Simple Patch Antenna with Filtering Function Using Two U-Slots

In this study, two U-slots of different sizes are used to combine the filtering function with a patch antenna. The U-shaped slots are etched into the patch, and currents in the opposite direction exist around these slots. Therefore, the currents cancel each other out, and a radiation null is formed. As a result, two radiation nulls are implemented on the left and right sides of the passband. To demonstrate the novelty of the proposed concept, a filtering patch antenna with a center frequency of 3.21 GHz and a 10 dB impedance bandwidth of 19.9% is designed and fabricated. High suppression levels of 25.33 and 19.32 dB in the lower and higher stopbands, respectively, are achieved. Therefore, a sharp band skirt and good selectivity are exhibited in the boresight gain response. The two radiation nulls are located at 2.4 and 3.7 GHz and can be independently adjusted.

Power Quality Enhancement in Four-Wire Systems under different distributed Energy Resource Penetrations

Reactive and harmonic currents that are being injected into the power supply by nonlinear loads, cause an increasing deterioration of the power system voltages and currents, whereas active power filter (APF) has been widely used to overcome this problem and to improve the power quality delivered by the power supply. In this paper, a three-level four-legged active power filter based on a neutral-point-clamped (NPC) inverter is presented. To fulfil the requirement of the active power filtering function under balanced, unbalanced, and distorted (including 3rd and 5th harmonics) power supply voltages, a control method based on the instantaneous power theory has been used and discussed. On the other side, the inverter switching state control has been achieved based on PWM current controller. The performance of the proposed topology under the control approach has been finally discussed through the obtained simulation results.

Design and Research of Firewall System of Communication Department Based on Network Information Technology

In the past, the structure of traditional firewalls was similar to that of checkpoints, and the design structure was relatively simple. At the same time, it is also convenient for subsequent maintenance. As an isolation technology, it can be accessed by people with consistent identity information. But for some relatively high-level data information, using traditional firewalls, foreign intruders can easily obtain relevant information. This article chooses to use the working mechanism of network information technology, and then analyzes the hardware structure of the firewall based on the IPX2400 processor. Finally, a preliminary design of a firewall system for the communications department based on the IPX2400 processor is implemented, and its packet filtering function is realized.

Standard hospital blanket warming cabinets can be utilized for complete moist heat SARS-CoV2 inactivation of contaminated N95 masks for re-use

Shortages of personal protective equipment for use during the SARS-CoV-2 pandemic continue to be an issue among health-care workers globally. Extended and repeated use of N95 filtering facepiece respirators without adequate decontamination is of particular concern. Although several methods to decontaminate and re-use these masks have been proposed, logistic or practical issues limit adoption of these techniques. In this study, we propose and validate the use of the application of moist heat (70 °C with humidity augmented by an open pan of water) applied by commonly available hospital (blanket) warming cabinets to decontaminate N95 masks. This report shows that a variety of N95 masks can be repeatedly decontaminated of SARS-CoV-2 over 6 h moist heat exposure without compromise of their filtering function as assessed by standard fit and sodium chloride aerosol filtration efficiency testing. This approached can easily adapted to provide point-of-care N95 mask decontamination allowing for increased practical utility of mask recycling in the health care setting.

Ex Vivo Microsphiltration Profile of Plasmodium Falciparum Infected Red Blood Cells in Patients with Malaria in Kéniéroba, Mali: Exploring the Spleen in Vivo Retention Function

Malaria pathophysiology is not still fully understood. The main mechanisms of malaria involve the synergistic interactions between host and parasite. Although, the role of the spleen has been mentioned in various clinical forms of malaria, a supportive clinical evidence is still needed. We conducted a pilot study to determine the impact of the spleen functional state in different clinical forms of malaria. Ex vivo microsphiltration was used to assess the splenic function in patients received during routine consultation with mild malaria at the Kéniéroba health center, a ​​high malaria endemic area in Mali. A total of 25 patients were enrolled for ex vivo microsphiltration. Spleen was non-palpable (Hackett stage 0) in two patients, palpable with deep inspiration (Hackett stage 1) in 22 patients and without deep inspiration (Hackett stage 2) in one patient, parasitaemia ranged from 5360 trophozoites/µl to 342720 trophozoites/µl with a mean parasitemia of 50774 trophozoites/µl ± 65540 trophozoites/µl. The mean hemoglobin level was 11.2g/dl ± 1.2 [8.7-13.4]. The retention rate of the infected red blood cell ranged from 11.11% to 94.44% with 65.4% ± 23.7% on average. A higher ex vivo retention rate of infected red blood cells was observed in patients with Hackett stage other than 0 (p= 0.03). This pilot study proved that it was feasible to use the ex vivo microsphiltration to explore the spleen filtering function in malaria patients.

Ex Vivo Microsphiltration Profile of Plasmodium Falciparum Infected Red Blood Cells in Patients with Malaria in Kéniéroba, Mali: Exploring the Spleen in Vivo Retention Function

Malaria pathophysiology is not still fully understood. The main mechanisms of malaria involve the synergistic interactions between host and parasite. Although, the role of the spleen has been mentioned in various clinical forms of malaria, a supportive clinical evidence is still needed. We conducted a pilot study to determine the impact of the spleen functional state in different clinical forms of malaria.Ex vivo microsphiltration was used to assess the splenic function in patients received during routine consultation with malaria at the Kéniéroba health center, a ​​high malaria endemic area in Mali.A total of 25 patients were enrolled for microsphiltration. Two patients (8%) had a no palpable spleen (Hackett stage 0), 22 patients (88%) had a palpable spleen with at deep inspiration (Hackett stage 1) and only one patient (4%) presented a palpable spleen (Hackett stage 2). Parasitaemia ranged from 5360 trophozoites/µl to 342720 trophozoites/µl with a mean parasitemia of 50774 trophozoites/µl ± 65540 trophozoites/µl; the mean hemoglobin rate was 11.2 ± 1.2 g/dl with the extremes of 8.7 g/dl and 13.4 g/dl. The retention rate of the infected red blood cell ranged from 11.11% to 94.44% with an average of 65.4% ± 23.7%. A higher ex vivo retention rate of infected red blood cells was observed in patients with Hackett stages greater than or equal to 1 (p= 0.03). This pilot study proved the feasibility of the exploration of the spleen filtering function in malaria patients using the ex vivo microsphiltration.

A compact dual-band D-CRLH-based antenna with self-isolation functionality

This paper presents a compact dual-band filtering antenna without extra employing of filter structures. The antenna is designed using a planar dual-composite right/left-handed (D-CRLH) transmission line unit cell, where the filtering function is achieved through current cancellation between the D-CRLH resonators. The antenna is designed to function at 3.0 and 5.1 GHz, which can serve different WLAN applications. The antenna is a co-planar waveguide fed with a very compact size of only 30 × 16 mm2. Compared to the conventional patch antenna, the antenna size is only 17% at 3.0 GHz and 31% at 5.1 GHz. Despite the small size, the antenna preserves a good omni-directional radiation pattern at the two resonant frequencies with a measured realized gain of 2 and 2.7 dB, respectively. At the stopband in-between the two resonant bands, the reflection coefficient is almost 0 dB at 4.25 GHz and complete non-radiation is proved with a −11 dB measured realized gain. The different antenna filtering functions are verified by full-wave simulation and measurements.