Effect of Solidifying Structure on Centerline Segregation of S50C Steel Produced by Compact Strip Production

Medium-high carbon steels having a high quality are widely used in China. It is advantageous to produce high value-added hot-rolled plates with the crystal refined and chemical composition homogenized in the casting slabs. However, element segregation occurs easily during high-medium carbon steels’ production. Generally, the centerline segregation is improved by enlarging the equiaxed zone with low-superheat casting and electromagnetic stirring (EMS). Studies were conducted on centerline segregation of S50C steel slabs with a thickness of 52 mm produced by the compact strip production (CSP) process in China without EMS equipped. By sampling along the width at different position, the secondary dendrite arm spacing (SDAS) was measured after etching and picture processing, based on which the cooling rate was calculated. It was found that the cooling rate increased from the center to the surfaces of the slabs ranging in 1~20 K/s, 10 times faster than that of a conventional process. The faster cooling rate led to a refined solidifying structure and columnar dendrite through the center of the slabs. The SDAS tended to increase from surfaces to the center, ranging only 32~120 μm smaller than that of a conventional process in 100~300 μm, indicating a finer solidifying structure by the CSP process. Results by EPMA indicated that elements C, Si, and Mn distribute in dispersed spots, increasing towards the center, and the centerline segregation changed in a narrow range: for C mainly in 1.0~1.1, Si in 0.98~1.08, Mn in 0.96~1.02, respectively, meaning a more chemical homogenization than that of thick slabs. Elements’ segregation originated from solute redistribution between solid and liquid. According to thermodynamic calculation, δ region of S50C is so narrow that the solute redistribution mainly occurred between γ-Fe and liquid during solidification. As the equilibrium partition coefficient of element C was the smallest, it was easy for C to be rejected to the residual liquid in the inter-dendritic space, leading to obvious segregation, relatively. Besides, as a result of high-cooling intensity, the solidifying structure became so fine that the Fourier number increased and the volume of the residual liquid decreased, making centerline segregation alleviated effectively both in volume and degree. Although bulging was observed during the industrial experiment, the centerline segregation was still inhibited obviously as the refining solidifying structure with permeability ranged only in 0.1~2.3 μm2 from the surfaces to centerline, which showed a good resistance on the residual flow towards the centerline.

Microstructure Characteristics and Strengthening Behavior of Cu-Bearing Non-Oriented Silicon Steel: Conventional Process versus Strip Casting

Based on conventional hot rolling processes and strip casting processes, Cu precipitation strengthening is used to improve the strength of non-oriented silicon steel in order to meet the requirements of high-speed driving motors of electric vehicles. Microstructure evolution was studied, and the effects of Cu precipitates on magnetic and mechanical properties are discussed. Compared with conventional processes, non-oriented silicon steel prepared by strip casting exhibited advantages with regard to microstructure optimization with coarse grain and {100} texture. Two-stage rolling processes were more beneficial for uniform microstructure, coarse grains and improved texture. The high magnetic induction B50 of 1.762 T and low core losses with P1.5/50, P1.0/400 and P1.0/1000 of 1.93, 11.63 and 44.87 W/kg, respectively, were obtained in 0.20 mm sheets in strip casting. Cu precipitates significantly improved yield strength over ~120 MPa without deteriorating magnetic properties both in conventional process and strip casting. In the peak stage aged at 550 °C for 120 min, Cu precipitates retained bcc structure and were coherent with the matrix, and the yield strength of the 0.20 mm sheet was as high as 501 MPa in strip casting. The main mechanism of precipitation strengthening was attributed to coherency strengthening and modulus strengthening. The results indicated that balanced magnetic and mechanical properties can be achieved in thin-gauge non-oriented silicon steel with Cu addition in strip casting.

Pressure Swing-Based Reactive Distillation and Dividing Wall Column for Improving Manufacture of Propylene Glycol Monomethyl Ether Acetate

Propylene glycol monomethyl ether acetate (PGMEA) is a commonly used solvent in the rapidly developing semiconductor industry. Ultra-high purity PGMEA is required for this ultra-precision industry and to satisfy the current strict waste management regulations. The traditional PGMEA production process consumes considerable energy and has a high production cost. In this study, a novel heat integrated and intensified design, which applies a dividing wall column, reactive distillation, and pressure swing techniques, was proposed for improving the energy efficiency and reducing the cost of PGMEA production. Heat integration was applied to maximize the heat recovery of the process. All processes were simulated using the commercial simulator Aspen Plus V11. The economic and environmental parameters of the process alternative were assessed for a fair comparison with the conventional process. The results showed that heat integration of the optimal pressure swing-based reactive distillation and dividing wall column processes could reduce the energy requirement and TAC by 29.5%, and 20.8%, respectively, compared to that of the optimal conventional process. The improved design provides a strong basis for achieving more sustainable PGMEA production.

Highly efficient patterning technique for silver nanowire electrodes by electrospray deposition and its application to self-powered triboelectric tactile sensor

A patterned transparent electrode is a crucial component of state-of-the-art wearable devices and optoelectronic devices. However, most of the patterning methods using silver nanowires (AgNWs), which is one of the outstanding candidate materials for the transparent electrode, wasted a large amount of unused AgNWs during the patterning process. Here, we report a highly efficient patterning of AgNWs using electrospray deposition with grounded electrolyte solution (EDGE). During electrospray deposition, a patterned electrolyte solution collector attracted AgNWs by strong electrostatic attraction and selectively deposited them only on the patterned collector, minimizing AgNW deposited elsewhere. The enhanced patterning efficiency was verified through a comparison between the EDGE and conventional process by numerical simulation and experimental validation. As a result, despite the same electrospray deposition conditions for both cases except for the existence of the electrolyte solution collector, the coverage ratio of AgNWs fabricated by the EDGE process was at least six times higher than that of AgNWs produced by the conventional process. Furthermore, the EDGE process provided high design flexibility in terms of not only the material of the substrate, including a polymer and a ceramic but also the shape of the substrate, including a 2D flat and 3D curved surface. As an application of the EDGE process, a self-powered touch sensor exploiting the triboelectric effect was demonstrated. Thus, the EDGE process would be utilized in further application in wearable or implantable devices in the field of biomedicine, intelligent robots, and human–machine interface.

A Comprehensive IOT Based Farm Supervision

Coming from a flourishing nation like India, Farming and Agriculture is the main source of income the recent stats shows it is about still IOT and application of automation and handheld devices engages an imperative role towards greatness and amelioration of the country. During these present times there have been some previous old methods being used in farming which have many limitations and also very demanding in terms of human labour and have to go out for supervision and check for any intruders or alerts or even to spray water. These conventional process have recurring costs and more demanding sometimes false human alarms or even a false crop information as a result substantial damages are foreseen hence it increases the costs and burden over the farmer. It has been observed that in some cases where farmers are cooperating with the technological advancements which are available in the present era have benefited from its fruitful outcome. The aim of this paper is to develop a smart farm supervision and protection system which comes in handy for getting regular farm alerts on a smart phone the alerts can be changed in the form of a text message or even an automated phone call hence the additional feature of this model is the improvement of crop growth according to different seasons and weather. Keywords: Arduino, IOT, Soil Sensor, Gas Sensor, PIR Sensor.

Modeling Production Facilities Using Conventional Process Simulators and Data Validation and Reconciliation DVR Methodology

The use of conventional process simulators is commonplace for system design and is growing in use for online monitoring and optimization applications. While these simulators are extremely useful, additional value can be extracted by combining simulator predictions with field inputs from measurement devices such as flowmeters, pressure and temperature sensors. The statistical nature of inputs (e.g., measurement uncertainty) are typically not considered in the forward calculations performed by the simulators and so may lead to erroneous results if the actual raw measurement is in error or biased. A complementary modeling methodology is proposed to identify and correct measurement and process errors as an integral part of a robust simulation practice. The studied approach ensures best quality data for direct use in the process models and simulators for operations and process surveillance. From a design perspective, this approach also makes it possible to evaluate the impact of uncertainty of measured and unmeasured variables on CAPEX spend and optimize instrument / meter design. In this work, an extended statistical approach to process simulation is examined using Data Validation and Reconciliation, (DVR). The DVR methodology is compared to conventional non-statistical, deterministic process simulators. A key difference is that DVR uses any measured variable (inlet, outlet, or in between measurements), including its uncertainty, in the modelled process as an input, where only inlet measurement values are used by traditional simulators to estimate the values of all other measured and unmeasured variables. A walk through the DVR calculations and applications is done using several comparative case studies of a typical surface process facility. Examples are the simulation of commingled multistage oil and gas separation process, the validation of separators flowmeters and fluids samples, and the quantification of unmeasured variables along with their uncertainties. The studies demonstrate the added value from using redundancy from all available measurements in a process model based on the DVR method. Single points and data streaming field cases highlight the dependency and complementing roles of traditional simulators, and data validation provided by the DVR methodology; it is shown how robust measurement management strategies can be developed based on DVR's effective surveillance capabilities. Moreover, the cases demonstrate how DVR-based capex and opex improvements are derived from effective hardware selection using cost versus measurement precision trade-offs, soft measurements substitutes, and from condition-based maintenance strategies.

Multi-Objective Assessment of Heat Pump-Assisted Ethyl Acetate Production

Multi-objective (energy–economic–safety) assessment of ethyl acetate production involving a heat pump is presented in this paper. The heat pump is designed to intensify ethyl acetate separation and to reduce the total operating cost. Two ethyl acetate production pathways are upgraded using a heat pump, conventional process and reactive distillation column with a separation unit. Detailed process models including the heat pump environment have been compiled and optimized in the Aspen Plus software. Both benefits and drawbacks of including the heat pump in the processes are evaluated using three different points of view: process energy, economics, and safety. As a result, using a heat pump is highly recommended in both conventional process and reactive distillation column with a separation unit. As a higher level of process integration is achieved using a heat pump, economic aspects are improved; however, safety aspects deteriorate. The final decision on the suitability of using a heat pump depends on whether it is proposed for an existing plant, or a completely new plant is designed. In a new plant, the concept of a thermally coupled process (reactive distillation column with a stripper column) has been proven to be the most promising.

Process Design Guided by Life Cycle Assessment to Reduce Greenhouse Gas-Related Environmental Impacts of Food Processing

Food processing can generate large amounts of carbohydrate-rich waste that inevitably has environmental and social impacts. Meanwhile, certain heterotrophic marine microorganisms, including algae and thraustochytrids, have the potential to convert carbohydrate-rich substrates into oil-rich biomass over relatively short time frames. To assess the merits of this apparent synergy, an initial conceptual process was developed based on the use of raw potato processing waste as feed in an algal bioreactor to produce bio-oil for further use within the food industry. A practical flowsheet was established with a conventional 200 kL bioreactor whereby the unit processes were identified, the mass balance developed, and estimates made of the various material and energy demands. These inputs were used to develop a baseline life cycle assessment (LCA) model and to identify opportunities for reducing environmental impacts. With the functional unit (FU) being 1 tonne cooking oil, the baseline configuration had a greenhouse gas (GHG) footprint of 2.4 t CO2-e/FU, which is comparable to conventional process routes. More detailed LCA revealed that electricity for stirring the bioreactor contributed approximately 78% of the total GHG footprint. By adjusting the operating conditions, the most promising scenario produced 0.85 t CO2-e/FU—approximately four times less than the conventional process—and shows the potential advantages of applying LCA as a tool to develop and design a new production process.

Packaging Training for Traditional Emping Melinjo Crackers’ Producers in Menes Village, Pandeglang Banten

Menes village in Pandeglang, Banten has long been known as the largest Emping Melinjo cracker producing area in Indonesia. The production process is carried out using a conventional process with family management, where each head of the family produces small to medium quantities of the cracker and then the middlemen or wholesalers collects them. The Emping producer’s community has some limitation in packaging knowledge and technology that makes them receive only a small profit. We provide a material regarding the good packaging concept to improve the knowledge of community. In addition, the booklet material also equipped with various explanations about marketing strategies to help the community develop products and increase sales. After receiving the booklet material, some feedbacks from participants gathered to find the effectiveness of such method of knowledge delivering.

Recovery of lactose from aqueous solution by application of ultrasound through millichannel

Instead of direct disposal of whey, extraction of valuable products from it may reduce the environmental pollution. In the present study, the effect of ultrasound irradiation through millichannel on recovery of lactose was investigated. The ultrasonic baths of varying amplitude (20–40%) and frequency (25–35 kHz), two different configurations of millichannel i.e., coil and serpentine, were used to know their individual and combined effect on the lactose yield. Box-Behnken design was employed to examine the interactive effect of different operating conditions. The recovery of lactose was enhanced approximately by 5–53% and induction time was reduced by 1.79–1.85 times in comparison to the conventional process. The size of the lactose crystals was reduced from 139.5 to 42.486 μm at 40% amplitude and 49.879 μm at 35 kHz frequency. Optimized condition showed 63% yield of lactose at 3.6 supersaturation, 35 kHz frequency, and 45 min of sonication time.