A Novel Loss Tolerant Data Transmission Schemes for Airborne Telemetry System of a Long Range Aerospace Vehicle

The on-board telemetry system of an aerospace vehicle sends the vehicle performance parameters to the ground receiving station at all instances of its trajectory. During the course of its trajectory, the communication channel of a long range vehicle, experiences various phenomena such as plume attenuation, stage separation, manoeuvring of a vehicle and RF blackout, causing loss of valuable telemetry data. The loss of communication link is inevitable due to these harsh conditions even when using the space diversity of ground receiving systems. Conventional telemetry systems do not provide redundant data for long range aerospace vehicles. This research work proposes an innovative delay data transmission, frame switchover and multiple frames data transmission schemes to improve the availability of telemetry data at ground receiving stations. The proposed innovative schemes are modelled using VHDL and extensive simulations have been performed to validate the results. The functionally simulated net list has been synthesised with 130 nm ACTEL flash based FPGA and verified on telemetry hardware.

Study on afterbody-effects of multi-stage separation at high-speed

The stage separation of high-speed vehicle is complicated at high dynamic pressure, usually accompanied by strong shock and vortex interaction. There exists a strong interaction between first stage and second stage, which called “afterbody-effects”. The aerodynamic mechanism of “afterbody-effects” is studied in this paper based on numerical simulation. The aerodynamic characteristics of a simplified three-dimensional projectile model at different distances between stages at 0° angle of attack is researched with structural mesh. The results show that the vortexes of stages have a significant impact on the aerodynamic characteristics of different stages, As the distance between stages increases, the drag coefficient of the first stage increases, and the drag coefficient of the second stage increases first and then decreases.

Evaluating the Spectral Response and Yield of Soybean Following Exposure to Sublethal Rates of 2,4-D and Dicamba at Vegetative and Reproductive Growth Stages

The commercialization of synthetic auxin-resistant crops and the commensurate increase in post-emergent auxin-mimic herbicide applications has resulted in millions of hectares of injury to sensitive soybeans in the United States since 2016. Visual yield loss estimations following auxin injury can be difficult. The goal of this research was to determine if spectral variations following auxin injury to soybean allow for more precise yield loss estimations. Identical field experiments were performed in 2018, 2019, and 2020 in Columbia, Missouri to compare the ability of established vegetative indices to differentiate between exposure levels of 2,4-D and dicamba in soybean and predict yield loss. Soybeans were planted at three timings for growth stage separation and were exposed to sublethal rates of 2,4-D and dicamba at the R2, R1, and V3 growth stages. A UAV-mounted multispectral sensor was flown over the trial 14 days after the herbicide treatments. The results of this research found that vegetative indices incorporating the red-edge wavelength were more consistent in estimating yield loss than indices comprised of only visible or NIR wavelengths. Yield loss estimations became difficult when soybean injury occurred during later reproductive stages when soybean biomass was increased. This research also determined that when injury occurs to soybean in vegetative growth stages late in the growing season there is a greater likelihood for yield loss to occur due to decreased time for recovery. The results of this research could provide direction for more objective and accurate evaluations of yield loss following synthetic auxin injury than what is currently available.

Single-Stage Fractionation of Vine Shoots Using Microwave Heating

Vine shoots are agricultural residues that can be used as a raw material in agro-biorefineries, in which their main constituents can be individually converted into valuable bioproducts. The treatment of vine shoots in uncatalyzed media containing water and 1-butanol enabled the single-stage separation of the major vine shoots constituents in different phases: the aqueous phase from treatments contained hemicellulose-derived products (mainly in the form of oligosaccharides), the organic phase accumulated the dissolved lignin, and the cellulosic fraction was recovered in solid phase. The aqueous phase from treatments was refined using membranes and processed with enzymes to obtain a refined product (RP) containing 92.2 g of oligosaccharides/100 g of non-volatile compounds. The oligosaccharides were mainly composed of anhydroxylose units substituted by acetyl and uronic groups. Enzymatic hydrolysis of RP with endo-xylanases reduced the average degree of polymerization to 2-3, which are preferred for application as healthy food ingredients. The solid phase from treatments was used as a substrate for enzymatic hydrolysis, enabling the production of solutions containing 34.9 g glucose /L and 4.2 g xylose /L.

The Antarctic Stratospheric Aerosol Observation and Sample-Return System Using Two-Stage Separation Method of a Balloon-Assisted Unmanned Aerial Vehicle

The authors have developed a system for the Antarctic stratospheric aerosol observation and sample-return using the combination of a rubber balloon, a parachute, and a gliding fixed-wing unmanned aerial vehicle (UAV). A rubber balloon can usually reach 20 km to 30 km in altitude, but it becomes difficult for the UAV designed as a low-subsonic UAV to directly glide back from the stratospheric altitudes because the quantitative aerodynamic characteristics necessary for the control system design at such altitudes are difficult to obtain. In order to make the observation and sample-return possible at such higher altitudes while avoiding the problem with the control system of the UAV, the method using the two-stage separation was developed and attempted in Antarctica. In two-stage separation method, the UAV first descends by a parachute after separating from the balloon at stratospheric altitude to a certain altitude wherein the flight control system of the UAV works properly. Then it secondly separates the parachute for autonomous gliding back to the released point on the ground. The UAV in which an optical particle counter and an airborne aerosol sampler were installed was launched on January 24, 2015 from S17 (69.028S, 40.093E, 607 m MSL) near Syowa Station in Antarctica. The system reached 23 km in altitude and the UAV successfully returned aerosol samples. In this paper, the details of the UAV system using the two-stage separation method including the observation flight results, and the preliminary results of the observation and analyses of the samples are shown.

Current Challenges and Advancements on the Management of Water Retreatment in Different Production Operations of Shale Reservoirs

Nowadays, water savings on industrial plants have become a significant concern for various plants and sections. It is vitally essential to propose applicable and efficient techniques to retreat produced water from onshore and offshore production units. This paper aimed to implement the PFF (Photo Fenton Flotation) method to optimize the water treatment procedure, as it is a two-stage separation technique. The measurements were recorded for the HF (hydraulic fracturing) and CEOR (chemically enhanced oil recovery) methods separately to compare the results appropriately. To assure the efficiency of this method, we first recorded the measurements for five sequential days. As a result, the total volume of 2372.5 MM m3/year of water can be saved in the HF process during the PFF treatment procedure, and only 20% of this required fresh water should be provided from other resources. On the other hand, the total volume of 7482.5 MM m3/year of water can be saved in CEOR processes during the PFF treatment procedure, and only 38% of this required fresh water should be provided from other resources. Therefore, the total water volume of 9855 MM m3 can be saved each year, indicating the efficiency of this method in supplying and saving the water volume during the production operations from oilfield units.

Separation of Fe from Mn in the Cryogenian Sedimentary Mn Deposit, South China: Insights from Ore Mineral Chemistry and S Isotopes from the Dawu Deposit

Manganese and Fe have similar geochemical properties in the supergene environment. Separation of Mn and Fe is an important process for the formation of high-grade sedimentary manganese deposits. Large-scale manganese carbonate deposits (total reserves of approximately 700 Mt) were formed during the interglacial of the Sturtian and Marinoan in South China. The orebodies are hosted in the black rock series at the basal Datangpo Formation of the Cryogenian period. The Fe contents in ores range from 1.15 to 7.18 wt.%, with an average of 2.80 wt.%, and the average Mn/Fe ratio is 8.9, indicating a complete separation of Mn and Fe during the formation of manganese ores. Here, we present element data of manganese carbonates and sulfur isotopes of pyrite from the Dawu deposit, Guizhou, China, aiming to investigate the separation mechanism of Mn and Fe and the ore genesis. The Fe in ores mainly occurs as carbonate (FeCO3) and pyrite (FeS2). The Mn, Ca, Mg and Fe exist in the form of isomorphic substitutions in manganese carbonate. The contents of FeCO3 in manganese carbonates are similar in different deposits, with averages of 2.6–2.8 wt.%. The whole-rock Fe and S contents have an obvious positive correlation (R = 0.69), indicating that the difference of whole-rock Fe content mainly comes from the pyrite content. The δ34SV-CDT of pyrite varies from 40.0 to 48.3‰, indicating that the pyrite formed in a restricted basin where sulfate supply was insufficient and the sulfate concentrations were extremely low. Additionally, the whole-rock Fe content is negatively correlated with the δ34S values of the whole-rock and pyrite, with correlation coefficients of −0.78 and −0.83, respectively. Two stages of separations of Mn and Fe might have occurred during the mineralization processes. The reduced seawater became oxidized gradually after the Sturtian glaciation, and Fe2+ was oxidized and precipitated before Mn2+, which resulted in the first-stage separation of Mn and Fe. The residual Mn-rich and Fe-poor seawater flowed into the restricted rift basin. Mn and Fe were then precipitated in sediments as oxyhydroxide as the seawater was oxidized. At the early stage of diagenesis, organic matter was oxidized, and manganese oxyhydroxide was reduced, forming the manganese carbonate. H2S was insufficient in the restricted basin due to the extremely low sulfate concentration. The Fe2+ was re-released due to the lack of H2S, resulting in the second-stage separation of Mn and Fe. Finally, the manganese carbonate deposit with low Fe and very high δ34S was formed in the restricted basin after the Sturtian glaciation.