92 research outputs found
Carry-Over Effect in Forage Rotations on Newly Reclaimed Sandy Soil in Egypt
This study was carried out to investigate the carry-over effect of a preceding crop on the productivity of the following crop in various rotations in newly reclaimed lands in Egypt. The productivity of peanut (Arachis hypogaea L.), soyabean (Glycine max (L.) Merr.), maize (Zea mays L.) and pearl millet (Pennisetum glaucum (L.) R. Br.) in summer season were much higher following berseem (Trifolium alexandrinum L.) or lentil (Lens culinaris Medic) than after wheat (Triticum aestivum L.) or barley (Hordeum vulgare L.) in both years of the study. Soyabean was the best summer season pre-crop for lentil and berseem, whereas peanut was best for barley. Maize was a suprisingly good pre-crop in this study. The carry-over effect from pearl millet was inferior to that of maize. Of the winter season crops berseem had the most positive effect on the four summer crops studied. Winter season crops had a decreasing positive effect in the order: berseem, lentil, barley and wheat. The data suggest that, cropping systems on newly reclaimed sandy soils should include legume crops (soyabean or peanut in summer, and berseem or lentil in winter) to maximise production of the following crop
Forage Production from Perennial vs. Annual Crop R~ on in Sandy Soils in Egypt
Forage production was studied on newly reclaimed sandy soil in Egypt trom perennial lucerne (Medicago sativa L.) and two annual crop rotations. The cropping systems were: A) lucerne, B) berseem clover (Trifolium alexandrinum L.) in the winter followed by pearl millet (Pennisetum glaucum R. Br. Emend. Stantz.) in the summer and C) triticale (XX Triticosecale Wittm.) (forage cut + grain harvest) in the winter followed by maize (Zea mays L.) (grain + stover) in the summer. Mean annual dry matter yields (t ha-1 ) were 20.65, 26.59 and 27.48 from A, B and C, respectively. However, lucerne provided the most even seasonal forage production
A comprehensive study on optical features, gamma photon buildup factors and neutron shielding capability of B2O3-SB2O3-LI2O-BI2O3 glasses
ABSTRACT. Linear, nonlinear optical properties, photon buildup factors, and neutron shielding capability of glasses with chemical composition (65-x)B2O3-10Sb2O3-25Li2O-xBi2O3, where x = 0 (BSLB0) – 20 (BSLB20) mol% with steps of 4 mol% were examined. Molar refractivity (Rmolar) and molar polarizability (αmolar) were increased as Bi2O3 content mol% increase in the examined BSLB-glasses. The values of metallization criterion (Mcriterion) confirmed that the BSLB-glasses were non-metallic materials. The static (εstatic) and optical (εoptical) dielectric constants having the same trend of the refractive index (noptical). Values of optical electronegativity (χ*) were reduced from 0.825 for BSLB0 (Bi2O3 = 0 mol%) glasses to 0.758 for BSLB20 (Bi2O3 = 20 mol%) glasses. The linear electric/dielectric susceptibility (χ(1)) increased from 0.370 to 0.397. The nonlinear optical susceptibility (χ3) and nonlinear refractive index n2optical were enhanced by increasing Bi2O3 content in the BSLB-glasses. The BSLB20 glasses presented the least exposure and energy absorption build-up factors (EBF and EABF) at all considered thickness. BSLB20 sample achieved the best fast neutron removal cross section ( ) shield among all glasses. The total stopping powers (TSP) follows the trend (TSP)BSLB0 < (TSP)BSLB4 < (TSP)BSLB8 < (TSP)BSLB12 < (TSP)BSLB16 < (TSP)BSLB20. The electron absorbing and hence shielding capacity of the BSLB-glasses improves as their Bi2O3 content increase.
KEY WORDS: Antimony lithium-borate glasses, Optical properties, Buildup factors, Neutron shielding
Bull. Chem. Soc. Ethiop. 2022, 36(4), 949-962.
DOI: https://dx.doi.org/10.4314/bcse.v36i4.19  
Characterization of zinc lead-borate glasses doped with Fe3+ ions: optical, dielectric, and ac-conductivity investigations
The optical, dielectric response, and ac-conductivity properties for six glasses of zinc lead-borate doped with different contents of Fe3+ (Fe2O3 = 0 to 10 wt%) have been investigated. UV–Vis spectra in 190–1100 nm wavelength have been carried out. Band gaps for optical energy (EOptical), Urbach’s energy (EU), index of refraction (n), steepness parameter (S), energy dispersion parameter of refractive index (Ed), single-oscillator energy (Eo), the dispersion refractive index (no), minimum reflectance wavelength (λo), and oscillator strength (So) were evaluated. Results reveal that the indirect energy gap varies from 2.57 to 1.01 eV, while the direct energy gap takes values from 2.80 to 1.45 eV. The EU values change from 0.232 to 0.966 eV for glasses with Fe2O3 = 0 and 10 wt%, respectively. Also, S and λo decrease with the enhancement of Fe2O3 content. The dielectric response and ac-conductivity of the prepared glasses were investigated by broadband dielectric spectroscopy, BDS, in the frequency range from 0.1 Hz to 10 MHz and at temperatures ranging between 300 and 430 K. Two trends of activation plot have been observed in the conductivity of the samples with low content of Fe2O3. Although these samples show a perfect insulation features, they obey an anomalous behavior at higher temperatures. Therefore, the investigated glasses can be applied in several optical and optoelectronic devices. © 2020, Springer Science+Business Media, LLC, part of Springer Nature
Binary contributions of Dy3+ ions on the mechanical and radiation resistance properties of oxyfluoroborotellurite Dyx-glasses
5CaF2–5BaF2 – 60B2O3–10TeO2 – (20-x)Na2O – xDy2O3: (0.5 ≤ x ≤ 2.5 mol percent) glasses were studied for their physical, mechanical, and gamma radiation resistance. The density of Dy0.5 and Dy2.5 glass samples containing 0.5 and 2.5 mol of Dy2O3 was changed from 2.98 to 3.09 g/cm3, respectively. The estimated values of longitudinal (LB-C) were altered from 171.085 to 165.390 GPa, bulk (KB–C) from 105.100 to 102.680 GPa, Young's (EB-C) from 128.602 to 122.674 GPa, and shear (SB–C) from 49.612 to 47.150 GPa for mechanical characteristics (GPa). The Poisson's ratio (σB-C) was varied between 0.296 and 0.300. The MCNPX code and Py-MLBUF online calculation platform were used to calculate mass attenuation coefficients for all Dyx-glasses. In terms of quantitative values, the acquired results are in good agreement. For all photon energies, the Dy2.5 glass sample exhibits the highest linear (μ) and mass (μm) attenuation coefficients. All analyzed Dyx-glasses exhibit a similar trend in half-value layer (T1/2) and mean free path (MFP), (T1/2, λ)Dy0.5 > (T1/2, λ)Dy1.0 > (T1/2, λ)Dy1.5 > (T1/2, λ)Dy2.0 > (T1/2, λ)Dy2.5. Over the whole gamma-ray energy range, the Dy2.5 sample has the highest effective atomic number (Zeff) values. Across the whole photon energy and penetration depth range, the Dy2.5 has the lowest EBF and EABF values. Because of the maximum contribution of Dysprosium (III)-oxide, the Dy2.5 sample can be deemed superior in terms of gamma-ray shielding qualities. © 2022 The Author(s)Taif University, TU: TURSP-2020/12The authors thank Taif University Researchers Supporting Project number (TURSP-2020/12), Taif University, Taif, Saudi Arabia
Fabrication, physical, structure characteristics, neutron and radiation shielding capacity of high-density neodymio-cadmium lead-borate glasses: Nd2O3/CdO/PbO/B2O3/Na2O
High-density glasses of neodymio-cadmium lead borate of chemical composition xNd2O3/20CdO/20PbO/(57-x)B2O3/3Na2O, where (0 (0Nd) ≤ x ≤ 5 (5Nd) wt%) have been fabricated by a melt quenching process. Physical, structure properties as well as gamma-radiation and neutron shielding effectiveness in wide photon energy range 0.015–15 MeV have been examined. The amorphous nature of xNd-glasses was confirmed, where there was a lack of their crystallinity. Density was gradually increased from 5.006 g/cm3 for 0Nd-glass sample to 5.245 g/cm3 for 5Nd-glass sample. In terms of the mass attenuation coefficient (MAC), introducing Nd3+ ions in the glass matrix has a direct constructive influence on the obtained values of MAC. Generally, the MAC trend follows the order (MAC)5Nd > (MAC)4Nd > (MAC)3Nd > (MAC)2Nd > (MAC)1Nd > (MAC)0Nd. The linear attenuation coefficient (LAC) has a similar trend as MAC for all xNd-glasses. In terms of the half-value layer (T1/2), the 5Nd-glasses possessed the minimum T1/2 values (0.004 cm at 15 keV to 4.301 cm at 15 MeV). Therefore, the T1/2 of the fabricated xNd-glasses has an inverse behavior of the MAC and LAC. Thus, (T1/2)0Nd > (T1/2)1Nd > (T1/2)2Nd > (T1/2)3Nd > (T1/2)4Nd > (T1/2)5Nd. The effective atomic number (Zeff) parameter follows the order (Zeff)5Nd > (Zeff)4Nd > (Zeff)3Nd > (Zeff)2Nd > (Zeff)1Nd > (Zeff)0Nd. In the energies preferred for radiation applications, 5Nd-glasses possess very low exposure (EBF) and energy absorption (EABF) buildup factor values. The fast neutron removal cross-section (FNRC) of the fabricated glasses is improved as the Nd3+ content increases in the glass matrix. © 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.Taif University, TUTaif University Researchers Supporting Project number (TURSP-2020/84), Taif University, Taif, Saudi Arabia
Mechanical properties as well as gamma-ray attenuation competence: A wide-ranging examination into Tb3+doped boro-germanate-aluminiophosphate (BGAP) glasses
The mechanical properties and radiation attenuation competence of Tb3+ ions doped boro-germanate-aluminiophosphate (BGAP) glasses with codes Tb15, Tb20, Tb25, Tb30, Tb35, and Tb40 have been investigated. Bond compression model (B-C) and Phy-X/PSD software are used to achieve these aims. All elastic moduli were reduced with increasing the Tb2O3 content in the BGAP glasses. Values of bulk (KB-C) elastic modulus were possessed decreasing from 86.676 GPa for Tb15 glass sample to 80.205 GPa for Tb40 sample. The values of Young's (EB-C) modulus were found to decrease from 118.197 to 115.641 Gpa and Poisson's ratio (σB-C) of the BGAP glasses were reduced from 0.272 to 0.259. The highest values of linear (μ) and mass (μm) attenuation coefficients were possessed for the Tb40 glass sample. Therefore, (mass, linear)Tb40 > (mass, linear)Tb35 > (mass, linear)Tb30 > (mass, linear)Tb25 > (mass, linear)Tb20 > (mass, linear)Tb15. Half value layer parameter (T1/2) and mean free path (λ) of BGAP glasses were have a similar trend; (λ, T1/2)Tb40 < (λ, T1/2)Tb35 < (λ, T1/2)Tb30 < (λ, T1/2)Tb25 < (λ, T1/2)Tb20 < (λ, T1/2)Tb15. Exposure (EBF) and energy absorption (EABF) buildup factors have a similar attitude for all BGAP glasses. However, the minimum values of EBF and EABF were recorded for the Tb40 sample. Results confirm that Tb40 sample can be considered as superior for radiation shielding among all studied glasses. © 2022 The Author(s)
The Influence of BaO on the Mechanical and Gamma / Fast Neutron Shielding Properties of Lead Phosphate Glasses
The mechanical features evaluated theoretically using Makishima-Mackenzie's model for glasses xBaO-(50-x) PbO–50P2O5 where x = 0, 5, 10, 15, 20, 30, 40, and 50 mol%. Wherefore, the elastic characteristics; Young's, bulk, shear, and longitudinal modulus calculated. The obtained result showed an increase in the calculated values of elastic moduli with the replacement of the PbO by BaO contents. Moreover, the Poisson ratio, micro-hardness, and the softening temperature calculated for the investigated glasses. Besides, gamma and neutron shielding ability evaluated for the barium doped lead phosphate glasses. Monte Caro code (MCNP-5) and the Phy-X/PSD program applied to estimate the mass attenuation coefficient of the studied glasses. The decrease in the PbO ratio has a negative effect on the MAC. The highest MAC decreased from 65.896 cm2/g to 32.711 cm2/g at 0.015 MeV for BPP0 and BPP7, respectively. The calculated values of EBF and EABF showed that replacement of PbO with BaO contents in the studied BPP glasses helps to reduce the number of photons accumulated inside the studied BPP glasses. © 2021 Korean Nuclear Society.Taif University, Saudi Arabia is kindly acknowledged for Supporting our work through the Project number (TURSP-2020/84)
Glass Fabrication Using Ceramic and Porcelain Recycled Waste and Lithium Niobate: Physical, Structural, Optical and Nuclear Radiation Attenuation Properties
The ceramic and porcelain industry in the Arab Republic of Egypt annually produces a huge amount of by-product waste. Public health is threatened by the accumulated ceramic and porcelain dust and crumbs. In this study, five different ceramic and porcelain waste samples were recycled in glass form of xLiNbO3-(40-x)Waste and investigated with different LiNbO3 contents of x = 8, 16, 20, 24, 32 wt.% for useful nuclear radiation shielding applications. The amorphous structure of prepared samples is assured with XRD analyses. The radiation protection features of the prepared samples were investigated experimentally and compared with theoretical calculations for photon energies in the range of 81–2614 KeV. Moreover, optical parameters of waste glasses such as absorption coefficient, skin depth, and extinction coefficient have been calculated. The radiation protection factors showed that the Waste32 sample with 32 wt.% LiNbO3 is the best shield out of the fabricated Waste-x samples. The insertion of ceramic and porcelain wastes in the glass system reached 32 wt.%. © 2021 The Author(s).This work was supported by Taif University Researchers Supporting Project number (TURSP-2020/109), Taif University, Taif, Saudi Arabia. The APC was covered by "Dunarea de Jos" University of Galati, Romania
Newly Developed Vanadium-Based Glasses and Their Potential for Nuclear Radiation Shielding Aims: A Monte Carlo Study on Gamma Ray Attenuation Parameters
This study aimed to investigate different types of glasses based on the 46V2 O5-46P2 O5-(8-x) B2 O3-xCuO system in terms of their nuclear radiation shielding properties. Accordingly, five different CuO-doped vanadate glasses were investigated extensively to determine the necessary gamma shielding parameters along with effective conductivity at 300,000 and buildup factors. Phy-x PSD software was used for determination of these vital parameters. Furthermore, these parameters, such as half value layer, tenth value layer, and mean free path were investigated in a broad energy range between 0.015 and 15 MeV. The results revealed that the amount of CuO reinforced in each sample plays an essential role in determination of the shielding abilities of the samples. The sample with the highest CuO content had the highest linear attenuation coefficient and mass attenuation coefficient values. Additionally, the lowest mean free path, half value layer, and tenth value layer values were recorded for glass sample VPCu8. There was an inverse relation between the effective conductivity and effective atomic number and photon energy; that is, as energy increases, the effective conductivity and effective atomic number decreased rapidly, especially in the regions of low energy. Glass sample VPCu8 reported the highest values for both parameters. Moreover, glass sample VPCu8 had the lowest exposure buildup factor and energy absorption buildup factor values. Our findings showed that CuO-reinforced vanadate glass composition, namely 46V2 O5-46P2 O5-8CuO, with a glass density of 2.9235 g/cm3, was reported to have superior gamma ray attenuation properties. These results would be helpful for scientists in determining the most appropriate additive rare earth type, as well as the most appropriate glass composition, to offer shielding characteristics similar to those described above, taking into consideration the criteria for usage and the needs of the community. The results of this research will be useful to the scientific community in evaluating the prospective characteristics of CuO-doped glass systems and related glass compositions. CuO-doped glass systems and associated glass compositions have a wide range of properties. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.This research received no external funding. The APC was funded by "Dunarea de Jos" University of Galati, Romania. The authors thank Taif University Researchers Supporting Project number (TURSP-2020/84), Taif University, Taif, Saudi Arabia. The work of the corresponding author A.E. was carried out at INPOLDE research center of Dunarea de Jos University of Galati, Romania. The researcher (HMHZ) is funded by a partial scholarship from the ministry of higher education of Egypt
- …