Spallation reactions. A successful interplay between modeling and applications

The spallation reactions are a type of nuclear reaction which occur in space by interaction of the cosmic rays with interstellar bodies. The first spallation reactions induced with an accelerator took place in 1947 at the Berkeley cyclotron (University of California) with 200 MeV deuterons and 400 MeV alpha beams. They highlighted the multiple emission of neutrons and charged particles and the production of a large number of residual nuclei far different from the target nuclei. The same year R. Serber describes the reaction in two steps: a first and fast one with high-energy particle emission leading to an excited remnant nucleus, and a second one, much slower, the de-excitation of the remnant. In 2010 IAEA organized a worskhop to present the results of the most widely used spallation codes within a benchmark of spallation models. If one of the goals was to understand the deficiencies, if any, in each code, one remarkable outcome points out the overall high-quality level of some models and so the great improvements achieved since Serber. Particle transport codes can then rely on such spallation models to treat the reactions between a light particle and an atomic nucleus with energies spanning from few tens of MeV up to some GeV. An overview of the spallation reactions modeling is presented in order to point out the incomparable contribution of models based on basic physics to numerous applications where such reactions occur. Validations or benchmarks, which are necessary steps in the improvement process, are also addressed, as well as the potential future domains of development. Spallation reactions modeling is a representative case of continuous studies aiming at understanding a reaction mechanism and which end up in a powerful tool.Comment: 59 pages, 54 figures, Revie

Ameliorating iron deficiency through seed treatment

Not AvailableA pot culture experiment was conducted on this soil to develop the protocol for seed treatment of iron using IR-64 and Pusa Sugandh- 3 as test cultivars of rice. Each processed soil (1.5 kg) was taken in 3 kg plastic pots. The soil was then mixed thoroughly and irrigated with water prior to sowing of soaked seeds of rice varieties. The basal application of N, P2O and K2O at the rate of 45, 26 and 18 mg kg-1 soil was made through AR-grade urea,monoammonium phosphate and potassium chloride. Four treatments of Fe included control, i.e. soaking of seed in distilled water as well as soaking seed in 0.5M FeSO4.7H2O, 0.25M FeSO4.7H2O and 0.05M Fe- EDTA. The duration of seed soaking was 12 and 24 h. Thus, in all, 16 treatment combinations (4 × 2 × 2) were laid out in a completely randomized design (CRD) with three replications. ForSeed soaking with 0.05M Fe-EDTA solution for 12 h prior to sowing was effective in alleviating Fe deficiency in aerobically-grown rice on the calcareous soil. Dry matter yield response of IR-64 was 10, 11 and 28% due to seed treatment with 0.25M, 0.5M FeSO4.7H2O and 0.05M Fe-EDTA respectively, over control.Not Availabl

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Not AvailableEnhancing the content of Fe in edible portion of rice for improving human health is a global challenge. A greenhouse experiment was conducted to evaluate the relative effectiveness of soil, foliar and seed treatment of Fe in alleviating Fe-deficiency using two rice cultivars (IR-64 and Pusa Sugandh-3) grown on alkaline, calcareous, acid and lime-treated acid soils. Results showed that on an average, soil application of Fe improved the available Fe status of soil (8.14 mg kg⁻¹ ) over control (6.79 mg kg⁻¹ ). The foliar application of Fe (3% FeSO4.7H2O solution, thrice 40, 60 and 75 days after sowing of rice) was more effective and economical in enhancing the yield (9.42%) as well as increasing Fe content (3.48%) of milled rice as compared to soil application (67 mg FeSO4.7H2O kg⁻¹ ). Among the soils, acid soil (without lime) produced highest yield (27.4 g pot⁻¹) of aerobic rice followed by alkaline (21.2 g pot⁻¹ ), calcareous (20.0 g pot⁻¹ ) and lime-treated acid soils (17.7 g pot⁻¹ ). Pusa Sugandh-3 (23.4 g pot⁻¹ ) performed better under aerobic condition compared to IR-64 (19.7 g pot⁻¹ ). Ferrous-iron content in rice plants proved to be a better index of Fe nutrition status compared to total plant Fe and chemically extractable soil Fe. The Fe²⁺ content of ≥ 42 mg kg⁻¹ in plants (on dry weight basis) appeared to be an adequate level at 45 days after sowing for rice grown under upland aerobic condition.Not Availabl

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Not AvailableAdsorption studies are important to determine the retention and release of applied plant nutrients and the efficiency of fertilization. The present study was conducted to delineate the zinc (Zn) adsorption behavior of soils with varying characteristics. In this study, adsorption behavior of Zn was studied at varying Zn concentrations and temperatures in three different soils collected from the Research Farm of Indian Agricultural Research Institute (IARI), New Delhi (Inceptisols, Typic Haplustepts), soil (Inceptisols, Typic Ustocrept) from a farmer’s field in Shamgarh, Karnal, Harayana, and the Hayathnagar Research Farm of Central Research Institute For Dryland Agriculture (CRIDA), Hyderabad, (Haplustalf). The results of this study revealed that the adsorption of Zn as well as differential buffering capacity (DBC) was greater in Typic Haplustepts of IARI and Typic Ustocrept of Karnal than Haplustalf of CRIDA, Hyderabad. However, the supply power as well as percentage saturation (% sat.) was greater in Haplustalf of CRIDA, Hyderabad, than Typic Haplustepts of IARI and Typic Ustocrept of Karnal The results also revealed that irrespective of the soil types, Zn adsorption increased with an increase in Zn concentration and increase in temperature from 20 ◦C to 35 ◦C. When the adsorption data were fitted to isotherms, Langmuir and Freundlich isotherm fits were excellent, as evidenced by high r2 (0.71 to 0.99) values. Thermodynamic parameters such as standard free energy ( G) were negative in both Typic Haplustepts and Typic Ustocrept soils, indicating spontaneous Zn adsorption reaction, but nonspontaneous reaction was observed in the case of Haplustalf soils.. Interestingly, both standard enthalpy ( H) and standard entropy ( S) were negative in all the three types of soils studies. The analogy and results of the present study would be useful in deciding the Zn fertilizer needs for a given soil type.CSIR, ICA

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Not AvailableInitially, a preliminary study was conducted to assess the variation of grain zinc (Zn) and iron (Fe) content of 10 basmati rice cultivars. Thereafter, comprehensive study was conducted to enhance the Zn density in grain using three cultivars (CSR 30, Pusa Basmati-6 and PusaSugandh 5) selected from the preliminary study, using three diverse soil types (Inceptisols of IARI, New Delhi; Inceptisols of farmer’s field, Karnal; and Alfisols of CRIDA, Hyderabad) and six zinc nutrient management treatments including control. The results in the preliminary study indicated that the Zn content in rice grain (after hulling) varied from 13.3 to 22.5 mg kg−1 with mean of 18.8 mg kg−1, while Fe content varied from 8.3 to 14.3 mg kg−1 with mean of 10.7 mg kg−1. In the comprehensive study, the highest Zn content in grain (21.2 mg kg−1) and straw (33.2 mg kg−1) was observed in CSR-30 Cultivar. Among the soil types, Alfisols of CRIDA, Hyderabad maintained significantly highest Zn content in grains and straw. Among the Zn containing nutrient management treatments, application of 5 mg Zn kg−1 (basal) + foliar spray of 0.5% ZnSO4 (bi-weekly) maintained significantly highest Zn content in grain (21.9 mg kg−1) and straw (41.3 mg kg−1). Further, based on the assumption that when an individual consumes rice @ 200 g day−1, his daily dietary intake of Zn would be 3.53 mg day−1 in control (without Zn application) as compared to 4.38 mg day−1 with the rice grown with soil and foliage application of ZnNot Availabl

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