OFF Mode Research Articles

Influence of electrical field on the susceptibility of gallium nitride transistors to proton irradiation

Radiation susceptibility of electronic devices is commonly studied as a function of radiation energetics and device physics. Often overlooked is the presence or magnitude of the electrical field, which we hypothesize to play an influential role in low energy radiation. Accordingly, we present a comprehensive study of low-energy proton irradiation on gallium nitride high electron mobility transistors (HEMTs), turning the transistor ON or OFF during irradiation. Commercially available GaN HEMTs were exposed to 300 keV proton irradiation at fluences varying from 3.76 × 1012 to 3.76 × 1014 cm2, and the electrical performance was evaluated in terms of forward saturation current, transconductance, and threshold voltage. The results demonstrate that the presence of an electrical field makes it more susceptible to proton irradiation. The decrease of 12.4% in forward saturation and 19% in transconductance at the lowest fluence in ON mode suggests that both carrier density and mobility are reduced after irradiation. Additionally, a positive shift in threshold voltage (0.32 V and 0.09 V in ON and OFF mode, respectively) indicates the generation of acceptor-like traps due to proton bombardment. high-resolution transmission electron microscopy and energy dispersive x-ray spectroscopy analysis reveal significant defects introduction and atom intermixing near AlGaN/GaN interfaces and within the GaN layer after the highest irradiation dose employed in this study. According to in-situ Raman spectroscopy, defects caused by irradiation can lead to a rise in self-heating and a considerable increase in (∼750 times) thermoelastic stress in the GaN layer during device operation. The findings indicate device engineering or electrical biasing protocol must be employed to compensate for radiation-induced defects formed during proton irradiation to improve device durability and reliability.

Contribution of the eye and of opn4xa function to circadian photoentrainment in the diurnal zebrafish.

The eye is instrumental for controlling circadian rhythms in mice and human. Here, we address the conservation of this function in the zebrafish, a diurnal vertebrate. Using lakritz (lak) mutant larvae, which lack retinal ganglion cells (RGCs), we show that while a functional eye contributes to masking, it is largely dispensable for the establishment of circadian rhythms of locomotor activity. Furthermore, the eye is dispensable for the induction of a phase delay following a pulse of white light at CT 16 but contributes to the induction of a phase advance upon a pulse of white light at CT21. Melanopsin photopigments are important mediators of photoentrainment, as shown in nocturnal mammals. One of the zebrafish melanopsin genes, opn4xa, is expressed in RGCs but also in photosensitive projection neurons in the pineal gland. Pineal opn4xa+ projection neurons function in a LIGHT ON manner in contrast to other projection neurons which function in a LIGHT OFF mode. We generated an opn4xa mutant in which the pineal LIGHT ON response is impaired. This mutation has no effect on masking and circadian rhythms of locomotor activity, or for the induction of phase shifts, but slightly modifies period length when larvae are subjected to constant light. Finally, analysis of opn4xa;lak double mutant larvae did not reveal redundancy between the function of the eye and opn4xa in the pineal for the control of phase shifts after light pulses. Our results support the idea that the eye is not the sole mediator of light influences on circadian rhythms of locomotor activity and highlight differences in the circadian system and photoentrainment of behaviour between different animal models.

Quantitative assessment of thermal effects on the auricle region caused by mobile phones operating in different modes

<p>To analyze thermal effects caused by mobile phones on the human auricle region, we performed an experiment with controlled exposure to mobile phones operating in different modes for a group of 40 men. Temperature changes were measured with the use of infrared thermography. Thermograms were taken before and after a standardized 15-minute phone call when the mobile phone was placed lightly against the skin surface in the auricle region. The measurements were performed in three modes: OFF, ON, and FLIGHT. Statistically significant differences (p = 0.03) were observed between the experimental temperature increase of the auricle region in OFF mode (average temperature rise = 1.1 °C ± 0.2 °C) and in ON mode (average temperature rise = 1.9 °C ± 0.3 °C), while between FLIGHT (average temperature rise = 1.4 °C ± 0.2 °C) and ON modes, no statistical differences were observed (p = 0.20). Based on thermographic measurements and the model of heat transfer between the ear and the phone, it was shown that the human ear is the largest heat source in the system and that the increase in skin temperature is mainly caused by the handheld mobile phone restricting heat dissipation from the skin surface.</p>

Combinatorial protein dimerization enables precise multi-input synthetic computations

Bacterial transcription factors (TFs) with helix-turn-helix (HTH) DNA-binding domains have been widely explored to build orthogonal transcriptional regulation systems in mammalian cells. Here we capitalize on the modular structure of these proteins to build a framework for multi-input logic gates relying on serial combinations of inducible protein–protein interactions. We found that for some TFs, their HTH domain alone is sufficient for DNA binding. By fusing the HTH domain to TFs, we established dimerization dependent rather than DNA-binding-dependent activation. This enabled us to convert gene switches from OFF-type into more widely applicable ON-type systems and to create mammalian gene switches responsive to new inducers. By combining both OFF and ON modes of action, we built a compact, high-performance bandpass filter. Furthermore, we were able to show cytosolic and extracellular dimerization. Cascading up to five pairwise fusion proteins yielded robust multi-input AND logic gates. Combinations of different pairwise fusion proteins afforded a variety of 4-input 1-output AND and OR logic gate configurations.

Tailoring of a bionic bifunctional cellulose nanocrystal-based gold nanocluster probe for the detection of intracellular pathological biomarkers

Gold nanoclusters with excellent fluorescence intensity, stability and biocompatibility have promising application prospects in the field of detection. Inspired by the growth behavior of sea squirts adhered to ropes, a novel bionic bifunctional cellulose nanocrystal (CNC)-based gold nanocluster probe was effectively constructed by directionally growing gold nanoclusters on CNCs modified with a specific DNA sequence. The constructed probe has excellent fluorescence properties and stability. The “ON or OFF” conversion mode of fluorescence was designed to detect different pathological markers in cells. In the “ON” mode, the probe readily combined with various sulfhydryl group containing markers (acetylcholinesterase, cysteine and glutathione) to produce fluorescence quenching and realize detection, the corresponding detection limits were as low as 0.015 mU/mL, 0.028 μM and 0.228 μM, respectively. Interestingly, the fluorescence of the probe could be regulated to the OFF mode via the assembly of the graphene oxide structure in accordance with Förster resonance energy transfer. The fluorescent probe with OFF mode could selectively recognize the carcinoembryonic antigen biomarker of malignant tumours via fluorescence enhancement, and its limit of detection was as low as 0.54 ng/mL. The as-developed novel strategy has positive significance for the early diagnosis of malignant tumours.

Railway signal light system using LED technology

The railway signal light system mainly uses incandescent light sources. Meanwhile, these lights operate in regular ON and OFF mode and suffer from fluctuations when a train passes by, these are all unfavourable factors that reduce the life of incandescent lamps. Therefore, the rating working time of incandescent bulbs is often short, leading to the requirements for maintenance conditions and replacement of supplies with a high frequency. This paper presents the solution of using LED technology to replace incandescent bulbs to solve the above problems. In addition, the article also mentions a solution that integrates IoT technology to help collect status data of each lamp in real time and support the deployment of smart maintenance solutions to improve operational efficiency and reliable and stable operation of the system.

Low-cost, compact, and reconfigurable antennas using complementary split-ring resonator metasurface for next-generation communication systems

AbstractAn innovative and simple method for attaining broadband frequency reconfigurable antenna structure is presented using low-cost materials and a compact design. The frequency reconfigurability is attained by the “OFF” and “ON” mechanisms of three PIN diodes. Many performance observations are carried out such as reflectance coefficient, bandwidth (BW), resonance frequency, electric field, feed position variation, and gain among different configurations. The suitability of the presented work for the different applications lies in the X frequency band. The resonating frequency for all switch OFF modes is achieved at 13.2 GHz and one switch ON mode at 10.7 GHz. The proposed design yields the frequency tunability behavior over the broadband of 2.5 GHz. The design yields the directivity of 5.58 dB, the minimum reflectance coefficient of −17.27 dB, and a total gain of 3.87 dB. This design offers an electric field of 46 558 v/m, a BW of 340 MHz, and a normalized directivity of 87° using low-cost substrates. The results of the presented design were also fabricated and related to simulated results. Performance observation of the proposed work with previously published research work is also included. The presented design provides the solution of the low-cost, compact, reconfigurable antennas, which can be used for next-generation communication systems.

Development of Two-Step Exhaust Rebreathing for a Low-NOx Light-Duty Gasoline Compression Ignition Engine

The global automotive industry is undergoing a significant transition as battery electric vehicles enter the market and diesel sales decline. It is widely recognized that internal combustion engines (ICE) will be needed for transport for years to come; however, demands on ICE fuel efficiency, emissions, cost, and performance are extremely challenging. Gasoline compression ignition (GCI) is one approach for achieving the demanding efficiency and emissions targets. A key technology enabler for GCI is partially-premixed, compression ignition (PPCI) combustion, which involves two high-pressure, late fuel injections during the compression stroke. Both NOx and smoke emissions are greatly reduced relative to diesel, and this reduces the aftertreatment (AT) requirements significantly. For robust low-load and cold operation, a two-step valvetrain system is used for exhaust rebreathing (RB). Exhaust rebreathing involves the reinduction of hot exhaust gases into the cylinder during a second exhaust lift event during the intake stroke to help promote autoignition. The amount of exhaust rebreathing is controlled by exhaust backpressure, created by the vanes on the variable nozzle turbine (VNT) turbocharger. Because of the higher cycle temperatures during rebreathing, exhaust HC and CO may be significantly reduced, while combustion robustness and stability also improve. Importantly, exhaust rebreathing significantly increases exhaust temperatures in order to maintain active catalysis in the AT system for ultra-low tailpipe emissions. To achieve these benefits, it is important to optimize the rebreathe valve lift profile and develop an RB ON→OFF (mode switch) strategy that is easy to implement and control, without engine torque fluctuation. In this study, an engine model was developed using GT-Suite to conduct steady-state and transient engine simulations of the rebreathing process, followed by engine tests. The investigation was conducted in four parts. In part 1, various rebreathe lift profiles were simulated. The system performance was evaluated based on in-cylinder temperature, exhaust temperature, and pumping work. The results were compared with alternative variable valve actuation (VVA) strategies such as early exhaust valve closing (EEVC), negative valve overlap (NVO), positive valve overlap (PVO). In part 2, steady-state simulations were conducted to determine an appropriate engine load range for mode switching (exhaust rebreathing ON/OFF and vice-versa). The limits for both in-cylinder temperature and exhaust gas temperature, as well as the external exhaust gas recirculation (EGR) delivery potential were set as the criteria for load selection. In part 3, transient simulations were conducted to evaluate various mode switch strategies. For RB OFF, the cooled external EGR was utilized with the goal to maintain exhaust gas dilution during mode switches for low NOx emissions. The most promising mode-switch strategies produced negligible torque fluctuation during the mode switch. Finally, in part 4, engine tests were conducted, using the developed RB valve lift profile, at various low-load operating conditions. The mode switch experiments correlated well with the simulation results. The tests demonstrated the simplicity and robustness of the exhaust rebreathing approach. A robust engine response, low CNL, high exhaust gas temperature, and low engine out emissions were achieved in the low load region.

Priority-Based Dynamic IoT-Downlink Communications with Blind Transmission-Mode Recognition

In downlink Internet of things (IoT) applications, certain nodes can be given a higher transmission priority than others, and hence might be allocated more transmission resources. Consequently, some nodes may face a resource-starvation problem. To overcome such a predicament, this article proposes an opportunistic non-orthogonal multiple access (NOMA) scheme to enable low priority (LP) nodes (LPNs) to share the transmission resources of high priority (HP) nodes (HPNs) while prioritizing the quality of service (QoS) requirements of the HPNs. In the proposed scheme, the control center (CC) may decide to multiplex the data of one or more LPNs with the HPN data using NOMA, which can improve the network throughput substantially. Such a decision is based on the channel conditions and QoS requirements for the HPNs and LPNs. Hence, the proposed system may operate in one of the following four modes, HPN orthogonal multiple access (OMA), LPN-OMA, (HPN, LPN)-NOMA, and the OFF mode where all nodes are muted. To improve the network efficiency and reduce overhead, the network is considered uncoordinated where the receiving nodes do not receive side information about the selected transmission-mode by the CC, leaving it to the receiving nodes to blindly recognize the transmission-mode. The network complexity and throughput trade-off is considered for fixed and adaptive power assignments. The results show that the proposed system can provide substantial throughput improvement over conventional NOMA transmission. For the example of a pair of HPN and LPN, the maximum throughput gain with opti-mal power allocation is about 0.85 bits/symbol, which implies that the throughput relative improvement is about 9 folds. The article also discuss the challenges and potential solutions of the proposed framework.

Detection of Cd2+ in Aqueous Solution by the Fluorescent Probe of CdSe/CdS QDs Based on OFF-ON Mode.

The detection of heavy metals in aqueous solutions has always attracted much attention from all over the world. A fluorescent probe of CdSe/CdS core-shell quantum dots (QDs) was designed to detect trace Cd2+ in aqueous solutions using the OFF–ON mode rapidly and efficiently, likely based on adsorption and desorption reactions between ethylenediaminetetraacetic acid disodium salt (EDTA) and CdSe/CdS QDs. In the OFF mode, the optical shielding function of EDTA results in fluorescence quenching owing to the strong adsorption ability of EDTA with Cd2+ on the sites of CdSe/CdS QDs surface. In the ON mode, the introduction of Cd2+ promotes the desorption of EDTA from the EDTA-CdSe/CdS QDs and restores the fluorescence intensity. There were two linear response ranges which were 0.1–20 µmol/L and 20–90 µmol/L for the EDTA-CdSe/CdS system to detect Cd2+. The detection limit was 6 nmol/L, and the standard deviation was below 4% for the detection of Cd2+ concentration in tap water.

Efficacy of coupling heat recovery ventilation and fan coil systems in improving the indoor air quality and thermal comfort condition

Mechanical Ventilation with Heat Recovery (MVHR) systems are gaining increasing interest in buildings with low energy demand, for improvement of the Indoor Air Quality (IAQ) and reduction of the ventilation energy loss. In retrofitted buildings, MVHRs are often integrated with an additional air heater to cover space heating demand. Hence, evaluation of the interactions between MVHR and heat emitter, and their effects on indoor airflow characteristics is of significant importance. The present study aims to investigate effects of a combined MVHR-fan-coil system in heating mode on IAQ and thermal comfort parameters inside a retrofitted room, by means of a computational fluid dynamic (CFD) code. The proposed CFD model is validated by comparing the numerical results with experimental data. The results yielded by numerical simulations allow evaluating the indoor environmental quality characteristics as well as addressing the MVHR and fan coil interactions. The results indicate that the airflow discharged from the fan coil could have a significant impact on the age of the air; while it provides a desirable thermal comfort condition within the room, it may hinder to some extent delivery of the fresh air to the occupied zone due to creation of counterflow fields. Furthermore, it is shown that although increasing the fan speed (ON mode) would slightly enhance the air change efficiency, the OFF mode yields not only a better distribution of the fresh air but also a higher ventilation efficiency than when fan coil operates.

Fiber Bragg grating-electromagnetically induced transparent fast optical switch

Here, an all-optical switch is modeled in the form of fiber Bragg grating (FBG) based on electromagnetically induced transparency (EIT) phenomena dealing with a three-level EIT silicon (Si) nanocrystalline medium. The EIT consists of two fields, namely a strong control and weak probe fields that interact with the medium. Fast-optical switching of the probe is achieved by applying a pulsed control field, which relies on both steady-state and transient density matrices. The effects of four significant parameters of interest, i.e., Rabi frequency of the control field, EIT nanocrystal density, FBG length, and spontaneous decay rate, have been extensively investigated to optimize the probe transmission. Subsequently, the time-dependent density matrix is solved to obtain the response time of the FBG-EIT switch. Eventually, FBG is modeled such that low index layers contain EIT material and the high index layers do not. The FBG-EIT switch satisfies the criteria of maximum transmission and minimum rise time to give out the optimal operational condition. Despite the optical switching is in OFF mode at Ωc=0 THz demonstrating a high FBG reflectance, the reflectance suddenly vanishes at a certain Ω c s to satisfy the equivalence of low and high refractive indices (switching ON). Therefore, a fast-optical switch is envisaged operating as large as 100 GHz in theory. The future applications of the FBG- EIT include the fast Q-switching of fiber lasers, ultra-fast modulation, optical quantum communication, and high speed optical processing and computation.

Reverse cardiac remodeling in patients with dilated cardiomyopathy post Cardiac Resynchronization Therapy (CRT) and its clinical implication

Aim: To track the reverse cardiac remodeling in patients with dilated cardiomyopathy post cardiac resynchronization therapy (ON and OFF modes) and its implication on patients clinical condition emphasizing the factors achieving that remodeling. Patients and Methods: 30 patients indicated for the device were enrolled and studied before and three to six months after device insertion by history taking, clinical examination, transthoracic echocardiogram, ECG and six minutes' walk test. Results: 30 patients (23 males and 7 females, mean age (54.50 ± 6.24years) with implanted CRT. All patients were in sinus rhythm, QRS duration ≥120 ms and LBBB with dilated cardiomyopathy (ischemic etiology was excluded by coronary angiography in patients having risk factors for IHD). There was clinical response to CRT as NYHA class improved p < 0.001 and 6 min walk test p < 0.001, electrocardiographically, there were significant differences in HR, PR interval, QRS duration ,axis and morphology between pre and post CRT measurements (P<0.001) and echocardiographic response as LV volume improved in 80%, EF in 76.6% and change (∆QRSD) significantly correlated with changes in NYHA, LVEDD, LVESD, and LVEF. s. Area under the curve was 0.824 for ∆QRSD (p=0.005), ∆QRSD of ≥-20 ms as a cutoff value had high specificity for predicting both clinical and Echocardiographic response. Coronary sinus lead selection and positioning had a major role in achieving that remodeling with best response was shown with the lateral veins (70 % of responders ) and worst response with mid vein ( 65 % of non- responders);Achieving that targeted significant ∆QRSD of ≥-20 ms sometimes required a more than usual programmable VV delay up to 60 ms in some patients. Conclusion: Reverse cardiac remodeling post CRT in patients with DCM in both (CRT ON + OFF modes ) was associated with a significant improvement in patients clinical conditions with subsequent reduction of the incidence of their need to hospital admissions.

A reconfigurable sandwich structure switchable DNA-based metamaterial

In this paper, a tunable DNA-based metamaterial is designed and simulated in 170–340 THz range. This metamaterial can be transformed from an ON mode with a low resistance state of the DNA strip to its OFF mode with a high resistance state. Three Structures with containing different combinations metal layers are designed and simulated. Structure 1 with Ag/DNA/Ag and Au/DNA/Au strategies achieves field enhancement factors (FEF) 2.18 and 2.07, respectively. Structure 2 (Au/DNA/Dirac, Dirac/DNA/Au, Ag/DNA/Dirac, or Dirac/DNA/Ag) achieves the FEF values 14.11, 10.70, 13.75, or 9.62, respectively, while the FEF value of Structure 3 with Dirac/DNA/Dirac reaches 59.8. The FEF value of Structure 3 can be modulated from 59.8 to 91.96 as Fermi energy increasing from 0 to 60 meV. Moreover, the FEF value is also enhanced through increasing the magnetic field strength. The Structure 3 exhibits convertibility and sustainable modulation lines between two opposing patterns. The proposed structure reveals a switchable feature based on the resistance characteristics of DNA strips, which can be revealed as an ON/OFF switch sensor. Moreover, the switching performance of Structures 3 and 2 is significantly higher than Structure 1. Therefore, Structures 3 and 2 can be set to be an optical memristor or optical gate.

X-ray irradiation-induced degradation in Hf0.5Zr0.5O2 fully depleted silicon-on-insulator n-type metal oxide semiconductor field-effect transistors

The n-type ultrathin fully depleted silicon-on-insulator (FDSOI) metal–oxide–semiconductor field-effect transistors (MOSFETs), with a Hf0.5Zr0.5O2 high dielectric permittivity (high-k) dielectric as gate insulator, were fabricated. The total ionizing dose effects were investigated, and an X-ray radiation dose up to 1500 krad(Si) was applied for both long- and short-channel devices. The short-channel devices (0.025–0.100 μm) exhibited less irradiation sensitivity compared with the long-channel devices (0.35–16 μm), leading to a 71% reduction in the irradiation-induced drain current growth and a 26% decrease in the shift of the threshold voltage. It was experimentally demonstrated that the OFF mode is the worst case among the three working conditions (OFF, ON and All0) for short-channel devices. Also, the determined effective electron mobility was enhanced by 38% after X-ray irradiation, attributed to the different compensations for charges triggered by radiation between the high-k dielectric and buried oxide. By extracting the carrier mobility, gate length modulation, and source/drain (S/D) parasitic resistance, the degradation mechanism on X-ray irradiation was revealed. Finally, the split capacitance–voltage measurements were used to validate the analysis.

Low profile pattern switchable multiband antenna for on/off body communication

A low profile, a multifrequency microstrip patch antenna with pattern reconfiguration is reported in this paper. The proposed antenna provides both omnidirectional and directional radiation characteristics suitable for Wireless Body Area Network (WBAN). Pattern switching is achieved using PIN diodes. The antenna is designed to operate at multiple frequencies, viz. 0.915 GHz (Industrial Scientific & Medical band), 2.38 GHz (Medical body area network), 3.5 GHz (Wireless Interoperability for Microwave Access), and 5.8 GHz (Wireless Local Area Network/Industrial Scientific & Medical band). The percentage bandwidths obtained are 2.89, 1.68, 2.85, 2.16 at the operating frequencies 0.915, 2.38, 3.5, 5.8 GHz, respectively. The peak gain and total efficiencies obtained for OFF mode are 3.22/4.27/4.65/4.82 dBi, 82/85/87/89%, and in ON mode are 1.12/1.80/2.44/2.68 dBi, 65/67/71/74% at the said operating bands, respectively. The path loss model is evaluated by measuring the transmission link between the antennas on the human body. The LOS path ranges from 30 to 45 dB and the NLOS ranges from 50 to 80 dB ensuring it satisfactory for WBAN application. Then human body loading characteristics are also studied. The SAR analysis is performed and it is found to be less than 1.6 W/Kg.

Two-Step Thermoinduced Metal-to-Metal Electron Transfer and ON/OFF Photoswitching in a Molecular [Fe2Co2] Square Complex.

A cyanide-bridged [Fe2Co2] molecular square complex, {[Fe(Tp)(CN)3]2[Co(L)2]2}(BF4)2·2CH3CN·6H2O [1; Tp = hydrotris(pyrazol-1-yl)borate and L = bis(1-ethyl-1H-imidazol-2-yl)ketone], has been synthesized and characterized fully by single-crystal X-ray diffraction, (photo)magnetic measurements, optical reflectivity, and other physical measurements. 1 exhibits a two-step metal-to-metal electron-transfer (MMET)-induced spin transition accompanied by thermal hysteresis (T1/2↑ = 332 and 407 K and T1/2↓ = 320 and 405 K, respectively), converting the low-temperature diamagnetic {FeIILS-CN-CoIIILS} ground state into the high-temperature paramagnetic {FeIIILS-CN-CoIIHS} state. Additionally, 1 displays reversible photoinduced MMET under light irradiation (ON mode using 808 nm laser light and OFF mode using 532 nm laser light), as confirmed by optical reflectivity and (photo)magnetic measurements. The photoinduced paramagnetic metastable state relaxes back to the diamagnetic ground state at 91 K (TLIESST = 91 K). Astonishingly, 1 also exhibits a 27 K wide light-induced thermal hysteresis below 100 K. The overall results show that 1 is a multistimuli-responsive bistable material that exhibits reversible switching between the diamagnetic state, {FeIILS-CN-CoIIILS}, and the paramagnetic state, {FeIIILS-CN-CoIIHS}, under the application of temperature and light.

Stochastic Inventory System With Different Rates of Production

This article analyzes a solitary item stochastic inventory model with two distinctive generation rates where a request pursues Poisson distribution and an item has a limited lifetime which is level dependent. It is expected that the framework be on a foreordained level and the framework is changed over to ON mode from OFF mode with a noteworthy exchanging time with exponential parameter α. During the switching time, no interest will be served, the interest during the exchange time is lost. Here, excesses are permitted and during accumulations, the production rate is higher than that of ordinary generation time. Some framework attributes are shown with time variety.

Impact Assessment of Houseplants on Atmospheric Relative Humidity in the Residential Buildings of Udaipur, Rajasthan

Flora is the nature’s most precious gift to man. In ancient times, regard and love for flora was so great that this kindred relationship was extended even to houseplants. In this study, relative humidity level in the selected rooms, i.e., drawing rooms and dining rooms of the 10 west facing residential buildings along with the National Highway- 8 in polluted zone, of Udaipur Rajasthan was analyzed. Four varieties of foliage and succulent plants were kept in one, two or four suitable corners with four different habits, viz., Opened and Closed windows and fan in ON and OFF mode. To find out the existing relative humidity level, all the experiments were done without any houseplants on day 1 in selected rooms. The houseplants were kept on day 2 to judge the impact of houseplants on humidity level and again houseplants were removed on day 3 to know the retention of impact of houseplants. As a result, it was found that foliage plants were more effective than succulents in maintaining the level of relative humidity of the atmosphere.

Radiation-Pattern Reconfigurable Phased Array With p-i-n Diodes Controlled for 5G Mobile Terminals

A p-i-n diodes-controlled radiation-pattern reconfigurable phased array for fifth-generation (5G) handsets is proposed in this article. The proposed beam scanning and switching hybrid system can significantly reduce the number of arrays and transmit–receive (TR) components when compared with multiarray systems while keeping the same spatial coverage. The array has wide working band from 24 to 27.5 GHz, which can cover the allocated 5G band for Europe. The four-element array is planar with a small clearance of only 4 mm, which is suitable for most of the current mobile phones. Each reconfigurable array element is fed by one shielded stripline and has three switchable radiation patterns: two broadside directions and one endfire direction. The beam switching is realized by applying two reconfigurable directors on both sides of the dipole, which also reduces the antenna profile. The directors are activated when the p-i-n diodes are at OFF mode, which minimizes the energy loss on the p-i-n diodes. The parasitic influence of the p-i-n diodes, the soldering process, and mobile environment are discussed in detail. The measured results show good agreement with the simulations.