Fairness-Aware Harvested Energy Efficiency Algorithm for IRS-Aided Intelligent Sensor Networks with SWIPT

In this paper,a novel fairness-aware harvested energy efficiency-based green transmission scheme for wireless information and power transfer(SWIPT)aided sensor networks is developed for active beamforming of multiantenna transmitter and passive beamforming at intelligent reflecting surfaces(IRS).By optimizing the active beamformer assignment at the transmitter in conjunction with the passive beamformer assignment at the IRS,we aimtomaximize the minimumharvested energy efficiency among all the energy receivers(ER)where information receivers(IR)are bound to the signal-interference-noise-ratio(SINR)and the maximum transmitted power of the transmitter.To handle the non-convex problem,both semi-definite relaxation(SDR)and block coordinate descent technologies are exploited.Then,the original problem is transformed into two convex sub-problems which can be solved via semidefinite programming.Numerical simulation results demonstrate that the IRS and energy beamformer settings in this paper provide greater system gain than the traditional experimental setting,thereby improving the fairness-aware harvested energy efficiency of the ER.

Dynamic Analysis of an Algae-Fish Harvested Model with Allee Effect

In this paper, an algae-fish harvested model with Allee effect was established to further explore the dynamic evolution mechanism under the influence of key factors. Mathematical theoretical work not only investigated the existence and stability of all possible equilibrium points, but also probed into the occurrence of transcritical and Hopf bifurcation. The numerical simulation works verified the effectiveness of the theoretical derivation results and displayed rich bifurcation dynamical behaviors, which showed that Allee effect and harvest have played a vital role in the dynamic relationship between algae and fish. In summary, it was expected that these research results would be beneficial for promoting the study of bifurcation dynamics in aquatic ecosystems.

A New Indicator for Global Food Security Assessment: Harvested Area Rather Than Cropland Area

Cropland area has long been used as a key indicator of food security.However,grain yield is not solely controlled by the area of the cropland.Therefore,we proposed a new indicator to assess food security.Results show that from 1992 to 2004,the global cropland area increased by 840200 km^(2)(99.4%),but the grain yield increased only by 310 million t(29.1%);and from 2004 to 2015,the cropland area decreased by 39000 km^(2)(4.64%),but the grain yield increased by 370 million t(70.84%).This result showed that grain yield was not linearly correlated with cropland area,and delimiting the threshold of cropland protection may not guarantee food security.Combined with further correlation analysis,we found that the increase in the global grain yield was more closely related to the harvested area(R^(2)=0.94),which indicated that the harvested area is a more scientific and accurate indicator than cropland area in terms of guaranteeing food security.Therefore,if governments want to ensure the food security,they should choose a new and more accurate indicator:harvested area rather than cropland area.

Supplementation of amylase combined with glucoamylase or protease changes intestinal microbiota diversity and benefits for broilers fed a diet of newly harvested corn

Background: The effect of amylases combined with exogenous carbohydrase and protease in a newly harvested corn diet on starch digestibility, intestine health and cecal microbiota was investigated in broiler chickens.Methods: Two hunderd and eighty-eight 5-day-old female chickens were randomly divided into six treatments: a newly harvested corn-soybean meal diet(control); control supplemented with 1,500 U/g α-amylase(Enzyme A);Enzyme A + 300 U/g amylopectase + 20,000 U/g glucoamylase(Enzyme B); Enzyme B + protease 10,000 U/g(Enzyme C); Enzyme C + xylanase 15,000 U/g(Enzyme D); and Enzyme D + cellulase 200 U/g + pectinase 1,000 U/g(Enzyme E). Growth performance, starch digestibility, digestive organ morphology, and intestinal microbiota were evaluated in the birds at 16 and 23 d of age.Results: Compared with the control diet, supplementation with Enzyme A significantly decreased ileum lesion scoring at 16 d of age(P < 0.05); supplementation with Enzyme B or Enzyme C showed positive effects on ileal amylopectin and total starch digestibility(P < 0.05); Broilers fed with a diet supplemented with Enzyme D had a tendency to decrease body weight gain at 23 d. Enzyme E supplementation improved lesion scoring of jejunum and ileum at 16 d(P < 0.05), and increased ileal amylopectin or total starch digestibility at 23 d(P < 0.05).Supplementation of enzymes changed cecal microbiota diversity. High numbers of Campylobacter, Helicobacter and Butyricicoccus, Anaerostipes and Bifidobacterium, Sutterella and Odoribacter were the main genera detected in supplementations with Enzymes B, C, D, and E respectively.Conclusions: Supplementation with amylase combined with glucoamylase or protease showed a beneficial effect on starch digestibility and intestinal microbiota diversity, and increased growth of broilers fed with newly harvested corn.

Analysis of Different Rare Metals, and Rare Earth Metals in Harvested Rain Water in Gaza Strip/Palestine by ICP/MS-Data and Health Aspects

This rain water samples harvested for drinking and agriculture from Gaza collected in November 2012 were analyzed for different rare metals (Rb, Zr, Ti, Tl, Sb, Sc, Y), and rare earth metals (La, and Ce). These metals usually have no maximum acceptable limits as there is no sufficient data about their toxicity to human health. Their control should be therefore controlled in water to monitor their concentration in water (ground, harvested, etc.). This study was conducted to determine the water quality of harvested water which is used for drinking in the study area. 43 water samples were collected in November 2012 during the first rain from house wells and rain water pools. The concentrations of the metals detected in the collected harvested rainwater vary significantly between the 43 samples, and all of them were detected in all water samples analyzed in this study. The results obtained from this study suggest a possible risk to the population of the study area given the high concentration of some metals that have no maximum allowed concentration, and the fact that for many people in the study area, harvested rain water is a main source of their water supply.

Design of Wireless Energy-Harvested UHF WSN Tag for Cellular IoT

In this paper,a wireless energy-harvested ultra-high frequency(UHF)wireless sensor network(WSN)tag is designed and implemented for cellular Io T applications.The WSN tag is made up of a wireless energy harvesting circuit,a temperature sensing circuit,and a radio frequency identification(RFID)tag.The developed WSN tag is compatible with the ISO/IEC18000-6C protocol.The WSN tag can receive the GSM RF energy operating in China GSM900 and GSM1800 bands in the surrounding environment and the solar energy,then converts the RF energy to direct current(DC)by schottky diode-based rectifying circuit,and finally stores the DC energy in a supercapacitor through a DC-DC booster circuit.The DC-DC booster circuit drives the front-end circuit,TI MSP430 microcontroller,temperature sensing circuit,and other active circuits in the tag.The MSP430 works in low-power mode when it is powered up,and it can also reduce power consumption more by reducing main clock(MCLK)frequency according to different forward link rates.The implemented WSN tag demonstrated that the RF-to-DC conversion efficiency is higher than 39% when the receiving 900 MHz RF signal power is from -14 dBm to 0 dBm and could make the tag work normally.The signal receiving sensitivity of the WSN tag is up to-32 dBm at the rate of 40 kbit/s from the Reader to the WSN tag.The WSN tag supports Miller coding and extended Miller coding.This wireless energy harvested UHF WSN tag,compared with conventional UHF passive tags and battery-powered active UHF RFID Tags,has many advantages,such as far communication distance,long service life,and sensing functionality.It will have wide applications in the Internet of Things(IoT).

Reducing intimal hyperplasia in vein grafts harvested by a no-touch harvesting technique

Objective To investigate the effect of no-touch harvesting technique in reducing vein graft intimal hyperplasia. Methods This longitudinal trial compared graft angiostenosis of two groups undergoing jugular vein to carotid artery interposition grafting in rabbit model. Conventional group:12 rabbits had their veins stripped,distended,and stored in heparinized saline solution. No-touch group:12 rabbits had veins removed with surrounding tissues,but were not distended,and stored in heparinized blood. The grafts were removed 4 weeks following grafting,and morphometry and immunohistochemistry assessment were performed. Results The intimal thickness,degree of angiostenosis and proliferation index of vascular smooth muscle cells of no-touch group were significantly reduced (P<0.01) compared with those of the conventional group. The proliferating cell nuclear antigen positive-staining cells were significantly increased (P<0.01) in the conventional group compared with whose in the no-touch group. Conclusion Harvesting the vein graft with no-touch harvesting technique could significantly reduce intimal hyperplasia of the vein graft.

Mycoflora and Mycotoxicological Quality of Four Freshly Harvested Paddy Rice Cultivars and Relation with Harvest to Industry Reception Timing

Grain quality and safety of four freshly harvested paddy rice （Oryza sativa L.） cultivars （Epagri 109, SCS 114 Andosan, Tio Taka 113 and Epagri 115 CL） grown under irrigation system in the north of Santa Catarina State, Brazil were studied. The quality parameters evaluated were mycoflora, mycotoxins （aflatoxins, ochratoxin A and zearalenone）, water distribution （moisture content and water activity） apart from environmental conditions （relative humidity and temperature） and the relation between harvest and the industry reception timing. All cultivars presented an average waiting time of 8.6 h （ranged from 0.3 to 24.9 h）, a total fungi load of 8.6x104 cfu/mL （ranged from 1.8x103 to 9.4x105 cfu/mL） with a rather high humidity condition of 19.0% moisture content （varied from 14.9% to 24.5%） and 0.92 water activity （varied from 0.78 to 0.99） under the average environmental conditions of 87.3% relative humidity （varied from 80.0% to 96.8%） and 25.4 ~C （varied from 22.5 to 27.5 ~C）, respectively. The conditions to which the samples were submitted allowed fungal growth, but no mycotoxins were detected. Regarding the rice cultivars fungal genera isolated, Aspergillus and Penicillium were the most often isolated among all the cultivars and variation on fungi distribution among them was not observed. Moreover, it was not found a correlation of the grain loading ＆ unloading time with the humidity conditions and the total fungi load. Furthermore, all results and the importance of monitoring the rice mycotoxicological quality and safety were discussed.

Quality of <i>Jatropha curcas</i>L. Seeds Harvested at Different Stages of Fruit Maturation

The aim of this study was to evaluate the physiological quality of Jatropha curcas L. seeds harvested at different stages of fruit maturation and two threshing methods. To analyze the mechanical damage rate an experiment was carried out with five stages of fruit maturation (green, yellow, ripe, dried on the ground and dried on the plant) threshed mechanically and manually. To evaluate the physiological quality, three tests were made;germination, vigor and electrical conductivity, all of them were applied in each storage (0, 120 and 240 days after harvest) and five stages of fruit maturation. It was feasible to infer that the maturation stage of yellow, ripe and dried on the plant fruits showed the best results of the physiological quality of the Jatropha curcas L. seeds. The manual threshing is also recommended in order to preserve the physiological quality of Jatropha curcas L. seeds. When the fruits were harvested at the appropriate stage of maturation (yellow, ripe and dry fruit on the plant) and threshing without mechanical damage, the Jatropha curcas L. seeds are possible to store for 240 days without loss in their germination. Regardless of the threshing system and the maturation stage, the seeds of Jatropha curcas L. lost their vigor from 120 days after harvested, when these seeds were stored in the shadow and in an environment without control on the relative humidity and air temperature.

Sustainable Water Supply for Domestic Use： Application of Roof-Harvested Water for Ground Water Recharge

Rain water harvesting offers a wealth of promising possibilities for many countries. This paper describes a study in which rainwater harvested from the rooftop is used for recharging groundwater in a household well in Ibadan. A rainwater harvesting structure was designed to be 1.2 m deep, 2.6 m long and 0.66 m wide, filled with gravel and fine sand at different layers. Rainwater harvested in a storage tank is passed with the aid of a hose pipe to the rainwater harvesting structure on a daily basis to recharge the groundwater in the well. A well in the neighborhood serves as control for this experiment, which went on for a month. The volume of rainwater used to recharge the groundwater in the well was recorded daily for the study period. The results indicated that using rainwater to recharge the groundwater in the well led to conservation of the water in the well through reduced evaporation. Thus, the well yields water all the year round as compared to the control well that dries up during the dry season.

Estimation of annual harvested runoff at Sulaymaniyah Governorate, Kurdistan region of Iraq

Kurdistan Region (KR) of Iraq has suffered from the drought period during the seasons 2007-2008 and 2008-2009 that affected the human and economic activities of the region. Macro rainwater harvesting (Macro RWH) is one of the techniques that can ensure water availability for a region having limited water resources. This technique is based on Soil Conservation ServiceCurve Number (SCS-CN) method and the Watershed Modeling System (WMS) was used to estimate the runoff. Rainfall records of Sulaymaniyah area for the period 2002-2012 were studied and an average season was selected (2010-2011). The results of the application of the WMS model showed that about 10.76 million cubic meters could be harvested. The results also showed that the quantity of the harvested runoff was highly affected by rainfall depth, curve number values, antecedent moisture conditions (AMC) and the area of the basins.

The underlying mechanism of variety–water–nitrogen–stubble damage interactions on yield formation in ratoon rice with low stubble height under mechanized harvesting

Agronomic measures are the key to promote the sustainable development of ratoon rice by reducing the damage from mechanical crushing to the residual stubble of the main crop, thereby mitigating the impact on axillary bud sprouting and yield formation in ratoon rice. This study used widely recommended conventional rice Jiafuzhan and hybrid rice Yongyou 2640 as the test materials to conduct a four-factor block design field experiment in a greenhouse of the experimental farm of Fujian Agricultural and Forestry University, China from 2018 to 2019.The treatments included fertilization and no fertilization, alternate wetting and drying irrigation and continuous water flooding irrigation, and plots with and without artificial crushing damage on the rice stubble. At the same time, a 13C stable isotope in-situ detection technology was used to fertilize the pot experiment. The results showed significant interactions among varieties, water management, nitrogen application and stubble status.Relative to the long-term water flooding treatment, the treatment with sequential application of nitrogen fertilizer coupled with moderate field drought for root-vigor and tiller promotion before and after harvesting of the main crop, significantly improved the effective tillers from low position nodes. This in turn increased the effective panicles per plant and grains per panicle by reducing the influence of artificial crushing damage on rice stubble and achieving a high yield of the regenerated rice. Furthermore, the partitioning of 13C assimilates to the residual stubble and its axillary buds were significantly improved at the mature stage of the main crop, while the translocation rate to roots and rhizosphere soil was reduced at the later growth stage of ratooning season rice. This was triggered by the metabolism of hormones and polyamines at the stem base regulated by the interaction of water and fertilizer at this time. We therefore suggest that to achieve a high yield of ratoon rice with low stubble height under mechanized harvesting, the timely application of nitrogen fertilizer is fundamental,coupled with moderate field drying for root-vigor preservation and tiller promotion before and after the mechanical harvesting of the main crop.

Dewatering of Scenedesmus obliquus Cultivation Substrate with Microfiltration:Potential and Challenges for Water Reuse and Effective Harvesting

In the microalgae harvesting process,which includes a step for dewatering the algal suspension,directly reusing extracted water in situ would decrease the freshwater footprint of cultivation systems.Among various algae harvesting techniques,membrane-based filtration has shown numerous advantages.This study evaluated the reuse of permeate streams derived from Scenedesmus obliquus(S.obliquus)biomass filtration under bench-scale and pilot-scale conditions.In particular,this study identified a series of challenges and mechanisms that influence the water reuse potential and the robustness of the membrane harvesting system.In a preliminary phase of this investigation,the health status of the initial biomass was found to have important implications for the harvesting performance and quality of the permeate stream to be reused;healthy biomass ensured better dewatering performance(i.e.,higher water fluxes)and higher quality of the permeate water streams.A series of bench-scale filtration experiments with different combinations of cross-flow velocity and pressure values were performed to identify the operative conditions that would maximize water productivity.The selected conditions,2.4 m·s^(-1)and 1.4 bar(1 bar=105 Pa),respectively,were then applied to drive pilot-scale microfiltration tests to reuse the collected permeate as a new cultivation medium for S.obliquus growth in a pilot-scale photobioreactor.The investigation revealed key differences between the behavior of the membrane systems at the two scales(bench and pilot).It indicated the potential for beneficial reuse of the permeate stream as the pilot-scale experiments ensured high harvesting performance and growth rates of biomass in permeate water that were highly similar to those recorded in the ideal cultivation medium.Finally,different nutrient reintegration protocols were investigated,revealing that both macro-and micro-nutrient levels are critical for the success of the reuse approach.

A Self-Healing Optoacoustic Patch with High Damage Threshold and Conversion Efficiency for Biomedical Applications

Compared with traditional piezoelectric ultrasonic devices,optoacoustic devices have unique advantages such as a simple preparation process,anti-electromagnetic interference,and wireless long-distance power supply.However,current optoacoustic devices remain limited due to a low damage threshold and energy conversion efficiency,which seriously hinder their widespread applications.In this study,using a self-healing polydimethylsiloxane(PDMS,Fe-Hpdca-PDMS)and carbon nanotube composite,a flexible optoacoustic patch is developed,which possesses the self-healing capability at room temperature,and can even recover from damage induced by cutting or laser irradiation.Moreover,this patch can generate high-intensity ultrasound(>25 MPa)without the focusing structure.The laser damage threshold is greater than 183.44 mJ cm^(-2),and the optoacoustic energy conversion efficiency reaches a major achievement at 10.66×10^(-3),compared with other carbon-based nanomaterials and PDMS composites.This patch is also been successfully examined in the application of acoustic flow,thrombolysis,and wireless energy harvesting.All findings in this study provides new insight into designing and fabricating of novel ultrasound devices for biomedical applications.

Energy Harvesting in the Wake of An Inverted C-Shaped Bluff Body

This paper proposes a novel wake-induced vibration(WIV)-based energy harvesting system consisting of two bluff bodies.An inverted C-shaped bluff body is stationary installed at the upstream position to generate an interference wake street,and a cylinder bluff body equipped with a transducer is elastically suspended at the downstream position to harness WIV energy.The hydrodynamics and energy harvesting(EH)performance of the proposed system are investigated via experimental studies.The reduced velocity(U*)ranging from 2 to 14(the corresponding Reynolds number ranging from 15100 to 106200)is considered in the present study.It is found that the wake generated by the inverted C-shaped bluff body significantly affects the EH performance.Enlarging the opening angle(α)of the C-shaped bluff body increases the vibration amplitude of the downstream cylinder,thereby increasing the harvested power.When the spacing(L)between two bluff bodies is two times the cylinder diameter(D),the wake-induced vibration(WIV)mode is observed,while the combined WIV and wake galloping(WG)mode occurs whenαis 150°,and L equals 3D or 4D.The average drag coefficient becomes negative when L is 2D,3D,or 4D.By carefully configuring a C-shaped bluff body,the wake generated by it can bring an augmenting effect on the vibration of the downstream EH cylinder.For example,the RMS power output of the proposed EH system reaches a maximum of 0.31 W at U*=8 and L=4D,which is 300%greater than that of its traditional counterpart.Furthermore,after a number of case stud-ies,it is identified that the proposed EH system can achieve the best performance whenαis 150°and L=2D.

Compliant Iontronic Triboelectric Gels with Phase-Locked Structure Enabled by Competitive Hydrogen Bonding

Rapid advancements in flexible electronics technology propel soft tactile sensing devices toward high-level biointegration,even attaining tactile perception capabilities surpassing human skin.However,the inherent mechanical mismatch resulting from deficient biomimetic mechanical properties of sensing materials poses a challenge to the application of wearable tactile sensing devices in human-machine interaction.Inspired by the innate biphasic structure of human subcutaneous tissue,this study discloses a skin-compliant wearable iontronic triboelectric gel via phase separation induced by competitive hydrogen bonding.Solvent-nonsolvent interactions are used to construct competitive hydrogen bonding systems to trigger phase separation,and the resulting soft-hard alternating phase-locked structure confers the iontronic triboelectric gel with Young’s modulus(6.8-281.9 kPa)and high tensile properties(880%)compatible with human skin.The abundance of reactive hydroxyl groups gives the gel excellent tribopositive and self-adhesive properties(peel strength>70 N m^(−1)).The self-powered tactile sensing skin based on this gel maintains favorable interface and mechanical stability with the working object,which greatly ensures the high fidelity and reliability of soft tactile sensing signals.This strategy,enabling skin-compliant design and broad dynamic tunability of the mechanical properties of sensing materials,presents a universal platform for broad applications from soft robots to wearable electronics.

Review of the Tuned Mass Damper Inerter(TMDI)in Energy Harvesting and Vibration Control:Designs,Analysis and Applications

Tuned mass damper inerter(TMDI)is a device that couples traditional tuned mass dampers(TMD)with an inertial device.The inertial device produces resistance proportional to the relative acceleration at its two ends through its“inertial”constant.Due to its unique mechanical properties,TMDI has received widespread attention and application in the past twenty years.As different configurations are required in different practical situations,TMDI is still active in the research on vibration control and energy harvesting in structures.This paper provides a comprehensive review of the research status of TMDI.This work first examines the generation and important vibration control characteristics of TMDI.Then,the energy harvesting performance of electromagnetic tuned mass damper inerter(EM-TMDI)is discussed.This work emphasizes the formation of a passive dynamic vibration absorber by coupling traditional TMD with inertial devices.This paper also summarizes the design and implementation of optimal vibration control and energy harvesting for TMDI.Furthermore,this paper details the applications of TMDI in the fields of bridges and building engineering.Finally,this paper summarizes the necessity of research on tuned mass-damper-inertia,the challenges faced currently,and future research directions,such as control of parameters in electromagnetic energy harvesting TMDI systems and low-cost TMDI.

Dynamic analysis of a novel multilink-spring mechanism for vibration isolation and energy harvesting

Due to technical limitations,existing vibration isolation and energy harvesting(VIEH)devices have poor performance at low frequency.This paper proposes a new multilink-spring mechanism(MLSM)that can be used to solve this problem.The VIEH performance of the MLSM under harmonic excitation and Gaussian white noise was analyzed.It was found that the MLSM has good vibration isolation performance for low-frequency isolation and the frequency band can be widened by adjusting parameters to achieve a higher energy harvesting power.By comparison with two special cases,the results show that the MLSM is basically the same as the other two oscillators in terms of vibration isolation but has better energy harvesting performance under multistable characteristics.The MLSM is expected to reduce the impact of vibration on high-precision sensitive equipment in some special sites such as subways and mines,and at the same time supply power to structural health monitoring devices.

Performance enhancement of a viscoelastic bistable energy harvester using time-delayed feedback control

This paper focuses on the stochastic analysis of a viscoelastic bistable energy harvesting system under colored noise and harmonic excitation, and adopts the time-delayed feedback control to improve its harvesting efficiency. Firstly, to obtain the dimensionless governing equation of the system, the original bistable system is approximated as a system without viscoelastic term by using the stochastic averaging method of energy envelope, and then is further decoupled to derive an equivalent system. The credibility of the proposed method is validated by contrasting the consistency between the numerical and the analytical results of the equivalent system under different noise conditions. The influence of system parameters on average output power is analyzed, and the control effect of the time-delayed feedback control on system performance is compared. The output performance of the system is improved with the occurrence of stochastic resonance(SR). Therefore, the signal-to-noise ratio expression for measuring SR is derived, and the dependence of its SR behavior on different parameters is explored.

Advances in Triboelectric Nanogenerators for Blue Energy Harvesting and Marine Environmental Monitoring

Blue energy,which includes rainfall,tidal current,wave,and water-flow energy,is a promising renewable resource,although its exploitation is limited by current technologies and thus remains low.This form of energy is mainly harvested by electromagnetic generators(EMGs),which generate electricity via Lorenz force-driven electron flows.Triboelectric nano genera tors(TENGs)and TENG networks exhibit superiority over EMGs in low-frequency and high-entropy energy harvesting as a new approach for blue energy harvesting.A TENG produces electrical outputs by adopting the mechanism of Maxwell’s displacement current.To date,a series of research efforts have been made to optimize the structure and performance of TENGs for effective blue energy harvesting and marine environmental applications.Despite the great progress that has been achieved in the use of TENGs in this context so far,continuous exploration is required in energy conversion,device durability,power management,and environmental applications.This review reports on advances in TENGs for blue energy harvesting and marine environmental monitoring.It introduces the theoretical foundations of TENGs and discusses advanced TENG prototypes for blue energy harvesting,including TENG structures that function in freestanding and contact-separation modes.Performance enhancement strategies for TENGs intended for blue energy harvesting are also summarized.Finally,marine environmental applications of TENGs based on blue energy harvesting are discussed.