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

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

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

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 2014 July. This paper describes the second data release from this phase, and the 14th from SDSS overall (making this Data Release Fourteen or DR14). This release makes the data taken by SDSS-IV in its first two years of operation (2014–2016 July) public. 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; 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 the 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 web site (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

Comparison of Reliability of Vth and VIth Generation Adhesive Systeme by Thermocycling

The target of the thestudy was to compare the reliability of adhesive systems of Vth. and VIth generation by thermocycling according to method ISO/TS 11405:2003 (E). For comparison there were chosen two representatives from each group - from the Vth generation materials Single Bond Adper and Prime&Bond NT and from the VIth generation materials Prompt-L Pop Adper and Xeno III. The materials of the Vth generation were combined with advised etching gels and by all adhesives the directions for use were strictly followed. Adhesive systems were combined with material Spectrum TPH. Each adhesive system was tested on 10 samples of intact third molars. The results showed extensive variability among reliability single adhesives without dependence to generations, that means self-etch or conventional total-etch. While measuring microleakage according to ISO/TS 11405:2003 (E) was the most reliable Prime&Bond NT, with score 12, than Xeno III with score 26. Between reliability of Single Bond Adper (score 37) and Prompt L-Pop Adper (score 38) there was no significant difference. The results demonstrated no significant difference between single generations of adhesive systems and proved that the quality of each product is the most important, whether it belongs to self-etch or conventional total-etch generations

Effect of Peroxide Bleaching Systems on the Marginal Integrity and Surface Hardness of Composite Restorations

Peroxide bleaching systems may affect resin composite restorations through their strong oxidative effect. The objective was to investigate the influence of bleaching systems on long-term stability of marginal integrity of composite restorations and composite surface resistance. Class V cavities were prepared at the enamel-dentine junction and filled using a total-etch adhesive system Gluma Comfort Bond (n=36) and self-etching adhesive iBond (n=36) in combination with the microhybrid resin composite material Charisma. The peroxide bleaching gel Opalescence PF 20% (20 wt. % carbamide peroxide) was applied 25 times on the restorations. The control groups were exposed to distilled water for 24 hours and two months before a microleakage test was performed. Composite hardness was characterized after 0, 2, 7, 14 and 25 applications of the gel and compared with the control group (each n=5) exposed to distilled water for two months. Surface morphology was evaluated using scanning electron microscopy. After the gel application no significant changes in marginal integrity were found for both groups of samples. With Gluma Comfort Bond due to its high bonding performance and with iBond due to its decreased performance on enamel causing marginal integrity failure at the beginning of the experiment. On the other hand, pronounced surface porosity and decreased hardness of the composite material indicated its significant degradation in the presence of the bleaching gel

The Effect of Surface Treatment on Composite Repair Bond Strength Longevity

Introduction: Composite restorations undergo degradation in the oral cavity, which may compromise their aesthetic and functional properties, cause failure of marginal integrity, increased abrasion or even partial fracture of the filling. Instead of complete removal of such restorations, they can be repaired. Aim: To study the bond strength of a new composite resin to an aged composite substrate after a 4-month storage in distilled water or sodium laurylsulphate solution (SLS). Two various surface treatments and two different adhesive systems were tested. Materials and methods: Light cured specimens of a micro-hybrid composite (Filtek Z250, shade A2) were aged in distilled water (37 °C) for 5 months. Composite surface was prepared either by grinding (SiC paper P320, mean grain size 46 µm, equivalent to red diamond bur) or by air abrasion (Rondoflex; Al2O3 50 µm; 3.2 bar; 60 s). Composite build-ups were made from the same composite material using two adhesive systems (Optibond FL, Gluma Comfort Bond). The microtensile bond strength (n = 13-16) was measured after a 4-month storage of specimens at 37 °C in distilled water or in a solution of sodium lauryl sulfate (1.5 wt. %). Control specimens were stored in distilled water for 24 hours (37 °C). Results: A decrease of the bond strength compared to the control group on the ground surface after the 4-month storage in distilled water or SLS was found to be adhesive system- dependant. The bond strength for Optibond FL decreased by 52% in SLS only (p < 0.001), but for Gluma Comfort Bond it decreased by 45% in distilled water (p < 0.001) and by 61% in SLS (p < 0,001). On the air-abraded surface the bond strength decreased only for Optibond FL in SLS (p < 0.01), by 31%. Conclusion: Long-term durability of composite repair can be maintained by preparing the original composite surface using air abrasion. The effect of the adhesive system on the bond strength was not significant