Fenugreek: productivity, nutritional value and uses

This paper reviews the available literature about the botanical aspects and productivity, properties and applications of fenugreek. The source of this species are seeds and leaves. The high yield of fenugreek is influenced on the environmental and agricultural factors. The unique properties of this species are determined by variety, agricultural technology and habitat conditions, too. One of this species is a crop fenugreek (Trigonella foenum – graecum L.). Fenugreek belongs to the legume plants and is an environmentally friendly plant. The yields of plants depend on the genotype, climate, environmental conditions, cultivation practices, use of fertilizers, irrigation. The seeds are rich in biogenic element such as phosphorus, sulfur, magnesium, calcium but were less abundant in zinc, manganese and copper. Fenugreek seeds and leaves contain biologically active substances (protein, amino acids, biogenic elements, lipids and fatty acids), and they are used in traditional medicine, as functional food and in the cosmetics industry. In traditional medicine, fenugreek is used to prepare infusions, water and alcohol extracts, tinctures, meads, tonics with antidepressant and psychotonic properties, and muscle growth supplements. Fenugreek constitutes high-quality feed for dairy cattle which improves the health status of livestock. The findings presented in this review paper will be useful for consumers hoping to improve their health by incorporating healthy biogenic elements and fatty acids into their diets

Effect of potassium fertilization, Rhizobium inoculation and water deficit on the yield and quality of fenugreek seeds

The paper presents results on the effect of agronomic factors on the content of chlorophyll, the biometric parameters of plants and quality of fenugreek seeds. It has been shown that potassium fertilization and inoculation of fenugreek seeds had no significant effect on the plant’s performance. The only trait influenced by those factors was the seed weight per plant; under higher doses of potassium fertilization K2.5 and K3.75, its value was about 10% higher, but fell down by 19.3% in treatments with inoculated seeds compared to non-inoculated ones. Soil water deficit caused reduction of plant height by 15.5%, number of pods by 18.3%, number of seeds per pod by 20%, weight of seeds by 28%, weight of the plant’s aerial parts by 18.0%, and harvest index by 13.2%. In response to water deficit, the content of chlorophyll decreased significantly from 57.8 SPAD units at 43 DAS to 52.4 and 54.0 SPAD units in the next phases (51 and 58 DAS), when 40% and 80% of pods attained the final length. Increasing doses of potassium caused a significant increase in the crude protein (by 3.2-5.4%) and potassium content (by 7-8%) in seeds of fenugreek grown under water deficit. After seed inoculation, an increase in the protein content was found

Gas Sensors Based on ZnO Structures

The paper presents the results of investigations concerning sensor structures based on porous layers of zinc oxide (ZnO) sensitive to a selected gaseous environment. The investigations comprised analyses of the influence of the gaseous environment on the optical properties of a sensor structure, in particularly on the change of the spectral characteristics of optical transmission within the range of ultraviolet light and in the visible range. These presented investigations were carried out in such a gaseous environment as nitrogen dioxide $NO_2$ in synthetic air

Optical investigations of ZnO layers affected by some selected gases in the aspect of their application in optical gas sensors

The paper presents the results of investigations of zinc oxide (ZnO) layers as a potential sensing material, being affected by certain selected gaseous environments. The investigations concerned the optical transmission through thin ZnO layers in wide spectral ranges from ultraviolet to the near infrared. The effect of the gaseous environment on the optical properties of zinc oxide layers with a thickness of ~ 400 nm was analyzed applying various technologies of ZnO manufacturing. Three kinds of ZnO layers were exposed to the effect of the gaseous environment, viz.: layers with relatively slight roughness (RMS several nm), layers with a considerable surface roughness (RMS some score of nm) and layers characterized by porous ZnO structures. The investigations concerned spectral changes in the transmission properties of the ZnO layers due to the effect of such gases as: ammonia (NH3), hydrogen (H2), and nitrogen dioxide (NO2) in the atmosphere of synthetic air. The obtained results indicated the possibility of applying porous ZnO layered structures in optical gas sensors

Characterization of Al2O3/4H-SiC and Al2O3/SiO2/4H-SiC MOS structures

The paper presents the results of characterization of MOS structures with aluminum oxide layer deposited by ALD method on silicon carbide substrates. The effect of the application of thin SiO2 buffer layer on the electrical properties of the MOS structures with Al2O3 layer has been examined. Critical electric field values at the level of 7.5–8 MV/cm were obtained. The use of 5 nm thick SiO2 buffer layer caused a decrease in the leakage current of the gate by more than two decade of magnitude. Evaluated density of trap states near the conduction band of silicon carbide in Al2O3/4H-SiC MOS is about of 1×1013 eV−1cm−2. In contrast, the density of the trap states in the Al2O3/SiO2/4H-SiC structure is lower about of one decade of magnitude i.e. 1×1012 eV−1cm−2. A remarkable change in the MOS structure is also a decrease of density of electron traps located deeply in the 4H-SiC conduction band below detection limit due to using of the SiO2 buffer layer

Investigation of the ZnO sensing structure on NH

The paper presents the results of experimental investigations of the layered Zn/Au/Cr sensor structure, which permits to detect and to measure the concentration of gaseous ammonia NH3. The elaborated sensor structure is deposited on BK7 glass substrate. The substrate with the layered sensor structure is coupled with the prism, and the whole constitutes the optical plasmon systems SPR of the ammonia sensor. The sensor is characterized by a short response time and a comparatively good regeneration of its sensing properties

ZnO sensing structure for NH

Layered structure for the detection and measuring of gaseous ammonia have been presented. The presented sensor structures hale Bern developed on the base of thin ZnO and Au/Cr layers deposited on a glass substrate. The technological as well as optical properties of the elaborated sensing structures have been discussed

ZnO - Wide bandgap semiconductor and possibilities of its application in optical waveguide structures

The paper presents the results of investigations concerning the application of zinc oxide - a wideband gap semiconductor in optical planar waveguide structures. ZnO is a promising semiconducting material thanks to its attractive optical properties. The investigations were focused on the determination of the technology of depositions and the annealing of ZnO layers concerning their optical properties. Special attention was paid to the determination of characteristics of the refractive index of ZnO layers and their coefficients of spectral transmission within the UV-VIS-NIR range. Besides that, also the mode characteristics and the attenuation coefficients of light in the obtained waveguide structures have been investigated. In the case of planar waveguides, in which the ZnO layers have not been annealed after their deposition, the values of the attenuation coefficient of light modes amount to a ≈ 30 dB/cm. The ZnO layers deposited on the heated substrate and annealed by rapid thermal annealing in an N2 and O2 atmosphere, are characterized by much lower values of the attenuation coefficients: a ≈ 3 dB/cm (TE0 and TM0 modes). The ZnO optical waveguides obtained according to our technology are characterized by the lowest values of the attenuation coefficients a encountered in world literature concerning the problem of optical waveguides based on ZnO. Studies have shown that ZnO layers elaborated by us can be used in integrated optic systems, waveguides, optical modulators and light sources