Vector Control Method Research Articles

Effect of predators on Anopheles arabiensis and Anopheles funestus larval survivorship in Homa Bay County Western Kenya

BackgroundThe rise of insecticide resistance against malaria vectors in sub-Saharan Africa has resulted in the need to consider other methods of vector control. The potential use of biological methods, including larvivorous fish, Bacillus thuringiensis israelensis (Bti) and plant shading, is sustainable and environmentally friendly options. This study examined the survivorship of Anopheles arabiensis and Anopheles funestus larvae and habitat productivity in four permanent habitat types in Homa Bay county, western Kenya.MethodsPredator densities were studied in a laboratory setup while habitat productivity and larval survivorship was studied in field setup.ResultsFish were observed as the most efficient predator (75.8% larval reduction rate) followed by water boatman (69%), and dragonfly nymph (69.5%) in predation rates. Lower predation rates were observed in backswimmers (31%), water beetles (14.9%), water spiders (12.2%), mayflies (7.3%), and tadpoles (6.9%). Increase in predator density in the field setup resulted in decreased Culex larval density. Larval and pupa age–specific distribution was determined and their survivorship curves constructed. Combined larvae (Stage I–IV) to pupa mortality was over 97% for An. arabiensis and 100% for An. funestus. The highest larval stage survival rate was from larval stages I to II and the lowest from larval stage IV to pupa. Stage-specific life tables indicated high mortality rates at every developmental stage, especially at the larval stage II and III.ConclusionDetermination of the efficiency of various larval predators and habitat productivity will help with the correct identification of productive habitats and selection of complementary vector control methods through environmental management and/or predator introduction (for instance fish) in the habitats.

Perancangan Self Tuning Dua Derajat Kebebasan dengan Metode Fuzzy Logic pada Pengendalian Kecepatan Motor Sinkron Magnet Permanen Menggunakan Metode Vector Control

Abstract — This paper proposes self tuning Proportional-Integral/Proportional gain controller parameter in a Two Degree of Freedom (2DoF) using fuzzy logic method for speed control of permanent magnet synchronous motor. The self tuning method can automatically determine the PI-P parameters using a fuzzy logic control system. Speed control of the 3-phase permanent magnet synchronous motor is carried out by changing the 3-phase system (a-b-c) to a 2-phase system (direct-quadrature) using the vector control method. SVPWM method is used to modulate six switches on a 3 phase inverter. The results obtained using MATLAB Simulink show that by using a self-tuning fuzzy logic control system, high motor performance results are obtained, where the speed response of the permanent magnet synchronous motor shows that the step response and disturbance response are close to the ideal response.
 Keywords— Permanent Magnet Synchronous Motor, Self Tuning, Two Degrees of Freedom, Fuzzy Logic, Vector Control.

Speed Control of PMSM Based on Fuzzy Active Disturbance Rejection Control under Small Disturbances

Permanent Magnet Synchronous Motors (PMSMs), with their simple design, small size, and high-power factor, are ideally suited for realizing high-power AC drives and are widely used in various industries. In this study, Fuzzy Active Disturbance Rejection Control (Fuzzy-ADRC) is used to control the speed of the PMSM. When a slight external disturbance occurs, this control strategy maintains the suppression characteristics of the self-excited control for the disturbance and enhances its ability to compensate for the disturbance. First, a mathematical model was developed to study the surface mount PMSM. Then, a motor control simulation model was created using PI control, vector control, and other control methods. The verification results indicate that the improved Fuzzy-ADRC system performs well under both internal and external minor disturbances. It exhibits a faster dynamic response and reduced regulation time (0.026 s to 0.017 s) compared to the traditional ADRC system. Furthermore, it shows less overshoot (reduced from 70% to 2.9%) compared to the Sliding Mode Observer (SMO). Taken together, the improved Fuzzy-ADRC system is characterized by small steady-state error, high load capacity, and control accuracy. With the assistance of this control strategy, the system can track speed with high accuracy and possesses stronger anti-interference capability to mitigate load disturbances.

Research on Active Disturbance Rejection Control of Brushless DC Motor Based on Vector Control

A Active Disturbance Rejection Control strategy based on vector control is proposed to address the problems of poor speed overshooting immunity in the control system of brushless DC motor. The motor magnetic chain and torque are decoupled by vector control method to simplify the control, and the traditional PI controller in the speed loop is replaced by a active disturbance rejection controller. The transition process is arranged by tracking differential (TD) to smooth the given speed, which overcomes the contradiction between speed overshoot and rapidity, and improves the response capability of the system; a second-order extended state observer (ESO) is introduced, which estimates and compensates the total system disturbance and improves the system's immunity to disturbance; and the nonlinear law state error feedback (NLSEF) is utilized by the Through the nonlinear law state error feedback (NLSEF), the control accuracy of the system is improved by utilizing the nonlinear control principle of "large gain with small error and small gain with large error". The simulation results show that the control strategy proposed in this paper is characterized by fast response, no overshooting, strong resistance to load disturbance, and strong robustness to changes in load and speed, which proves the feasibility and advancement of this strategy.

Quantitative proteomics analysis of permethrin and temephos-resistant Ae. aegypti revealed diverse differentially expressed proteins associated with insecticide resistance from Penang Island, Malaysia.

Synthetic insecticides are the primary vector control method used globally. However, the widespread use of insecticides is a major cause of insecticide-resistance in mosquitoes. Hence, this study aimed at elucidating permethrin and temephos-resistant protein expression profiles in Ae. aegypti using quantitative proteomics. In this study, we evaluated the susceptibility of Ae. aegypti from Penang Island dengue hotspot and non-hotspot against 0.75% permethrin and 31.25 mg/l temephos using WHO bioassay method. Protein extracts from the mosquitoes were then analysed using LC-ESI-MS/MS for protein identification and quantification via label-free quantitative proteomics (LFQ). Next, Perseus 1.6.14.0 statistical software was used to perform differential protein expression analysis using ANOVA and Student's t-test. The t-test selected proteins with≥2.0-fold change (FC) and ≥2 unique peptides for gene expression validation via qPCR. Finally, STRING software was used for functional ontology enrichment and protein-protein interactions (PPI). The WHO bioassay showed resistance with 28% and 53% mortalities in adult mosquitoes exposed to permethrin from the hotspot and non-hotspot areas. Meanwhile, the susceptibility of Ae. aegypti larvae revealed high resistance to temephos in hotspot and non-hotspot regions with 80% and 91% mortalities. The LFQ analyses revealed 501 and 557 (q-value <0.05) differentially expressed proteins in adults and larvae Ae. aegypti. The t-test showed 114 upregulated and 74 downregulated proteins in adult resistant versus laboratory strains exposed to permethrin. Meanwhile, 13 upregulated and 105 downregulated proteins were observed in larvae resistant versus laboratory strains exposed to temephos. The t-test revealed the upregulation of sodium/potassium-dependent ATPase β2 in adult permethrin resistant strain, H15 domain-containing protein, 60S ribosomal protein, and PB protein in larvae temephos resistant strain. The downregulation of troponin I, enolase phosphatase E1, glucosidase 2β was observed in adult permethrin resistant strain and tubulin β chain in larvae temephos resistant strain. Furthermore, the gene expression by qPCR revealed similar gene expression patterns in the above eight differentially expressed proteins. The PPI of differentially expressed proteins showed a p-value at <1.0 x 10-16 in permethrin and temephos resistant Ae. aegypti. Significantly enriched pathways in differentially expressed proteins revealed metabolic pathways, oxidative phosphorylation, carbon metabolism, biosynthesis of amino acids, glycolysis, and citrate cycle. In conclusion, this study has shown differentially expressed proteins and highlighted upregulated and downregulated proteins associated with insecticide resistance in Ae. aegypti. The validated differentially expressed proteins merit further investigation as a potential protein marker to monitor and predict insecticide resistance in field Ae. aegypti. The LC-MS/MS data were submitted into the MASSIVE database with identifier no: MSV000089259.

Design of a low-frequency ultrasound diagnostic sensor based on skin mechanical impedance

Skin integrity assessment is a very important matter in the nursing care, especially for patients with low mobility. However, the methodology of skin analysis is limited by a lack of reliable yet portable tools. In this paper, a new sensor is proposed for skin mechanical impedance characterisation, aiming to provide an objective assessment of skin health. The device consists in a microcontroller connected to a Langevin transducer. Using the vector control method, the reference vibration of the transducer is assured, and the mechanical impedance is observed. To ensure the repeatability of the measurements, tests in the morning and in the afternoon were taken. To verify if the device can distinguish sites with different mechanical properties on the same body, tests were made on 2 different body sites: the palm of the hand and the volar forearm. Measurements of skin hydration were also taken, to find a potential correlation of these parameters and skin acoustical mechanical impedance. Results have shown that the measurements provided by the device are mostly reliable, and reveal a fair correlation between mechanical impedance and hydration, in the level of stratum corneum, the outermost layer of skin. Also, the device is able to show the difference on the mechanics of the skin in the different body sites tested, independently of the hydration.

INDIGENOUS BACILLUS SPECIES ISOLATED FROM AEDES AEGYPTI LARVAE: ISOLATION, LARVICIDAL TOXICITY SCREENING, PHENOTYPIC CHARACTERIZATION, AND MOLECULAR IDENTIFICATION

Vector-borne diseases transmitted by mosquitoes are considered a significant public health problem worldwide. Aedes aegypti is one of the mosquito species responsible for transmitting these diseases. One environmentally friendly method of vector control is the use of microbial agents such as Bacillus species. This study aimed to explore investigate indigenous entomopathogenic bacteria of Bacillus species isolated from A. aegypti larvae. Larvae samples were collected from breeding sites of A. aegypti. All isolates underwent screening and affirmation confirmation tests to assess their larvicidal toxicity against A. aegypti larvae. Phenotypic characterizations and molecular identifications were conducted to determine the species of the Bacillus isolates based on similarity index and percent identity (%ID). Phylogenetic trees were used to compare the isolates with other Bacillus species. The results revealed 120 isolates of Bacillus species from A. aegypti larvae samples. Among them, three isolates (LS3.3, LS9.1, and LSD4.2) exhibited the highest larvicidal toxicity in the confirmation test, resulting in larval mortality rates of 100%, 96.7%, and 100%, respectively, after 48 hours of exposure. Molecular identifications, showed that LSD4.2 had a 99.16% ID with Bacillus velezensis, LS3.3 had a 98.22% ID with Bacillus mojavensis, and LS9.1 had a 99.93% ID with Bacillus subtilis. These three bacteria from the Bacillus genus have been reported to offer significant benefits to humans.

A Mid-fidelity Model in the Loop Feasibility Study for Implementation of Regenerative Antilock Braking System in Electric Vehicles

&lt;div&gt;The tailpipe zero-emission legislation has pushed the automotive industry toward more electrification. Regenerative braking is the capability of electric machines to provide brake torque. So far, the regenerative braking feature is primarily considered due to its effect on energy efficiency. However, using individual e-machines for each wheel makes it possible to apply the antilock braking function due to the fast torque-tracking characteristics of permanent magnet synchronous motors (PMSM). Due to its considerable cost reduction, in this article, a feasibility study is carried out to investigate if the ABS function can be done purely through regenerative braking using a mid-fidelity model-based approach. An uni-tire model of the vehicle with a surface-mount PMSM (SPMSM) model is used to verify the idea. The proposed ABS control system has a hierarchical structure containing a high-level longitudinal slip controller and a low-level SPMSM torque controller. Given the uncertainties of the tire–road dynamics, a sliding mode control method is designed and employed as a high-level slip controller. Also, a PID vector control method is used to keep the SPMSM braking torque at the optimal value requested by the high-level controller. Moreover, in order to estimate the tire longitudinal slip and vehicle velocity, an extended Kalman filter (EKF) is developed that estimates both parameters at the same time. The results show that the proposed hierarchical control and estimators can keep the tire longitudinal slip at the optimal value and prevent the wheel from locking in a variety of road conditions.&lt;/div&gt;

Resistance of Anopheles stephensi to selected insecticides used for indoor residual spraying and long-lasting insecticidal nets in Ethiopia

BackgroundMalaria, transmitted by the bite of infective female Anopheles mosquitoes, remains a global public health problem. The presence of invasive Anopheles stephensi, capable of transmitting Plasmodium vivax and Plasmodium falciparum, was first reported in Ethiopia in 2016. The ecology of this mosquito species differs from that of Anopheles arabiensis, the primary malaria vector in Ethiopia. This study aimed to evaluate the efficacy of selected insecticides, which are used in indoor residual spraying (IRS) and selected long-lasting insecticidal nets (LLINs) for malaria vector control against adult An. stephensi.MethodsAnopheles stephensi mosquitoes were collected as larvae and pupae from Awash Subah Kilo Town and Haro Adi village, Ethiopia. Adult female An. stephensi, reared from larvae and pupae collected from the field, aged 3–5 days were exposed to impregnated papers of IRS insecticides (propoxur 0.1%, bendiocarb 0.1%, pirimiphos-methyl 0.25%), and insecticides used in LLINs (alpha-cypermethrin 0.05%, deltamethrin 0.05% and permethrin 0.75%), using diagnostic doses and WHO test tubes in a bio-secure insectary at Aklilu Lemma Institute of Pathobiology, Addis Ababa University. For each test and control tube, batches of 25 female An. stephensi were used to test each insecticide used in IRS. Additionally, cone bioassay tests were conducted to expose An. stephensi from the reared population to four brands of LLINs, MAGNet™ (alpha-cypermethrin), PermaNet® 2.0 (deltamethrin), DuraNet© (alpha-cypermethrin) and SafeNet® (alpha-cypermethrin). A batch of ten sugar-fed female mosquitoes aged 2–5 days was exposed to samples taken from five positions/sides of a net. The data from all replicates were pooled and descriptive statistics were used to describe features of the data.ResultsAll An. stephensi collected from Awash Subah Kilo Town and Haro Adi village (around Metehara) were resistant to all tested insecticides used in both IRS and LLINs. Of the tested LLINs, only MAGNet™ (alpha-cypermethrin active ingredient) caused 100% knockdown and mortality to An. stephensi at 60 min and 24 h post exposure, while all other net brands caused mortality below the WHO cut-off points (< 90%). All these nets, except SafeNet®, were collected during LLIN distribution for community members through the National Malaria Programme, in December 2020.ConclusionsAnopheles stephensi is resistant to all tested insecticides used in IRS and in the tested LLIN brands did not cause mosquito mortality as expected, except MAGNet. This suggests that control of this invasive vector using existing adult malaria vector control methods will likely be inadequate and that alternative strategies may be necessary.

Effect of onchocerciasis elimination measures on the incidence of epilepsy in Maridi, South Sudan: a 3-year longitudinal, prospective, population-based study

High onchocerciasis transmission predisposes endemic communities to a high epilepsy burden. The 4·4% epilepsy prevalence documented in 2018 in Maridi, South Sudan, prompted the strengthening of onchocerciasis elimination measures. Community-directed treatment with ivermectin was implemented annually in 2017, 2018, and 2019, interrupted in 2020, and re-implemented biannually in 2021. We aimed to assess the effect of these interventions, along with slash and clear vector control on the incidence of epilepsy, including nodding syndrome. In this longitudinal, prospective, population-based study, we did a two-stage house-to-house epilepsy survey before (May 10-30, 2018) and after (March 9-19, 2022) the strengthening of onchocerciasis elimination interventions in South Sudan. Strengthening also included the implementation of a community-based slash and clear vector control method that we initiated in 2019 at the Maridi dam (the main blackfly breeding site). Eight sites were surveyed near the Maridi dam and inclusion required residence in one of these sites. All household residents were first screened by community workers, followed by confirmation of the epilepsy diagnosis by trained clinicians. The primary outcome was epilepsy incidence, including nodding syndrome, which was assessed via self-reported new-onset epilepsy in the previous 4 years of each survey, confirmed by clinician assessment. The preintervention survey included 17 652 people of whom 736 had epilepsy (315 female and 421 male), and the post-intervention survey included 14 402 people of whom 586 had epilepsy (275 female and 311 male). When biannual community-directed treatment with ivermectin was initiated in 2021, the intervention's coverage rose by 15·7% (95% CI 14·6-16·8); although only 56·6% of the population took ivermectin in 2021. Between 2018 and 2022, epilepsy incidence decreased from 348·8 (307·2-395·8) to 41·7 (22·6-75·0) per 100 000 person-years. Similarly, the incidence of nodding syndrome decreased from 154·7 (127·6-187·3) to 10·4 (2·7-33·2) per 100 000 person-years. The identified risk factors for epilepsy were: living closer to the Maridi dam, being aged between 6 and 40 years, not taking ivermectin, and being male. In onchocerciasis-endemic areas with high epilepsy prevalence, strengthening onchocerciasis elimination interventions can decrease the incidence of epilepsy, including nodding syndrome. Additional efforts are needed to increase community-directed treatment with ivermectin coverage and sustain blackfly control in Maridi. Research for Health in Humanitarian Crisis, European Research Council, Research Foundation-Flanders, Research Foundation-Flanders, the Italian Agency for Development Cooperation, and La Caixa Foundation.

The Impact of COVID-19 Pandemic on Arthropod-Related Diseases.

The Covid-19 pandemic that caused by the infection with the novel Coronavirus SARS-CoV-2 has revealed individual and global vulnerabilities all over the world. Many countries that had been struggled with arthropod-borne diseases (VBDs) are now embroiled in another challenge caused by COVID-19 pandemic. The situation that poses major obstacles 1) by misdiagnosis 2) delay in early and appropriate treatment of VBDs 3) difficulties in applying regular strategy for vector control and prevention methods and finally 4) irregularity in financing supports. Given the possible scenario of syndemics, it is important to plan integrated and combined measurement with the maximum participation of the people and health authorities. Here, the impact of COVID-19 pandemic on some major arthropod-related diseases will be discussed. To access the collective data all related databases such as Science direct, PubMed, Elsevier, Google scholar, as well WHO web page were searched with key words "arthropoda-related diseases, COVID-19 with the name of each individual disease". The results showed that the management, control, and treatment of most important arthropod-related diseases could be delayed due to COVID-19 pandemic. Dealing with COVID-19, it is crucial to consider the other main killers such as malaria, dengue fever, etc. more especially in vulnerable populations by greater political, financial and global commitment. Continued surveillance will be essential to monitor for any possible changes.

Bulanık Anahtarlama Algoritması ile DTC Kontrollü Asenkron Makine için İyileştirilmiş Tork ve Hız Performansları

Direct Torque Control (DTC) is a vector control method based on the control of the stator flux vector in the desired direction. The control of the stator flux vector is achieved by direct selection of the optimum inverter output voltage vectors. The limit values of the trajectory determined in the rotation of the stator flux vector are determined using hysteresis controllers. In this study, performance analysis of two different control methods for reducing speed and torque oscillations of a three-phase asynchronous motor controlled by direct torque control are presented. In Matlab/Simulink based simulation studies, performance analyses were made for different speed and torque references of the motor, and both the transient and steady state speed and torque changes were presented comparatively. When the obtained results are examined, it is seen that the performance of the new fuzzy-based controller, which is offered instead of the Proportional Integral Derivative (PID) controller used in traditional control, significantly decreases in the specific conditions of motor speed and torque oscillations. However, considering the control structure of the direct torque controller, the simple and plain control structure has been preserved. According to the results obtained, it has been shown that the Fuzzy Logic (FL) controller gives a better result than the PID controller at t=4.5 seconds.

Recurring Outbreaks of Lassa Fever in Nigeria: Understanding the Root Causes and Strategies for the Future

Lassa fever is a severe public health problem in Nigeria with far-reaching political, social, cultural, and religious ramifications. Thus, a further understanding of the disease is critical. Despite attempts to end the viral epidemic, the illness has persisted, leading to several major outbreaks in decades. Additionally, the country’s epidemic in 2019– 2020 set a new global record for the number of Lassa fever cases. This year, 244 cases and 37 deaths had been reported as of January 2023. To identify gaps and provide recommendations for the complete eradication of Lassa fever in the country. This paper investigates the underlying causes of the continuous outbreaks of the illness in Nigeria and the measures to prevent it. The frequent outbreaks of Lassa fever in Nigeria have been linked to several factors, including inadequate waste management, poor sanitation, restricted access to healthcare, and abject poverty. The reoccurring outbreaks are also attributed to a lack of political will, funding, poor coordination and communication, and low public awareness of the illness and its prevention. To effectively stop outbreaks of Lassa fever in Nigeria, the government and partners must continuously put into practice tried-and-true prevention measures such as improved surveillance to detect outbreaks earlier, increased funding and resources to support effective control measures, better primary healthcare facilities and training for healthcare professionals, heightened community engagement and education to raise awareness, and more effective vector control methods to reduce rodent populations, while looking for innovative approaches and dealing with the underlying social and economic problems contributing to the viral persistence.

Research on Pump Speed Control System Based on Fuzzy PID

In this paper, based on MATLAB/simulink, the PID vector frequency conversion control of permanent magnet synchronous motor has better drive control performance in the multi-stage centrifugal pump speed control system. The electric-hydraulic coupling system of centrifugal pump has a good evaluation and research function. In view of the low efficiency of the traditional PID control method and the poor adaptability to the change of working environment, a vector control method of permanent magnet synchronous motor based on adaptive and self-adjusting fuzzy control principle is proposed for the speed regulation system of water pump. The simulation results show that the PMSM system controlled by the fuzzy PID controller is superior to the traditional PID control, and has better disturbance resistance, dynamic and steady performance.

Crude saliva of Amblyomma cajennense sensu stricto (Acari: Ixodidae) reduces locomotor activity and increases the hemocyte number in the females of Aedes aegypti (Diptera: Culicidae)

Aedes aegypti are vector insects of arboviruses such as dengue, Zika, and chikungunya. All available vector control methods have limited efficacy, highlighting the urgent need to find alternative ones. Evidence shows that arachnids like ticks are sources of biologically active compounds. Moreover, chemical modulation of the locomotor and immune systems of vector insects can be used to control arbovirus transmission. The present study evaluated the effectiveness of crude saliva of female Amblyomma cajennense sensu stricto (s.s.) ticks in reducing locomotor activity and inducing an immune response in Ae. aegypti females. Additionally, the study evaluated the protein constitution of tick saliva. For this purpose, the crude saliva obtained from several semi-engorged A. cajennense females was used. A volume of 0.2 nL of crude tick saliva was administered to mosquitoes by direct intrathoracic microinjection. The effect of the tick's saliva on the locomotor activity of the mosquito was observed using Flybox, a video-automated monitoring system, and the hemolymph hemocyte levels were quantified by reading slides under a light microscope. The protein concentration of the crude tick saliva was 1.27 μg/μL, and its electrophoretic profile indicates the presence of proteins with a molecular weight ranging between ∼17 and 95 kDa. Microplusins, ixodegrins, cystatin, actins, beta-actin, calponin, albumin, alpha-globulins, and hemoglobin were the main proteins identified by proteomics in the saliva of A. cajennense. The microinjected saliva had low toxicity for Ae. aegypti females and significantly reduced their locomotor activity, especially in the transition between the light and dark phases. The crude tick saliva did not change the period and rhythmicity of the circadian cycle. The tick saliva significantly increased the number of hemocytes two days after injection and reduced it after five days. These results suggest that further evaluation of the biological properties of tick saliva proteins against Ae. aegypti would be of interest.

Test bench setup for emulating electric vehicle on-road conditions

This work provides an electric vehicle (EV) test bench with a motor/dynamometer setup with a battery and ultracapacitor (UC) hybrid energy storage. Extending the driving range and enhancing the battery life are the main concerns with EVs nowadays. The drive motor (DM) used is a three-phase induction motor (IM), which is controlled by the current sensorless indirect vector control method. This fault-tolerant method can be used in the case of current sensor failure. All the resistive forces acting on an EV are emulated based on the concept of vehicle equivalent rotational inertia for different real-life driving cycles, namely ECE R15 and NYCC. The battery alone is not capable of handling the surge current requirement during the acceleration period and is not able to capture the total power during regenerative breaking as it has a low power density. Hence, a high power density source like UC is a must to handle these conditions during frequent stop and go city traffic conditions as per ECE R15 and NYCC driving cycles. This EV emulation technique helps in getting the DC-link power profile for an EV for any driving scenario. Hence, it is possible to test the different powertrain components of an EV using this proposed technique.

Opportunities for Improved Dengue Control in the US Territories

This Viewpoint from the CDC discusses the prevalence of dengue infection in US territories and opportunities to combat it, such as vaccines and novel vector control methods.

Study of the flow structure during the injection of detonation products into the supersonic nozzle

The gradual unloading of the space stage by undocking objects from it or an emer-gency situation due to the undocking of one of the spacecraft leads to mass asymmetry. In outer space there is also the problem of the collision of a space object with elements of space debris. Therefore, the relevance of the topic of this work is determined by the need to develop a system for avoiding the collision of a rocket with elements of space de-bris and controlling the flight, observing the programmed trajectory of movement. The gas-dynamic aircraft system is characterized by the highest speed control. Injection of detonation products into the supercritical part of the nozzle was used as a gas-dynamic system. Modeling was carried out in the SolidWorks application software package. The purpose of the work is to develop alternative methods of the thrust vector control of the upper stage rocket engine. The scheme of the system for the thrust vector control of a rocket engine by the effect of a detonation wave on the gas flow in its nozzle has been developed. The simulation was carried out in a non-stationary flat model at angles to the axis of the combustion chamber of 90°, 60°, 45°, 30° and parallel to the axis, - 0°. The location of the detonation gas generator was near the nozzle section. Numerical simulation revealed that the impact of the detonation wave on the main gas flow in the nozzle causes two power factors. The first force factor is due to the reactive force when detonation products are thrown into the nozzle and on the wall of the high pressure zone where the detonation gas generator is located. The second force factor is due to the change in pressure distribution on the nozzle surface, where high pressure zone creates reflecting on it. The dependence of the relative lateral force on the injection angle of detonation products into the combustion chamber over time has been obtained. The structure of the flow according to the patterns of the velocity distribution in the nozzle during the injection of detonation products is also considered. In cases when the injec-tion is blown at 900 and 450, the release of detonation products initiates a shock wave of high intensity, which moves against the supersonic flow, retarding it. The developed scheme can be used for maneuvering the upper stage of a prospective launch vehicle to avoid its collision with elements of space debris.

Nanoparticles: A Potential and Effective Method to Control Insect-Borne Diseases.

Insects act as vectors to carry a wide range of bacteria and viruses that can cause multiple vector-borne diseases in humans. Diseases such as dengue fever, epidemic encephalitis B, and epidemic typhus, which pose serious risks to humans, can be transmitted by insects. Due to the absence of effective vaccines for most arbovirus, insect control was the main strategy for vector-borne diseases control. However, the rise of drug resistance in the vectors brings a great challenge to the prevention and control of vector-borne diseases. Therefore, finding an eco-friendly method for vector control is essential to combat vector-borne diseases. Nanomaterials with the ability to resist insects and deliver drugs offer new opportunities to increase agent efficacy compared with traditional agents, and the application of nanoagents has expanded the field of vector-borne disease control. Up to now, the reviews of nanomaterials mainly focus on biomedicines, and the control of insect-borne diseases has always been a neglected field. In this study, we analyzed 425 works of the literature about different nanoparticles applied on vectors in PubMed around keywords, such as"nanoparticles against insect," "NPs against insect," and "metal nanoparticles against insect." Through these articles, we focus on the application and development of nanoparticles (NPs) for vector control, discussing the lethal mechanism of NPs to vectors, which can explore the prospect of applying nanotechnology in the prevention and control of vectors.

A novel thrust vector nozzle with conical surface based on Coanda effect

In this paper, a novel thrust vector control method based on Coanda effect is proposed for conical surface. The effect of thrust vector control is studied by computation fluid dynamic (CFD) numerical simulation. When there is no side plate on both sides of Coanda surface, there are large vortex structures on both sides of nozzle wake, and the vector control cannot be realized. After adding the side plate, the comprehensive control of the pitch and yaw thrust vectors was realized. When the nozzle pressure ratio (NPR) is 2~2.4, the pitch and yaw vector angles decreased with the increase of NPR, and the maximum pitch vector angle is 8°. And the yaw vector angle is 8°.