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The article presents an illegal drug detector that utilizes photonic crystal fiber (PCF). The fiber structure of the H-PCF comprises a dodecagonal core and circular air gaps in cladding areas. We have analyzed the designed terahertz (THz) frequency range utilizing the Finite Element Method (FEM) and the COMSOL Multiphysics application. The revised design has a high sensitivity in detecting amphetamine (n = 1.518) and cocaine (n = 1.5022) at a frequency of 3 THz, via detection rates of 99.43% and 99.20%, correspondingly. Furthermore, the suggested fiber, which operates at a frequency of 3 THz, has a relatively tiny confinement loss of 4.93×10-08 dB/m and 6.16×10-09 dB/m and a minimal effective material loss of construction of 0.0032 cm-1. In conclusion, it may be stated that drug misuse not only leads to immediate repercussions but also has severe and enduring impacts on human health, potentially resulting in fatality. Hence, it is imperative to accurately and effectively detect illicit substances. H-PCF architecture we offered is well-suited to detect illegal drugs. Doi: 10.28991/ESJ-2024-08-06-020 Full Text: PDF

Methanol (CH₃OH) is a volatile, transparent, and toxic substance widely used in chemical substrates, antifreeze, and industrial applications. Ethanol (C₂H₅OH), in contrast, is commonly used in alcoholic beverages, as a fuel additive, and as an antiseptic. Differentiating between methanol and ethanol is critical due to the severe health risks associated with methanol ingestion, while ethanol is safe for consumption in moderation. To tackle this challenge, we present a highly sensitive and accurate Photonic Crystal Fiber (PCF) sensor designed for the detection of both methanol and ethanol. The proposed sensor demonstrates impressive performance, with maximum relative sensitivities (RS) of 95.72 % for methanol and 97.55 % for ethanol, while operating within the 2.2 to 3.2 THz range. Additionally, it achieves low Effective Material Loss (EML) values of 0.0066 cm⁻1 for ethanol and 0.0044 cm⁻1 for methanol, with Numerical Aperture (NA) values of 0.257 and 0.270, respectively. The key advantages of this sensor include its exceptional precision, high sensitivity, and low material loss, making it a reliable solution for accurately distinguishing between methanol and ethanol in various industrial and commercial applications. By providing enhanced detection capability in the THz range, this sensor improves safety monitoring and quality control processes in sectors where these substances are frequently used.

Cyanide is very poisonous and raises environmental problems because of its industrial application and potential as a terrorist weapon. Given CN's toxicity and possible hazard to people, an effective and adaptive detection approach is needed. This specification suggests using a PCF to build a terahertz Hexagonal Core and Curved rectangular air holes sensor to detect NaCN and KCN. The recently created PCF analysis, which was promptly delivered, reveals an RS concentration of 99.62 % for NaCN and a maximum concentration of KCN is 99.08 %. In addition, we analyzed the Confinement Loss (CL) at a value of 5.88 × 10−09 dB/m and 2.07 × 10−05 dB/m, as well as EML at values of 0.0020 cm−1 and 0.0026 cm−1, accordingly, about these hazardous substances. The designed detector can identify NaCN and KCN at low concentrations even with small RI shifts due to its high sensitivity. Real-time NaCN and KCN detection and monitoring through nerve reflexes is essential for life-threatening conditions. It can selectively work in NaCN and KCN, ensuring accurate detection even in complex chemical compositions. Additionally, its tiny size allows for emergency use.

In this paper, we simulate the macroeconomic and distributional impacts of exchange rate devaluation in Ethiopia using a dynamic single country Computable General Equilibrium model. We find that although devaluation helps exports to be more competitive in the short term, thereby increasing export earnings, over the long term the policy is found to have a contractionary and inflationary impact in a developing country like Ethiopia. It also comes at the cost of a reduction in household welfare and investment. In terms of distributional impact, the policy simulation result suggests that devaluation disproportionately affects urban households than rural households in Ethiopia given the nature of their consumption basket.