Ilmenite Inclusion: A Solution towards Solid Sagging for Hematite-Based Invert Emulsion Mud

The sagging tendency of hematite in drilling mud is a common challenge occurring at high-pressure and high-temperature (HP/HT) applications. This work studies the performance of hematite-based invert emulsion mud for HP/HT conditions and provides a solution to prevent the hematite settlement using a combination of ilmenite with hematite. Practical mud formulation was utilized over a range of ilmenite/hematite ratios (0/100, 20/80, 40/60, and 50/50%) to study sagging behaviour. From the sag tests, the optimum combination proportion was determined. Thereafter, the density, emulsion stability, rheological and viscoelastic properties, and filtration conduct for the formulated mud were evaluated. The experiments were conditioned as per the standards of the American Petroleum Institute. The obtained results of sagging experiments indicated that including 50% of ilmenite mitigated the hematite settling and reduced the sag tendency towards the safe range. A slight drop (4%) in mud weight was noticed upon adding the ilmenite, whereas the emulsion stability was enhanced from 551 to 574 volts with the 50% ilmenite content. The rheology and viscoelasticity measurements showed that 50/50% combination improved the yield point (YP) by 50% with a trivial 1 cP increment on plastic viscosity (PV), hence enhancing the YP/PV ratio by 46%. Also, the gelling strength was enhanced resulting in flat rheology and better gel structure. The filtration behaviour of 50% ilmenite mud was improved compared to blank hematite as it resulted in 21, 15, and 17% reduction on the filtrated volume, filter cake weight, and thickness, respectively. This study provides a solution for hematite sagging issue at HP/HT using combined weighting agents, which contributes to enhancing the mud stability and avoiding several well control issues and related operational and technical challenges that eventually will economize the drilling cost and time.

DEVELOPMENT AND TEST OF CORN STRAW KNEADING AND CONVEYING DEVICE

Aiming at the low comprehensive utilization rate of corn straw resources, a straw kneading and cutting conveyor suitable for corn harvester was designed to improve the utilization rate of corn straw resources. The workbench module of ANSYS is used to carry out modal analysis of the two blades, and it is determined that the vibration frequency will not cause damage to the blade sweeping bore. By changing the structure of the movable blade shaft, the speed of the blade shaft can be reduced while ensuring the effect of straw crushing and collecting. In order to determine the best working parameters, three-factor and three-level orthogonal test was carried out with blade arrangement, blade shaft speed and length of feed straw as test factors, and the crushing rate of straw as evaluation index. The results show that the main factors influencing the crushing rate of straw are blade shaft speed, blade arrangement and the minor factor is the length of feed straw. Finally, the optimum combination parameters, blade arrangement, blade shaft speed 400 r/min and whole plant feed with straw, were determined. The corresponding straw crushing rate was 96.39%. The research meets the requirements of straw crushing and can provide technical scheme for comprehensive utilization of corn straw.

Using finite element analysis to discuss the study of drawing of servo stamping curve

This study employed different molding parameter combinations, the Taguchi method, ANOVA, and response surface methodology to perform experiments. Finite element analysis was executed to find the optimum molding parameters and increase the depth of drawing molding. The material is aluminum alloy 6016, and the servo press was adopted for the experiments. The factors influencing the drawing molding including punch fillet radius, die fillet radius, die clearance, molding curve, and mold temperature were determined. To find the optimum combination of parameters and to design 16 experimental combinations, the L16 orthogonal array of the Taguchi method was employed. According to the experimental results, the optimum parameters include punch fillet radius of 8.5 mm, die fillet radius of 8.5 mm, clearance of 1.5 t, curve 3, and the mold temperature of 20°C. Using the optimum parameter combination the molding depth could be increased greatly and the thickness ratio could be improved.

Comparison of mixed and plug flow reactor for enhancing the cell concentration of Haematococcus pluvialis growth

Photo bioreactions are employed for abating carbon dioxide emissions. The economics depends upon the choice of the type of the reactor. Photo bioreactions can be explained similarly to an autocatalytic reaction. A combined reactor mixed flow reactor followed by plug flow reactor could be the best choice. Using the data on cell concentration of Haematococcus pluvialis with respect to time in 2x concentration of Kobayashi’s basal medium available in the literature, it has been proved that the combined reactor could be the best choice. The optimum combination was also determined.

Optimal Water-Fertilizer Combinations for Efficient Nitrogen Fixation by Sugarcane at Different Stages of Growth

High fertilizer application and over-irrigation in sugarcane systems can cause considerable N2O emissions. Optimized water-fertilization management which reduces N2O emissions, while maintaining sugarcane biomass, is crucial, but may affect nitrogen fixation by sugarcane. This study evaluated the combined effect of water-fertilization on sugarcane biomass and nitrogen fixation in field trials in southern China. Treatments included drip and spray irrigation, with three levels (0% (low), 50% (medium), 100% (high)) of irrigation and of fertilizer. A rain-fed crop (no irrigation or fertilizer) was included as the control. The results showed that (1) spray irrigation with medium water and high fertilization increased biomass. The optimum combination in sugarcane elongation stage was drip irrigation with medium water and high fertilization, while drip irrigation with high water and high fertilization was the best choice for maturity stage. (2) For sugarcane nitrogen (δ15N) content, spray irrigation with medium water and high fertilization was the best combination in seedling and tillering stages. The optimum combination in the elongation stage was drip irrigation with medium water and high fertilization, and in maturity stage was drip irrigation with high water and high fertilization. (3) For soil (δ15N content), drip irrigation with high water and high fertilization proved optimal for seedling, tillering, and maturity stages. (4) In seedling stage, sugarcane (δ15N content) was found to be strongly correlated with leaf area index, soil water, soil temperature, and soil electrical conductivity. Soil (δ15N content) was correlated with photosynthesis and soil temperature. In conclusion, drip irrigation appears most suitable for field planting, while the best treatment in seedling and tillering stages is medium water-high fertilization, and that the best in elongation stage is high water-medium fertilization. The optimum water-fertilizer combinations identified here can provide a scientific basis for optimization and management of irrigation and fertilization in China and other regions with similar environments.

Denoising MAX6675 reading using Kalman filter and factorial design

This paper aims to tune the Kalman filter (KF) input variables, namely measurement error and process noise, based on two-level factorial design. Kalman filter then was applied in inexpensive temperature-acquisition utilizing MAX6675 and K-type thermocouple with Arduino as its microprocessor. Two levels for each input variable, respectively, 0.1 and 0.9, were selected and applied to four K-type thermocouples mounted on MAX6675. Each sensor with a different combination of input variables was used to measure the temperature of ambient-water, boiling water, and sudden temperature drops in the system. The measurement results which consisted of the original and KF readings were evaluated to determine the optimum combination of input variables. It was found that the optimum combination of input variables was highly dependent on the system's dynamics. For systems with relatively constant dynamics, a large value of measurement error and small value of process noise results in higher precision readings. Nevertheless, for fast dynamic systems, the previous input variables' combination is less optimal because it produced a time-gap, which made the KF reading differ from the original measurement. The selection of the optimum input combination using two-level factorial design eased the KF tuning process, resulting in a more precise yet low-cost sensor.

A techno-economic analysis of the roof top off-grid solar PV system for Jamshedpur, Jharkhand, India

As the exhaust rate of the conventional sources has geared up already, this is compelling the power industries to install the power plants based on the non-conventional sources so that future demand of the energy supply can be fulfilled. Among the various sources of renewable energy like wind, hydro, tidal etc., solar energy is the most easily accessible and available renewable energy source. Ensuring the feasibility of any energy source not only technical but also the economical perspective is the most important criteria. This paper has incorporated both the perspective and has done the techno-economic analysis to determine the optimum combination of the PV array size and battery size to minimize the overall electricity generation per unit. In this paper, a standalone solar PV system has been analyzed for the location of Jamshedpur, where an effort has been done to choose the optimum combination of the solar array and battery size within the desired range of LLP so that the electricity generation cost per unit can be minimized. The overall duration of the analysis has been done for a year and the outcome of the research has been verified with the help of MATLAB software.

Comparison of Preservation and Extraction Methods on Five Taxonomically Disparate Coral Microbiomes

All animals are host to a multitude of microorganisms that are essential to the animal’s health. Host-associated microbes have been shown to defend against potential pathogens, provide essential nutrients, interact with the host’s immune system, and even regulate mood. However, it can be difficult to preserve and obtain nucleic acids from some host-associated microbiomes, making studying their microbial communities challenging. Corals are an example of this, in part due to their potentially remote, underwater locations, their thick surface mucopolysaccharide layer, and various inherent molecular inhibitors. This study examined three different preservatives (RNAlater, DNA/RNA Shield, and liquid nitrogen) and two extraction methods (the Qiagen PowerBiofilm kit and the Promega Maxwell RBC kit with modifications) to determine if there was an optimum combination for examining the coral microbiome. These methods were employed across taxonomically diverse coral species, including deep-sea/shallow, stony/soft, and zooxanthellate/azooxanthellate: Lophelia pertusa, Paragorgia johnsoni, Montastraea cavernosa, Porites astreoides, and Stephanocoenia intersepta. Although significant differences were found between preservative types and extraction methods, these differences were subtle, and varied in nature from coral species to coral species. Significant differences between coral species were far more profound than those detected between preservative or extraction method. We suggest that the preservative types presented here and extraction methods using a bead-beating step provide enough consistency to compare coral microbiomes across various studies, as long as subtle differences in microbial communities are attributed to dissimilar methodologies. Additionally, the inclusion of internal controls such as a mock community and extraction blanks can help provide context regarding data quality, improving downstream analyses.

Variable returns to scale DEA—Taguchi approach for ternary additives optimization in expansive soil subgrade enhancement

In this study, variable returns to scale (VRS) data envelopment analysis was integrated into the Taguchi approach to optimize ternary additives for expansive soil enhancement. The ternary additives selected were sawdust ash (SDA), quarry dust (QD) and ordinary Portland cement (OPC). The additives were set as the input variables while multiple responses obtained from the experiments performed with the Taguchi orthogonal array were set as the output variables. Each row in the orthogonal array were defined as a decision making unit (DMU) in the optimization process and output-oriented VRS model was used to obtain the efficiency score for each DMU. Next, benevolent formulation was utilized to obtain the multipliers for the inputs and outputs which were subsequently used to determine the cross efficiency scores for each DMU. The cross-efficiency scores were used to construct the cross-efficiency matrix. Thereafter, the mean cross-efficiency score (MCES) was determined for each DMU. Parameter level that maximizes the MCES was chosen as the optimal level for that parameter. Optimum combination of additives was found at A6 B2 C3. Lastly, confirmatory experiments performed by blending the soil with the optimum combination of additives showed the effectiveness of this method in the enhancement of expansive soil properties.