The Effects of Soil-Applied Humic Substances to the Dry Weight and Mineral Nutrient Uptake of Maize Plants under Soil-Salinity Conditions

The aim of this study was to examine the effects of the soil application of humus substances on the dry weight and the nutrient uptake of selected elements in maize grown under salt stress in greenhouse conditions. Sodium chloride was added to the soil to obtain 0, 15, 30, 45 or 60 mM NaCl. Three different doses of solid humus (0, 1 or 2 g kg-1) were applied to the soil one month prior to planting. High levels of salt (45 and 60 mM NaCl) had negative impacts on the dry weight and the N, P, K, Ca, Mg, Fe, Cu, Zn and Mn uptake of the maize plants. The highest mean dry weight, Mg and Mn uptake were observed for the 1 g humus kg-1 treatment and the highest mean Cu content was in the 2 g humus kg-1 treatment. On the contrary, the highest mean uptakes of N and P were found in the soils in which humic substances was not added. The interactions of NaCl and the soil humus content were significant for the uptake of Cu (p? 0.01), and we found that adding humus increased the content of Cu in maize plants under slight salt stress (15 mM NaCl) (p?0.01)

3D printed microfluidic reactor for high throuhput chitosan nanoparticle synthesis

The major bottleneck for the commercialization of nanoparticle related technologies is the mass production of the nanoparticles. One approach to overcome this bottleneck is use of microfluidic devices. In this paper, a 3D printed, high throughput micro-reactor that is capable of synthesizing both chitosan and chitosan coated iron oxide nanoparticles is presented

Paramagnetic signature of microcrystalline silicon carbide

Abstract. The most important challenge on the way to optimized solar cells is to make the thickness of the individual layers smaller than the diffusion length of the charge carriers, in order to keep the collection efficiency close to unity. Here, we propose ß-SiC microcrystals grown by a sol-gel based process as a promising acceptor material. The samples are characterized by optical spectroscopy and electron paramagnetic resonance (EPR). With the help of band structures for selected surface states calculated in the framework of density functional theory (DFT) a possible scenario for the observed acceptor process is discussed

Ablation-cooled material removal at high speed with femtosecond pulse bursts

We report exploitation of ablation cooling, a concept well-known in rocket design, to remove materials, including metals, silicon, hard and soft tissue. Exciting possibilities include ablation using sub-microjoule pulses with efficiencies of 100-mJ pulses. © OSA 2015

A SURVEY ON HEURISTICS FOR THE TWO-DIMENSIONAL RECTANGULAR STRIP PACKING PROBLEM

ABSTRACT Two-dimensional rectangular strip packing problems belong to the broader class of Cutting and Packing (C&P) problems, in which small items are required to be cut from or packed on a larger object, so that the waste (unused regions of the large object) is minimized. C&P problems differ from other combinatorial optimization problems by the intrinsic geometric constraints: items may not overlap and have to be fully contained in the large object. This survey approaches the specific C&P problem in which all items are rectangles, therefore fully characterized by a width and a height, and the large object is a strip, i.e. a rectangle with a fixed width but an infinite height, being the problem's goal to place all rectangles on the strip so that the height is minimized. These problems have been intensively and extensively tackled in the literature and this paper will focus on heuristic resolution methods. Both the seminal and the most recent approaches (from the last decade) will be reviewed, in a rather tutorial flavor, and classified according to their type: constructive heuristics, improvement heuristics with search over sequences and improvement heuristics with search over layouts. Building on this review, research gaps are identified and the most interesting research directions pointed out

Agricultural use of wastewater sludge from various sources with special emphasis on total and DTPA-extractable heavy metal content

This study was conducted to evaluate wastewater sludge from various sources for agricultural utilization. The results showed that sludge from municipal and food industrial wastewater treatment plants (WWTPs) have high fertilizing value with respect to nutrients and organic matter levels. When the sludge samples were evaluated for their total heavy metal contents, the Pb, Cd and Cu concentrations in all of the sludge samples were found to be below the limit specified by Turkish regulations. However, the Cr, Ni and Zn contents of domestic type, organized industrial zone, food industry sludge samples exceeded these thresholds. Other sludges were found to be suitable for agricultural usage in terms of plant nutrient and heavy metal content. The analysis of the sludge samples from twelve different WWTP’s showed that the agricultural properties and the total and bioavailable (DTPA-extractable) heavy metal fraction varies depending on the sludge samples. Therefore discussed sludges should be evaluated separately for the agricultural utilization potential in terms of soil pollution