Maximum Penetration Depth Research Articles

Changes in the Seasonally Frozen Ground Over the Eastern Qinghai-Tibet Plateau in the Past 60 Years

The Qinghai-Tibet Plateau (QTP) has the largest extent of high altitude permafrost at the middle and low latitudes in northern hemisphere and is surrounded by dozens of seasonally frozen ground. Rising air temperatures have resulted in frozen ground degradation over QTP since the last century. Based on the daily frozen soil depth, annual mean daily minimum air temperatures and annual mean air temperatures obtained from 19in-situobservations over QTP, the changes in the thickness, temporal and spatial distributions of frozen ground, as well as the associated attributions, are analyzed for the period of 1960-2019. The results show that the maximum depth of frost penetration, the beginning time of soil freezing and the ending time of soil thawing have changed considerably. On average, the maximum depth of frost penetration (MDFP) has reduced by 0.14 similar to 1.71 m at most stations. The annual frozen period has decreased by about 40 days. The changes in seasonal freezing of soils appear to be attributed to the rising of minimum air temperatures in winter, especially at the higher elevations range from 4500 to 5000 m.

Evaluation of Antibacterial Efficacy of Vitex negundo Linn. extract as Root Canal Irrigant against Enterococcus faecalis and its penetration into Root Dentin: An in-vitro study

Introduction: The aim of this study was to evaluate the antibacterial efficacy of Vitex negundo Linn. extract as root canal irrigant against Enterococcus faecalis and its penetration into root dentin. Methods and Materials: Forty single rooted premolars were randomly divided into 4 groups: 3% Sodium hypochlorite (NaOCl), 2% Chlorhexidine (CHX) , 100mg/ml Vitex negundo Linn. and saline as control all mixed with Rhodamine B dye. Test samples were analysed for bacterial count before and after irrigation using absorbent paper points and the colony forming units were recorded and measured. Sectioning of the samples was performed at three levels 3mm,6mm,9mm from apex and then these samples were analysed using confocal laser scanning microscopy for penetration depth of the irrigant within the dentinal tubules. Paired t-test and ANOVA test were used to perform statistical analysis with level of significance set at 0.05 Results: The mean CFU/ml count of Enterococcus facealis reduced significantly in all the groups post irrigation. All the irrigants showed maximum penetration depth at coronal third level compared to middle and apical third level respectively. The penetration depth of NaOCl group was better when compared to CHX group and Vitex negundo Linn. group but the difference was statistically not significant. Conclusion: Although 3% NaOCl was the most effective irrigant, all agents exerted acceptable antimicrobial activity against Enterococcus faecalis and penetration depth within tubules of dentin.

Моделирование глубины проникновения дизельного топлива в защитную песчаную подушку

When deploying a temporary fuel storage warehouse, the primary source of soil contamination by oil products is technological losses related to the leakage of isolation valves. To protect the soil from contamination, containers are placed on a layer of sand. The thickness of the sand layer depends on the volume of possible losses. The purpose of the work is to model the depth of diesel fuel penetration into the protective layer of sand bed. The method of performing the experiment imitated a high rate of fuel penetration in the form of droplets onto the protective layer. The article considers the mechanism of fuel penetration into sand and factors, determining the penetration depth. It is established that the mechanism of fuel penetration into the protective layer has two stages, on each of which the penetration depth and rate of fuel distribution are different. The maximum penetration depth is reached on the first stage and depends on the quantity of fuel. The author developed the model, which allows the determination of the thickness of the sand bed protective layer with known granulometric particle composition necessary for the prevention of diesel fuel penetration into soil.

The effect of 17% EDTA and QMiX ultrasonic activation on smear layer removal and sealer penetration: ex vivo study

This study aimed to compare the effect of conventional irrigation (CI) and passive ultrasonic irrigation (PUI) with 17% EDTA and QMiX on the maximum depth and percentage of sealer penetration into the dentinal tubules by confocal laser scanning microscopy (CLSM) and to describe the cleaning of root canal walls by scanning electron microscopy (SEM). Eighty single-rooted human mandibular premolars were instrumented and randomly assigned to four groups (n = 20): EDTA + CI, QMiX + CI, EDTA + PUI, and QMiX + PUI. Ten samples from each group were examined by SEM (2,000×) and the remaining 40 roots were filled with a single gutta-percha cone and AH Plus sealer mixed with 0.1% rhodamine B for analysis by CLSM (10×). Images were assessed at distances of 2 mm (apical), 5 mm (middle), and 8 mm (coronal) from the apex with the Leica Application Suite V4.10 software. The EDTA + PUI and QMiX + PUI protocols presented higher rates of debris/smear layer removal in the apical and middle thirds. The PUI was superior to CI in the maximum depth of sealer penetration at the middle third. The QMiX + PUI group had a higher percentage of sealer penetration at the apical third. The PUI and QMiX protocol improved debris/smear layer removal and tubular dentin sealer penetration.

Sealer penetration: effect of separated file's cross-section, taper and motion characteristics.

The separated root canal instruments may affect the quality of root canal filling, hence the success of endodontic treatment. The aim of this study was to evaluate the effects of separated file fragments of nickel-titanium rotary systems with different cross-section, taper and motion characteristics on the apical sealer penetration in oval-shaped root canals via confocal laser scanning microscope (CLSM). Distal roots of 60 mandibular molars with oval-shaped root canals were randomly divided into 4 groups as follows: group 1, FlexMaster Nickel Titanium Rotary File System (NTRFS) (separated instrument: 30/.06); group 2, ProTaper Next NTRFS (X3); group 3, ProTaper Universal NTRFS (F3); group 4, Revo-S NTRFS (AS30/.06). Root canals were filled with gutta-percha and AH plus labelled with 0.1% rhodamine B using a warm vertical compaction technique. Each specimen was horizontally sectioned at 1st, 3rd and 5th mm from apical foramen. Amount of maximum and average penetration depths, penetration percentage and sealer penetrated area were measured and analysed with one-way repeated measures of ANOVA and the Bonferroni post hoc tests. p < 0.05 was considered significant. The penetration depth, percentage and penetrated area of the sealer increased from apical to coronal in all systems. The maximum and average penetration depths and penetration areas were higher in FlexMaster and Revo-S groups at the 3rd mm (p < 0.05). At the 5th mm, the Revo-S group had a higher penetration percentage, when compared with ProTaper Next and ProTaper Universal groups (p < 0.05). In the 1st mm, separated fragments of any system did not allow the penetration of the sealer, while it was observed that the files with constant taper showed more positive results in terms of sealer penetration at apical 3rd and 5th mm. In the presence of a separated file, the taper of the file might significantly affect the amount of penetrated sealer into the dentinal tubules as compared with the cross-section and motion characteristics of the file.

New light-weight concrete foam to absorb debris-flow-entrained boulder impact: Large-scale pendulum modelling

Rock-filled gabions are widely used to attenuate concentrated impact loads exerted by boulders entrained in debris flows. However, rock fragments used to construct gabion may not always be available and the performance of rock-filled gabion can be highly variable, depending on size and angularity of the rock fragments used. In this study, light-weight concrete foam is proposed as an alternative cushioning material to overcome some of the limitations of rock-filled gabion. Physical large-scale pendulum impact tests were conducted to study the performance of concrete foam, which was used to shield a reinforced concrete barrier from boulder impact. Six successive boulder impacts were carried out at energies of up to 70 kJ. Two different concrete foam thicknesses, 0.4 m and 0.6 m, were investigated. Increasing the cushioning thickness from 0.4 m to 0.6 m can reduce the maximum transmitted load by 48% and 71% for the first and sixth impacts at an impact energy of 70 kJ, respectively. The larger cushioning thickness enhances load spreading on the wall and reduces stress concentration. Furthermore, the maximum penetration depth on the 0.4-m thick concrete foam is 0.29 m for the sixth impact at an impact energy of 70 kJ, which is equivalent to 72% of the initial cushioning layer thickness. Based on the existing design guidelines (ASTRA 2010) and the Gibson and Ashby model, the required minimum thickness for up to six successive impacts at an impact energy of 70 kJ is 0.58 m.

Critical design factors for polyvinyl alcohol hydrogel entrapping ammonia-oxidizing bacteria: biomass loading, distribution of dissolved oxygen, and bacterial liability

The single-stage configuration of the partial nitritation (PN)–anaerobic ammonium oxidation (AMX) process is preferred due to low pH fluctuation and the low concentration of inhibitory NO2-. The novel core-shell structure integrates ammonia-oxidizing reaction in the outer layer to protect AMX bacteria in the core gel bead from oxygen inhibition and provide NO2-. Here, the initial activity of ammonia-oxidizing bacteria (AOB) in the outer layer was assessed by the specific oxygen uptake rate (OUR). AOB activity was positively correlated with biomass loading in the outer layer. A maximum OUR of 10.5 mg-DO/L∙h was achieved with AOB loading of 0.23 mg-VSS per bead. During AOB enrichment, the NO2- production rate was linearly increased up to 0.65 kg-N/m3-d for 17 days (PVA hydrogel packing ratio=17%). The maximum oxygen penetration depth (OPD) was reduced from 966.7±52.3 μm before enrichment to 333.3±36.4 μm after the AOB enrichment. The liable bacteria were observed within a range of 165 μm of the outer layer using the live and dead cell staining. Based on the OPD and liable cell distribution results, a minimal outer layer thickness of approximately 350 μm was suggested to facilitate a successful PN–AMX process.

Application of ultrasound-mediated adapalene-coated lysozyme-shelled microbubbles in UVA-induced skin photoaging.

Photoaging, the premature aging of skin induced by ultraviolet rays, is characterized by wrinkling, roughness, laxity, and pigmentary changes. Various natural and synthetic retinoids have been explored for the treatment of aging. Among retinoids, adapalene (Ada, 0.3%) is one of the most potent and widely used drugs to treat photoaging. However, it causes irritant reactions that limit its acceptance by patients. Several studies have shown the applicability of Lysozyme (Lys)-shelled microbubbles (MBs) for drug delivery through sonophoresis, and recently we have shown its efficiency to treat inflammatory skin disease. Here, we report the construction of novel Ada-LysMBs based on opposite electric charges for combined effects to treat photoaging. The Ada-LysMBs were self-assembled and had a mean diameter of 2857 nm. The maximum loading efficiency of Ada onto LysMBs was 13.99 ± 0.59%. An acoustic power density of 3 W/cm2 for 1 min revealing maximum penetration depth of LysMBs was optimized for further in vitro and in vivo studies of Ada-LysMBs. It was observed that in vitro Ada release from Ada-LysMBs at 6 h after ultrasound (US) treatment was more rapid at pH 7.4 (82%) than at pH 5.5 (73%). Franz diffusion experiments on isolated porcine skin indicated that US approximately doubled Ada delivery by Ada-LysMBs and Ada + LysMBs at 12 h and six-fold Lys permeation by LysMBs at 6 h, compared to these treatments alone. A 5-week in vivo study in mice identified significant wrinkle reduction in animals treated with US plus Ada-LysMBs. Our findings indicate that US may be used with Ada-LysMBs in the water phase to treat photoaging by normalizing hyperkeratinization and promoting collagen synthesis.

Effect of Vehicle and Agitation Methods on the Penetration of Calcium Hydroxide Paste in the Dentinal Tubules

IntroductionThe aim of this ex vivo study was to analyze the effect of different vehicles combined with agitation methods on the penetration of calcium hydroxide (CH) paste in the dentinal tubules. MethodsSixty freshly extracted, single-rooted human premolars were prepared using WaveOne Gold (Dentsply Sirona, York, PA) and randomized into 6 experimental groups (n = 10) according to the vehicle and method of paste agitation as follows: propylene glycol (PG) + Lentulo, PG + Lentulo + ultrasound, PG + Lentulo + sonic, distilled water (DW) + Lentulo, DW + Lentulo + ultrasonic, and DW + Lentulo + sonic. The CH paste was manipulated with sodium fluorescein dye and was inserted to completely fill the root canal. Two 1-mm thick sections at 2 mm and 5 mm from the apex of each root were obtained. The sections were scanned using confocal laser scanning microscopy, and the images were analyzed using ImageJ software (Bethesda, MD) to calculate the percentage penetration and maximum penetration depth of CH paste. Statistical analysis was performed using 1-way analysis of variance and Tukey honestly significant difference post hoc tests. ResultsNo statistically significant differences between study factors at a distance of 2 mm from the apex were observed (P > .05). However, at 5 mm, a significant difference between the vehicles (P < .05) in percentage penetration was demonstrated with higher means for PG. ConclusionsVehicles interfered with the penetration of CH in the dentinal tubules at 5 mm from the apex with better results for PG.

Penetration characteristics of pyramidal projectile into concrete target

The mechanisms governing penetration of pyramidal projectile into concrete medium were studied. The relationship of normal stress and normal velocity on the surface of the projectile nose was modified based on the assumption that the shape of the tunnel section is the same as that of the projectile. Then, in the low velocity range, a formula for predicting the final penetration depth of the pyramidal projectile is proposed, and the penetration ability of pyramidal projectiles with and without a shank is discussed. The results showed that the penetration depth decreases with the increasing side numbers of the projectile section shape, and the maximum depth of penetration corresponds to the triangular cross-section. In addition, the penetration processes of triangular and circular projectiles into concrete targets were simulated by employing the finite element software LS-DYNA. The Mises stress, tunnel shape, depth of penetration and velocity were investigated. It suggested the triangular projectile has a slight penetration advantage over the circular projectile when the penetration velocity is less than threshold velocity, and this advantage gradually disappears with the increase of impacting velocity. Finally, the shear weakening effect is used to explain the resistance characteristics of the triangular projectile in various velocity ranges, and a method to estimate the upper limit of threshold velocity is given by using the dynamic cavity expansion theory.

Effectiveness of Various Final Irrigation Techniques on Sealer Penetration in Curved Roots: A Confocal Laser Scanning Microscopy Study.

Objective To compare the efficacy of various techniques used for final irrigation on sealer penetration in the apical one-third of curved root canals. Material and Methods. Sixty-five freshly extracted maxillary first molar teeth with mesiobuccal roots having more than 20° of root curvature were used. The root canals were instrumented and randomly divided into four experimental groups and one control group. In the 4 experimental groups, 3 ml of 17% EDTA followed by 3 ml of 5.25% NaOCl was delivered with the use of the following protocols: Group 1: manual dynamic activation (MDA), Group 2: sonic irrigation (SI), Group 3: passive ultrasonic irrigation (PUI), and Group 4: conventional needle irrigation (CI). All teeth were obturated with gutta-percha and AH Plus sealer labeled with fluorescent dye. Transverse sections at 2 mm and 4 mm distance from the root apex were examined with the aid of confocal laser scanning microscopy. Total percentage (%) and maximum depth (μm) of sealer penetration were measured. Results All the experimental groups exhibited significantly higher penetration rates than the control group at both sections (p < 0.05). However, no significant differences were found in the penetration depth and percentage among the four experimental groups evaluated at both sections (p > 0.05). Conclusion PUI, SI, and MDA did not significantly improve sealer penetration in the apical portion of curved root canals when compared to conventional needle irrigation.

Microstructure of titanium alloy modified by high-intensity implantation of low- and high-energy aluminium ions

This study focuses on the analysis of microstructural, elemental and phase compositions of surface and near-surface layers of titanium after the implantation of aluminium. A titanium alloy with a chemical composition close to commercially pure titanium (grade 2) was used as the target material. Ion implantation was performed using two modes of irradiation: 1. repetitively pulsed ion beams with a mean ion energy of 35 keV; 2. low-energy-focused ion beams of high intensity with a mean ion energy of 2.6 keV. The irradiation fluence reached 1.1 × 1018 ion/cm2 using the first mode and 1.6 × 1021 ion/cm2 using the second mode. In both cases, the beam itself heated the targets. The peak concentration of aluminium after the implantation of medium-energy ions was ~65 at.%, and the maximum depth of dopant penetration was 2.6 μm. On the contrary, in the case of high-intensity low-energy ion implantation, the surface concentration of dopant reached a maximum of 25 at.%, but the depth of penetration increased significantly and achieved 50 μm. The results of X-ray diffraction (XRD) and transmission electron microscopy (TEM) showed that fine-grained intermetallic phases, Ti3Al and TiAl, and solid solutions of various compositions were possibly formed after the medium-energy ion implantation. The mean grain size of the intermetallic phases was ~50 nm. XRD and TEM analyses in the case of low-energy high-intensity ion implantation demonstrated the formation of the ion-alloyed layer, which comprised intermetallic phase Ti3Al and solid solutions of aluminium in titanium. The grain size of Ti3Al phase can be 5 μm and more.

The effect of different obturation methods on sealer penetration alongside apically separated rotary nickel–titanium instruments: A confocal laser scanning microscopy study

The effects of different obturation techniques on calcium silicate-based sealer penetration in the presence of apically separated rotary files were evaluated. Forty-eight extracted mandibular incisors were used. ProTaper F2 rotary files were separated at the apical thirds. Samples were divided into four groups (n = 12) according to obturation technique used: (a) cold lateral compaction (CLC); (b) single cone; (c) bulk-fill (BF) without a core material; and (d) thermoplastic injection (TI). Specimens were sectioned horizontally at 1 and 3 mm from the apex and studied using a confocal scanning laser microscope. The maximum tubule penetration depth and percentage of penetration were measured. Data were statistically analyzed using parametric and nonparametric tests with a significance level of 5%. Regarding penetration depth, a significant difference was found at 1 mm (p < .05), while no significant difference was found at 3 mm (p > .05). At the 3 mm level, all of the obturation techniques showed similar penetration depths. Regarding penetration percentage, the values of the CLC and TI groups were statistically less when compared with the BF group at 1 and 3 mm levels, respectively (p < .05). Under the limitations of this in vitro study, results suggest that the obturation technique may present a significant effect on sealer penetration.

Effect of heat input and weld chemistry on mechanical and microstructural aspects of double side welded austenitic stainless steel 321 grade using tungsten inert gas arc welding process

AbstractStainless steel 321 is a stabilized austenitic grade that prevents the formation of chromium carbides at the grain boundaries and subsequently reduces the risk of corrosion attack at the weld surface by forming titanium carbide. It is primarily used in industries such as pressure vessels, boilers, nuclear reactors, carburetors and car exhaust systems. In order to assess the effect of gas tungsten arc welding process parameters on weld penetration, the proposed Taguchi L9 orthogonal matrix has been selected with two factors and three levels for welding austenitic stainless steel 321 by adjusting the welding current and welding speed. Bead‐on‐plate experiments were performed on base metal of 6 mm thick plate by changing the process parameters, and corresponding weld bead measurement and macrostructure images are examined. Maximum depth of penetration −3.3017 mm is achieved with a heat input −1.4058 kJ/mm, i. e., welding current‐220 A and welding speed‐120 mm/min. Double‐side arc welding technique is used to obtain full penetration on 6 mm thick plate. The quality of the weldment was assessed using non‐destructive radiography inspection. Mechanical integrity and microstructural characteristics of the weldments were studied using tensile (transverse and longitudinal), bend, impact, microhardness, optical microscopy, energy dispersive x‐ray spectroscopy, x‐ray diffraction analysis, ferrite number measurement and scanning electron microscope. The results reveal that the double side‐tungsten inert gas weldment have better mechanical properties. It is corroborated from the weld metal microstructure that it contains γ‐austenite, δ‐ferrite and titanium carbides (intermetallic compounds). X‐ray diffraction analysis and energy dispersive x‐ray spectroscopy plots confirm the increase in the ferrite phase in weld metal. The ferrite measurement results show that the ferrite volume in the base metal and weld metal is 1.2 percent and 6.1 percent respectively. In addition, the higher δ‐ferrite volume in the weldment helps in attaining superior mechanical integrity. Fractography shows that the failure mode of the weld metal and the base metal is ductile.

Theoretical and Numerical Simulation of Small High-speed Projectiles Penetrating Brick Masonry

The process of small high-speed projectiles penetrating brick masonry was studied. The cavity expansion theory used in the study of small high-speed projectile penetration was programmed and the penetration process was calculated. At the same time, LS-DYNA was used to simulate the mechanical process of small high-speed projectiles as they penetrate brick masonry. The results show that the numerical simulation results are more consistent with the theoretical calculation results; the numerical simulation of the finite boundary of the brick masonry and the mortar layer will cause some errors, making the brick masonry less resistant to small high-speed projectiles; When the masonry is compressible, the brickwork has less resistance to small high-speed projectiles; the larger the CRH value describing the geometry of the small high-speed projectile head, the maximum penetration depth and remaining of the small high-speed projectile The speed is greater.

Effect of geometrical parameters on the fluid dynamics of air-powered needle-free jet injectors

Needle-free jet injectors are non-invasive systems having intradermal drug delivery capabilities. At present, they revolutionize the next phase of drug delivery and therapeutic applications in the medical industry. An efficiently designed injection chamber can reduce the energy consumption required to achieve the maximum penetration depth in skin tissue. In this study, the authors explored the effect of various geometrical parameters using a computational fluid dynamics tool. Peak stagnation pressure during the initial phase of the injection procedure was considered as the quantifier for comparison because of its proportional relationship with the initial penetration depth during the injection process. Peak stagnation pressure indicates the maximum energy transformation that could happen between the microjet and skin tissues for an injection procedure. The results of this study indicated a tradeoff that exists between the attainable density and velocity of the microjet on the skin surface with variation in nozzle diameter; the optimum nozzle diameter was found to be within 200–250 μm under the present conditions. The authors also observed a discrepancy in the peak stagnation pressure value for lower filling ratios with variation in chamber diameter; hence, filling ratio of at least 50% was recommended for such systems. Furthermore, a 150% increase in the peak stagnation pressure was obtained with an angle of entry of 10°. In general, this study could provide valuable insights into the effect of geometrical parameters in the fluid dynamics characteristics of propelled microjets from the nozzle of a needle-free jet injector. Such information could be useful for the design of a mechanically driven needle-free jet injector having limited control over the energizing mechanism.

Optimization of GTA Welding Parameters for AISI 304 Stainless Steel using Taguchi Method

This paper presents analyze the effects of process parameters on weld distortion and depth of weld penetration of GTA welded stainless steel plate of AISI 304 stainless steel Grade. The main aim of varying process parameter is to achieve minimum weld distortion and maximum weld bead penetration or depth of penetration. Design of experiment approach was used to plan and design the experiment to study the effect of welding process parameter on weld penetration of GTA welded stainless steel plate of AISI 304 stainless steel grade. Four input parameter- welding current, gas flow rate, root face and welding speed were selected to ascertain their effect on the distortion and depth of penetration. L9 Orthogonal Array technique is used to formulate the experiment layout. From the results obtained it is found that the Welding speed (WS) is the most significant parameter for distortion during gas tungsten arc welding. The recommended parametric combination for optimum distortion is welding current (90 A), gas flow rate (10 LPM), root face (1 mm) and welding speed (31.578 mm/min) and the optimum response value is 2.3996 mm. A confirmation experiment was also performed and verified for the effectiveness of the Taguchi method and the % error between predicted optimal and experimental values for selected response parameters were found well within the acceptable limit.

Micromorphological features of soils of semidesertic solonetzic complexes under different herbaceous communities with the participation of fodder plant Kochia prostrata (Caspian lowland)

The aim of the study was to research the relationship of chemical and micromorphological properties of soils with the growth ofKochia prostrata. The objects of study were the soils on natural pastures of the North-Western part of the Caspian lowland. It was laid 4 soil pits (soils – light solonetz, solonetzic chestnut) with the maximum penetration depth of the main mass of roots of the studied plants.K. prostratais a very plastic forage species that can grow on soils with a wide range of morphological properties, different salt content and their chemical composition. It is revealed that on the background of almost the same content of humus and high content of exchangeable magnesium micromorphological features represent the different degree of manifestation of primary pedogenic processes – humus accumulation, leaching of soluble salts, gypsum accumulation, carbonate enrichment, solonetzization. Despite the different content of exchangeable sodium, in all soils there are fresh clay or humus-clay illuvial coatings, indicating the manifestation of the modern eluvial-illuvial redistribution of fine matter (lessivage or illimerization).

Small droplet bouncing on a deep pool

Droplet bouncing on liquid surfaces frequently occurs for low-Weber-number impacts. Previous studies typically used large droplets with oscillation initiated by their creation process but without determining the effects of these oscillations. Here, we use small droplets, providing the means to reduce oscillations to show that the probability of the droplet bounce does not depend on the droplet oscillations. The time from the moment of contact to the maximum penetration depth was found to be independent of the Weber number for droplets of fixed diameter but increased with an increase in diameter. Both the maximum penetration depth and the maximum rebound height increased monotonically with the Weber number. A simple model predicting the maximum penetration depth was proposed and validated through comparison with experimental data.

Effects of Different Welding Parameters on Weld Joint Penetration in TIG Welded Stainless Steel Plate

The effects of process parameters of TIG welding on weld depth of penetration of welded joints of stainless steel plate of SS304 grade has been studied. The optimum combination of process parameters has been suggested to achieve maximum depth of penetration. Design of experiment (DOE) was used to plan and design the experiment to study the effects of parameter on these stresses. The input parameters considered in present investigation were welding current, gas flow rate, root face and welding speed. L9 Orthogonal Array (OA) technique was used to formulate the experimental layout. It was concluded that the maximum depth of penetration (DOP) was found at optimal setting of parameters of welding current (110 A), gas flow rate (10 LPM), root face (1.5 mm) and welding speed (31.578 mm/min.) and the optimum response value is 5.6961 mm.