Pool Volume Research Articles

A metallurgical phase transformation framework applied to SLM additive manufacturing processes

While significant progress has been made in the last few years, the reliability of Additively Manufactured (AM) parts is often less than desirable as they suffer from manufacturing defects and hence subpar strength and fatigue life. To address this challenge, numerical methods are sought to provide insight into the process and help accelerate progress in raising the quality of AM parts. In metal AM applications, assessing the amount of unfused powder, melt pool volumes, and metallurgical phase transformations is often of interest. In this work, we introduce a generic framework for assessing metallurgical phase transformations, building on a previously-developed general simulation framework for predicting temperature evolution, distortions, and residual stresses. Experimental work was conducted to validate numerical predictions and included temperature measurements, EBSD/XRD microstructural examinations. Additional test data from the published literature was used to validate melt pool sizes and unfused powder predictions. We conclude that the continuum-level internal state variable approach proposed here can be calibrated with a reasonable amount of effort and can be used directly to link processing conditions to microstructural features. Upcoming work investigates the influence of microstructure features on mechanical performance to address the process-structure-property-performance relationship in SLM additive manufacturing.

Quantitative MRI assessment of mucinous rectal adenocarcinoma to predict tumour response after neoadjuvant therapy

To evaluate the association between volume ratio of the mucus pool and tumour response to neoadjuvant therapy in patients with mucinous rectal adenocarcinoma (MC). The volume of the mucus pool and whole tumour on pre-therapeutic T2-weighted magnetic resonance imaging (MRI) of 79 patients was measured using semi-automated software. Mucus pool volume, whole tumour volume, and volume ratio of the mucus pool were compared to tumour response and tumour and lymph node downstaging after neoadjuvant therapy using receiver operating characteristic curve (ROC) and multivariate logistic regression analysis. After preoperative neoadjuvant therapy of rectal MC, the rate of pathological complete response, tumour downstaging, tumour response, and lymph node downstaging were 9%, 48%, 39% and 58%, respectively. Tumour downstaging more frequently occurred in patients with a mucus pool volume ratio of at least 68.3% (area under the ROC curve [AUC], 0.793 with 95% confidence interval [CI]: 0.693-0.893), and at least 62.1% for identifying those with a higher tumour response with an AUC of 0.739 (95% CI: 0.630-0.847). A higher volume ratio of mucus pool in patients with MC may be related to more tumour downstaging and therapy response, and therefore, could serve as an independent imaging biomarker for predicting tumour response to neoadjuvant therapy.

Prediction of lab and manufacturing scale chromatography performance using mini-columns and mechanistic modeling

Chromatography is a cornerstone of biologics downstream purification processes, and there is an ever increasing demand for improved speed and efficiency in process development. Scale-down models are used in process development to optimize operating conditions and study process robustness while expending as little time and material as possible. The advent of automated liquid handling systems and miniature columns has taken the efficiency of process development to another level by allowing up to eight column runs in parallel with column volumes under 1 ml. As expected, results between these miniature columns and typical lab/manufacturing scale columns can deviate due to scale dependent and/or configuration dependent differences. Regulatory guidelines do not require an exact match in scale-down and large scale data, but do require that small scale models account for scale effects, be representative of the commercial process, and be scientifically justified. Therefore, it is important to gain insight into what causes differences between scales and account for them during development. Mechanistic models can be used to understand the physics of the process (fluid flow, mass transfer, etc.) as a function of scale, and provide explanation for deviations that may be observed. We have used mechanistic modeling to study the factors leading to differences in pool sizes observed between scales, and to make predictions on lab scale pool sizes from miniature column data. Results indicate that changes in mass transfer parameters, specifically axial dispersion, between scales leads to the observed differences in pool size. Additionally, we have studied the effect of system differences between automated liquid handling systems and conventional preparative chromatography systems on elution pool volume. This work provides new insight into the fundamental differences observed between scales and overcomes the challenge of enabling the use of miniature column chromatography as a scale-down model for process characterization.

Experimental study on the smoke temperature distribution alongside the lining in tunnel fires

Tunnel fire temperature is a key factor for tunnel structural safety and evacuation. This study aimed to investigate the smoke temperature distribution alongside the lining across the section and effects of pool sizes and fuels on it through a series of small-scale experiments. The results showed the heat release rates of diesel were significantly lower than gasoline?s when they had the same pool size and volume. Nevertheless, the duration of diesel combustion increased obviously. As a result, the maximum smoke temperature under the ceiling for gasoline was significantly higher than diesel?s. The results were subsequently adopted to compare with other test results and illustrated a similar result. The initial temperature rising rates for gasoline pool fires were shown to agree well with the standardized temperature curves, but they were significantly lower for diesel pool fires. Two exponential correlations on vertical temperature distribution were provided, respectively, for gasoline and diesel fires. These findings are expected to be useful for the design of the thermal boundary on the lining in tunnel fires.

Особенности становления структуры и объёма фонда превителлогенных ооцитов у радужной форели

Особенности становления структуры и объёма фонда превителлогенных ооцитов у радужной форели

Corrigendum to: Size, depth and position affect the diversity and structure of rock pool communities in an urban estuary

Rock pools provide a range of ecological niches that can support diverse assemblages on rocky shores. As intertidal shores are increasingly lost to developments, understanding the drivers of diversity in rock pools is important for the conservation and construction of these key habitats. In this study we investigated relationships between physical characteristics of rock pools and their biota in an urban estuary. We sampled the biota every 6 weeks for 1 year at sites in the inner and outer zones of Sydney Harbour. In the well-flushed and exposed outer zone, sessile and mobile taxa richness was positively related to rock pool width, whereas only mobile taxa richness was related to depth and volume. In the more urbanised and less exposed inner zone, mobile taxa richness was positively related to rock pool width and volume. In both zones, sessile taxa richness decreased with increasing height on shore. Our results suggest that the biodiversity of intertidal rock pools varies depending on their position in Sydney Harbour and the available species pool. Therefore, restoration efforts should consider rock pool size parameters and local environmental conditions, including location, so designs can be optimised to maximise species diversity in these pools.

The Effect of Disclosure Opacity on Trading Opacity: New Evidence from ADR Trades in Dark Pools

As volume increasingly migrates away from exchanges to dark pools, we revisit the link between disclosure opacity and volume, conditional on the choice to trade in a dark venue. We exploit the exogenous variation in home-country reporting opacity to examine how disclosure opacity affects the fraction of ADR volume traded in dark pools. Using multiple metrics for reporting opacity and controlling for firms’ information environment and country-specific governance issues, we find that dark pool volume is positively correlated with home-country reporting opacity. This relation holds after controlling for observable differences between ADRs and other securities that trade in dark pools (matched sample analysis), volume migration to dark pools during earnings announcements, informed trading in lit versus dark venues, ADR levels, IFRS reporting requirements, and the possible endogenous determination of home-country reporting opacity and dark pool volume. The positive relation is stronger for ADRs held by institutions with low turnover and diversified holdings (quasi-indexers), and weaker for ADRs favored by institutions that trade frequently (transient) and institutions that hold concentrated portfolios (dedicated). Bid-ask spreads are greater for higher opacity ADRs that trade in dark pools, indicating that disclosure opacity magnifies the negative effect of dark pool trading on market quality.

Size, depth and position affect the diversity and structure of rock pool communities in an urban estuary

Rock pools provide a range of ecological niches that can support diverse assemblages on rocky shores. As intertidal shores are increasingly lost to developments, understanding the drivers of diversity in rock pools is important for the conservation and construction of these key habitats. In this study we investigated relationships between physical characteristics of rock pools and their biota in an urban estuary. We sampled the biota every 6 weeks for 1 year at sites in the inner and outer zones of Sydney Harbour. In the well-flushed and exposed outer zone, sessile and mobile taxa richness was positively related to rock pool width, whereas only mobile taxa richness was related to depth and volume. In the more urbanised and less exposed inner zone, mobile taxa richness was positively related to rock pool width and volume. In both zones, sessile taxa richness decreased with increasing height on shore. Our results suggest that the biodiversity of intertidal rock pools varies depending on their position in Sydney Harbour and the available species pool. Therefore, restoration efforts should consider rock pool size parameters and local environmental conditions, including location, so designs can be optimised to maximise species diversity in these pools.

Physical tidepool characteristics affect age- and size-class distributions and site fidelity in tidepool sculpin (Oligocottus maculosus)

Rapidly changing environments pose unique challenges to the resident organisms. Tidepools in coastal environments vary in biophysical characteristics spatially and temporally, and how they vary determines their short- and long-term suitability as habitats and therefore influence on the distributions of tidepool organisms. Biophysical effects on distribution could differ between age classes, depending on their intrinsic ontogenetic requirements and dominance relations. In this study, we investigate the influence of physical pool characteristics on the site fidelity and population distribution of tidepool sculpin (Oligocottus maculosus Girard, 1856). We assessed short-term recapture of marked individuals and size-class distribution among four pool sets. The proportion of adults varied between pools primarily in association with water temperature and pool volume. Smaller adult and larger juvenile fish occupied warmer, small-volume pools, whereas larger adults occupied larger, cooler pools. Between 24% and 56% of marked fish were recaptured, with a higher probability of recapture in pools with “smooth” basins than in those with more rugose basins. Few fish moved among study pools, but the proportion of adults declined with repeated sampling, suggesting greater pool fidelity of juveniles. These results illustrate that intrinsic habitat features influence age- and size-class distributions in a resident tidepool sculpin species, with corresponding consequences for site fidelity.

Impact of remote ischemic preconditioning preceding coronary artery bypass grafting on inducing neuroprotection

BackgroundNeurological complications after coronary artery bypass grafting (CABG) reduce quality of life, increase mortality, and inflate resource utilization. The risk of postoperative neurological complications parallels the increasing risk burden of the contemporary patient population. We evaluated the efficacy of remote ischemic preconditioning (RIPC) on inducing neuroprotection. MethodsSeventy patients undergoing first-time CABG were randomly assigned to RIPC or a sham procedure. Structural brain magnetic resonance imaging (MRI) was complemented with functional connectivity MRI to gain a whole-brain global connectivity analysis. Paired neurocognitive and MRI data were acquired pre- and postoperatively. The primary end point was a composite of new ischemic brain lesions and neurocognitive impairment. Secondary end points included brain connectivity profiles, pooled ischemic volumes, and individual components of the primary outcome. The Shapiro–Wilk test was used to determine whether a data set followed a normal distribution. The Fisher exact test was used to calculate the measures of association for categorical variables, whereas continuous data were tested with either the Mann–Whitney U test or the Student t test. ResultsThere was no between-group difference in the incidence of the primary end point (9 [27%] in the RIPC group vs 8 [24%] in the control group, odds ratio, 1.17 [95% confidence interval, 0.34-4.06]; P = 1.0). Although RIPC did not reduce the incidence of brain ischemia (8/33 [24%] vs 7/33 [21%]; P = 1.0), the pooled ischemic volume was lower in the RIPC group (157 [interquartile range, 125-231] vs 777 [interquartile range, 564-965] mm3; P = .004). Postoperative neurocognition was marginally superior in the RIPC group as evidenced by a lower absolute number of abnormal neurocognitive tests in the RIPC group (7/99 [7%] vs 16/99 [16%]; odds ratio, 0.40 [95% confidence interval, 0.14-1.09]; P = .074). Robust reductions of functional connectivity profiles for the associative thalamus were documented in both groups, irrespective of RIPC (RIPC group, t = 3.31; P < .01; and the control group, t = 3.52; P < .01). ConclusionsSilent brain ischemia occurs frequently after CABG. RIPC did not reduce the incidence of the primary outcome. However, RIPC significantly reduced the pooled volume of ischemic brain lesions. Surgery adversely affected global brain connectivity, with RIPC conferring no demonstrable protection. The association of RIPC with superior neurocognitive test scores failed to cross the threshold for significance.

LEFT VENTRICULAR EJECTION FRACTION: COMPARISON BETWEEN TRUE VOLUME-BASED MEASUREMENTS AND AREA-BASED ESTIMATES.

Left ventricular ejection fraction (LVEF) is a critical measure of cardiac health commonly acquired in clinical practice, which serves as the basis for cardiovascular therapeutic treatment. Ultrasound (US) imaging of the heart is the most common, least expensive, reliable and non-invasive modality to assess LVEF. Cardiologists, in practice, persistently use 2D US images to provide visual estimates of LVEF, which are based on 2D information embedded in the US images by examining the area changes in LV blood pool between diastole and systole. There has been some anecdotal evidence that visual estimation of the LVEF based on the area changes of the LV blood pool significantly underestimate true LVEF. True LVEF should be calculated based on changes in LV volumes between diastole and systole. In this project, we utilized both idealized models of the LV geometry - a truncated prolate spheroid (TPS) and a paraboloid model - to represent the LV anatomy. Cross-sectional areas and volumes of simulated LV shapes using both models were calculated to compare the LVEF. Further, a LV reconstruction algorithm was employed to build the LV blood pool volume in both systole and diastole from multi-plane 2D US imaging data. Our mathematical models yielded an area-based LVEF of 41 4.7% and a volume-based LVEF of 55 ±5.7%, while the 3D recon-struction model showed an area-based LVEF of 35 11.9% and a volume-based LVEF of 48.0 ± 14.0%. In summary, the area-based LVEF using all three models ±underestimate the volume-based LVEF using corresponding models by 13% to 14%. This preliminary study confirms both mathematically and empirically that area-based LVEF estimates indeed underestimate the true volume-based LVEF measurements and suggests that true volumetric measurements of the LV blood pool must be computed to correctly assess cardiac LVEF.

Habitat features mediate selective consumption of salmon by bears

Salmon provide a key source of marine-derived nutrients to aquatic and surrounding terrestrial habitats in coastal areas of the North Pacific. Bears are a major predator of salmon and provide an important pathway for carcass transfer to riparian zones. We studied selective consumption of salmon (Oncorhynchus keta and Oncorhynchus gorbuscha) by bears (Ursus arctos and Ursus americanus) on 12 streams on the central coast of British Columbia, Canada. We predicted that bears would select more energy-rich parts, and eat less of each fish (i.e., selective consumption), in streams with more prey and simpler habitat (i.e., streams that facilitate salmon capture). Bears were 12% more likely to consume fish selectively in narrow, shallow streams with less pool volume, where salmon are easier to catch, than in deep, wide streams. However, bears were also 21% more likely to selectively consume fish in streams with more wood obstacles and undercut banks, where hunting was predicted to be more difficult. This suggests that stream characteristics can have significant indirect effects on riparian nutrient subsidies to ecosystems through selective feeding by bears.

The ecology of a system of natural mesocosms: Rock pools in the Atlantic Forest

Abstract The methodological trade‐off between the realism of natural systems and the tractability of artificial systems has led ecologists to praise the qualities of natural micro‐ and mesocosms as an ideal means for investigating the processes that organise biological communities. Among the different types of naturally occurring micro‐ and mesocosms, clusters of rock pools combine a global distribution with the simplicity, replicability, tractability and structural homogeneity that are desirable in model experimental systems. However, critical geographical data gaps in the study of rock pools must be filled if ecologists are to use these as global model systems in community ecology. In a year‐long study of a cluster of 181 rock pools in the Atlantic Forest of eastern Brazil, we conducted the first study on the ecology of freshwater rock pool communities in the entire Neotropical region, to the best of our knowledge. Building on published descriptions of the factors that drive community assembly within rock pools, we tested the hypotheses (1) that the effects of environmental factors prevail over those of spatial factors and (2) that pool volume and secondarily species interactions between consumers (anuran larvae), resources (leaf litter) and predators (dragonfly larvae) have a dominant role in driving species patterns of occurrence and abundance. Our hypotheses were generally supported as community structure was clearly influenced by the environmental characteristics of individual pools, and not to the spatial relations among them. Pool volume had a consistent, positive influence on the probability of occurrence of dragonflies and tadpoles of three anuran species, possibly through the influence of volume on hydroperiod. However, the species most strongly associated with larger pools were not those with longer times until metamorphosis, but those with larger egg clutches. In addition, species occurrences were positively associated with resource availability as measured by leaf litter mass (significantly so for Rhinella and dragonflies). These observations suggest that within these severely confined freshwater systems, indicators of environmental stability and reduced intraspecific competition could be important ultimate criteria for oviposition site selection. The ease of sampling and manipulating the rock pools at our Atlantic Forest site combined with the observation that these pools are governed by some of the same factors influencing community organisation in other rock pool systems around the world reinforces the merit of the system as a means to conduct global comparative studies of the ecology of communities and metacommunities.

Evaluation of recent Protein A stationary phase innovations for capture of biotherapeutics

We describe a comprehensive evaluation of 12 Protein A stationary phases for capture of biotherapeutics. We first examine the morphological properties of the stationary phases using a variety of orthogonal techniques including electron microscopy, particle sizing, pressure-flow behavior, and isocratic pulse response. A panel of nine proteins spanning a wide range of structures and biochemical properties was then used to assess equilibrium uptake, mass transport, dynamic binding capacity, and elution pH. Process performance and product quality were also examined under realistic bioprocess conditions using clarified mammalian cell culture broth. Equilibrium isotherms were found to be highly favorable, with equilibrium binding capacity for monoclonal and bispecific antibodies ranging from 47–100 mg/mL packed bed across all stationary phases tested. Effective pore diffusivities, De, were obtained by fitting the chromatography general rate model to breakthrough data. The fitted De values for monoclonal antibodies ranged from 1.1–5.7 × 10−8 cm2/s. The stationary phases had high dynamic binding capacities for the model proteins. The highest dynamic capacities for monoclonal and bispecific antibodies were seen with MabSelect SuRe pcc and MabSelect PrismA, which ranged from 58–74 mg/mL packed bed at 4 min residence times. Product capture using clarified cell culture broth as a feedstock showed high yields and elution pool volumes that ranged from 2–3 column volumes in most cases. Host cell protein, DNA, and aggregate levels in the elution pool were dependent on the specific nature of protein being purified, and levels were consistent between stationary phases. Lastly, we perform an analysis of bivariate correlations and discuss considerations for process design and optimization.

The Impact of MiFID II/MiFIR on European Market Structure: A Survey among Market Experts

This study presents the views of leading financial market experts concerning the impact of MiFID II/MiFIR on the European market structure and the future relative importance of different types of trading venues and over-the-counter (OTC) trading. In an online questionnaire among experts on trading and/or market structure, 111 respondents shared their opinions concerning the impact of the MiFIR trading obligation, dark pool volume caps, the new trading venue category organized trading facility (OTF) for non-equities, and the impact of Brexit.

Water‐level dynamics in natural and artificial pools in blanket peatlands

AbstractPerennial pools are common natural features of peatlands, and their hydrological functioning and turnover may be important for carbon fluxes, aquatic ecology, and downstream water quality. Peatland restoration methods such as ditch blocking result in many new pools. However, little is known about the hydrological function of either pool type. We monitored six natural and six artificial pools on a Scottish blanket peatland. Pool water levels were more variable in all seasons in artificial pools having greater water level increases and faster recession responses to storms than natural pools. Pools overflowed by a median of 9 and 54 times pool volume per year for natural and artificial pools, respectively, but this varied widely because some large pools had small upslope catchments and vice versa. Mean peat water‐table depths were similar between natural and artificial pool sites but much more variable over time at the artificial pool site, possibly due to a lower bulk specific yield across this site. Pool levels and pool‐level fluctuations were not the same as those of local water tables in the adjacent peat. Pool‐level time series were much smoother, with more damped rainfall or recession responses than those for peat water tables. There were strong hydraulic gradients between the peat and pools, with absolute water tables often being 20–30 cm higher or lower than water levels in pools only 1–4 m away. However, as peat hydraulic conductivity was very low (median of 1.5 × 10−5 and 1.4 × 10−6 cm s−1 at 30 and 50 cm depths at the natural pool site), there was little deep subsurface flow interaction. We conclude that (a) for peat restoration projects, a larger total pool surface area is likely to result in smaller flood peaks downstream, at least during summer months, because peatland bulk specific yield will be greater; and (b) surface and near‐surface connectivity during storm events and topographic context, rather than pool size alone, must be taken into account in future peatland pool and stream chemistry studies.

Analysis of transient thermo-fluidic behavior of melt pool during spot laser welding of 304 stainless-steel

In this study, the transient evolution of temperature and velocity field, melt pool geometry (width, depth of penetration and melt pool volume), melting and solidification behavior during spot laser welding of 304 stainless-steel is presented. The transport phenomena associated with the melting and the solidification stage are appropriately accounted in the computational model. The predicted melt pool geometry shows a good agreement with the published and in-house experimental data for spot laser welding. Analysis of important dimensionless numbers revealed the significant role of melt pool convection on the heat transfer and the melt pool geometry. Thermal cycles at several strategic locations were also investigated during the melting and the solidification stage. To analyze the solidification behavior of the melt pool, the relevant solidification parameters such as temperature gradients, solidification rates, and cooling rates were described. With progress in solidification of the melt pool at the melt pool interface, the solidification rate increases while the temperature gradient decreases. Also, an attempt has been made to account the free surface deformation in the melt pool by developing a separate numerical model considering the free/deformable top surface. A qualitative and quantitative comparison of the melt pool characteristics obtained from the free/deformable and the flat top surface model has been carried out. The predicted depth of penetration of the melt pool with the free/deformable top surface is found to be slightly larger than that with the flat top surface.

Phylogenetic theory of general pathology. Pericytes, function of the distal arterial bed, metabolic arterial hypertension and hypovolemic shock.

The in vivo roles of pericyte contractile sphincters, smooth muscle cells, endothelial monolayer, precapillary muscle arterioles, exchange and volume capillaries in the physiological balance between peripheral blood pool and the blood pool volume in the distal arterial bed are not fully understood. However, it is highly probable that: 1. There is no primary arterial hypertension. The compensatory biological reaction of arterial pressure (AP) is always secondary, thus indicating the presence of symptomatic or metabolic arterial hypertension (AH). 2. Elevation of AP in proximal arterial bed is a compensatory response to metabolic disorders and impaired microcirculation and metabolism↔microcirculation biological reaction. The response develops locally in the distal arterial bed (muscle arterioles, functional sphincters, pericytes). 3. Metabolic AH is a pathology of the phylogenetically early distal arterial bed , endothelial monolayer, smooth muscle cell and pericyte function. 4. We believe that formation of acute hypovolemic shock is the condition of sphincter (pericyte) atonia in precapillary muscle arterioles with formation of a nonphysiological blood volume in the distal arterial bed when physiological volume of peripheral blood is insufficient to fill the bed. 5. When local disorder in the biological reaction metabolism↔microcirculation is not compensated by endothelium-dependent vasodilation, an efferent innervation signal from the vasomotor center at the entire organism level is sent to the heart and systemic AP increases first in the proximal then in the distal arterial bed. 6. Systemic AP elevation impairs function of the target organs: kidneys, brain and lungs. Each of these organs regulates hydrodynamics in the local pool of extracellular medium, their dysfunction inducing a compensatory response. 7. Metabolic arterial hypertension results from discoordinated systemic compensation of local disorders in the following biological functions: homeostasis, endoecology, trophology and adaptation. This discoordination occurs at the level of paracrine regulated cell communities of functionally different cells which are structural units of each internal organ.

Determination of nine pyrethroid pesticide residues in tea by gas chromatography-tandem mass spectrometry combined with accelerated solvent extraction and solid phase extraction

A method has been developed for the simultaneous detection of nine pyrethroid pesticide residues in tea by gas chromatography-tandem mass spectrometry (GC-MS/MS) combined with accelerated solvent extraction (ASE) and solid-phase extraction (SPE). The pesticide residues in tea were extracted using acetone/n-hexane (1:1, v/v) for 5 min at 100℃ before preheating the extraction pool for 3 min, under extractive pressure of 10 MPa for one cycle. After extraction, the extraction pool was washed with acetone/n-hexane (1:1, v/v) having volume of 40% of the pool volume, followed by purging for 100 s with nitrogen. The extract was purified by a Cleanert TPT solid-phase extraction column. After purification, the target compounds were detected by GC-MS/MS and quantified by the external standard method. Under the optimized conditions, good linearities were obtained for the nine pyrethroid pesticides in the range of 2-1000 μg/L, with correlation coefficients exceeding 0.99. The limits of detection (LODs) were 0.2-4.5 μg/kg and the limits of quantitation (LOQs) were 0.8-15.0 μg/kg. At four spiked levels (0.02, 0.1, 0.4 mg/kg, and the LOQ level) in green tea and black tea, the recoveries of all the pesticides were between 69.87% and 110.0%, with relative standard deviations (RSDs) varying from 0.7% to 11.2%. This method effectively reduces the matrix interference and shows high sensitivity, good reproducibility, and stable recovery, and can thus be used for the detection of pyrethroid pesticide residues in tea.

Parametric study of surface morphology for selective laser melting on Ti6Al4V powder bed with numerical and experimental methods

A three-dimensional (3D) selective laser melting (SLM) model comprising coupled heat transfer and flow behavior is proposed. The free surface of the melt pool is calculated by the volume-of-fluid (VOF) method, which is a means of acquiring the surface morphology. In this research, laser powers and laser scanning speeds were normalized to characterize the influence on the surface morphology. Results showed that when the scanning speed was increased, the surface morphology initially became flatter, but then roughness developed again at high speed case. Further, as the laser power was increased, the surface morphology gradually roughened. To better describe the surface-morphology phenomenon according to different laser parameters, the melt pool volume and melt pool lifetime were also investigated. With these two factors constrained, a fine surface could be obtained with a low melt pool volume and proper lifetime (approximately 100 to 130 μs). The surface morphology and the width of the melt track were experimentally acquired, and are in a good agreement with the results predicted by simulation.