Slit Type Research Articles

Characteristics of Gas–Liquid Two-Phase flow in rectangular narrow slits with varying cross sections driven by large pressure drop

Pressure pipelines and vessels inevitably contain some defects. Under the most unfavorable load combinations, these defects may gradually develop into through-wall cracks. High-pressure subcooled fluid leaks through these cracks, and two-phase gas–liquid flow often occurs within the cracks. In this study, natural through-wall cracks were replaced with narrow rectangular slits with varying cross sections. Experiments were conducted to investigate the variation patterns of gas–liquid two-phase leakage flow rates and pressure drops. The study focused on four types of rectangular narrow slits with varying cross sections, a width of 28 mm, a length of 80 mm, and a gap gradually ranging from 0.134 to 0.334 mm. The liquid-phase mass flow rate ranged from 150 to 700 kg/h, whereas the gas-phase mass flow rate varied from 0 to 20 kg/h. A one-dimensional homogeneous flow model was established by coupling two-phase velocity of speed calculations. This calibrated model was then used to predict pressure drops and flow parameters for gas–liquid two-phase flow in narrow rectangular slits with varying cross sections. The experimental data were analyzed to determine the two-phase leakage characteristics of different test pieces. The results show that the inlet–outlet pressure drop and flow quality are key factors affecting the two-phase leakage flow rate. The frictional pressure drop constitutes a major part of the total pressure drop along the flow path in different test pieces. Compared with the acceleration pressure drop in the expanding slit, that in the constricting slit is higher, with an increase of approximately 32 %. Among several commonly used empirical formulas for calculating two-phase viscosity, the McAdams and Dukler empirical correlations were found to be less suitable for high-velocity two-phase flows. In contrast, the Cicchitti empirical correlation provides better predictions, with a mean absolute deviation (MAD) and mean relative deviation (MRD) of no more than 8 %. The viscosity of the gas-phase medium affects the two-phase flow characteristics in narrow slits, which should be considered in practical engineering applications.

Morphological variants of Rouviere's sulcus and its significance in a patient undergoing laparoscopic cholecystectomy: An emerging paradigm.

Laparoscopic cholecystectomy (LC) is the gold-standard treatment for symptomatic cholelithiasis. To prevent bile duct injuries, various practices are recommended, one of which is the identification of Rouviere's sulcus (RS) and starting dissection above its level. So far, no uniform anatomical description of RS is available in the literature. After prospective observation of 302 patients, we have proposed a new classification based solely on gross morphology. The purpose of this study is to make surgeons well acquainted with its different anatomical variations and its significance for the prevention of complications. We performed a prospective analysis of 302 patients during LC, and various morphological variants of RS and its relationship with hepatobiliary anatomy were recorded. We have used the nomenclature as described by previous authors and added a few. A total of 330 patients were included in our study. We could not visualise the sulcus due to dense adhesion in 28 patients. RS was absent in 24.1% of cases and was present in various forms in 75.8% of cases. Amongst these, the open type was found in 28.8% of cases, fused type was found in 4.8% of cases, groove type was found in 24.8% of cases, pit type was found in 8.2% of cases, close type was found in 14.4% of cases, slit type was found in 8.7% of cases and scar type was found in 10% of cases. Using RS as a landmark, we could perform surgery safely in all cases. The RS can be described as closed, slit, open, fused, groove, pit or scar type.

Effective Stiffness and Damping Analysis of Steel Damper to Lateral Cyclic Loading

Steel dampers are components used in building structures to reduce vibration and energy generated by dynamic loads such as earthquakes. Several factors affect the effectiveness of steel dampers in reducing energy, including the cross-sectional area, mass distribution, cross-sectional geometry, and material stiffness. The cross-sectional geometry or shape of the steel damper can affect how energy is absorbed and dissipated in the structural system. Cross sections with different geometric variations can have different mechanical responses to dynamic loads. This study aims to analyze which type of steel damper is effective in terms of stiffness and damping capacity against lateral cyclic loads. The steel damper cross-sectional variations used are slit steel dampers (SSDs), tapered steel dampers (TSDs), and oval steel dampers (OSDs). Cyclic testing of the dampers used displacement control with the same target deviation for all three damper types. The results showed that the stress and strain distributions of the oval steel damper were more even than those of the other two models. The variations in the energy dissipation capacities of the three cross-section variations are relatively the same. However, the slit steel damper type has the best stiffness compared to the other two types. This research is ultimately expected to influence the science of the structure of a building in preventing and anticipating earthquakes or other disasters. Doi: 10.28991/CEJ-2024-010-07-017 Full Text: PDF

The Effect of Hot Pressing on the Mechanical Properties of Metal Composites (AI/Sic) Result from Metallurgical Processes with Heating Temperature Variations in Bushing Making

The manufacture of Al/SiC alloy matrix composites has been widely carried out by researchers through powder metallurgy techniques. Bushings are slit cylindrical type bearings that serve to support the shaft. Bushings can be made by powder metallurgy, to get the perfect compaction process, compaction can be done by high temperature or Hot Pressing. A hot press will make the powder softer/plastic, making it easier during the perfect compaction process. For this reason, heating must be controlled in order to obtain a homogeneous product. Al/SiC metal matrix composites are alloyed materials of different types of materials, as matrices in this case are aluminum and as reinforcement are SiC particles (ceramics) made by powder metallurgy techniques. In this study, the Al/SiC composite composed of 70% Al - 30% SiC and Hot Pressing temperature variations of 100, 150 and 200°C with a pressure of 5000 kg and a holding time of 10 minutes. In the sintering process, the temperature used is 450, 500 and 550°C with a holding time of 2 hours. The results of this study show, in hardness testing it is known that the value of bushing hardness increases as the temperature of Hot Pressing increases.

A comparative study of internal heat transfer enhancement of impingement/effusion cooling roughened by solid rib and slit rib

In the present study, we conducted a conjugate heat transfer (CHT) analysis for double-wall cooling with impingement and effusion, incorporating various types of ribs, using the Reynolds-averaged Navier–Stokes (RANS) method and the modified shear stress transport (SST) turbulence closure model (SST-KIC), accounting for the Kato-Launder modification (K), intermittency (I), and crossflow (C) transition effects. We comprehensively discussed the impact of slit type (parallel, inclined, convergent, and divergent), open-area ratio (β = 5%, 20%, and 40%), and jet Reynolds number on the turbulent flow and heat transfer in a double-wall cooling with slit ribs. Our findings indicated that the introduction of slit ribs significantly improved heat transfer and its uniformity on the target wall, albeit with a slight increase in pressure loss. The overall Nusselt number and thermal-hydraulic performance (THP) in cases with slit ribs gradually decreased with β, yet remained up to 17% and 13% higher than those observed on a smooth target wall. Notably, the open-area ratio of the slit rib exhibited a more pronounced effect on heat transfer over the target plate. For the divergent slit rib within the Reynolds number range of 4000–16 000, the heat transfer enhancement ratio reached the highest value at β of 0.05. In addition, we computed the entropy production caused by fluid friction and heat transfer, as well as the overall entropy production in double-wall cooling at different β and Re. The analysis revealed that the slit rib target plate performed better than the solid rib target plate, showing a distinct advantage in terms of total entropy production.

Design and calibration of a beta ray spectrometer for laboratory applications

This article presents the design, construction, and characterization of a low-cost, home-built, open-air magnetic field-based β-ray spectrometer suitable for use in graduate physics laboratories. Prime equipment such as electromagnet and GM tube with counter were characterized for their working. Two types of slits were designed and later one type of slit was used in the measurement. Finally, the working of the spectrometer setup was characterized by β -rays of the ‘204Tl’ source. The measured endpoint energy ‘Emax’ for the ‘204Tl’ source was found to be 0.658 MeV and 0.825 MeV respectively for θ = 30° and θ = 60°. These were only slightly different from the standard value of 0.764 MeV for the ‘204Tl’ source.

Factors Controlling the Pore Development of Low-Mature Marine–Continental Transitional Shale: A Case Study of the Upper Permian Longtan Shale, Western Guizhou, South China

The Upper Permian Longtan Shale is a significant reservoir in western Guizhou. To clarify the main factors controlling the low-mature marine–continental transitional shale pore development in western Guizhou, pore types were classified with scanning electron microscopy (SEM), and the pore developmental stages and morphological structures were quantitatively characterized by nitrogen adsorption isotherm analyses. Additionally, the qualitative or semi-quantitative relationships between the pore developmental stages and the main controlling factors were established via geochemical analysis. The results showed that the Longtan Shale pores include intergranular pores, intragranular pores, organic pores, and microfractures. The intergranular pore structures were categorized into ink-bottle, slit, layered, and irregular types. The intragranular pores were found to be of the elliptical, nearly circular, ink-bottle, and irregular varieties. The organic pores were categorized into elliptical, bubble-like, and irregular polygonal variants. The microfractures were only of the elongated type. The clay-mineral-related intergranular pores were the predominant pore type. The organic pores were found to be poorly developed. The mesopores were predominant, followed by macropores. The shale pore diameters ranged between 1 nm and 100 nm, and they are characterized by multiple peaks. The specific surface area (SSA) was primarily provided by nanopores in the range of 5 nm to 10 nm, such that the smaller pores provided a greater contribution to the SSA, and they are more conducive to shale gas adsorption and accumulation. Clay mineral content was the dominant internal factor controlling pore development and the SSA, with the illite–smectite mixed layer being the most obvious controlling factor. While too low or too high clay mineral content is adverse to macropore development, brittle mineral content, carbonate mineral content, and total organic carbon (TOC) content are adverse to pore development and the SSA. Thermal maturity has no remarkable control effect on pore volume and the SSA of non-organic pores.

Initial fabrication and characterization of chemically etched silicon slits for KOSMOS

KOSMOS is a low-resolution, long-slit, optical spectrograph that has been upgraded at the University of Washington for its move from Kitt Peak National Observatory’s Mayall 4-m telescope to the Apache Point Observatory’s ARC 3.5-m telescope. One of the additions to KOSMOS is a slitviewer, which requires the fabrication of reflective slits, as KOSMOS previously used matte slits machined via wire electrical discharge machining. We explore an innovative method of slit fabrication using nanofabrication methods and compare the slit edge roughness, width uniformity, and the resulting scattering of the new fabricated slits to the original slits. We find the kerf surface of the chemically etched reflective silicon slits are generally smoother than the machined matte slits, with an upper limit average roughness of 0.42 ± 0.03 μm versus 1.06 ± 0.04 μm, respectively. The etched slits have width standard deviations of 6 ± 3 μm versus 10 ± 6 μm, respectively. The scattering for the chemically etched slits is higher than that of the machined slits, showing that the reflectivity is the major contributor to scattering, not the roughness. This scattering, however, can be effectively reduced to zero with proper background subtraction. As slit widths increase, scattering increases for both types of slits, as expected. Future work will consist of testing and comparing the throughput and spectrophotometric data quality of these nanofabricated slits to the machined slits with on-sky data, in addition to making the etched slits more robust against breakage and finalizing the slit manufacturing process.

Effects of water on gas flow in quartz and kerogen nano-slits in shale gas formations

Understanding the gas-water two-phase flow behavior in a shale gas formation is important for reservoir simulation and production optimization. A molecular simulation study of gas-water flow in quartz and kerogen nano-slits (2–6 nm) at shale reservoir conditions (temperature: 313.15–393.15 K, pressure: 20–60 MPa) is reported in this work. The simulation results show that the existence of water in the hydrophilic quartz slits will form water films on the slit walls; while the presence of water in the hydrophobic kerogen slits will form water clusters in the central of the gas phase at low water saturation and a water layer at high water saturation. In both wetting conditions, water will take flow space and reduce gas flow path. However, water affects gas flow velocities in the two wetting types nano-slits in different ways due to the two opposite occupancies in the slits. The momentum transfer between water and methane molecules in the gas-water interface region plays an important role in the gas-water two-phase flow. The gas flow is more readily affected by water content in the quartz slit with an aperture greater than 2 nm. When the slit aperture is reduced to 2 nm, it is difficult to form a continuous gas or water phase, and the existence of water in both types of slits will reduce the velocity of methane. Increasing the temperature will accelerate the flow of methane and water because hydrogen bonds between water molecules as well as hydrogen bonds between water molecules and the walls are reduced. High pressure promotes the mixing of the methane and water molecules, resulting in the gas velocity decreasing in both quartz and kerogen slits. The flow mechanism of methane and water in nano-slits provide insights into theoretical models for shale gas production.

Simultaneous switching noise mitigation in high speed pcb using novel planar EBG structure

ABSTRACT Electronic circuits must address electromagnetic interference due to high-speed transmissions and simultaneous switching actions. This paper proposes a design of novel planar EBG structure L Bridge with embedded slit type with 3 × 3 array fashion, which can be used in a plane layer of a printed circuit board to reduce simultaneous switching noise (SSN). Two sets of pattern such as alternate structure and entire embedded pattern are considered and measured the cut-off frequencies. The performance of the structure is simulated, experimentally verified using R&S®ZVH Vector Network Analyser for the frequency range 0.1 to 10 GHz and compared the outcomes. It is observed that for the −50 dB of noise depth, proposed structure is achieved 1.6 GHz to 10 GHz as lower and upper cut-off frequency. In addition, this concluded the noise suppression using equivalent circuit model and parallel plate wave guide theory. Signal integrity on this structure is also analysed with single-ended and differential mode signal transition. Eye pattern is generated and compared for measuring and validating the signal quality while using this EBG structure.

Infrared slit light-based scanning type portable device for monitoring of cataract

Age-related cataracts are reported to be responsible for over 50% of world blindness and are considered a priority eye disease by the World Health Organization. Cataracts progress slowly and often have no subjective symptoms, so regular examination is required for early detection and treatment. We report on the design and development of a portable slit-light-based cataract detection device using near-infrared light and a scanning mirror. Imaging results were obtained by scanning cataract model eyes made from dimethylpolysiloxane and starch mixture and enucleated swine eye with induced cataracts. The fabricated system has adequate sensitivity to detect the smallest cataract formation and progress of cataract in the induced cataract eye and such measurements are useful for early detection of cataract. The results indicate that our fabricated slit-light device could be an easy-to-handle and low-cost tool for remote/routine detection and diagnosis of ocular diseases (like cataracts) without a need for an ophthalmologist.

Rouviere's sulcus - An anatomical landmark for safe laparoscopic cholecystectomy: A cross-sectional study

IntroductionLaparoscopic cholecystectomy (LC) has been established as the gold standard treatment for symptomatic gallstones, however surgeons face the risk of injuring bile ducts and vessels due to the inherent limitations of laparoscopy. MethodsThis is a cross-sectional study done in the Department of Surgery, Shree Birendra Hospital (SBH) on patients who were posted for LC. The study period was through April 2021 to September 2021. During LC, the anatomy of RS was noted and classified into Group A (RS present) or Group B (RS absent). Data analyses were performed considering a p-value of <0.05 as statistically significant. ResultsRS was present in 169 (93.9%) out of 180 cases. The open sulcus type was found in 114 cases (67.5%), followed by closed type in 26 (15.4%), slit sulcus type in 22 (13.0%), and scar type in 7 (4.1%) cases. Injury to cystic artery occurred in one case (0.15%) of Group A while in two cases (18.18%) of Group B (p-value = 0.001). The adjusted operative time in Group A and Group B were 50.61 ± 10.33 min and 69.86 ± 15.28 min respectively (p-value = 0.005). There was significant difference between Group A and Group B in conversion to open surgery - 01 (0.59%) and 04 (36%) respectively (p-value < 0.001). Surgical Site Infection (SSI) was detected in nine (5.33%) cases among Group A and in three (27.2%) cases among Group B (p-value = 0.028). ConclusionRS can be considered as an important anatomical landmark for safer LC with fewer injuries to cystic artery, SSI, conversion to open surgery and shorter operative time.

Analysis of Several Electromagnetic Band Gap Topologies for Reducing Simultaneous Switching Noise

In the case of high-speed PCB design, the use of electromagnetic band gap (EBG) structure technology is useful in reducing simultaneous switching noise (SSN) in high-frequency applications. In high-frequency processes, parasitic filters are ineffective. Conducted emission is reduced by including the planar EBG structure into PCB plane layers. Various planar structures are taken and simulated in this research, including LC type, Z-Bridge with embedded double square, L-Bridge with slit type, alternating impedance, slit type EBG, Triple square type, and two topology type structures. A frequency sweep of 0 GHz to 10 GHz is used with a FEM solution. Theoretical calculations of the structures are performed and compared to simulation results, which show that they are very similar. Based on the best bandwidth and noise depth, the L-Bridge with slit and Triple square type cases were chosen, constructed, and analyzed using a vector network analyzer; it was discovered that the noise depth and bandwidth are in good accord. In addition, the AC analysis-Electric Field distribution for power and ground planes is explored, and the maximum and minimum field levels may be understood as a consequence.

ROUVIERE'S SULCUS : A NOVEL ANATOMICAL LANDMARK FOR SAFE LAPAROSCOPIC CHOLECYSTECTOMY

Introduction-The information of surgical anatomy is imperative for the safe implementation of any surgical procedure. A less well-recognized xed internal anatomical landmark in laparoscopic cholecystectomy is Rouviere's sulcus. The current literature provides only scarce and heterogeneous data regarding this groove. The present study is intended to identify and study the frequency, orientation, and anatomic subtype of Rouviere's sulcus in cases of laparoscopic cholecystectomy. A prospective obse Material And Method- rvational study was conducted on 70 patients from May 2020 to October 2021 at Department of General Surgery, Dr. S. N. Medical College, Jodhpur, Rajasthan. Patients from both sex and above 18 years of age with symptomatic gall stone disease were included. Databases were searched with the following keywords: ssure or sulcus of the caudate process, incisura dextra, incisura dextra of Gans, Rouviere's sulcus, sillon du processus caudé. Statistical analysis done and results and observations were concluded. Out of 70 patients, 58 (82.86%) patients had Rouviere' Result- s sulcus. Open type of sulcus was present in 45 (64.28%) patients. Closed type of sulcus was present in 13 (18.57%) patients. Slit type was present in 5 (7.14%) patients. Scar like was present in 4 (5.71%) patients and sulcus was not identiable in 3 (4.26%) patients. We hereby concl Conclusion- ude that, Rouviere's sulcus is a consistent surgical landmark during laparoscopic cholecystectomy. Identication of the sulcus during laparoscopic cholecystectomy help us to avoid bile duct injuries

Comparison of Bubble Characteristics and Their Application Effects in Shearing Type and Pressurized Dissolution Type Microbubbles

Microbubbles are tiny bubbles with a 1–100 μm diameter. They have unique chemical and physical characteristics compared to ordinary bubbles that have diameters on the order of several tens of micrometers．However, the effect of generation method on microbubble characteristics has not been fully understood and these findings can have important implications in a wide range microbubble applications. The aim of this study is to investigate the characteristics of microbubbles generated by different generation methods and evaluate the application effect. Two types of microbubble generator (shear type and pressurized dissolution type) were used in this experiment. The shear type generator used in this study was a slit shear type generator developed in our laboratory. It was confirmed that microbubble size distributions and the microbubble adsorption to substances in water were affected by the generation method.

Cyclic Responses of Two-Side-Connected Precast-Reinforced Concrete Infill Panels with Different Slit Types

This study aimed to study the cyclic behavior of two-side-connected precast-reinforced concrete infill panel (RCIP). A total of four RCIP specimens with different slit types and height-to-span ratios modeled at a one-third scale were tested subjected to cyclic lateral loads. The failure mode, hysteretic behavior, lateral strength, stiffness degradation, ductility, and energy dissipation capacity of each RCIP specimen were determined and analyzed. The specimens experienced a similar damage process, which involved concrete cracking, steel rebar yielding, concrete crushing, and plastic hinge formation. All the specimens showed pinched hysteretic curves, resulting in a small energy dissipation capacity and a maximum equivalent viscous damping ratio lower than 0.2. The specimens with penetrated slits experienced ductile failure, in which flexural hinges developed at both slit wall ends. The application of penetrated slits decreased the initial stiffness and lateral load-bearing capacity of the RC panel but increased the deformation capacity, the average ultimate drift ratios ranged from 1.41% to 1.99%, and the lowest average ductility ratio reached 2.48. The specimens with high-strength concrete resulted in a small slip no more than 1 mm between the RC panel and steel beam, and the channel shear connectors ensured that the RC infill panel developed a reliable assembly with the surrounding steel components. However, specimens with concealed vertical slits (CVSs) and concealed hollow slits (CHSs) achieved significantly higher lateral stiffness and lateral strength values. Generally, the specimens exhibited two-stage mechanical features. The concrete in the CVSs and CHSs was crushed, and flexural plastic hinges developed at both ends of the slit walls during the second stage. With increasing concrete strength, the initial lateral stiffness and lateral strength values of the RCIP specimens increased. With an increasing height-to-span ratio, the lateral stiffness and strength of the RC panels with slits decreased, but the failure mode remained unchanged.

Petrographic and Geochemical Controls on Methane Genesis, Pore Fractal Attributes, and Sorption of Lower Gondwana Coal of Jharia Basin, India.

The Barakar coal seams of Jharia Basin have been evaluated for the geochemical and petrographic control of coalbed methane (CBM) reservoir characteristics. The coal core samples are analyzed for the total gas content, gas chromatography, stable isotopes (δ13C1), and geochemical, petrographic and vitrinite reflectance. The significant face (1.6–7.6%) and butt (0.9–5.3%) cleat intensities specify the brittle characteristics of coal seams and also favor the gas flow mechanism. The thermal cracking position of hydrocarbon compounds was evaluated, which signifies the excellent source rock potential of coal for gas genesis. The inputs of type III and IV organic matter illustrated by the van Krevelan diagram signify thermally matured coal seams. The low values of sorption time (τ) between 2.1 and 5.6 days designate excellent diffusion characteristics that is favored by the cleat intensities. The values of total gas content and sorption capacity (VL) reveal that moderate saturation indicates a higher gas content, attributed to the seam thickness and thermal maturity. Similarly, the CH4 concentrations (89.4–96.6 vol %) display that the genesis pattern is a function of thermal maturity; however, some samples fall under the mixed type substantiated by the stable isotope (δ13C1) (−25.40 to −64.90‰), emphasizing bacterial hold by seasonal influx of freshwater. The ternary facies diagram (Vmmf, Immf, Lmmf) also supports notable generation of methane gas and storage in the coal seams of the Jharia Basin. The volume percentage of each maceral determined from petrographic study was used to estimate the fraction of conversion (f) of the organic content (0.19–0.97). The values of “f” indicate that the Barakar coal has undergone maximum conversion, which may be attributed to the older early Permian coal and placed at a greater depth after deposition due to the basin sink. The high fraction of conversion and thermal maturity may also be explained due to the existence of volcanic intrusion (sills and dykes). The uniformity in the distribution of functional groups is shown by Fourier transform infrared spectra representing moderate to stronger peaks of aromatic carbon (CO and C=C) between 1750 and 1450 cm–1, which indicates that the presence of a larger total organic carbon content likely validates the removal of aliphatic compounds during gas genesis. The variations in the BET curve have been categorized as H1 hysteresis following the type II adsorption pattern, suggesting that cylindrical pores and some of the coal samples have a type IV H4 hysteresis pattern, characterized as the slit type of pores. The average values of the pore diameter indicate the dominance of mesopores suitable for gas storage and release and hence a major part of the pore volume is contributed by the mesopores having a width mainly between 2.98 and 4.48 nm. The significant role of the meso-macropore network (D1 fractals) in methane storage of the coal matrix is represented by a moderate positive relationship of VL with D1, which accentuated that meso-macropores developed due to devolatilization and dehydration of organic matter and also by geochemical alteration of macerals and minerals formed heterogenetic inner surfaces suitable for gas adsorption. The estimated recoverable resource applying Mavor Pratt methods is 8.78 BCM, which is found to be a more realistic resource value for the studied CBM block.

Significance of Rouviere’s Sulcus in Hepatobiliary Surgery: A Cadaveric study

Background: Rouviere’s sulcus (RS) was first identified in 1924 by Henri Rouviere. It lies oblique to the anterior and inferior border of the liver and holds the right portal pedicle. Material and Methods: The study was conducted in the Department of Anatomy of a Medical College in Maharashtra, India, on 45 cadaveric livers. The morphological observations made were: presence/ absence RS; direction of RS (oblique/ horizontal/ vertical); sulcus type ( deep/ slit/ scar); length, width and depth; presence of right hepatic pedicle; distance of the hepatic vessels from edge of the sulcus . Results: 40 livers showed the presence of Rouviere’s Sulcus. It was absent in five specimens. Direction was horizontal in 40%, oblique in 57.5% and vertical in 2.5% .26 livers showed a deep type of sulcus, 12 showed the slit type and 2 showed scar type .29 livers showed the right hepatic pedicle entering the RS. Average length, depth, of the RS was 2.35 cm and1.07 cm respectively. The average width was 0.32cm at medial end, 0.22cm at midpoint and 0.1cm at lateral end. Present study has added the details of depth of vessels from the edge of RS, which was not recorded in earlier studies. Depth of vessels from the edge of the sulcus was average 5mm (0.5cm) for the right branch of the hepatic artery and was 12mm (1.2cm) for the right branch of portal vein. Conclusion: Rouviere’s sulcus is a reference landmark for surgeons during laparoscopic surgeries on gall bladder and during hepatic resection to avoid injuries. This study wishes to provide detailed morphological data of the Rouviere’s Sulcus to hepatobiliary surgeons including depth of hepatic vessels in the RS as an added parameter to aid them in their surgical endeavor. KEY WORDS: Rouviere’s sulcus, Anatomical Landmark, Morphology, Depth, Hepatobiliary Surgery.

Performance Analysis of a Permanent Magnet Synchronous Generator using SS400 Rolled Steel Sheets for the Rotor Core

This paper deals with a permanent magnet synchronous generator (PMSG) for diesel engine generators. Generally, a silicon steel sheet is used to minimize eddy current losses of the stator and rotor cores of a generator. However when a silicon steel sheet is employed to produce the core of the stator and rotor, manufacturing costs increase due to the high cost of the silicon steel sheet. To reduce these costs, a 5 mm SSC400 rolled steel can be used as an alternative to the silicon steel sheet. However, the SS400 rolled steel with a thickness of 5 mm can increase the eddy current losses of the core. In this paper, in order to overcome this problem, a slit type rotor core is employed. In this case, eddy current losses can be reduced, resulting in improved THD (Total Harmonics Distortion) of the induced EMF (Electro-Motive Force). The eddy current losses and THD of the induced EMF according to the number of slits is also analyzed. Moreover, a prototype is produced for the final model, and the effectiveness is confirmed through experiments.

Experimental investigation on bend-region crack detection using TE11 mode microwaves

ABSTRACT This study experimentally investigates the efficacy of TE11 mode microwaves in detecting bend-region cracks. Three types of bends with different dimensions were deployed in a 3 m piping system and then tested, with an axial or circumferential slit machined at different angular positions to simulate a crack. The TE11 mode microwaves were excited using self-designed TE11 mode microwave probes and utilised for crack detection. The experimental results show clear reflection peaks at the bend position, demonstrating the feasibility of applying TE11 mode microwaves in the detection of bend-region cracks. Furthermore, the peak location of reflection is in accordance with the angular position of the slit. The findings also indicate that the peak amplitude of reflection is affected by the factors of mode conversion of microwaves at a bend. In addition, the experimental results also manifest an excellent signal-to-noise ratio to both two types of slits, suggesting that the microwave NDT is a powerful tool for bend-region inspection.