In the context of contemporary global challenges such as the COVID-19 pandemic, geopolitical conflicts, and climate change, food security assumes particular significance, being an integral part of national security. This study aims to investigate the interplay between food security and national security systems, with a focus on identifying gaps in the literature and determining directions for further research. The study conducted a systematic literature review on food security and national security systems employing a rigorous and transparent process. The qualitative analysis is grounded in the quantitative one, encompassing studies from Scopus. The examination of the selected peer-reviewed articles revealed several methodological and thematic limitations in existing research: i Geographic imbalance: There is a predominant focus on developed countries, while food security issues in developing countries remain insufficiently studied; ii Insufficient explication: There is a lack of research dedicated to managerial and economic aspects of food security in the context of national security; iii Methodological constraints: There is a predominance of quantitative methods and retrospective/cross-sectional studies. Recommendations include developing comprehensive strategies at both global and national levels to enhance food stability and accessibility.
Urbanization plays a crucial role in facilitating the integration of population growth, industrial development, economic expansion, and energy consumption. In this paper, we aim to examine the relationships between CO2 emissions and various factors including economic growth, urbanization, financial development, and energy consumption within Pakistan’s building sector. The study utilizes annual data spanning from 1990 to 2020. To analyze the cointegration relationship between these variables, we employ the quantile autoregressive distributed lag error correction model (QARDL-ECM). The findings of this research provide evidence supporting the presence of an asymmetric and nonlinear long-term relationship between the variables under investigation. Based on these results, we suggest the implementation of tariffs on nonrenewable energy sources and the formulation of policies that promote sustainable energy practices. By doing so, policymakers and architects can effectively contribute to minimising environmental damage. Overall, this study offers valuable insights that can assist policymakers and architects in making informed decisions to mitigate environmental harm while fostering sustainable development.
The content of flavonoids in mesophyll cells of wheat was studied under the condition of enhanced UV-B radiation intensity. In this experiment, four groups of six days of control were treated with He-Ne laser group (L), enhanced UV-B radiation group (B), He-Ne laser and UV-B combined treatment group (B + L ), Normal light group (CK). Since the flavonoids carry some unsubstituted hydroxyl or glycosyl groups, it is a polar compound. By the 'similar compatibility' principle, they have some level of solubility in polar solvents, such as methanol, ethanol, n-butanol, propanol, and water. In this experiment, 70% ethanol was used to extract flavonoids. Finally, the total content of flavonoids in mesophyll cells was determined by visible spectrophotometry. The OD value of flavonoids was determined by rutin reagent 'The standard curves because rutin is a representative of flavonoids, it scavenging the role of free radicals significantly. The results showed that when the UV-B UV radiation intensity was enhanced, the content of flavonoids in wheat mesophyll cells increased, that is, the content of flavonoids in wheat leaves was higher than that in UV-B Strength was positively correlated. The results showed that the content of flavonoids in the mesophyll cells of the four control groups was the same as that of the B group> BL group> CK group> L group. With the prolonging of the treatment time of wheat, the content of flavonoids in wheat leaves at jointing-booting stage was significantly higher than that in seedling stage and panicle stage. This means that flavonoids are a protective substance that absorbs UV-B in plants, that is, the absorption of UV-B by flavonoids reduces the damage of UV-B to organs in plants [8] [10]; UV-B The smaller the damage, the less the content of flavonoids; laser damage caused by UV-B have a certain role in the repair. In this study, we further studied the effect of enhanced UV-B radiation on the content of flavonoids in mesophyll cells of wheat. The effects of UV-B radiation on the content of flavonoids in wheat were studied. Whether it has a very important significance for wheat has become a stress [5].
With the progress of science and technology, the research and development of silver nanoparticles has also developed. This paper attempts to prepare a silver nanoparticle by electrolyzing AgNO3 solution with electrochemical reduction method and citric acid as a complexing agent in a certain current and time. The crystal morphology and sample purity of silver nanoparticles were analyzed by X-ray diffractometer. The crystal structure of the nanoparticles was analyzed by scanning electron microscopy (SEM). The crystal structure of the nanoparticles was analyzed by X-ray diffraction. The particle size distribution of the particles was in the range of 125-199 nm, and the carbon paste electrode was modified with the prepared silver nanoparticles. The electrocatalytic activity of the carbon paste electrode was preliminarily explored.
The main objective of this article is to analyze the relationship between increases in freight costs and inflation in the markets due to the increases reflected in the prices of the products in some economies in destination ports such as the United States, Europe, Japan, South Africa, the United Arab Emirates, New Zealand and South Korea. We use fractionally integrated methods and Granger causality test to calculate the correlation between these indicators. The results indicate that, after a significant drop in inflation in 2020, probably due to the confinement caused by the pandemic, the increases observed in inflation and freight costs are expected to be transitory given their stationary behavior. We also find a close correlation between both indicators in Europe, the United States and South Africa.
The range migration algorithm (RMA) is an accurate imaging method for processing synthetic aperture radar (SAR) signals. However, this algorithm requires a big amount of computation when performing Stolt mapping. In high squint and wide beamwidth imaging, this operation also requires big memory size to store the result spectrum after Stolt mapping because the spectrum will be significantly expanded. A modified Stolt mapping that does not expand the signal spectrum while still maintains the processing accuracy is proposed in this paper to improve the efficiency of the RMA when processing frequency modulated continuous wave (FMCW) SAR signals. The modified RMA has roughly the same computational load and required the same memory size as the range Doppler algorithm (RDA) when processing FMCW SAR data. In extreme cases when the original spectrum is significantly modified by the Stolt mapping, the modified RMA achieves better focusing quality than the traditional RMA. Simulation and real data is used to verify the performance of the proposed RMA.
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