate). The capabilities of these methods in the quality control process are presented. © 2016 IEEE

The effect of scratching direction in AFM nanolithography

In this paper, we investigated the effect of scratching direction in AFM scratching. The understanding of this effect is one of the key factors in the patterning process. In our experiment, several testing grooves were engraved in all four basic directions (forward, backward, right and left) on polycarbonate substrate using Si probe. Both the fabrication and subsequent characterization were performed using the identical atomic force microscope. Our results were compared to previous reports. It was found that scratching in the backward direction is the most suitable for the common usage. © 2017 IEEE.Ministry of Education, Youth and Sports of the Czech Republic within the National Sustainability Programme [LO1303 (NISMT-7771/2014)

Vacuum Fluctuation in 2 × 13 Herringbone Milking Parlour in Dependence on Vacuum Control Method

Vacuum fluctuation was measured using three different vacuum control methods. Firstly, the use was made of a control valve delivered by the manufacturer; then, an additionally installed frequency converter was used. Lastly, a frequency converter fitted with the stabilisation device prototype was used. First, control sensitivity according to ISO was measured in all the three alternatives. Then, vacuum fluctuation during milking was measured. To conduct the measurements under objectively identified conditions, another measurement was conducted with air feed during milking being replaced with a precisely defined variable flow rate. The conducted measurement confirmed the fact that when the frequency converter is used, vacuum fluctuation in stabilised condition is at the same level as when the control valve is used. If there are sudden changes in flow rate and the frequency converter is used, vacuum fluctuation increases. The proposed stabilisation device prototype can reduce the fluctuation in small milking plant but it is not suitable in large milking parlours

Nano-steganography using atomic force microscopy

This paper presents physical nano-steganography for secret data transmission. The experimental code was engraved into the base polycarbonate plastic layer of a compact disc by atomic force microscopy nanolithography. The advantage is that such information cannot be found using optical microscopes and it is very problematic to find it even by the most of electron microscopes due to the subtle variations in height. © 2016 IEEE.Ministry of Education; Youth and Sports of the Czech Republic within the National Sustainability Programme [LO1303, MSMT-7778/2014

The effect of tip speed in AFM scratching

In this study, we investigated the effect of tip speed in AFM scratching. Three testing patterns were engraved on polycarbonate substrate at different scratching parameters. The subsequent characterization of fabricated structures was performed using the identical atomic force microscope. It was found that the depth and width depend only weakly on tip speed. © 2016 IEEE.MOE, Ministry of Educatio