Suitability of 2.4 GHz and 5 GHz wireless communications in production processes

ArticleToday, it is increasingly modern to use wireless transmissions in production. It is possible to send information messages, control messages and it is often possible to access the technologies as IoT (the Internet of Things). The aim of this work was to find out which of the selected Wi-Fi frequencies is more suitable for use in syrup processing equipment. The evaluation was performed on the basis of attenuation and download speed at each frequency (2.4 GHz and 5 GHz bandwidth). These frequencies have been chosen due to their massive deployment for wifi networks that currently dominate wireless communications. Measurements were made downloading files on different frequency bands. Mean and maximum data throughput and signal strengths were also measured. By measuring, it has been found that when using 2.4 GHz wireless Wi-Fi technology, you can very often encounter strong interference effects. Despite the theoretically worse 5 GHz frequency spread, you can achieve up to 30% better data throughput on average. The results show the suitability of 2.4 and 5 GHz Wi-Fi technology. The main finding is that, despite the worse frequency spread of 5 GHz, it is more appropriate. Not only due to speed but also in the future due to better transmission capacities and future channel expansion

The potential of energy recovery from by–products of small agricultural farms in Nigeria

ArticleAgricultural by–products are renewable energy sources from which essential amount of energy can be recovered, which can be used to replace the use of conventional fossil fuel, reduces the potential of greenhouse gas (GHG) emission and at the same time reduces deforestation, especially in rural areas. Energy values of biomass from small Agricultural farms, in particular waste generated from different tropical crops, viz; Maize, Millet, Rice, Sorghum and Groundnut were determined, to ascertain their potentials as alternative fuel sources for rural use. The materials were found to be of importance judging by their combustion potentials in all the forms investigated. The Energy values of the by-products considered ranged between 11.68 MJkg-1 to 17.48 MJkg-1 with Groundnut pods and millet husk having the highest and least respectively. Moisture and ash had effect on the energy values of these biomass. Our results are relevant to the problems posed by the management of farm residues in developing countries

The impact of weather conditions on microclimate in storage facilities

ArticleThe key to maintaining good qualitative parameters of stored grain on farms is to achieve and maintain suitable storage temperatures relative to the outside temperature. In the framework of this research, the main focus was on typical representatives of grain storage facilities used in the Czech agriculture. In the post - harvest period after the crops were stored in the chosen storage facilities, the temperature of the material was monitored at 15 - minute intervals using an external temperature probe as well as the temperature and dew point of the outdoor air. A simple linear regression model was used for data analysis. The correlated temperature d ependence of the stored grain varies considerably in the monitored storage facilities. The storage halls were characterized by a low dependence (r = 0.2208) of the temperature of the material on the outside air temperature in the first 4 months following t he harvest when the grains were being stabilized by active aeration. In addition to the grain and the air temperature, the second focus was monitoring the dew point, i.e. assessing the risk of water vapour condensation on the surface in the upper layer of the stored grain, which is very undesirable for maintaining the quality of the stored grain. The results show that the monitored storage hall can be characterized by the ability to maintain the required climate due to outdoor climatic conditions. In genera l, this ability mainly depends on the type and design of the storage facility, the aeration system and also the storage capacity. Mainly during spring the dew point and water vapour condensation can often happen within the grain, therefore the need to focu s on appropriate measures such as reduced aeration or increased grain mixing, and thus avoiding the formation of critical spots

Energy consumption of milking pump controlled by frequency convertor during milking cycle

ArticleThe article deals with selected parameters affecting the energy consumption of a vacuum pump in a milking system during the whole milking cycle in variants with and without regulation by a frequency convertor. When put into practice, the latest research of creation, control and stabilization of vacuum in milking devices allows dairy farmers to obtain a vacuum system that ensures maximum stability of milking pressure, which is a basic requirement affecting the health of dairy cows. The choice of vacuum system prioritizes in particular high performance, maximum operational reliability, minimum maintenance, long service life, environmental friendliness and economy. The vacuum pump was a Roots vacuum pump with a rotary piston which is typical for this use. Use of a frequency convertor significantly affected the efficiency of this pump for control of vacuum pressure level and pump performance by varying the rotation frequency according to the actual airflow requirement. Using this control system, only as much vacuum pressure is produced as necessary. By measurement of an experimental setup, it was found that the average power requirement of a setup with a control valve was 3.8 kW compared to 1.7 kW in the case of the variant with frequency convertor. Measurements and calculations have shown that this system is capable of saving more than 50% of electric energy

Separation and recovery of materials from scrap printed circuit boards

Printed circuit boards from waste computers, televisions, and mobile phones were pyrolysed in a fixed bed reactor with the aim of separating and recovering the organic and metallic materials. A selection of printed circuit boards from each of the three waste classes was pyrolysed at 800°C and the pyrolysis products were analysed using GC-FID, GC-TCD, GC-MS, GC-ECD, ICP-MS, and SEM-EDX. The pyrolysis oils contained high concentrations of phenol, 4-(1-methylethyl)phenol, and p-hydroxyphenol, as well as bisphenol A, tetrabromobisphenol A, methyl phenols, and bromophenols. The pyrolysis oils also contained significant concentrations of organo – phosphate compounds and a number of tetrabromobisphenol A pyrolysis products were also identified. The pyrolysis residues were very fragile and the organic, glass fibre, and metallic fractions could easily be separated and the electrical components could easily be removed from the remains of the printed circuit boards. The ash in the residue mainly consisted of copper, calcium, iron, nickel, zinc, and aluminium, as well as lower concentrations of valuable metals such as gallium, bismuth, silver, and gold, silver was present in particularly high concentrations. Many other metals were also identified in the ash by ICP-MS and SEM EDX. The pyrolysis gases mainly consisted of CO2 and CO but all of the C1 – C4 alkanes and alkenes were present, as were some inorganic halogens

The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment

The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since July 2014. This paper describes the second data release from this phase, and the fourteenth from SDSS overall (making this, Data Release Fourteen or DR14). This release makes public data taken by SDSS-IV in its first two years of operation (July 2014-2016). Like all previous SDSS releases, DR14 is cumulative, including the most recent reductions and calibrations of all data taken by SDSS since the first phase began operations in 2000. New in DR14 is the first public release of data from the extended Baryon Oscillation Spectroscopic Survey (eBOSS); the first data from the second phase of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2), including stellar parameter estimates from an innovative data driven machine learning algorithm known as "The Cannon"; and almost twice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous release (N = 2812 in total). This paper describes the location and format of the publicly available data from SDSS-IV surveys. We provide references to the important technical papers describing how these data have been taken (both targeting and observation details) and processed for scientific use. The SDSS website (www.sdss.org) has been updated for this release, and provides links to data downloads, as well as tutorials and examples of data use. SDSS-IV is planning to continue to collect astronomical data until 2020, and will be followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14 happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov 2017 (this is the "post-print" and "post-proofs" version; minor corrections only from v1, and most of errors found in proofs corrected