Control Of Process Parameters Research Articles

Fuzzy assessment of process parameter interactions on warpage defect modeling in plastic injection molding

AbstractStudying the interactions among major plastic injection molding process parameters is necessary to understand how they collectively influence major defects such as warpage hence enabling optimization of the process for improved product quality. Existing process parameter interaction studies have used statistical approximations, which have limitations such as reduced predictive power and limited accuracy. To overcome these limitations, this study presents an alternative method of analysis of the interactions among process parameters based on fuzzy logic intelligent algorithm. Through computer aided engineering, factorial design of experiment and fuzzy logic modelling, the study evaluated the effects of major injection molding process parameter interactions on warpage. The results obtained indicated a general increase in warpage with increase in parameters such as melt temperature, mold temperature, injection pressure and cool time whereas an increase in parameters such as ambient temperature and packing pressure decreased warpage. Parameter interactions were obtained both statistically and based on fuzzy logic model and their significance tested through ANOVA. Ambient temperature (30.6%) and melt temperatures (18.7%) had the greatest effect on warpage all with P-values of 0.000 whereas cooling time (0.1%) had the least effect with P-value of 0.250. The largest two way interaction affecting warpage involved melt temperature and cooling time with a contribution of 12.2% whereas the largest three way interaction involves ambient temperature, packing pressure and injection pressure with a contribution of 2.7%. Also, despite cooling time having the least mains effect, most interaction terms with greater effect on warpage involved cooling time and melt temperature. The results from this study provides an insight on targeted injection molding process parameter control for defect minimization.

Research Status and Development Trend of Wire Arc Additive Manufacturing Technology for Aluminum Alloys

It is difficult for traditional aluminum alloy manufacturing technology to meet the requirements of large-scale and high-precision complex shape structural parts. Wire Arc additive manufacturing technology (WAAM) is an innovative production method that presents the unique advantages of high material utilization, a large degree of design freedom, fast prototyping speed, and low cast. As a result, WAAM is suitable for near-net forming of large-scale complex industrial production and has a wide range of applications in aerospace, automobile manufacturing, and marine engineering fields. In order to serve as a reference for the further development of WAAM technology, this paper provides an overview of the current developments in WAAM both from the digital control system and processing parameters in summary of the recent research progress. This work firstly summarized the principle of simulation layering and path planning and discussed the influence of relative technological parameters, such as current, wire feeding speed, welding speed, shielding gas, and so on. It can be seen that both the welding current and wire feeding speed are directly proportional to the heat input while the travel speed is inversely proportional to the heat input. This process regulation is an important means to improve the quality of deposited parts. This paper then summarized various methods including heat input, alloy composition, and heat treatment. The results showed that in the process of WAAM, it is necessary to control the appropriate heat input to achieve minimum heat accumulation and improve the performance of the deposited parts. To obtain higher mechanical properties (tensile strength has been increased by 28%–45%), aluminum matrix composites by WAAM have proved to be an effective method. The corresponding proper heat treatment can also increase the tensile strength of WAAM Al alloy by 104.3%. In addition, mechanical properties are always assessed to evaluate the quality of deposited parts. The mechanical properties including the tensile strength, yield strength, and hardness of the deposited parts under different processing conditions have been summarized to provide a reference for the quality evaluation of the deposition. Examples of industrial products fabricated by WAAM are also introduced. Finally, the application status of WAAM aluminum alloy is summarized and the corresponding future research direction is prospected.

Optimization of defects and high temperature corrosion resistance of laser cladding FeCrAl coatings: Influence of process parameters

To enhance the surface quality and high-temperature corrosion resistance of FeCrAl coatings further, a laser cladding technique was employed to deposit Fe-13Cr-7Al coatings on the surface of 12Cr1MoV heat-resistant steel. The study investigated the influence of laser power, scanning speed, and powder feed rate on the quality and high-temperature corrosion resistance of the Fe-13Cr-7Al coatings. Utilizing 25 orthogonal experiments, coatings were prepared and evaluated through high-temperature corrosion tests to explore the corrosion resistance and mechanisms microstructural analysis of the coatings, including their elemental distribution and corrosion mechanisms, was conducted using optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The optimal parameter combinations for laser cladding coatings were discussed. The results indicated that the coating quality was optimal within specific ranges of parameters (laser power 1875–2250 W, scanning speed 33–44 mm/s, powder feed rate 12–18 g/min); deviations outside these ranges led to issues such as incomplete coverage or coating detachment from the substrate. The structure of the laser cladded Fe-13Cr-7Al coatings consisted of columnar grains and α-Fe phase. In high-temperature corrosion testing, the coatings exhibited superior corrosion resistance compared to the substrate, with nearly twice the corrosion resistance variation observed under different process parameters. This study provides a scientific basis for optimizing laser cladding process parameters of Fe-13Cr-7Al coatings, demonstrating that precise control of process parameters significantly enhances the high-temperature corrosion resistance of coatings, thereby opening new possibilities for improving material performance in high-temperature applications.

Quantitative predictive model for screening optimal processing methods of Polygonati rhizoma

Polygonati rhizoma (Huangjing in Chinese) is a common clinical tonic with the traditional effects of tonifying Qi, nourishing Yin. However, the lack of precise control of processing parameters has led to the uneven quality of processed Huangjing. A prediction model using the CRITIC method optimizes processing by correlating method, component contents, and biological activity, ensuring consistent quality and efficacy.

Enhancing High-Alloy Steel Cutting with Abrasive Water Injection Jet (AWIJ) Technology: An Approach Using the Response Surface Methodology (RSM).

The common machining technologies for difficult-to-machine materials do not remarkably ensure acceptable efficiency and precision in bulk materials cutting. High-energy abrasive water injection jet (AWIJ) treatment can cut diverse materials, even multi-layer composites characterized by divergent properties, accurately cutting complex profiles and carrying them out in special circumstances, such as underwater locations or explosion hazard areas. This work reports research on the AWIJ machining quality performance of X22CrMoV12-1 high-alloy steel. The response surface method (RSM) was utilized in modeling. The most influencing process control parameters on cut kerf surface roughness-abrasive flow rate, pressure, and traverse speed-were tested. The result is a mathematical model of the process in the form of a three-variable polynomial. The key control parameter affecting the cut slot roughness turned out to be the traverse speed. In contrast, pressure has a less significant effect, and the abrasive mass flow rate has the slightest impact on the cut slot roughness. Under the optimal conditions determined as a result of the tests, the roughness of the intersection surface Sq does not exceed 2.3 μm. Based on the ANOVA, we confirmed that the model fits over 96% appropriately with the research outcomes. This method reduces the computations and sharply determines the optimum set of control parameters.

Microstructural homogenization and mechanical enhancement of aluminum matrix composites via multi-pass friction stir processing with SiC reinforcements

In this study, the environmentally friendly friction stir processing (FSP) method was utilized to fabricate surface composites employing technical aluminum matrix 1050-H14 and aluminum alloy 6060-T4 reinforced with silicon carbide (SiC) particles. Microstructure analysis, employing light and scanning electron microscopy, in conjunction with comprehensive evaluations of hardness, compressive strength, and tribological properties, was conducted to elucidate significant findings. The results reveal that an augmented number of FSP passes contributes to the homogenization of microstructure, leading to the alteration of SiC particle morphology and fragmentation. Consequently, this phenomenon results in improved mechanical properties, particularly noteworthy in the case of AA6060-T4 alloy matrix composites, and enhanced wear resistance. Both AA1050-SiC and AA6060-SiC composites demonstrate notable increases in compressive strength compared to their unreinforced matrices. Particularly noteworthy is the substantial enhancement in compressive strength observed in the AA6060-SiCp composite, escalating from 249 to 331 MPa (at ε = 0.1) and from 398 to 715 MPa (at ε = 0.2) with an increase in the number of FSP passes. Additionally, FSP’s ability to precisely control process parameters such as tool rotational speed and traverse speed allows for the optimization of mechanical properties and microstructural characteristics tailored to specific application requirements. This study highlights the potential of FSP in fabricating high-performance aluminum matrix composites with superior strength and wear resistance, positioning it as a viable technique for advanced engineering applications. The environmentally friendly nature of FSP, due to its solid-state operation and reduced energy consumption, further underscores its suitability for sustainable manufacturing practices.

The sulfurization precipitation and competition mechanisms of Cu(II) and As(V) in electrolyte towards efficient recovery of copper

The sulfide precipitation has been widely used to recover Cu(II) and remove As(V) in copper smelting electrolyte based on the Cu(II)-As(V) separation. However, the recovery efficiency was undesirable due to the inaccurate control of process parameters. It was necessary to investigate the process and mechanisms of sulfurization precipitation for accurate adjustment. Herein, under the single and mixed solutions of Cu(II) and As(V), the process parameters were investigated and the precipitation mechanisms were explored. And when using actual electrolytes, the corresponding sulfurization process and mechanisms were also revealed. The sulfurization results of single component solutions suggested that Cu(II) was rapidly precipitated in one step, but As(V) firstly generated intermediate, then it was gradually reduced to As(III) for a longer time and quickly precipitated in the form of amorphous. This phenomenon caused the significantly faster removal speed of Cu(II) than that of As(V). For their mixed solutions, only a small amount of As(V) were removed by adsorbing the precipitate at the low S/Cu molar ratios (RS/Cu), and Cu(II) and As(V) could achieve a good separation. Simultaneously, it revealed that the sulfidation competitive mechanisms were related to the solubility product constant (Ksp) and initial As(V) concentrations. In addition, the similar rules were also observed in actual electrolytes. Moreover, under RS/Cu = 1.2 and reaction time of 10 min, the arsenic content of sulfide precipitates in the actual electrolyte was less than 2.5%, which showed a great separation also could be obtained for the actual electrolyte. This result met the requirement of Cu(II) recovery. It can provide a good reference for adjusting sulfidation parameters in the actual process to achieve efficient copper recovery, reduce the production of hazardous waste containing arsenic at the source and realize the cleaner production of copper smelting system.

Critical factors for enhancing electrical performance in LaGdO3 capacitor

This study investigates the characteristics of metal/LaGdO3/Si capacitors using LaGdO3 as the dielectric material. LaGdO3 thin films were deposited using radio-frequency magnetron sputtering, and the effects of different process parameters, such as annealing temperature, electrode materials, and oxygen ratio, on the capacitance characteristics were investigated. Results showed that the presence of oxygen vacancies affects the dielectric constant, flat-band voltage, and breakdown field of LaGdO3 films. The optimal annealing temperature for the LaGdO3/Si stack was identified to be 600 °C, resulting in a dielectric constant of 13.9 and a flat-band voltage shift of 0.1 V. Introducing 10 % O2 during deposition effectively repaired oxygen vacancies in the film, while excessively high oxygen proportions resulted in a lower dielectric constant and a higher flat-band voltage shift. Moreover, the electrode material was found to affect the capacitance characteristics. The dielectric constants for Al/LaGdO3/Si, Ti/LaGdO3/Si, and Pt/Ti/LaGdO3/Si capacitors were 10.0, 16.3, and 17.3, respectively. The flat-band voltage shifts were −0.7, −0.42, and −0.03 V, with hysteresis voltages of 345, 117, and 32 mV, respectively. The Pt/Ti/LaGdO3/Si device exhibited the lowest oxide defect density, indicating superior interface quality and potentially enhanced device performance. In addition, the band diagrams for metal/LaGdO3/Si were constructed. This study demonstrates that oxygen vacancies and electrode materials are crucial factors influencing the capacitance characteristics of LaGdO3 films. The electrical properties of LaGdO3 films can be effectively improved by controlling process parameters, enhancing their potential for applications in capacitors and other electronic devices.

Analysis of Opaque, Peel-Off and Flex Rejects in the Electro Plating Process Using the Six Sigma Dmaic Method

The modern manufacturing industry is faced with increasing pressure to achieve high levels of quality while remaining efficient in its production processes. One of the challenges faced by PT. Plating services in electroplating production have a high reject rate, which can cause increased costs and have a negative impact on the company's reputation. PT. Jasa Plating in the production process still has a high number of rejects, the rejects are dominated by opaque, peel-off and spots. PT. Plating services for each production contribute a high average of 2% defects per day, DPMO 20,000 and Sigma value 3.55. Quite a few rejections resulted in a decrease in turnover and increased production costs. The costs incurred due to these rejects are an average of Rp. 1,268,593 per day and an average of Rp. 35,698,907 per month as a result of data collection from January – September 2023. In this business process, this is very detrimental for the company. The aim of this research is to suppress blurry rejects, peel-offs and spots in the electro plating process at PT. Plating Services. The steps taken in conducting research include: identification stage, data collection and processing, analysis and recommendations for improvement, and conclusions. The method used in this research is the Six Sigma DMAIC (Define, Measure, Analysis, Improvement, Control) method. Through analysis, you can find several factors that cause high reject rates, including operational errors, discrepancies in the production process, or raw material quality problems. After implementing the improvement plan, then evaluate the results. This can include re- measuring the DPMO, analysis of the resulting products to see a decrease in reject rates, and comparisons between before and after implementing improvements. From the comparison results after the repairs were carried out, the data before the repairs were carried out, the NG amount was 1.99%, the DPMO was 6,646 and the Sigma value was 3.98. After improvements to NG 0.84%, DPMO 2,791 sigma value 4.28. Factors causing high levels of blurring, peel-off and spots, namely insufficient or excessive cleaning of the metal surface before the electroplating process, can cause problems such as peel-off. Contamination of the electroplating solution by foreign materials can cause blurring and flecks in the final layer. Machinery or equipment that is not properly calibrated, or experiences wear and tear, can produce products that do not meet standards. Variations in temperature, time, or electric current in the electroplating process can produce inconsistent coatings. Carefully monitor and control process-parameters to ensure stability.

Food Rheology: An Introduction and Fundamentals Concepts

Food rheology is the study of the flow and deformation of food materials. It involves understanding the physical and mechanical properties of food, such as how it behaves when subjected to external forces or changes in temperature. Understanding food rheology is essential in various food processing and manufacturing industries as it helps in product development, quality control, and optimization of processing parameters. Some fundamental concepts in food rheology include as follows. Viscosity refers to a material’s resistance to flow. In food rheology, it is a measure of how easily a food material flows under an applied force. Food materials can exhibit different types of viscosity, such as Newtonian, pseudoplastic, dilatant, and viscoelastic behavior. Shear stress is the force per unit area applied to a food material, while the shear rate is the rate at which the food material deforms. In food rheology, these two variables are used to describe the flow behavior of food materials. Different food materials have different flow behaviors. Some foods, like water, exhibit Newtonian flow behavior, where the viscosity remains constant regardless of the applied shear rate. Other foods, like ketchup or mayonnaise, exhibit non-Newtonian flow behavior, where the viscosity changes with the shear rate. Elasticity refers to a material’s ability to regain its original shape after deformation. In food rheology, elasticity is important in determining the texture and shelf life of food products. Viscoelasticity refers to the combined properties of both viscosity and elasticity, where a material exhibits both liquid-like (viscous) and solid-like (elastic) behavior. Yield stress is the minimum amount of shear stress required to initiate flow in a material. Many food materials, such as gels or semisolid foods, exhibit yield stress where they behave like a solid until a certain stress threshold is reached. By understanding these fundamental concepts, food scientists and engineers can manipulate and control the rheological properties of food materials to achieve the desired texture, mouthfeel, and sensory attributes, as well as optimize processing conditions to improve the overall quality of food products.

Recent development of grain oriented electrical steel in Shougang steel

Shougang Steel has been pursuing the development of low iron loss and high permeability grain oriented electrical steels for more than a decade. Grain oriented electrical steel requires a very strong Goss {110}〈001〉 texture and as such a comprehensive control of thermo-mechanical processing parameters is required to achieve a strict control of texture. In this paper the key metallurgical problems associated with manufacture of grain oriented electrical steel are discussed, including the factors that affect both primary recrystallization and secondary recrystallization leading to the development of a strongly textured final sheet. The metallurgical factors affecting magnetostriction of electrical steels are also analyzed, and a technological approach for domain refinement, and its effect on magnetic properties, is described. Examples of magnetic properties under non-sinusoidal magnetization conditions are also reported and analyzed. As a result of continuous research and development efforts the high permeability low iron loss grain oriented electrical steel of thin gauge products of 0.2 mm/0.18 mm thickness have recently been developed to meet the requirements of the new China national standard of energy efficiency grades for power transformers.

Laser Machining at High ∼PW/cm2 Intensity and High Throughput

Laser machining by ultra-short (sub-ps) pulses at high intensity offers high precision, high throughput in terms of area or volume per unit time, and flexibility to adapt processing protocols to different materials on the same workpiece. Here, we consider the challenge of optimization for high throughput: how to use the maximum available laser power and larger focal spots for larger ablation volumes by implementing a fast scan. This implies the use of high-intensity pulses approaching ∼PW/cm2 at the threshold where tunneling ionization starts to contribute to overall ionization. A custom laser micromachining setup was developed and built to enable high speed, large-area processing, and easy system reconfiguration for different tasks. The main components include the laser, stages, scanners, control system, and software. Machining of metals such as Cu, Al, or stainless steel and fused silica surfaces at high fluence and high exposure doses at high scan speeds up to 3 m/s were tested for the fluence scaling of ablation volume, which was found to be linear. The largest material removal rate was 10 mm3/min for Cu and 20 mm3/min for Al at the maximum power 80 W (25 J/cm2 per pulse). Modified surfaces are color-classified for their appearance, which is dependent on surface roughness and chemical modification. Such color-coding can be used as a feedback parameter for industrial process control.

Optimizing the Rolling Process of Lightweight Materials

Conventional rolling is a plastic deformation process that uses compression between two rolls to reduce material thickness and produce sheet/plane geometries. This deformation process modifies the material structure by generating texture, reducing the grain size, and strengthening the material. The rolling process can enhance the strength and hardness of lightweight materials while still preserving their inherent lightness. Lightweight metals like magnesium alloys tend to lack mechanical strength and hardness in load-bearing applications. The general rolling process is controlled by the thickness reduction, velocity of the rolls, and temperature. When held at a constant thickness reduction, each pass through the rolls introduces an increase in strain hardening, which could ultimately result in cracking, spallation, and other defects. This study is designed to optimize the rolling process by evaluating the effects of the strain rate, rather than the thickness reduction, as a process control parameter.

Variable Layer Heights in Wire Arc Additive Manufacturing and WAAM Information Models

In Wire Arc Additive Manufacturing (WAAM), variable layer heights enable the non-parallel or non-planar slicing of parts. In researching variable layer heights, this paper documents printing strategies for a reference geometry whose key features are non-orthogonal growth and unsupported overhangs. The complexity of 3D printing with welding requires parameter optimization to control the deposition of molten material. Thus, 3D printing with welding requires the precise deposition of molten material. Currently, there is no standard solution for the customization of process parameters and intelligent collection of data from sensors. To address this gap in technology, this research develops an Internet of Things (IoT)-enabled, distributed communication protocol to control process parameters, synchronize commands, and integrate device data. To intelligently collect sensor information, this research creates a query-able database during pre-planning and production. This contributes to fundamental research in WAAM by documenting strategies for printing variable layer heights, the customization of control parameters, and the collection of data through a WAAM Information Model (WIM).

Impact of dry aging on quality parameters and microbiological safety of beef

The market of dry aged meat is rapidly increasing. However, few papers report the impact of specific dry aging parameters on quality and microbiological safety of dry aged meat. In this study we assessed the impact of a 90 days dry aging process, performed in a commercial cabinet, on the quality parameters and microbiological safety of Holstein beef loins. Meat pH, colour indexes and fatty acids were stable during the process. Main volatile compounds’ concentration increased over time. Any oxidation of protein residues was detected and the main proteins undergoing proteolytic degradation early in the process were myoglobin, myofibrillar constituents and sarcoplasmic enzymes. The most significant histological changes started at 30 days and striation impairment was observed, not related to oxidative processes. The total bacteria count increased without signs of spoilage, Enterobacteriaceae were not enumerated and few reads of foodborne pathogens were detected by shotgun metagenomic. These results show that when the dry aging process is performed in a dedicated cabinet under strictly controlled process parameters, the microbiological safety of the meat is preserved. Our study provides the first insights of dry aged Holstein loins, whose valorisation would certainly enhance the economic, social and environmental sustainability of the Parmigiano Reggiano food system.

A 2D equivalent linear inversion model of bedrock motions in a layered transversely isotropic half-space

Inversion is the process that evaluates input motion on the bedrock from surface motions, primarily for use as input excitation for site seismic response or soil-structure interaction analyses. The paper presents a two-dimensional (2D) equivalent linear inversion model for bedrock motion in a multi-layered transversely isotropic (TI) half-space. Based on the exact dynamic stiffness matrices of TI soil layer and bedrock half-space, an inversion objective function is established from both horizontal and vertical surface acceleration records, and the optimization method is adopted to update the control parameters for the inversion process. Moreover, an equivalent linear method is used to account for the TI soil nonlinearity, thus realizing the nonlinear inversion for bedrock motion and incident angle. The inversion procedure is verified by using a single-layered TI soil profile model with three different materials. The numerical results demonstrate that the bedrock motion and the incident angle in the TI medium can be accurately inversed according to the surface motions and the TI site characteristics, indicating that the inversion method can be used for reliable engineering applications in the TI medium.

A Pressure and Proximity Sensor Based on Laser-Induced Graphene.

Smart wearable devices are extensively utilized across diverse domains due to their inherent advantages of flexibility, portability, and real-time monitoring. Among these, flexible sensors demonstrate exceptional pliability and malleability, making them a prominent focus in wearable electronics research. However, the implementation of flexible wearable sensors often entails intricate and time-consuming processes, leading to high costs, which hinder the advancement of the entire field. Here, we report a pressure and proximity sensor based on oxidized laser-induced graphene (oxidized LIG) as a dielectric layer sandwiched by patterned LIG electrodes, which is characterized by high speed and cost-effectiveness. It is found that in the low-frequency range of fewer than 0.1 kHz, the relative dielectric constant of the oxidized LIG layer reaches an order of magnitude of 104. The pressure mode of this bimodal capacitive sensor is capable of detecting pressures within the range of 1.34 Pa to 800 Pa, with a response time of several hundred milliseconds. The proximity mode involves the application of stimulation using an acrylic probe, which demonstrates a detection range from 0.05 mm to 37.8 mm. Additionally, it has a rapid response time of approximately 100 ms, ensuring consistent signal variations throughout both the approach and withdrawal phases. The sensor fabrication method proposed in this project effectively minimizes expenses and accelerates the preparation cycle through precise control of laser processing parameters to shape the electrode-dielectric layer-electrode within a single substrate material. Based on their exceptional combined performance, our pressure and proximity sensors exhibit significant potential in practical applications such as motion monitoring and distance detection.

Experimental Investigations and Optimum Performance Evaluation of Wire-EDM Characteristics of Aluminium 6061-Magnesite Composites

It is essential to determine the most suitable machining method for magnesite-reinforced Aluminium 6061 composites, which possess excellent mechanical properties, especially notable tensile strength and hardness. The composites were produced using a stir-casting technique, incorporating reinforcements of lightly-calcined magnesite, dead burnt magnesite, and waste magnesite in weight fractions of 2.5%, 5%, and 7.5% within an aluminium 6061 matrix. Wire electrical discharge machining was employed to investigate the machining characteristics of these composites, using controllable process parameters such as cutting speed, pulse-on and pulse-off times, and the weight fraction of magnesites. Two performance indicators such as surface roughness and material removal rate were tested for various parameter combinations by central composite design. To comprehend the impact of the study parameters, contour charts were drawn. MRR increases at a high cutting speed of 2 mm/min when the pulse-on time changes from 120 μs to 125 μs. SR increases when the pulse-on times above 120 μs at all cutting speeds. High cutting speeds make high MRR irrespective of the weight fractions of reinforcement. High pulse-on times make the material melt more, which increases the material removal rate. Because specimen surface material erodes quickly and forms microcracks, high pulse-on time also results in high surface roughness. To optimize the WEDM machining conditions for each composite, hybrid SSO-DF and DFO-DF optimizers were developed by combining the desirability function with Salp-swarm optimization and Dragonfly optimization algorithms. The cutting speed of 2 mm/min and the pulse-on time of 114 μs produce the best performances on the composites.

Production of microalgae in wastewater and brackish waters: kinetic, lipid content, bioremediation and cost analysis studies

ABSTRACT The cultivation of microalgae in domestic wastewater offers a sustainable solution for the treatment of effluents, while at the same time producing biomass rich in lipids, potentially usable in the production of biofuels. Furthermore, reuse contributes to the treatment of wastewater, transforming a byproduct into a valuable source of nutrients for the production of microalgae biomass. This study involves the production of microalgae in open cultivation, using domestic effluents as a source of nutrients in brackish environments, to study the potential for biodiesel production. Intracellular lipids were between 17 and 20%. As for the bioremediation capacity, the results showed removal levels greater than 95% of nutrients, as well as bacterial and pollutant load reduction. The growth kinetics and the prediction of theoretical kinetic models through the use of computational tools show significant differences, due to the lack of control of process parameters in open cultivations. Based on the literature review and market research, a cost analysis for large-scale production in open crops was made, comparing with closed crops and finding lower costs in the implementation, maintenance and production of biodiesel in the production open.

High-speed X-ray imaging of droplet-powder interaction in binder jet additive manufacturing

Binder jetting (BJ) is an additive manufacturing process that uses a powder feedstock in a layer wise process to print parts by selectively depositing a liquid binder into the powder bed using inkjet technology. This study presents findings from high-speed synchrotron imaging of binder droplet-interaction during the BJ printing process. A custom laboratory-scale BJ test platform was used for testing which enabled control of relevant process parameters including powder material, print geometry, spacing between droplets, powder bed density, and powder moisture content. Powder ejection was observed above the powder bed surface and powder relocation due to droplet impact was observed below the powder bed surface. Powder relocation was observed to be sensitive to powder material, powder bed density, powder bed moisture, droplet spacing, and print geometry. Increasing powder bed density was found to increase particle ejection velocity but reduce the total number of particles ejected. Process parameters that increase binder / moisture content in the powder bed were found to reduce powder ejection. The number of ejected powder particles was reduced for lower droplet spacings. Both powder ejection and powder relocation below the powder bed were reduced by treating the surface of the powder bed with a water/triethylene glycol (TEG) mixture before printing. Results from this study help to build understanding of the physical mechanisms in the BJ printing process that may contribute to formation of defects observed in final parts.