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Flunitrazepam is one of the frequently used hypnotic drugs to incapacitate victims for sexual assault. Appropriate diagnostic tools should be available to victims regarding the growing concern about “date-rape drugs” and their adverse impact on society. Miniaturized screen-printed potentiometric sensors offer crucial point-of-care devices that alleviate this serious problem. In this study, all solid-state screen-printed potentiometric flunitrazepam sensors have been designed. The paper device was printed with silver and carbon ink. Formation of an aqueous layer in the interface between carbon-conducting material and ion-sensing membrane nevertheless poses low reproducibility in the solid-contact electrodes. Accordingly, poly(3,4-ethylenedioxythiophene) (PEDT) nano-dispersion was applied as a conducting hydrophobic polymer on the electrode surface to curb water accumulation. Conditioning of ion-sensing membrane in the vicinity of reference membrane has been considered carefully using special protocol. Electrochemical characteristics of the proposed PEDT-based sensor were calculated and compared favorably to PEDT-free one. The miniaturized device was successfully used for the determination of flunitrazepam in carbonated soft drinks, energy drink, and malt beverage. Statistical comparison between the proposed sensor and official method revealed no significant difference. Nevertheless, the proposed sensor provides simple and user-friendly diagnostic tool with less equipment for on-site determination of flunitrazepam.

Detection of erythromycin (ERY) residues in commercial milk samples is crucial for the safety assessment. Herein, a printed circuit board was patterned as a feasible miniaturized potentiometric sensor for ERY determination in dairy samples. The proposed chip design fits to a 3.5-mm female audio plug to facilitate the potential measurements of working electrode versus reference one in this all-solid-state system. The sensor utilizes molecular imprinted polymer (MIP) for the selective recognition of the studied drug in such challenging matrix. The electrode stability is achieved through the addition of poly (3,4-ethylenedioxythiophene) nano-dispersion on its surface. The proposed device detects down to 6.6 × 10−8 M ERY with a slope of 51 mV/decade in the 1 × 10−7–1 × 10−3 M range. The results display high accuracy (99.9% ± 2.6) with satisfactory relative standard deviation for repeatability (1.6%) and reproducibility (5.0%). The effect of common antibiotic classes, namely, amphenicols, beta-lactams, fluoroquinolones, sulfonamides, and tetracyclines, can be neglected as evidenced by their calculated binding capacities towards the proposed MIP. The calculated selectivity coefficients also show a good electrode performance in the presence of naturally present inorganic ions allowing its application to different milk samples.

The concept of smart cities is not a new one, but it appeared by the latest innovations and developments of new smart technologies. Smart cities of the future, digitized cities and augmented cities are new theories and ideas that represent new norms based on the implementation of innovative technologies in cities’ planning and design. The COVID-19 crisis has forced all governments and people worldwide to work from home. These contingency measures forced government, organizations and citizens to get deeply involved in exploiting smart and digital technologies to pursue their daily businesses (higher education institutions, schools, hospitals, banks, companies and government entities). Due to such emergency of lockdown actions in cities resulted from the wide and rapid spread of such pandemic globally, a need for less polluted, cleaner and sustainable urban spaces is highly vital to limit the coronavirus spreading. This research focuses on the dimensions, characteristics and indicators of smart and sustainable cities that engaged with sustainability by highlighting its contribution to Sustainable Development Goals (SDGs) and discusses its role in creating healthier cities in the age of COVID-19. The paper aims at developing smart and sustainable cities’ solutions in urban areas to confront COVID-19 impacts. The research methodology is based on two approaches: a critical literature review of the main concepts and definitions of smart cities, the integration between smart cities’ concept and SDGs in addition to highlighting the impact of COVID-19 on the urban environment with emphasis on the lessons learned and actions needed to be adopted; and an analytical approach that proposes a matrix combining both smart and sustainability indicators to achieve greener and healthier cities, yet to control the spread of coronavirus; a raising need for urban life amidst/after the pandemic and its crisis. The matrix couples both the goals of smart cities and sustainable cities in order to map the contribution to SDGs in attaining a better and sustainable future. Results indicate that newly developed measures, in planning smart sustainable urban areas in cities, can assist in the adaptation of and achieving SDGs in the time of COVID-19.

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Copper concentrations in drinking-water is very important to be monitored which can cause cancer if it exceed about 10 mg/liter. In the present work, we have developed a simple, low laser power method to improve the detection limits of laser induced plasma spectroscopy LIBS for copper in aqueous solutions with different concentrations. In this method a medium density fiberboard (MDF) wood have been used as a substrate that absorbs the liquid sample to transform laser liquid interaction to laser solid interaction. Using the fundamental wavelength of Nd:YAG laser, the constructed plasma emissions were monitored for elemental analysis. The signal-to-noise ratio SNR was optimized using low laser fluence of 32 J cm-2, and detector (CDD camera) gate delay of 0.5 μs. Both the electron temperature and density of the induced plasma were determined using Boltzmann plot and the FWHM of the Cu at 324.7 nm, respectively. The plasma temperature was found to be 1.197 eV, while the plasma density was about 1.66 x 1019 cm-3. The detection limits for Cu at 324.7 nm is found to be 131 ppb comparable to the results by others using complicated system. © 2014 SPIE.

In this work, I report measuring the pulse duration of few-cycle pulses using spectral phase interferometry for direct electric-field reconstruction (SPIDER) with high accuracy. These few-cycle pulses were generated via self-phase modulation (SPM) in nonlinear medium (neon gas) in a one meter hollow-fiber followed by a pair of chirped mirrors performed the dispersion compensation. The observed reconstructed pulse intensity autocorrelation function varied from 5.35 fs to almost 13 fs. Moreover, the applied method allows for direct controlling of the pulse duration through variation of the chirping of input pulses at different pressure of neon gas. The observed results indicate that the SPM was enhanced for high neon pressure (2.5 atm.) and short input pluses (32 fs) without chirping. The obtained results may give an opportunity to monitor and control ultrafast transit interaction in femtosecond chemistry. © 2015, Electromagnetics Academy. All rights reserved.

Elementary and high-level functions can be computed in hardware using polynomial approximation techniques. There are many techniques in the literature to calculate the coefficients of such polynomials. Remez algorithm [1] provides the optimal polynomial in the Chebyshev sense that is minimizing the maximum error (minimax approximation). This paper presents an algorithm for truncating the coefficients of the minimax polynomials obtained from Remez algorithm using an algorithmic method. A gain of 3 and 4 bits of accuracy over the direct rounding is reported. Muller [2] addressed the same problem but his algorithm is applicable for the second order polynomials only. This paper presents an algorithm that is applicable for any order.