Humans spend most of their lifetime indoors; thus, it is important to keep indoor air quality within acceptable levels. As a result, many initiatives have been developed by multiple research centers ...or through academic studies to address the harmful effects of increased indoor pollutants on public health. This research introduces a system for monitoring different air parameters to evaluate the indoor air quality (IAQ) and to provide real-time readings. The proposed system aims to enhance planning and controlling measures and increase both safety and occupants’ comfort. The system combines microcontrollers and electronic sensors to form an Internet of Things (IoT) solution that collects different indoor readings. The readings are then compared with outdoor readings for the same experiment period and prepared for further processing using artificial intelligence (AI) models. The results showed the high effectiveness of the IoT device in transferring data via Wi-Fi with minimum disruptions and missing data. The average readings for temperature, humidity, air pressure, CO2, CO, and PM2.5 in the presented case study are 30 °C, 42%, 100,422 pa, 460 ppm, 2.2 ppm, and 15.3 µ/m3, respectively. The developed model was able to predict multiple air parameters with acceptable accuracy. It can be concluded that the proposed system proved itself as a powerful forecasting and management tool for monitoring and controlling IAQ.
This study presents an integrated analog front-end (AFE) tailored for photoplethysmography (PPG) sensing. The AFE module introduces a novel transimpedance amplifier (TIA) that incorporates capacitive ...feedback techniques alongside common drain feedback (CDF) TIA. The unique TIA topology achieves both high gain and high sensitivity while maintaining low power consumption. The resultant PPG sensor module demonstrates impressive specifications, including an input noise current of 4.81 pA/sqrt Hz, a transimpedance gain of 18.43 MΩ, and a power consumption of 68 µW. Furthermore, the sensory system integrates an LED driver featuring automatic light control (ALC), which dynamically adjusts the LED power based on the strength of the received signal. Employing 0.35 µm CMOS technology, the AFE implementation occupies a compact footprint of 1.98 mm × 2.475 mm.
This work aims to study the technical problems of algal blooms that hinder the purification process of surface water used for drinking purposes and not its harmful effect on human health and the ...surrounding environment. It is also related to the demonstration of the improved coagulation process as an efficient technique in the algal removal from surface water by its application in jar tests. The study was carried out in the water purification plant in Nazlet Abdellah near the city of Assiut, Egypt. To achieve that, many ores and natural materials which aid in the removing of the algal blooms from surface water during the purification processes were tested. The examined materials should be technically and economically proper for improving the removal of algae from treated surface water for drinking purposes. The results showed that the kaolinite and bentonite (K and B) when coupled separately with aluminum sulfate (alum.) (the main coagulant agent) associated with the raw surface water in the flocculation basin were more efficient in the algae removal from treated surface water before reaching the sand filters by ratio up to 90%.
Recently published CMOS optical receivers consist of a limited-bandwidth first-stage transimpedance amplifier (TIA) followed by an equalizer. Limiting the TIA's bandwidth improves the gain and ...reduces the noise but introduces a significant inter-symbol interference (ISI) that is dealt with by the subsequent equalizer. Continuous-time linear equalizer (CTLE) is a commonly used equalizer in both electrical and optical links. However, recent research reported different findings about CTLE-based optical receivers. Some research papers concluded that CTLEs boost high-frequency noise compared to a full-bandwidth design. Other publications reported that high-frequency noise remains unaffected while white noise is significantly reduced. This work aims to solve this discrepancy by presenting an accurate analysis for CTLE-based optical receivers considering noise, gain, and jitter. We show that the noise performance depends on the pole/zero locations of the limited-bandwidth (LBW)-TIA and the follow-on equalizer. A properly designed CTLE-based receiver achieves a 2.5 × higher gain and a 1.74× better noise than the full-bandwidth design. The CTLE is also compared to the well-known decision feedback equalizer (DFE). The noise performance of the CTLE-based receiver lies between that of finite and infinite impulse response DFE-based receivers but achieves better gain than both architectures.
The world’s interest now is focusing on the applying of the principles of sustainable development in managing natural resources, especially in managing freshwater, which is one of the greatest ...challenges the whole world face. In this paper, the illite ore was tested to remove the excess of iron and manganese from groundwater which is used for drinking and household purposes in Assiut. To accomplish this goal, the study was based on two directions. The first direction focused on achieving a physicochemical analytical survey for all the groundwater produced by wells in Assiut governorate, and its averages are plotted on GIS maps, to illustrate the difference in the concentrations of iron and manganese. However, the second direction focused on the preparation and examination of the modified illite ore, and it was characterized by using XRD, SEM, FT-IR, and XRF techniques. The results showed that the sodalite-bearing modified illite (SBMI) was able to remove the excess of iron and manganese from raw groundwater with the efficiency of 99% and 97%, respectively.
► The safety of synthetic antioxidants as food additives has received increasing attention. ► There is need components to act as antioxidants and to make food products safer. ► Detection of natural ...antioxidant sources for food use would be beneficial for healthy life. ► Antioxidant capacity of thyme, sage and marjoram extract was screened using DPPH assay. ► Thyme sage and marjoram exhibited stronger antioxidant activity than BHT and BHA.
The antioxidant properties and total phenolic of different extracting solvents of thyme, sage, and marjoram were examined using the stable 2,2-diphenyl-1-picrylhydrazyl-hydrate (DPPH) free radical scavenging method and Folin–Ciocalteu method, respectively. Methanol exhibited the highest extraction ability for such phenolic compound, where the total phenols were 8.10, 5.95, and 5.20 (mg gallic acid equivalent/g dry weight) for thyme, sage, and marjoram, respectively and also exhibited the strongest antioxidant capacity. On the basis of the results obtained, thyme, sage, and marjoram have a potential use as natural antioxidants due to their significant antioxidant activity. HPLC analysis of methanolic extract showed the presence of: rosmarenic acid, methyl rosmarenate, caffeic acid, cinnamic acid, chlorogenic acid and quinic acid as phenolic acids, besides some flavonoids such as ferulic acid, apigenin, luteolin and quercetin. The results demonstrated that thyme methanol extract possessed the best antioxidative activity, which were better than those of other plants, α-tocopherol and BHA.
This article presents a Photoplethysmography (PPG) sensory system for continuous health monitoring. The PPG chip is fabricated using <inline-formula> <tex-math notation="LaTeX">0.35~\mu \text{m} ...</tex-math></inline-formula> standard CMOS technology and occupies 2.3 mm <inline-formula> <tex-math notation="LaTeX">\times </tex-math></inline-formula> 1.7 mm. The average power consumption of the receiver analog front-end (AFE) is <inline-formula> <tex-math notation="LaTeX">50.75~\mu \text{W} </tex-math></inline-formula>, the LED driver is power <inline-formula> <tex-math notation="LaTeX">29.3~\mu \text{W} </tex-math></inline-formula>. The consumed power is dramatically reduced due to the using of both low duty cycle for LED lighting and automatic light control (ALC). The PPG sensor has a low input noise current of 41.3 pA and can reject a DC photocurrent up to <inline-formula> <tex-math notation="LaTeX">24~\mu \text{A} </tex-math></inline-formula> because of the integrated background light cancelation (BLC) loop. 12-b SAR-ADC and Serial Peripheral Interface (SPI) are integrated for communication with MCU used for signal processing and results display. Readings of 9 subjects show mean absolute error (MAE) and standard deviation (SD) of 1.95±2.13 beats per minute (BPM), 6.00±4.18mmHg, and 6.13±3.93mmHg, for heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP), respectively.
This study aims to review the potential benefits of peak load shaving in a microgrid system. The relevance of peak shaving for a microgrid system is presented in this research review at the outset to ...justify the peak load shaving efficacy. The prospective benefits of peak shaving in microgrid systems, including technological, economic, and environmental advantages, are thoroughly examined. This review study also presents a cost–benefit numerical analysis to illustrate the economic viability of peak load shaving for a microgrid system. Different peak shaving approaches are briefly discussed, as well as the obstacles of putting them into practice. Finally, this review study reveals some potential future trends and possible directions for peak shaving research in microgrid systems. This review paper lays a strong foundation for identifying the potential benefits of peak shaving in microgrid systems and establishing suitable projects for practical effectuation.
This article presents a low-power, high-gain, and wide-dynamic range (DR) photoplethysmography (PPG) sensory system with a novel direct current (dc) compensation loop and light-emitting diode (LED) ...dimming control. The proposed PPG system exhibits a signal-aware performance, where, at strong PPG signal levels, the dc compensation loop's capability of removing dc photocurrent is increased and the LED's driving current is reduced. This ability allows the entire DR to be utilized by the useful alternating current (ac) component of the signal and reduces power dissipation. Fabricated in 0.35-<inline-formula> <tex-math notation="LaTeX">\mu \text {m} </tex-math></inline-formula> standard CMOS technology, the proposed PPG sensor occupies an area of <inline-formula> <tex-math notation="LaTeX">1.744~{\text {mm}}^{{2}} </tex-math></inline-formula>. The proposed system exhibits a high gain and a low input-referred noise current of 19.6 <inline-formula> <tex-math notation="LaTeX">\text{M}\Omega </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">11.23~{\text {pA}}_{\text {rms}} </tex-math></inline-formula>, respectively, while dissipating only <inline-formula> <tex-math notation="LaTeX">9.9~\mu \text {W} </tex-math></inline-formula> of power at the receiver's analog frontend. The proposed dc compensation loop can remove up to <inline-formula> <tex-math notation="LaTeX">80~\mu \text {A} </tex-math></inline-formula> of dc photocurrent for 2% total harmonic distortion (THD), achieving a DR of 137 dB. An external microcontroller unit (MCU) uses a machine learning (ML) algorithm to extract blood pressure (BP) from the analog output of the implemented PPG sensor chip. Measurements from eight human subjects show a mean absolute error (MAE) and a standard deviation of 2.25 ± 2.82 mmHg for systolic BP (SBP) and 5.01 ± 2.10 mmHg for diastolic BP (DBP).
