Parameter Window Research Articles

Influence of Process Parameters on Flatness During Single-Track Laser Cladding

During the laser cladding process, poor flatness of the cladding track can cause the surface structure to be uneven or corrugated, affecting the geometrical accuracy of the workpiece. Adjusting process parameters is an effective way to achieve high cladding track flatness. This study established a mesoscale model of the laser cladding process for CoCrMoSi powder to simulate the formation of a single cladding track. Subsequently, the formation mechanism of cladding track flatness was revealed by analyzing the flow within the molten pool and the solidification behavior of the molten pool edge. The influences of laser power, scanning speed, and powder feeding rate on flatness were determined through simulations and physical experiments. Finally, a parameter window of flatness was established using simulation and experimental results. The window indicates that high flatness is achieved with a high scanning speed (v > 260 mm/min), high laser power (P > 2300 W), and low powder feed rate (Pf < 5.5 g/min). The accuracy of the numerical model was verified by comparing the simulated results with the experimental measurements.

Research on power metering method for nonlinear loads in power system based on improved S-transform

Abstract Traditional power metering algorithms are no longer suitable for new power systems to address the issue of distorted voltage and current waveforms caused by a growing number of nonlinear loads in modern power systems. The paper proposes a power-metering algorithm based on an Improved Stockwell Transform (IST). Based on the Stockwell transform, several parameters that can control the Gaussian window are introduced to improve the flexibility of the Gaussian window. Additionally, the inequality constraint based on the energy concentration measure is used to optimally select the best window parameters, enhancing the time–frequency domain analysis capability of the IST. The study uses IST to decompose and reconstruct the voltage and current fundamental characteristic signals and distortion characteristic signals in the power system. This provides good time resolution at low frequencies and good frequency-domain resolution at high frequencies. Power metering based on unsteady voltage and current is achieved by calculating the resulting fundamental and harmonic powers, respectively. The simulation results demonstrate that the IST-based power metering method has a higher level of accuracy than the existing metering methods.

Application of a customized 3D-printed osteotomy guide plate for tibial transverse transport

Enhance the efficiency of tibial transverse transport by employing customized 3D-printed osteotomy guide plates and striving to improve precision through CT evaluation for enhanced guide design. 17 diabetic foot patients were treated with the plate for tibial transverse transport. Preoperatively, we collected DICOM data from the affected tibia’s CT and designed the geometric parameters of the tibial cortical bone window. A customized 3D-printed osteotomy guide plate was then fabricated using 3D printing technology. Postoperative X-ray and CT evaluations, conducted at two and five weeks post-surgery, assessed five crucial geometric parameters of the bone window. Measurements included the distance from the upper edge of the tibial cortical bone window to the tibial plateau, the distance from the anterior edge of the tibial cortical bone window to the bone ridge, the height of the tibial cortical bone window, the center-to-center distance between the 4.0 mm diameter Schanz pin and the osteotomy Kirschner pin, and the center-to-center distance of the 4.0 mm diameter Schanz pin. These measured parameters were subsequently compared to the preoperative design parameters. The Clinical trial registration number is ChiCTR2400087174. CT measurements showed no significant differences (P > 0.05) from preoperative design parameters across the five evaluated aspects. The average osteotomy duration was 35 ± 15 min with no bone window fractures. The bone window aligned effectively with the tibial shaft, achieving complete incorporation after distraction. A 4 to 8-month postoperative follow-up confirmed full healing of the tibial surgical wound and diabetic foot wounds. Utilizing customized 3D-printed osteotomy guide plates in tibial transverse bone transport surgery enables accurate translation of preoperative virtual designs into real-time procedures, enhancing surgical efficiency and quality.

Process simulation and optimization of process parameters of single-pulse femtosecond laser processing Invar 36 alloy

Invar 36 alloy has an extremely low coefficient of thermal expansion and is suitable for preparing a fine metal mask (FMM) for the evaporation of silicon-based organic light emitting display microdisplays. The higher the resolution and the greater the number of pixels, the finer and more delicate the holes required. Femtosecond laser processing technology is an effective technical means for processing Invar 36 alloy FMM due to its characteristics of extremely short pulse width, extremely high pulse energy density, smaller heat-affected zone, and more regular machining edges. The femtosecond laser processing parameters directly affect temperature distribution and then affect the manufacturing quality and efficiency of Invar 36 alloy FMM. At present, femtosecond laser processing of Invar 36 alloy FMM is still in the exploration stage, and the processing mechanism and technology are not clear. In this paper, a simulation model of single-pulse femtosecond laser processing Invar 36 alloy is established based on the two-temperature equation. By comparing the ablation morphology of the simulation output with the experimental measurement results, the validity of the simulation model is verified and the processing mechanism is preliminarily explored. Based on the simulation model, the effects of femtosecond laser energy density, pulse duration, and spot diameter on the electron temperature field, lattice temperature field, and ablation morphology of the craters are explored. The process window of laser processing parameters is determined. A full-factor test is conducted. Take the minimum length of the heat-affected zone, the maximum depth of the ablation crater, and the minimum diameter of the ablation crater as three optimization objectives and obtain Pareto optimal solutions based on genetic algorithm. The optimization of single-pulse femtosecond laser drilling Invar 36 alloy is realized.

Optimizing the diamond wire sawing of polycrystalline silicon: An experimental approach

This study aims to determine the optimized cutting conditions for diamond wire sawing of polycrystalline silicon (poly-Si) wafers using a laboratory machine-tool that employs continuous cutting movement and reach cutting conditions similar to those in the industry. The experimental cutting was carried out following a central composite design, varying the wire cutting speed (vc) and feed rate (vf). A response surface methodology was employed to find the optimized cutting conditions for minimum surface roughness and subsurface micro-crack depth of the as-sawn poly-Si wafer. The results showed that the as-sawn poly-Si exhibited ductile scratches and fragile fractures in its surface morphology, with high vc and low vf resulting in a smooth surface. The response surfaces indicated that increasing vf led to increased Ra and Rq values, while increasing vc reduced them. Median micro-cracks were slightly inclined in the subsurface region, with the response surface indicating that their depth reduced with increasing vc and decreasing vf. The vf/vc ratio significantly affected surface integrity, with a lower vf/vc ratio being more suitable for reaching a smoother surface and shallower subsurface damage. The following material removal mechanisms was identified: optimal ductile region, ductile-to-brittle transition, brittle-ductile mixture region, and brittle region. Simulations using the response surface models indicated minimum values of Ra = 0.35 μm, Rq = 0.48 μm and SSD = 3.29 μm. Thus, this study provides a processing parameter window for diamond wire sawing of poly-Si wafers, which could be useful for both the photovoltaic and microelectronic industries.

Investigating the process parameter window for laser powder bed fusion of copper chrome zirconium

ABSTRACT Copper-based alloy UNS C18150 has become an attractive material for laser powder bed fusion (LPBF) processing. However, the complexity of LPBF mandates that unique process parameters be devised for each alloy as these are highly sensitive to material chemistry. This work aims to clarify the general boundaries of the process window for the most influential parameters alongside an exploration into the effects of scan strategy on the density. A series of statistical design of experiments were utilised to model density as a response and predict process parameters that would result in minimised residual porosity. Using optimised parameters, specimen with up to 99.1% of theoretical density were produced, and a window of process parameters was established that yielded similarly dense products. Post-build aging of the LPBF parts was also explored. Here, direct aging of the as-built product at 390°C for 100 h resulted in a peak hardness of 83.3 ± 0.6 HRB.

Postoperative Orbital Morphology Observations Following Fronto-Orbital Advancement and Cranial Vault Remodeling in Patients With Unilateral Coronal Synostosis.

Observations of preoperative and postoperative orbital morphology following fronto-orbital advancement and cranial vault remodeling (FOA and CVR) in patients with unilateral coronal synostosis (UCS). This retrospective cohort included patients diagnosed with unilateral coronal synostosis and treated with fronto-orbital advancement and cranial vault remodeling at the Children's Hospital of Fudan University. The orbital height, orbital width, and orbital volume were obtained from head 3-dimensional computed tomography of preoperation and postoperation. The DICOM data of CT were then imported into mimics research version 21.0. The authors measured OH and OW according to the bony landmarks, then reset the parameters of the soft tissue window, and conducted a 3-dimensional reconstruction of the orbital soft tissue to get OV. The preoperative and postoperative measurements of the intact side were compared with the affected side, respectively. Statistical analysis was performed using SPSS version 25.0 (Ρ=0.05). Twelve patients with UCS (5 male, 7 female) meeting criteria were included in the study. There were 4 patients with UCS on the left and 8 on the right. The average age at initial surgery was 19.50 months. Before the operation, the data of the intact side and the affected side were compared, respectively, and the difference was found to be significant in OH (Ρ=0.005) and OW (Ρ=0.005), while the OV (Ρ=0.106) was not statistically significant. After procedures of FOA and CVR, the data of the intact side and the affected side were compared, respectively, the significant difference was found in OV (Ρ=0.002), while not in OH (Ρ=0.060) or OW (Ρ=0.066). After undergoing the operation of FOA and CVR, the OH and OW of the ipsilateral and contralateral sides of patients with UCS were basically symmetrical, while the volume of the affected orbit was still relatively smaller.

Optimization design and interface characteristics research of high damping NiTi - Nickel-Aluminum Bronze functional gradient composite coating additively manufactured by high-speed laser-directed energy deposition

The near-equatomic NiTi shape memory alloy demonstrates exceptional damping performance due to its distinctive low-temperature self-cooperative martensitic internal friction. This study successfully fabricated NiTi-NAB (Nickel-Aluminium bronze shape memory alloy) functionally graded composite coatings with excellent metallurgical bonding between layers on Q235 steel substrates by designing an appropriate interlayer structure and employing the high-speed laser-directed energy deposition (LDED). Through comprehensive evaluation of the composite coating's performance and the numerical simulations of heat transfer within the molten pool, we elucidated the impact of process parameter levels on the microstructure and phase transformation characteristics of the NiTi alloy coating (NTC). The phase composition and phase interface characteristics of the NTC surface and bonding interface were analyzed using an electron probe microanalyzer and transmission electron microscopy, while dynamic thermomechanical analysis was employed to evaluate the damping performance of the NTC. The results indicate that an optimal parameter combination area still exists within the NTC-LDED process parameter window, even with equal laser energy density. Insufficient parameter levels can lead to an increase of micro-defects within the NTC, consequently causing a deterioration in both the cohesion and deformation resistance of the coating. Excessively high parameter levels can lead to significant element loss and residual stress, which in turn contributes to an increase in microcracks within the coating. A considerable quantity of reaction product mixture phases was formed at the interface between NTC and NAB, tending to align coherently with the NAB phase interface. The NTC, prepared with optimal process parameters, exhibits exceptional damping performance with a damping ratio of 0.498 at internal friction equilibrium, rendering it highly promising for applications in surface erosion protection for fluid machinery.

Ultrasonic Influence on Macrostructure and Mechanical Properties of Friction Stir Welded Joints of Al/Mg Sheets with 2 mm Thickness.

Friction stir welding (FSW) and ultrasonic vibration enhanced FSW (UVeFSW) experiments were conducted by using 6061-T6 Al alloy and AZ31B-H24 Mg alloy sheets of thickness 2 mm. The suitable process parameters windows were obtained for the butt joining of Al/Mg sheets. The effect of ultrasonic vibration on the macrostructure and mechanical properties of the dissimilar joints was studied. The results showed that the width of the weld nugget zone (WNZ) was enlarged to some extent and the hardness distribution in WNZ was more uniform in UVeFSW. In addition, the application of ultrasonic vibration effectively promoted the interpenetration degree of dissimilar materials in the WNZ so that the mechanical interlocking on the bonding interface of dissimilar Al/Mg materials was enhanced. The facture positions were changed from the bonding interface in FSW to the boundary between WNZ and the thermo-mechanical affected zone, and the ductile fracture zone was expanded. The highest ultimate tensile strength was 205 MPa at the process parameters set of 1200 rpm-50 mm/min in UVeFSW in this experiment. The average ultimate tensile strength of FSW/UVeFSW joints was 172.3 MPa and 184.4 MPa, respectively, and the average ultimate tensile strength was increased by 7.02% with the introduction of ultrasonic vibration.

Evaluating annual thermal discomfort time ratio of indoor occupants caused by solar radiation using a novel model

Thermal comfort of indoor occupants exposed to solar radiation is receiving widespread attention. Researchers have proposed many models to predict solar radiation and related indexes are used to evaluate thermal comfort. However, there are some limitations in the existing solar radiation models and evaluation indexes, such as only applying to sunny weather and requiring intensive modeling work. This study adopts a mathematical model called the improved HNU Solar Model and proposes a new evaluation index called the annual thermal discomfort time ratio by solar radiation (ratiotd, solar) to evaluate thermal comfort of indoor occupants exposed to solar radiation. The effects of different window parameters, i.e. window direction, window transmittance (Tsol) and window-to-wall ratio (WWR) on ratiotd, solar were also analyzed. The results show that the indoor area less than 2.0 m away from the window is easy to have solar discomfort. And for every 0.1 reduction in WWR, the average values of the four directions are reduced by 3% to 4%; and for every 0.1 reduction in Tsol, the ratiotd, solar values of four window directions are reduced by 4% to 6%. This study provides references for evaluating and optimizing the window design to create thermally comfortable environments for indoor occupants.

Structural modal parameter identification with the Power-Exponential window function

In view of the demand for accurate modal identification, and based on the characteristics of free vibration response, this paper introduces a new window function for Fourier Transform called the Power–Exponential window. The Power–Exponential window addresses the characteristics of free vibration response. It significantly enhances the accuracy of modal identification by improving the spectral properties of structural response. The proposed window function consists of exponential and power terms. This study focuses on the additional damping and frequency-domain differentiation introduced by the Power–Exponential window function. The exponential term weakens the boundary effect related to the time-domain truncation and suppresses the spectral leakage. Moreover, it can be interpreted in clear physical terms as providing additional damping to the signal. The power term in the window function corresponds to frequency domain differentiation, and it alleviates the spectral broadening that arises due to the additional damping. Furthermore, the analytical expression for the response spectrum confirms that the Power–Exponential window not only aligns the peak response frequency with the damped natural frequency but also establishes an explicit linear relationship between the actual structural damping ratio and the identification result from the half power bandwidth method. Both contribute to an improved accuracy and usability of certain frequency-domain modal identification methods. The influence of the Power–Exponential window parameters on modal parameter identification is analyzed, and the optimal selection principle and suggested parameter values are proposed. Finally, numerical simulations and an experimental frame model test are conducted to verify the accuracy and validity of modal parameter identification based on the Power–Exponential window.

Cosmology in R2-gravity: Effects of a higher derivative scalar condensate background

A well known extension of Einstein's General Relativity is the addition of an R2-term, which is free of ghost excitations and in the linearized framework, reduces to the conventional spin-2 graviton and an additional higher derivative scalar. According to Chakraborty and Ghosh (2022), the above scalar sector can sustain a Time Crystal-like minimum energy state, with non-trivial time dependence. Exploiting previous result that the scalar can sustain modes with periodic time dependence in its lowest energy, we consider this condensate as a source and study the Friedmann-Lemaître-Robertson-Walker (FLRW) cosmology in this background. The effect of the R2-term is interpreted as a back reaction. A remarkable consequence of the condensate is that, irrespective of open or close geometry of the Universe, for an appropriate choice of parameter window, the condensate can induce a decelerating phase before the accelerated expansion starts and again, in some cases, it can help to avoid the singularity in the deceleration parameter (that is present in conventional FLRW Cosmology).

Directed Self-Assembly by Sparsely Prepatterned Substrates with Self-Responsive Polymer Brushes.

The guiding pattern in the chemoepitaxially directed self-assembly (DSA) of block copolymers is often fabricated by periodically functionalizing homogeneously random copolymer brushes tethered on a substrate. The prepatterned copolymer brushes constitute a soft penetrable surface, and their two components can in principle locally segregate in response to the overlying self-assembly process of block copolymers. To reveal how the self-responsive behavior of the copolymer brushes affects the directing effect, we develop a dissipative particle dynamics model to explicitly include the prepatterned polymer brushes and implement it to simulate the DSA of a cylinder-forming diblock copolymer melt on the sparse pattern of polymer brushes. Through large-scale dynamic simulations, we identify the windows of the content of the random copolymer, the film thickness, and the diameter of the patterned spot, for the formation of perfectly ordered hexagonal patterns composed of perpendicular cylinders. Our dynamic simulations reveal that the random copolymer brushes grafted on the unpatterned area exhibit a remarkable self-responsive ability with respect to the self-assembly of the diblock copolymers overlying them, which may widen the effective window of the content of the random copolymer. Within the processing windows of these key parameters, defect-free patterns are successfully achieved both in simulations and in experiments with sizes as large as a few micrometers for 4-fold density multiplications. This work demonstrates that highly efficient computer simulations based on an effective model can provide helpful guidance for experiments to optimize the critical parameters and even may promote the application of DSA.

Embedding Bioprinting of Low Viscous, Photopolymerizable Blood-Based Bioinks in a Crystal Self-Healing Transparent Supporting Bath.

Protein-based hydrogels have great potential to be used as bioinks for biofabrication-driven tissue regeneration strategies due to their innate bioactivity. Nevertheless, their use as bioinks in conventional 3D bioprinting is impaired due to their intrinsic low viscosity. Using embedding bioprinting, a liquid bioink is printed within a support that physically holds the patterned filament. Inspired by the recognized microencapsulation technique complex coacervation, crystal self-healing embedding bioprinting (CLADDING) is introduced based on a highly transparent crystal supporting bath. The suitability of distinct classes of gelatins is evaluated (i.e., molecular weight distribution, isoelectric point, and ionic content), as well as the formation of gelatin-gum arabic microparticles as a function of pH, temperature, solvent, and mass ratios. Characterizing and controlling this parametric window resulted in high yields of support bath with ideal self-healing properties for interaction with protein-based bioinks. This support bath achieved transparency, which boosted light permeation within the bath. Bioprinted constructs fully composed of platelet lysates encapsulating a co-culture of human mesenchymal stromal cells and endothelial cells are obtained, demonstrating a high-dense cellular network with excellent cell viability and stability over a month. CLADDING broadens the spectrum of photocrosslinkable materials with extremely low viscosity that can now be bioprinted with sensitive cells without any additional support.

Performance Evaluation of Ultrasound Images Using Non-Local Means Algorithm with Adaptive Isotropic Search Window for Improved Detection of Salivary Gland Diseases: A Pilot Study.

Speckle noise in ultrasound images (UIs) significantly reduces the accuracy of disease diagnosis. The aim of this study was to quantitatively evaluate its feasibility in salivary gland ultrasound imaging by modeling the adaptive non-local means (NLM) algorithm. UIs were obtained using an open-source device provided by SonoSkills and FUJIFILM Healthcare Europe. The adaptive NLM algorithm automates optimization by modeling the isotropic search window, eliminating the need for manual configuration in conventional NLM methods. The coefficient of variation (COV), contrast-to-noise ratio (CNR), and edge rise distance (ERD) were used as quantitative evaluation parameters. UIs of the salivary glands revealed evident visualization of the internal echo shape of the malignant tumor and calcification line using the adaptive NLM algorithm. Improved COV and CNR results (approximately 4.62 and 2.15 times, respectively) compared with noisy images were achieved. Additionally, when the adaptive NLM algorithm was applied to the UIs of patients with salivary gland sialolithiasis, the noisy images and ERD values were calculated almost similarly. In conclusion, this study demonstrated the applicability of the adaptive NLM algorithm in optimizing search window parameters for salivary gland UIs.

Research on the Welding Process and Weld Formation in Multiple Solid-Flux Cored Wires Arc Hybrid Welding Process for Q960E Ultrahigh-Strength Steel.

This paper proposes a novel welding process for ultrahigh-strength steel. The effects of welding parameters on the welding process and weld formation were studied to obtain the optimal parameter window. It was found that the metal transfer modes of solid wires were primarily determined by electrical parameters, while flux-cored wires consistently exhibited multiple droplets per pulse. The one droplet per pulse possessed better welding stability and weld formation, whereas the short-circuiting transfer or one droplet multiple pulses easily caused abnormal arc ignition that decreased welding stability, which could easily lead to a "sawtooth-shaped" weld formation or weld offset towards one side with more spatters. Thus, the electrical parameters corresponding to one droplet per pulse were identified as the optimal parameter window. Furthermore, the weld zone (WZ) was predominantly composed of AF, and the heat-affected zone (HAZ) primarily consisted of TM and LM. Consequently, the welded joint still exhibited excellent mechanical properties, particularly toughness, despite higher welding heat input. The average tensile strength reached 928 MPa, and the impact absorbed energy at -40 °C for the WZ and HAZ were 54 J and 126 J, respectively. In addition, the application of triple-wire welding for ultrahigh-strength steel (UHSS) demonstrated a significant enhancement in post-weld deposition rate, with increases of 106% and 38% compared to single-wire and twin-wire welding techniques, respectively. This process not only utilized flux-cored wire to enhance the mechanical properties of joints but also achieved high deposition rate welding.

Annealing of bismuth telluride-based thick films by laser irradiation

Interest towards fabrication and post-processing of thermoelectric micro-sized devices has increased in recent years. The coupling of inexpensive deposition technologies and fast laser treatments on “as-deposited” films is an attractive solution for industrial scalability. In this work, we propose an approach never reported before in literature: the utilization of a ns-pulsed active fibre laser to directly densify p-type bismuth telluride-based thick films deposited on silicon. A feasibility study was conducted on the material to determine optimal laser parameters: the treated products were characterized, and it was concluded that a value of laser fluence as low as 4.5 mJ cm−2 is sufficient for densification. The material resulted cracked after the laser treatment, and it was demonstrated by SEM and profilometric analyses that shrinking occurs and sintering necks are formed; further, the arising of second phases after annealing was excluded by means of XRD analysis. Envisioning an industrial large area process with linear diode arrays source, a prediction of the laser power requirements to irradiate 1 mm2 films in selected conditions is presented. More extensive studies will be performed to determine a narrower parameters window and determine a relationship between the film thickness and laser parameters for future applications to as-deposited films.

Exploration of improved, roller-based spreading strategies for cohesive powders in additive manufacturing via coupled DEM-FEM simulations

Spreading of fine (D50 ≤20μm) powders into thin layers, such as required by layer-wise additive manufacturing (AM) processes, typically requires a mechanism such as a roller that provides adequate shear and compression to overcome the cohesive forces between particles. We explore improved, roller-based spreading strategies for highly cohesive powders using an integrated discrete element-finite element (DEM-FEM) framework. We find that optimal roller-based spreading, quantified by maximum packing density and uniformity of layer thickness, relies on a combination of surface friction of the roller and roller kinematics, e.g., counter-rotation or angular oscillation, that impart sufficient kinetic energy to break cohesive bonds between powder particles. However, excess rotation speed (or shear stress) can impart excessive kinetic energy to the powder causing ejection of particles and a non-uniform layer, suggesting the existence of a process window of optimal spreading parameters. Interestingly, the identified optimal parameters for both investigated roller kinematics, i.e., angular velocity for counter-rotation as well as angular frequency and amplitude for rotational oscillation, result in a very similar range of roller surface velocities, suggesting roller surface velocity as the critical kinematic parameter. When these conditions are chosen appropriately, layers with packing fractions beyond 50% are predicted for layer thicknesses as small as ∼2 times D90 of the exemplary cohesive powder, and the layer quality is robust with respect to substrate adhesion over a 10-fold range. The latter is an important consideration given the spatially varying substrate conditions in AM due to the combination of fused/bound and bare powder regions. As compared to counter-rotation, the proposed rotational oscillation kinematics are particularly attractive because they can overcome practical issues with mechanical runout of roller mechanisms (which limit their precision).

Optimization of process parameters of refractance window drying for aonla slices and comparison with other drying techniques.

Aonla is as a good source of antioxidants due to its high ascorbic acid and polyphenol contents. However, because of its high acidity and astringent taste, aonla is rarely consumed in its fresh form. As the constituents in aonla are heat sensitive, it is essential to find a suitable drying method for preservation. Therefore, refractance window drying (RWD) of aonla slices was studied as it has the potential of retaining heat-sensitive compounds. The effect of RWD process variables, namely water temperature (75, 82.5, 90 °C) and slice thickness (2, 4, 6 mm), on different quality parameters of dehydrated aonla was studied. Increasing water temperature resulted in significantly higher ascorbic acid content, titratable acidity and product temperature, while total phenolic content, free radical scavenging activity and moisture content decreased. With the exception of product temperature, higher slice thickness led to an increase in the values of all the parameters. At the optimized processing conditions of 83 °C water temperature and 4 mm slice thickness, the ascorbic acid content, total phenolic content, free radical scavenging activity, titratable acidity and moisture content values were found to be 269.03 mg (100 g)-1, 242.33 mg (100 g)-1, 87.11%, 3.62% and 4% respectively. The aonla slices subjected to RWD also possessed 4-6% higher phytochemical content than osmotically dried and hot-air-dried samples. This research highlights the effectiveness of RWD in preserving heat-sensitive compounds in food like aonla. The RW-dried slices had a smoother and more uniform microstructure compared to osmotically dried and hot-air-dried samples. © 2024 Society of Chemical Industry.

Relationship between deposition techniques and nanoparticle dispersions for flexible and printed electronics

Reverse micelles composed of polystyrene-b-poly(2-vinylpyiridine) have been used to synthesize nanoparticles composed of a wide range of materials, including metals, metal oxides, dielectrics, semiconductors perovskites, and core–shell nanoparticles. In this contribution, we examine the effect of deposition parameters on two-dimensional nanoparticle arrangements from colloidal solutions created using spin coating, dip coating, slot-die coating, and electrospray deposition. Despite the importance of achieving uniform coatings of ordered arrays of colloidal particles, previous studies have not thoroughly addressed this challenge. We show that the adjustability of interparticle distance depends on the deposition technique used and only occurs within the stable defect-free operating window of the deposition parameters. Establishing the specific operating window for each technique for a model system, we propose general guidelines that can be used for ensuring uniform coatings regardless of precursor loading and provide a guide for adjusting the deposition conditions when coating defects occur. We introduces a novel application of ellipsometry to evaluate interparticle spacing in nanoparticle arrays, enhancing our ability to assess film uniformity, allowing for quick and easy tuning of nanoparticle dispersion. Comparisons between spin, dip, and slot-die coating techniques reveal insights into the correlation between interparticle spacing and ordering, highlighting the importance of fitting relationships for various coating samples. This comprehensive comparison and discussion provide a roadmap for future research, outlining current challenges and trends and offering insights into achievable spacings and ordering in coating processes. This allows the classification of various deposition techniques with respect to their suitability for tailored applications.