Search results for "engineering"
showing 10 items of 44231 documents
Development of an immunochromatographic assay based on carbon nanoparticles for the determination of the phytoregulator forchlorfenuron
2013
Rapid analytical methods enabling the determination of diverse targets are essential in a number of research areas, from clinical diagnostics to feed and food quality and safety. Herein, the development of a quantitative immunochromatographic assay for the detection of the synthetic phytoregulator forchlorfenuron (CPPU) is described. The competitive lateral flow immunoassay (LFIA) was based on the immobilization onto a nitrocellulose membrane of an ovalbumin-CPPU conjugate (test line) and on the use of an immunodetection ligand consisting of carbon nanoparticles labeled with an anti-CPPU monoclonal antibody through interaction with a secondary antibody. The presence of CPPU in horticultural…
Levels and Potential Health Hazards of Chlorinated Pesticidesin Surface Water Samples of Charsadda Area of Pakistan Using SPME-GC-ECD Technique
2021
In the present study, we determined the levels of chlorinated pesticide residues in surface water samples collected from the Charsadda district (KPK, Pakistan). SPME-GC-ECD with COMBI PAL CTC autosampler was used for extraction and analysis of 20 organochlorine pesticides in the collected water samples. For maximum efficiency of the SPME procedure, several parameters were studied, including the extraction and desorption time of the fiber, solution pH, agitation of samples, and stirring speed, etc. This method showed good liner response, with R2 values in the range of 0.9887 to 0.9999 for all pesticides. This method also provided good percent recoveries at 1 µg L−1 (87.5 to 106.0%) and at 2 …
Transformations Accompanying a Shift from Surface to Drip Irrigation in the Cànyoles Watershed, Valencia, Spain
2017
Drip irrigation is widely promoted in Spain to increase agricultural production and to save water. In the Cànyoles watershed, Valencia, we analysed the consequences of change from surface irrigation to drip irrigation over the past 25 years. There were a number of transformations resulting from, or accelerated by, this change including the 1) intensification of well construction causing a redistribution in access to groundwater, water shortages and a lowering of the groundwater table; 2) expansion of irrigation into former rain-dependent uphill areas resulting in increased water use; 3) shift to higher- value monoculture fruit crops, but with associated higher crop water requirements; 4) in…
X-ray tomographic method for measuring three-dimensional deformation and water content distribution in swelling clays
2015
A non-invasive method for simultaneous measurement of the 3D displacement field and the water content distribution of a wetted solid material is developed. The method is based on comparison of X-ray tomographic images of a material sample in the reference state and in the wetted and deformed state. The deformation and water content analyses were successfully compared with numerical results for a cylindrical rubber test sample under axial compression, and with gravimetric results from axially wetted and sliced cylindrical bentonite samples, respectively. The methods were applied in a 4D study (three spatial dimensions and time) of wetting and deformation of purified swelling bentonite doped …
Evaluation of the wave energy density on the Sicilian coast
2016
In this article the wave energy density of the northern Sicilian coasts is evaluated and is used to evaluate the producibility of a wave nergy converter to be installed in an area in the north west part of Sicily. In particular, the objective of the study is the evaluation of a potential installation in an area between Trapani and Palermo, which are the largest cities in the north west part of Sicily. In particular in this research, the wave energy density of Sicily has been analyzed by using an analysis of wave data carried out in a 10-year period, using the measurements of buoyant of National Wave measuring System (RON - Rete Ondametrica Nazionale). The analysis shows that the north-weste…
The mechanically based non-local elasticity: an overview of main results and future challenges
2013
The mechanically based non-local elasticity has been used, recently, in wider and wider engineering applications involving small-size devices and/or materials with marked microstructures. The key feature of the model involves the presence of non-local effects as additional body forces acting on material masses and depending on their relative displacements. An overview of the main results of the theory is reported in this paper.
The Effect of Electrolytic Solution Composition on the Structure, Corrosion, and Wear Resistance of PEO Coatings on AZ31 Magnesium Alloy
2020
Plasma electrolytic oxidation coatings were prepared in aluminate, phosphate, and silicate-based electrolytic solutions using a soft-sparking regime in a multi-frequency stepped process to compare the structure, corrosion, and wear characteristics of the obtained coatings on AZ31 magnesium alloy. The XRD results indicated that all coatings consist of MgO and MgF2, while specific products such as Mg2SiO4, MgSiO3, Mg2P2O7, and MgAl2O4 were also present in specimens based on the selected solution. Surface morphology of the obtained coatings was strongly affected by the electrolyte composition. Aluminate-containing coating showed volcano-like, nodular particles and craters distributed over the …
Synergistic effect of W incorporation and pulsed current mode on wear and tribocorrosion resistance of coatings grown by plasma electrolytic oxidatio…
2019
Ceramic coatings were grown by plasma electrolytic oxidation on 7075 Al alloy using unipolar and bipolar pulsed current waveforms with 20 and 40% cathodic duty cycles, from a silicate-based bath without and with the addition of Na2WO4. Pancake-like morphology was dominant on the coatings grown by unipolar waveform, while the bipolar waveforms promoted volcano-like morphology, increased the roughness of the coating surface and the formation of more compact layers. The coatings produced using the bipolar waveforms provided higher resistances toward both tribocorrosion and dry sliding conditions, while further improvement was achieved by the presence of tungsten. The coatings produced in tungs…
Effect of Boron Doping on the Wear Behavior of the Growth and Nucleation Surfaces of Micro- and Nanocrystalline Diamond Films
2016
B-doped diamond has become the ultimate material for applications in the field of microelectromechanical systems (MEMS), which require both highly wear resistant and electrically conductive diamond films and microstructures. Despite the extensive research of the tribological properties of undoped diamond, to date there is very limited knowledge of the wear properties of highly B-doped diamond. Therefore, in this work a comprehensive investigation of the wear behavior of highly B-doped diamond is presented. Reciprocating sliding tests are performed on micro- and nanocrystalline diamond (MCD, NCD) films with varying B-doping levels and thicknesses. We demonstrate a linear dependency of the we…
Tribological and Mechanical Properties of the Nanostructured Superlattice Coatings with Respect to Surface Texture
2022
This research is funded by the Latvian Council of Science, project “Carbon-rich self-healing multifunctional nanostructured smart coatings (NSC) for high-tech applications using high-power confined plasma technology for their deposition”, project No. 2019/1-0385.