Concave Surface Research Articles

Characterization of Secondary Vortices in Supercritical CO<sub>2</sub> Flow in a Channel Formed by a Concave Surface of a Pyramid

Characterization of Secondary Vortices in Supercritical CO<sub>2</sub> Flow in a Channel Formed by a Concave Surface of a Pyramid

Ritual connections: altars and installations of Late Bronze Age Cyprus and Iron Age Philistia as examples of continuity, change and nostalgia

The two-horned Philistine altar from the site of Tell es‑Safi/Gath is a hallmark find. Whilst this altar is the earliest of its kind in the Iron Age Levant, there are remarkable Late Bronze Age connections to the Cypriot horns of the consecration and slaughtering blocks/altars from Late Cypriot cult sites. The Philistine altar is hewn from stone and unworked on the back and rear sides, bearing resemblance to these Late Bronze Age Cypriote cult and ritual furnishings in both aesthetic design and possible use. Slaughtering blocks from Late Bronze Age Cyprus are rectangular stone blocks with shallow concave surfaces usually set into the floor. They have been historically interpreted as blocks for ritual slaughter of animals due to their proximity to faunal remains, however there is no concrete evidence which would suggest sacrificial use, such as blood or residue atop the surfaces. This paper will further investigate and illuminate these connections between the Levant and Cyprus as possible Philistine symbols of nostalgia, prestige and status emulating (or remembering) both the Aegean and Cyprus, a process which was prevalent up until around the 9th century BCE in Philistia and the wider Mediterranean. This paper will further analyze the Area D altar from Tell es‑Safi/Gath which may be an attempt at imitating the basic form of a Cypriot LC IIC/IIIA stepped altar with horns of consecration as a way of remembering parts of the Philistine Mediterranean past.

Encapsulation of hydroxycamptothecin within porous and hollow poly(L-lactide-co-ε-caprolactone) microspheres as a floating delivery system for intravesical instillation.

Intravesical instillation is an effective post-treatment for bladder cancer performed by delivering medications directly into the bladder to target the remaining cancer cells. The current study thus aimed to develop porous poly(L-lactide-co-ε-caprolactone) (PLCL) microspheres encapsulated with 10-hydroxycamptothecin (HCPT) via microfluidics to serve as a drug delivery system with persistent floating capacity and sustained HCPT-release property for intravesical instillation. A microfluidic device was designed to fabricate PLCL microspheres and encapsulate HCPT (HCPT-MS) within them; methanol and tridecane were introduced into an oil phase as a co-solvent and pore-forming agent, respectively, to regulate the floating ability of microspheres. The physicochemical properties of the resulting microspheres were characterized, and the floating behavior, release profile and anti-tumor effects of HCPT-MS were investigated. The obtained spherical HCPT-MS were 119.23 μm in size, monodisperse, and featured a porous concave surface and hollow structure. The encapsulation efficiency and drug loading of HCPT within HCPT-MS was around 67% and 4.9%, respectively. HCPT-MS exhibited impressive floating capabilities in water, PBS and artificial urine even in a simulated bladder dynamic environment. These microspheres remained afloat after being subjected to 90 repeated simulated urination processes. The sustained release of HCPT from these floating microspheres lasted for more than 10 days. The IC50 (half maximal inhibitory concentration) of HCPT-MS was calculated to be 52.14 μg mL-1. T24 cells (human bladder cancer cells) when cultured with HCPT-MS at such a concentration were severely inhibited, and the inhibition further enhanced with an increase in culture time. Hence, the feasibility of the current porous and floating HCPT-MS as a formulation for intravesical instillation to deliver medications into the bladder with sustained release and stability was thus substantiated.

Influence of spike anchors in the bond behaviour of FRCM systems applied on concave masonry substrates

One of the methods that can be used for strengthening masonry arch structures is through the use of composite systems bonded to the external surfaces, preferably to the intrados, such as textile reinforced mortar systems (FRCM, TRM, SRG etc). The application of such systems to the intrados allows the ultimate load to be increased while keeping the structure in service. The load increment depends on the performance of the bond between the matrix and the masonry substrate and between the matrix and the fabric, and also the radial detachment stresses (normal for the strengthening system) that are generated when applying this technology to concave surfaces must also be taken into account, as they have a negative effect on the load transfer mechanism. Spike anchors are generally used to reduce the negative effect of curvature in order to postpone the debonding process of the strengthening system. This paper presents the results obtained from a direct shear test campaign on curved masonry specimens strengthened with a fiber-reinforced cement-based matrix (FRCM) with pozzolanic reaction and a carbon fiber fabric. In particular, the effects of spike anchors on the load transfer mechanism between FRCM and the masonry substrate are shown. The use of such spike anchors produced, on average, a higher maximum ultimate force than specimens without spike anchors.

Adaptive Ultrasonic Full Matrix Capture Process for the Global Imaging of Complex Components with Curved Surfaces.

This work proposes a new global FD-RTM method to solve the problem of ultrasonic inspection of parts with complex geometric shapes. With this method, the frequency domain reverse time migration (FD-RTM) algorithm is used to adapt to the complex refraction of ultrasonic waves by the surface, while an interface solution algorithm based on tangent fitting is used to solve the interface position with high precision through the full matrix reception data. Based on high-precision interface information, a hybrid extrapolation algorithm and a situation-specific probe movement strategy are used to enable the probe to find the next sampling point according to the direction of the workpiece surface, allowing complex surface topography features to be identified without relying on the workpiece CAD drawing. This makes it possible to achieve the automated inspection of workpieces. To verify the proposed method's effectiveness, an aluminum alloy model with side-drilled holes (SDH) is used. The geometry of the model consists of multiple convex and concave surfaces. By comparing the local FD-RTM imaging with images synthesized using the entire scan path, it is shown that gFD-RTM improved the imaging performance. Compared with FD-RTM, the average signal-to-noise ratio of gFD-RTM was increased by 20%, and the array performance index (API) was reduced by 70%, indicating effective detection coverage.

Structural evidence for protein-protein interaction between the non-canonical methyl-CpG-binding domain of SETDB proteins and C11orf46

SETDB1 and SETDB2 mediate trimethylation of histone H3 lysine 9 (H3K9), an epigenetic hallmark of repressive chromatin. They contain a non-canonical methyl-CpG-binding domain (MBD) and bifurcated SET domain, implying interplay between H3K9 trimethylation and DNA methylation in SETDB functions. Here, we report the crystal structure of human SETDB2 MBD bound to the cysteine-rich domain of a zinc-binding protein, C11orf46. SETDB2 MBD comprises the conserved MBD core and a unique N-terminal extension. Although the MBD core has the conserved basic concave surface for DNA binding, it utilizes it for recognition of the cysteine-rich domain of C11orf46. This interaction involves the conserved arginine finger motif and the unique N-terminal extension of SETDB2 MBD, with a contribution from intermolecular β-sheet formation. Thus, the non-canonical MBD of SETDB1/2 seems to have lost methylated DNA-binding ability but gained a protein-protein interaction surface. Our findings provide insight into the molecular assembly of SETDB-associated repression complexes.

One-step Mo-doped praseodymium oxide construction of oxygen vacancies for efficient photothermal co-catalytic Suzuki coupling reaction

The photothermal synergistic catalytic Suzuki coupling reaction is a sustainable approach to generate biphenyl compounds using clean and renewable solar energy. The one-step Mo doping engineering resulted in more oxygen vacancies and surface free electrons on the PrxOy surface of hollow porous nanotube morphology. Subsequently, energy-efficient and environmentally friendly catalysts (PdO/PrxOy−Moz) with higher catalytic activity were successfully prepared by deposition precipitation method. The concave and convex surfaces of the carriers could better capture visible light. Mo doping greatly extends the visible absorption range of PrxOy. More OVs defects in the PrxOy−Moz carrier inhibit the complexation of photogenerated electron-hole pairs and induce the transfer of free and photogenerated electrons to Pd. The electron-rich Pd accelerated the oxidative addition step of aryl halides to aryl phenylboronic acids, which greatly improved the catalytic performance of PdO/PrxOy−Moz in the photothermal co-catalytic Suzuki coupling reaction.

Comparing densely calculated facial soft tissue depths for craniofacial reconstruction: Euclidean vs. perpendicular distances

ABSTRACT For surgical craniofacial reconstruction, preoperative planning may be limited by missing 3D skeletal geometry. In forensic sciences, ‘reconstruction’ models the 3D facial structure from skull geometries using soft-tissue depth mapping. This work investigates ‘reverse engineering’ the forensics’ TD Morpheus model to infer the bony shape from 3D facial surfaces by subtracting tissue depths inwards along the normal vectors. This approach using Euclidean tissue depths successfully estimated the upper and outermost skeletal regions (i.e. frontal, zygoma, and nasal bones) in 24 head CT scans, but concave skeletal surfaces were inaccurately evaluated where the face is convex yielding misshapen anatomy around the orbits and zygomatic arches. A perpendicular tissue depth algorithm was developed to probe inwards along the face’s normal vectors until contacting bone, demonstrating superior performance to the Euclidean depth approach. Accurate regional tissue depths achievable with this approach may provide a useful bridge to connect the 3D face and underlying skull geometry, with the potential for application in craniofacial reconstruction.

The effect of the vibratory surface finishing process on surface integrity and dimensional deviation of selective laser melted parts

Selective laser melting (SLM) is an additive manufacturing method used in aerospace and biomedical industries due to its ability to fabricate complex geometries with excellent mechanical properties. However, achieving the desired surface quality can be challenging. Vibratory surface finishing (VSF) is a widely used post-processing technique in engineering industries to improve surface quality. In this study, SLM-produced stainless steel 316L samples with different geometries, including samples with flat surfaces (SFS), samples with bulged surfaces (SBS), and samples with concave surfaces (SCS), were processed using triangular, spherical, and cylindrical media shapes for different processing times. The research aimed to analyze the surface integrity and dimensional deviation of each sample type after VSF. Our study employed a full factorial design of experiments (DoE) to assess the influences on the surface integrity, dimensional deviations, surface morphology, and surface hardness of 316L stainless steel parts produced via SLM. After VSF, the average Ra value was reduced by 75% after 9 h of operation, achieving the lowest Ra value (1.68 μm) using spherical media. Spherical media also reduced Ra values on concave surfaces by approximately 71%, with a reduction from 14.55 to 4.15 μm. The study found that VSF helps improve surface roughness while affecting the components’ average dimensional deviation and subsurface microhardness. The microhardness measurement showed a value of 220 HV, which was approximately 6.4% higher than the bulk hardness.

3D Imaging of PEMFC Electrode Microstructure by Electron Tomography and 3D FIB/SEM

Scanning and transmission electron microscopies (SEM and TEM) are two imaging techniques widely used in the study of PEMFC electrode microstructure. They have played a significant role in the improvement of electrode components and the understanding of their main degradation mechanisms. However, the currently available description of the electrode microstructure does not allow yet to unambiguously identify the key microstructural factors that limit gas and proton transport within the electrode. These factors are crucial as they control the performance of the PEMFC, especially at high current density, and are therefore the subject of numerous studies, using either fine electrochemical measurements or modeling approaches.The objective of our work is to provide an improved description of the electrode microstructure by giving quantitative information on its porosity at different scales as well as on the ionomer distribution. For this purpose, we develop 3D characterization techniques applied to the PEMFC electrodes such as electron tomography and 3D FIB/SEM.The studied cathode electrode was prepared using TEC10E50E catalyst from Tanaka that is 50 wt % loading of Pt deposited on high-specific area carbon (HSAC), and Nafion D2020. The Pt loading of the electrode is 0.2 mgPtcm-2 and the ionomer/carbon ratio is 0.8.As a first step, electron tomography analyses were performed on the Pt/HSAC powder to determine the distribution of Pt nanoparticles (NPs) which can be located either on the carbon surface (outer NPs) or inside the carbon porosity (inner NPs)[1-3]. Our strategy is to record tilt image series by using two annular detectors: i) a high angle annular detector avoiding Pt NP diffraction contrast for the 3D image reconstruction of Pt NPs (without diffraction artifact) and ii) a lower angle annular detector that enhances carbon contrast for the 3D image reconstruction of the carbon phase. These two segmented images were then combined (Figure 1), allowing the calculation of the NP size histogram but also of the volume and the surface area of the two NP populations (inner and outer NPs).On the second step, the porosity of the electrode was analyzed by 3D FIB/SEM. A volume of around 10 X 10 x 5 μm3 was imaged with a cubic voxel size of 5 × 5 × 5 nm3. The solid phase (carbon, Pt NPs and ionomer) segmentation was based on a composite image created from two electron detectors (secondary and backscattered electrons) and using a machine learning software. Quantitative data such as the total porosity, the pore size distribution or the agglomerate size distribution of the solid phase were extracted from this volume. Figure 2a shows a 2D slice of this segmented volume where the solid phase is in black and the porosity in white.In order to analyze the electrode porosity with a higher spatial resolution, electron tomography experiment was also performed on a 150 nm thick slice of the electrode cut by ultramicrotomy after being embedded in an epoxy resin. The tilt image series were recorded with a pixel size of 0.5 nm and a field of view of 2 x 2 µm2. The 2D slice of the reconstructed volume (Figure 2b) shows that the largest solid agglomerates detected on the 3D FIB/SEM image can be identified as an agglomeration of numerous carbon particles. The challenge now is to quantify the porosity created between these carbon particles and to determine how many Pt NPs are located in these large agglomerates.Finally, the distribution of the ionomer was analyzed within the electrode similarly to [4]. For this analysis, a 150 nm slice of the electrode was cut by cryo-ultramicrotomy without embedding in epoxy resin as described in [5]. TEM images show that the ionomer is not homogeneously distributed on the surface of the entire carbon particles but is often observed in the concave surface created between the carbon particles (Figure 3). These observations suggest a ionomer distribution in agreement with the heterogeneous ionomer coating model proposed by Inoue et al. [6]. We also suggest that a part of the ionomer could be localized in the small pores located inside the large carbon agglomerates described in the previous paragraph. This could explain why the ionomer is so difficult to detect on TEM images. This work has been done in the frame of the FURTHER-FC project. This project has received funding from the Fuel Cells and Hydrogen 2 Joint Undertaking (now Clean Hydrogen Partnership) under Grant Agreement No 875025. This Joint Undertaking receives support from the European Union’s Horizon 2020 Research and Innovation program, Hydrogen Europe and Hydrogen Europe Research. Figure 1

Effect of multiple protrusions on thermal performance of jet impingement with smooth concave surface

Effect of multiple protrusions on thermal performance of jet impingement with smooth concave surface

Accelerated Confined Mass Transfer of MoS2 1D Nanotube in Photo-Assisted Metal-Air Batteries.

Applying solar energy into energy storage battery systems is challenging in achieving green and sustainable development, however, the efficient progress of photo-assisted metal-air batteries is restricted by the rapid recombination of photogenerated electrons and holes upon the photocathode. Herein, a 1D-ordered MoS2 nanotube (MoS2-ONT) with confined mass transfer can be used to extend the lifetime of photogenerated carriers, which is capable of overcoming the challenge of rapid recombination of electron and holes. The tubular confined space cannot only promote the orderly separation and migration of charge carriers but also realize the accumulation of charge and the rapid activation of oxygen molecules. The concave surface of MoS2-ONT can improve the carrier separation ability and prolong the carrier lifetime. Meanwhile, the ordered tubular confined space can effectively realize the rapid transfer of charge, ion, and oxygen. Under light irradiation, a fast oxygen reduction reaction kinetics of 70mWcm-2 for photo-assisted Zn-air battery is achieved, which is the highest value reported for photo-assisted Zn-air batteries. Significantly, the photo-assisted Li-O2 battery based on MoS2-ONT also shows superior rate capability and other exciting battery performance. This work shows the universality of the confined carrier separation strategy in photo-assisted metal-air batteries.

Numerical analysis of concentric jet impingement heat transfer to the concave surface of the cone

This work includes numerical investigation of concentric jet impingement heat transfer to the concave surface of 30° apex angle conical surface. Heat transfer results are represented in terms of nondimensional heat transfer coefficient Nusselt number along the slant edge of the cone. Turbulence intensity, static pressure distribution along slant edge of the cone, and velocity contours in the domain are also presented for a detail understanding of the flow behavior. Different geometrical parameters like diameter of pipe (10 mm, 14 mm, and 20 mm) and L/D (4.25, 6.25, and 10.25) are considered for heat transfer analysis. Jet Reynolds number is varied between 25000 and 82000 for each diameter and L/D case. It is observed that Nusselt number value is minimum close to the apex of the cone due to stagnation region, then increases with increase in the distance from the apex of the cone and becomes maximum due to maxima in the turbulence intensity and decreases with increases in the distance. Nusselt number value decreases with increase in the L/D. Nusselt number increases with increase in the jet Reynolds number. There is an insignificant influence of the diameter of pipe on Nusselt number for identical jet Reynolds number and L/D.

Long‐cycling Zinc Metal Anodes Enabled by an In Situ Constructed ZnO Coating Layer

AbstractSuppressing dendrite growth in zinc (Zn) anodes for aqueous Zn batteries remains a significant challenge. Modifying the Zn/electrolyte interface stands out as one of the most promising strategies to tackle this problem. In this study, a nanometer‐thick ZnO coating layer with a uniform concave surface geometry is in situ constructed to modify the Zn anode for the first time. The chemical bond formed between the ZnO layer and the Zn foil enhances the structural stability of the synthesized ZnO modified‐Zn anode. Finite element simulations indicate that the ZnO coating layer facilitates uniform electric field distribution and zinc flux on the Zn electrode. In situ optical observations unveil how the modification interface regulates zinc plating behaviors on the Zn anode. Impressively, the symmetrical ZnO‐Zn cell displays a remarkable cycling stability of 1765 h at a current density of 5 mA cm−2 with an areal capacity of 1 mAh cm−2. Even when subjected to a very high current density of 50 mA cm−2, it maintains stable operation over 3800 cycles. This success highlights the immense application potential of the rationally tailored ZnO‐Zn anode.

The behavior of surface nanobubbles on different substrates in electrochemistry

In the gas evolution reaction, surface nanobubbles generally nucleate heterogeneously and grow on the electrode. It is important to understand the relationship between the evolution of nanobubbles and the structure of the electrode surface. In this work, we used molecular dynamics simulation to study the effect of different surface structures on the nucleation and growth of nanobubbles. The simulation shows that the current in the induction stage is proportional to the conversion frequency. The reaction rate in the nucleation and growth stages increases with the increase of the conversion frequency. During the stable stage, the reaction rate is higher on the plane than on the concave surface, independent of the conversion frequency. The gas influx at the contact line in the dynamic equilibrium model of nanobubbles on the electrode surface is reconsidered. The gas flux into the nanobubbles at the concave surface during the stable stage is smaller and the contact angle is smaller compared to the plane. The concave substrate restricts the flow of water molecules to the electrode surface's contact line.

Plate-curving cell culture as a model for assessing curvature-induced cellular responses during neural tube morphogenesis

ABSTRACT Neurulation is an important shape-transforming event during embryonic development where a flat neural plate is converted into a neural tube. Failure in this morphogenetic process accounts for one of the most common birth defects. Mechanical biology has provided key insights into neural tube formation and curvature among many physical properties that are eliciting attention. However, the lack of a proper model to study the effect of curvature has limited the potential to reveal its role in neurulation. In this study, we introduce a novel cell culture method called plate-curving cell culture where a polydimethylsiloxane (PDMS) plate of desired physical properties is curved in either a concave or convex form while the human pluripotent stem cell culture induced to have early neural plate identity is placed on top of its surface. With this method, we observed the elongation of cell colony morphology, as well as the perpendicular alignment of the cell division axis in the concave surface; the oriented cell division does not seem to explain the colony elongation. Transcriptome comparison in search of alternate possibilities suggested selectively altered pathways in the concave surface culture. Our new method is widely available, easy-to-use and culture-friendly, facilitating future mechanobiological studies of neurulation.

Complex-Shape Solid-State Photonic Droplets Prepared via Phase Separation and Microfluidics.

Complex-shape solid-state cholesteric liquid crystal (CLCsolid) droplets were prepared via solvent removal, phase separation, and photopolymerization of uniformly sized reactive CLC (rCLC)/fluorocarbon oil (FCO)/dichloromethane (solvent) droplets produced via a microfluidic method. The interfacial energies between rCLC and FCO, rCLC and water, and FCO and water of a rCLC/FCO droplet in an aqueous solution were precisely controlled through the specified surfactants. The shape of the rCLC/FCO droplet was strongly dependent on the balances among these interfacial energies, enabling the preparation of complex-shape droplets through the controlled concentration of the used surfactants. The complex-shape rCLC/FCO droplets showed photonic patterns consisting of a central reflection from a convex surface, cross-communication from a convex surface between adjacent particles, a photonic reflection band from the outer upward-facing concave surface, and total internal reflection from the inner upward-facing surface. Complex-shape CLCsolid particles obtained after photopolymerization and extraction of a nonreactive chiral dopant and FCO showed photonic patterns similar to those before photopolymerization without much deterioration of the photonic structure. These complex patterns make CLCsolid and rCLC/FCO droplets promising anticounterfeiting materials.

Cu Tailoring Pt Enables Branched-Structured Electrocatalysts with High Concave Surface Curvature Toward Efficient Methanol Oxidation.

Surface engineering offers opportunities for the design and synthesis of Pt-based alloyed electrocatalysts with high mass activity and resistance to CO poisoning, which is of great significance for methanol electrooxidation. Surface curvature regulation may endow electrocatalysts with enhanced atomic utilization and abundance of unsaturated atoms; however, a reliable synthetic route for controlled construction of tailorable curved surface is still lacking. Here, a colloidal-chemical method to synthesize two types of PtCu branched-structured electrocatalysts, where the concave curvature can be customized is reported. These studies show that, among various synthesis parameters, the concentration of CuCl2·2H2O precursor is the key factor in manipulating the reaction kinetics and determining the concave surface curvature. Significantly, PtCu branched nanocrystals with long and sharp arms (PtCu BNCs-L), featuring a high concave surface curvature, exhibit remarkable activity and stability toward MOR, which is mainly attributed to advanced features of a highly concave surface and the synergistically bifunctional effect from introduced oxophilic Cu metal. In situ Raman spectroscopy and CO stripping test demonstrates weakened CO adsorption and accelerated CO removal on PtCu BNCs-L. This work highlights the importance of surface curvature, opening up an appealing route for the design and synthesis of advanced electrocatalysts with well-defined surface configurations.

Investigation on local monitoring paradigms of in-situ conformally fabricated piezopolymer coating-based array transducers: Ultrasonic bulk waves and local ultrasonic resonances

Realistic structures with complex features have been intricate challenges for structural health monitoring (SHM) with permanently installed transducers. Poor conformability of conventional rigid and brittle piezoceramic wafers is a typical issue of applications on surfaces with complex geometry. Moreover, the accompanied high-stress concentration requires high-sensitivity defect detection which is difficult to achieve with large-area monitoring methods like lamb waves at tens to hundreds kHz. Previously, in-situ conformally fabricated piezopolymer coating-based array transducers (PCATs) have been developed to build large-area, lightweight, flexible, and tunable Lamb wave networks. In this study, two novel local monitoring methods were investigated with PCATs, namely ultrasonic bulk wave array inspection and local ultrasonic resonance spectroscopy. For thick structures, ultrasonic bulk waves were generated and detected by PCATs with broadband operating frequencies (1–10 MHz) and flexible array parameters. Simulation tools and imaging algorithms of array inspection in non-destructive testing (NDT) were well implemented based on the analogous directivity pattern and normal-pressure coupling mechanism. As proof of concept, PCATs were applied on example structures with flat, concave, and convex surfaces for internal defect imaging. For thin-walled and/or multilayer structures, PCATs were used to measure local ultrasonic resonances, comparable to conventional non-contact methods. With negligible influence on local mechanical properties and broadband frequency response, multiple resonance peaks from 0 to 25 MHz were identified as zero group velocity (ZGV) Lamb modes and thickness vibration modes of host structures, which can be used as damage indices for local monitoring of corrosion, delamination, stiffness degradation, etc. Through embracing advanced NDT techniques with PCATs, high-sensitivity and quantitative local monitoring could be achieved with conformal networks, offering the possibility to integrate with large-area monitoring as multi-scale SHM for complex structures.

Formation mechanisms and control strategies of metallurgical defects and microstructures during laser powder bed fusion of AlSi10Mg lattice structures

Lattice structures fabricated using laser powder bed fusion (LPBF) are pivotal for lightweight design. However, their small dimensions and intricate geometry intensify the likelihood of defect formation, such as lack of fusion (LOF), near-spherical pores, and microstructural coarsening. In this study, it was observed that the central region of lattice struts was especially susceptible to large-sized LOF in conjunction with the concave top surfaces due to frequent laser jumps. Furthermore, overheating during turnaround was identified as a contributor to excessive pores and surface bulging. Intriguingly, a unique layered melt mode emerged, characterized by coarse columnar grains exceeding 30 μm in size. A novel approach is proposed to reduce defects, refine grains, and enhance hardness during LPBF process, utilizing low laser power and a continuous scanning strategy. Using this manipulation strategy on typical lattice structures, porosity levels decreased by over 40 %. Ultimately, this research offers invaluable insights into refining printing conditions for lattice structures.