Small Internal Diameter Research Articles

Adrenal SGLT1 or SGLT2 as predictors of atherosclerosis under chronic stress based on a computer algorithm.

Chronic stress promotes the development of atherosclerosis, causing disruptions in the body's hormone levels and changes in the structural function of organs. The purpose of this study was to investigate the pathological changes in the adrenal gland in a model of atherosclerosis under chronic stress and to verify the expression levels of Sodium-glucose cotransporter (SGLT) 1 and SGLT2 in the adrenal gland and their significance in the changes of adrenal gland. The model mice were constructed by chronic unpredictable stress, high-fat diet, and Apoe-/- knockout, and they were tested behaviorally at 0, 4, 8 and 12 weeks. The state of the abdominal artery was examined by ultrasound, and the pathological changes of the aorta and adrenal glands were observed by histological methods, and the expression levels and distribution of SGLT1 and SGLT2 in the adrenal gland were observed and analyzed by immunofluorescence and immunohistochemistry. The predictive value of SGLT1 and SGLT2 expression levels on intima-media thickness, internal diameter and adrenal abnormalities were verified by receiver operating characteristic (ROC) curves, support vector machine (SVM) and back-propagation (BP) neural network. The results showed that chronic stress mice had elevated expression levels of SGLT1 and SGLT2. The model mice developed thickening intima-media and smaller internal diameter in the aorta, and edema, reticular fiber rupture, increased adrenal glycogen content in the adrenal glands. More importantly, analysis of ROC, SVM and BP showed that SGLT1 and SGLT2 expression levels in the adrenal glands could predict the above changes in the aorta and were also sensitive and specific predictors of adrenal abnormalities. SGLT1 and SGLT2 could be potential biomarkers of adrenal injury in atherosclerosis under chronic stress.

Investigation of shot sleeve distortion and oil cooling in high pressure die casting

It is well known that thermomechanical distortion reduces the service life of shot sleeves in high pressure die casting (HPDC) processes. However, the underlying phenomenon which causes the distortion is still not well characterized. While finite element models (FEM) have been used to analyze shot sleeve distortion, these have typically used simplified 2D representations and do not consider the effect of transient molten metal flow on heat transfer. In the present study, a 3D finite element (FE) model based on ANSYS used a staggered approach to study the sources of shot sleeve distortion and the effect of active oil cooling. Transient flow behavior during pouring, settling, and slow shot phases was simulated using a computational fluid dynamics (CFD) based model after which the temperature field and internal pressure distribution were imported into a structural model which was used to predict shot sleeve distortion at selected instants during a representative steady-state cycle. The simulation results were validated using data obtained from an HPDC machine and demonstrated good agreement. A comparison of large and small internal diameter (ID) shot sleeves showed that the former distort the most and that cooling channels are only moderately effective at minimizing distortion. Based on the complex 3D nature of shot sleeve distortion, the use of total indicator runout (TIR) is also proposed as a metric for minimizing distortion in shot sleeve designs. In addition to distortion, the thermal gradient in the shot sleeve was analyzed and it was noted that the largest source of heat loss is through the mounting flange attached to the HPDC machine frame, which is not an area typically considered for thermal management.

КОЛИВАЧ ЗВАРЮВАЛЬНОГО ІНСТРУМЕНТУ ДЛЯ АПАРАТА ПІДВОДНОГО ЗВАРЮВАННЯ МОКРИМ СПОСОБОМ

The paper defines the problem of automatic wet welding at a great depth in compressed conditions. A new design of the flux-cored wire feeding mechanism in an automatic wet welding machine with an original device for oscillating the electrode wire to ensure a continuous seam in the presence of non-guaranteed gaps in terms of space limitations is considered. This problem arises when special metal plugs are installed inside pipes of a small internal diameter to isolate or demarcate different environments, for example, coolant in deep pump systems, when plugging pipe outlets of oil and gas wells. Electric arc automatic welding is efficient enough to solve such a problem. Plug welding has certain problems associated with uneven gaps between the plug and the inner wall of the pipe, where the corner joint must be made. The original design of the oscillator of the welding tool is proposed and technically implemented in an automatic machine for the electric arc process, which provideswelding of such a joint. Ways for further development of the oscillator design with interesting improvements of capabilities are defined. A method of calculating such an oscillator based on structural kinematic schemes of its action has been developed. Presented on the real design of the oscillator as part of the welding machine feed mechanism. The developed oscillator is compact and efficient, and this can be seen from the given comparative plots and corresponding oscillograms. A successful industrial test of the development of a welding machine with a new feed mechanism took place with further commissioning. The new development can be used on other objects with conditions similar to those specified in the material of the article.

Development of Pipe Inspection Robot

Abstract: Pipelines have been a major source to transfer oil and gas from one destination to another as they are economical when compared to other transportation means. Usually metal pipes are used which can undergo corrosion, develop cavities and holes leading to leakage of fluid and develop irregularities on the inner surface. And therefore require proper periodic maintenance. The inspection of pipes is difficult as they carry toxic chemicals, fluids and most of the time have small internal diameter or bends and also usually underground which become inaccessible to humans. This brings the need to develop an inspection device.

Abstract No.: ABS1770: Cuffed versus uncuffed endotracheal tubes in infants undergoing elective surgery in prone position:peritubal leak at standardised ventilator settings

Background & Aims:The purpose of this study was to compare peritubal leak in cuffed and uncuffed tubes in infants at standardised ventilatorsettings. Secondary objective was to see incidence of accidental extubation and postoperative respiratory complications such as stridor and sore throat.Methods:With ethics committee approval, a prospective,randomised,clinical study was conducted. Patients aged between birth to 1 year, American Society of Anesthesiologists ASA grade I,II and III, requiring general anaesthesia with orotracheal intubation in prone position during elective surgery were included and children with parents not giving consent,children with airway anomaly, laparoscopic surgery, and emergency surgery were excluded. Tracheal tube size was judged as adequate if the leak pressure was 20 cm H2O or less. Tube was exchanged to next larger size if the leak pressure was too high and tube size was exchanged to next smaller size, when cuff pressure exceeded 20 cm H2O.Results:60 infants were studied.In group 1 in which cuffed tube was used, there were no leaks,on the other hand, in group 2,17 out of 30 patients had peritubal leak and tube was exchanged to next larger size uncuffed tube, p value was <0.001. Moreover, the incidenceof accidental extubation, post extubation sore throat and stridor was more in uncuffed group, It was 2/6/6 in uncuffed group and 0/3/4 in cuffed group respectively. Tracheal tube exchange rate was also higher in uncuffed group.Conclusion:We found that in microcuff paediatric endotracheal tube, there is less peritubal leak; selection of cuffed tube with small internal diameter compared to uncuffed tubes implicates a higher chance for adequate fit of the tube at cricoid ring and due to this there is least chance of accidental extubation in the prone position.Peritubal leakGroup I (n=30)Group II (n=30)Total (n=60) No.%No.%No.%Absent30100.01343.34371.7Present00.01756.71728.3

WC Decomposition Phenomena in ID-HVOF-Sprayed WC-CoCr Coatings Using Fine Powder Feedstock

Over the last few decades, the high velocity oxygen fuel (HVOF) spraying of WC-CoCr for internal diameter (ID) coating has attracted much interest for hard chrome replacement. Current demands for the ID coating of small cylindrical parts necessitates the use of specialized spray gun equipment and powder feedstocks with small particle size fractions. Due to the limited spray distance inside cylindrical parts with small IDs, the process control, spraying fine WC-CoCr powders, meets new challenges to avoid significant WC decomposition, which increases the risk of mechanical degradation. Within the scope of this study, ID-HVOF spraying using a fine-structured WC-CoCr (−15 + 5 μm) feedstock with a mean WC particle size of 400 nm is examined with respect to the WC decomposition phenomena using X-ray diffraction (XRD). Hence, a statistical design of experiments (DoE) is utilized to systematically analyze various spray parameter settings along with their interaction as part of the WC to W2C conversion.

Nests, eggs, clutch size, and nestlings of the Chestnut Seedeater (Sporophila cinnamomea), a vulnerable species of South America

We present information on the nests, eggs, clutch size, and nestlings of the Chestnut Seedeater (Sporophila cinnamomea), a migratory, globally vulnerable species restricted to the natural grasslands of South America. Despite its vulnerability, there is currently a remarkable lack of basic information on this species. We searched for nests from October to March 2018–2019 and 2019–2020 at 2 grassland areas in southern Brazil and monitored a total of 98 nests of 50 different breeding pairs throughout this period. Birds placed their nests on shrubs, clumps, and herbaceous plants, 42–51 cm above humid or dry ground, or water. Nests were low cups built out of native grass stems, inflorescences, and rootlets, held together with spider webs. Nests measured 4.86 cm (SD 0.40) largest internal diameter, 4.17 cm (SD 0.37) smallest internal diameter, 6.31 cm (SD 0.57) largest external diameter, 5.42 cm (SD 0.51) smallest external diameter, 4.04 cm (SD 0.45) internal height, and 4.74 cm (SD 0.52) external height. Clutches had 1–3 eggs. Eggs were mostly ovate, with a whitish to light beige background mottled with blotches and spots of darker beige and brownish tints. The mean egg size was 16.15 mm (SD 1.07) by 12.11 mm (SD 0.34) (n = 23). Results are part of ongoing research in the southern Brazilian grasslands, which aims to fill the gaps in the knowledge of the breeding biology of Chestnut Seedeater and thereby contribute to its conservation.

Effect of simple interventions on the performance of a miniature MFC fed with fresh urine

The aim of the present study is to enhance the performance of a microbial fuel cell (MFC) design by making simple interventions. Specifically, terracotta “t” and mullite “m” ceramics are tested as membranes while carbon veil and carbon cloth are used as electrodes. In the case of “m” cylinders different dimensions are examined (m: ID 30 mm x height 11.5 mm; sm: ID 18 mm x height 18 mm). The units operated continuously with urine as the feedstock. The best performing is the sm type (60–100 μW), followed by the t type (40–80 μW) and the m type (20–40 μW). Polarisation experiments indicated that activated carbon on the anode enhances the power output (t: 423 μW, sm: 288 μW). Similarly, the increase of the surface area and the addition of stainless steel mesh on the cathode improves the power performance for the “sm” and the “t” units. Furthermore, it is shown that the design with the smaller internal diameter, performs better and is more stable through time.

Carotid Occlusion Accentuates Aortic Stenosis and Cardiac Remodeling With Preserved Systolic Function in LDL Receptor-Deficient Mice.

Background: Carotid atherosclerotic disease is associated with aortic stenosis and reduced cardiac function. The causality between carotid and cardiac pathologies is unknown. We aim to explore the effects of carotid stenosis or occlusion on cardiac pathology and function.Methods and Results: We produced carotid obstruction or stenosis in 36 atherogenic mice with 150- or 300-μm tandem surgery or sham surgery. The structure and function of the heart were assessed by histology and animal ultrasound. The 150-μm group had larger plaque burden and thicker valve leaflets in the aortic root than did the control group. Also, the two surgery groups had a thicker left ventricular posterior wall and smaller internal diameter compared with controls. Increased myocardial fibrosis was also found in the 150-μm group compared with controls, although the surgery groups had preserved systolic function compared with that of controls.Conclusions: In a mouse model, carotid occlusion accentuated the formation of aortic stenosis and promoted ventricular remodeling without impairing systolic function. Carotid atherosclerotic plaque may be a pathogenic factor for aortic stenosis and ventricular remodeling.

Rolling spool—the question

When you pull and unwind a toilet roll, it rolls away from you, whatever angle the force is applied. But what happens when you pull on a spool with a smaller internal diameter than the outside?

Effect of surface characteristics on the antibacterial properties of titanium dioxide nanotubes produced in aqueous electrolytes with carboxymethyl cellulose.

Nanotubular structures were produced on a commercially pure titanium surface by anodization in an aqueous electrolyte that contained carboxymethyl cellulose and sodium fluoride. The internal diameters obtained were about 100, 48, and 9.5 nm, respectively. Several heat treatments at 200, 350, and 600°C were made to produce nanotubes with different titanium dioxide polymorphs (anatase, rutile). All tested surfaces were superhydrophilic, this behavior was maintained after at least 30 days, regardless of the heat treatment. Although in previous works the nanotube features effect on the bacteria behavior had been studied; this item still unclear. For the best of our knowledge, the effect of small internal diameters (about 10 nm) with and without heat treatment and with and without ultraviolet (UV) irradiation on the bacteria strains comportment has not been reported. From our results, both the internal diameter and the postanodized treatments have an effect on the bacteria strains comportment. All nanotubular coatings UV treated and heat treated at 350 and 600°C; despite they have different inner diameters, inhibit the bacteria growth of both Staphylococcus aureus and Pseudomonas aeruginosa strains. The nanotubular coatings obtained at 20 V and heat treated at 350°C produced the lower bacteria adhesion against both strains evaluated.

EXPERIMENT STUDY ON SEISMIC PERFORMANCE OF RUBBER FLEXIBLE PIPES FOR SEISMICALLY ISOLATED BUILDINGS

Rubber flexible pipes have been increasingly used in seismically isolated buildings. Whether it could work normally after the earthquake directly affects the function of the building. The vertical rubber flexible pipeline is selected as the research object. Base on the deformation requirement of 400 mm, the seismic performance test is carried out considering the influence of two nominal inner diameters and four different design lengths. The seismic damage evolution model, deformation and bearing capacity characteristics of this type of pipeline are compared and analyzed. The test results indicate that: The pipes with smaller design length cannot meet the expected deformation target. Such pipes experienced two key states： pipe stretching and single-sided fracture. And such pipes must be replaced after the earthquake; For pipes with a design length consistent with the code recommendations, deformation requirements can be met; The quantitative relationship between the nominal inner diameter and design length of the pipeline and its horizontal deformation ability was obtained through regression analysis; For pipes with an identical design length, the nominal inner diameter of the pipeline and the horizontal ultimate load at the time of failure are positively related. Meanwhile the ratio of ultimate load for the pipe with a large and small nominal internal diameter is smaller than the ratio of correspond inner diameter.

Radiographic evaluation of tracheal collapse in dogs by compressive technique

ABSTRACT The purpose of this study was to verify the applicability of the compressive radiographic technique (pressures of 5, 10, 15 and 20mmHg) in the diagnosis of tracheal collapse in small breed dogs, in lateral cervicothoracic radiography. Out of the 50 dogs evaluated, 25 presented tracheal collapse (TG group), 23 did not present tracheal collapse (CG) and two were excluded because they did not tolerate a pressure of 20 mmHg. The TG group presented a smaller internal diameter of the trachea in the region of the fourth cervical vertebra (D4) and at the entrance of the thorax (TDE) compared to the CG group, in all the radiographic projections performed, as well as within the TG group where the compressive technique differed from conventional. Furthermore, there was a correlation between the clinical sign of coughing during cervical collar use and the presence of radiographic tracheal collapse at a pressure of 20 mmHg. It was concluded that the compressive radiographic technique was feasible and efficient in confirming the diagnosis of tracheal collapse in dogs, especially in the pressure of 20 mmHg, where it was associated with clinical signs, and can be used in isolation or complementary to the conventional technique.

Experiments support simulations by the NEPTUNE_CFD code in an Upflow Bubbling Fluidized Bed reactor

Long tubes with small internal diameter find increasing applications in indirect concentrated solar receivers using an Upflow Bubbling Fluidized Bed of Geldart-A powders as heat carrier. Although successfully demonstrated for tubes of 0.5 to 1 m length, longer tubes are required to increase the solar energy capture efficiency and capacity. The fluidization phenomena differ with the tube length, and freely bubbling fluidization will be transformed into slugging, thus hampering the heat transfer. The behavior of Geldart-A powders in tall tubes of small I.D. has not been extensively studied. The research experimentally investigated the different fluidization modes in a 4 m long tube, and demonstrated the occurrence of freely bubbling at the bottom section of the bed, and slugging from a bed depth in excess of about 1.25 m. Slug characteristics (frequency, length, velocity) were measured and correlated. The results were used to validate 3D numerical simulations based on an Euler-Euler approach in the NEPTUNE_CFD code applied to a fine mesh of 15,000,000 cells. A positive match between experimental and simulation results concerning frequency and velocity of large bubble structures was obtained. The effect of mesh refinement on the slugging behavior prediction was discussed.

Electrochemically Modulated Liquid Chromatography in Fused Silica Capillary Columns.

Electrochemically modulated liquid chromatography (EMLC) uses electrical potentials, applied to a conductive chromatographic stationary phase (e.g., porous graphitic carbon [PGC]), to manipulate analyte retention. This paper reports the design of a capillary EMLC column with a smaller internal diameter (ID; 250 μm) than that of the standard bore predecessor (3.3 mm ID). The new capillary EMLC columns are configured so that the PGC stationary phase serves as the working electrode in a two-electrode electrochemical cell and simplifies electrode placement by obviating the need for a counter electrode. This configuration also eliminates the internal Nafion sleeve that is critical to operation for the standard bore columns, thereby avoiding Nafion deformation as a source of chromatographic band broadening and rupturing as a mode of column failure. Indeed, values for chromatographic efficiency obtained on the capillary columns meet or exceed those measured for the standard columns (20 000-40 000 vs 14 000 plates/m, respectively) with near symmetric elution bands (asymmetry factors of 1.1-1.4 for well-packed capillaries) that surpass band symmetries observed in all prior studies. A test suite of aromatic sulfonates was used to characterize the chromatographic performance of the capillary EMLC columns. Separations of this test mixture showed that retention factors for individual analytes could be manipulated by as much as 21× by changing the applied potential at the PGC stationary phase. Changes in retention behavior at different potential ranges, hypothesized to result from differences in adsorption orientation, were also observed and are consistent with past work. Collectively, the retention behavior unique to EMLC is operative in this new capillary configuration and promises to open new avenues in tuning LC separations.

Comparing ANSYS Fluent® and OpenFOAM® simulations of Geldart A, B and D bubbling fluidized bed hydrodynamics

PurposeThe purpose of this study is to assess the performance of ANSYS Fluent® and OpenFOAM®, at their current state of development, to study the relevant bubbling fluidized bed (BFB) characteristics with Geldart A, B and D particles.Design/methodology/approachFor typical Geldart B and D particles, both a three-dimensional cylindrical and a pseudo-two-dimensional arrangement were used to measure the bed pressure drop and solids volume fraction, the latter by digital image analysis techniques. For a typical Geldart A particle, specifically to examine bubbling and slugging phenomena, a 2 m high three-dimensional cylindrical arrangement of small internal diameter was used. The hydrodynamics of the experimentally investigated BFB cases were also simulated for identical geometries and operating conditions using OpenFOAM® v6.0 and ANSYS Fluent® v19.2 at identical mesh and numerical setups.FindingsThe comparison between experimental and simulated results showed that both ANSYS Fluent® and OpenFOAM® provide a fair qualitative prediction of the bubble sizes and solids fraction for freely-bubbling Geldart B and D particles. For Geldart A particles, operated in a slugging mode, the qualitative predictions are again quite fair, but numerical values of relevant slug characteristics (length, velocity and frequency) slightly favor the use of OpenFOAM®, despite some deviations of predicted slug velocities.Originality/valueA useful comparison of computational fluid dynamics (CFD) software performance for different fluidized regimes is presented. The results are discussed and recommendations are formulated for the selection of the CFD software and models involved.

Optimization of capillary tube dimensions using different Refrigerants for 1.5 ton mobile air conditioner

Capillary tube is one of the commonly used throttling devices in the refrigeration and the air conditioning systems. The capillary tube is made up of copper tube of very small internal diameter. It is of very long length and it is coiled to several turns so that it occupies less space. The internal diameter of the capillary tube used for the refrigeration and AC applications varies from 0.5 to 2.28 mm (0.020–0.09 inches). Capillary tube used as the throttling device in the refrigerators, deep freezers, water coolers and air conditioners.The objective of this research was to evaluate the optimum size of a capillary tube dimensions in a Air Conditioning system and to determine the Pressure drop across the capillary tube. The optimization was determined by mathematical calculation to evaluate increment length.

Morphological Phase Diagram of Gadolinium Iodide Encapsulated in Carbon Nanotubes

The melt phase encapsulation of gadolinium iodide (GdI3) in small internal diameter carbon nanotubes (CNTs) was explored to understand how the tubular structure of the host could chemically stabilize a hygroscopic metal halide. However, given the distribution of diameters in the as-received CNTs, the final sample consisted of mixed encapsulation products. These varied from the monoelemental iodine chain to the atomic layer deposition of the binary halide. Supported by density functional theory calculations, these observations led to the proposition of a morphological phase diagram for GdI3 encapsulation in CNTs as a function of the host’s internal diameter.

The Magic of Covered Self Expanding Metallic Stents: A Novel Therapeutic Approach for Bile Leaks

Introduction Bile leak is not an uncommon complication following hepatobiliary surgery. Leaks are treated with endoscopic sphincterotomy with or without stenting. Plastic stents have been used traditionally for this indication; however, CSEMS (covered self-expanding metallic stent) is a novel therapeutic approach. Case Presentation A 61-year-old gentleman with history of significant ethyl alcohol abuse, was brought to Orange Park Medical Center Emergency with complaints of right upper quadrant abdominal pain for 1 week along with fever and vomiting. Right upper quadrant was tender on palpation. There was no hepatosplenomegaly. White blood cell count was 18.6/L, bilirubin was 1.3 mg/dl. Computed tomography (CT) scan and ultrasound of gallbladder showed findings consistent with acute cholecystitis. Gallbladder was found to be gangrenous during laparoscopic cholecystectomy. Open cholecystectomy was performed. No bile leak was noted at the time of closure. Next day patient was found to have 100 ml of bile in Jackson-Pratt drain. Endoscopic retrograde cholangiopancreatography (ERCP) was done. A single filling defect was noted in the distal common bile duct suggestive of a stone with extravasation of the contrast material into the gallbladder fossa suggesting bile leak. A 1 cm biliary sphincterotomy was performed. A 10-French 7 cm long plastic biliary stent was placed across the area of leak. Patient had persistent bile leak. Repeat ERCP revealed bile leak from cystic duct remnant. A 10 cm plastic stent was placed. Patient had persistent bilious output after 2nd ERCP. Third ERCP was executed and a CSEMS was placed with proximal end above the cystic duct origin and the distal part into the duodenum. Drainage decreased markedly after that. Metallic stent was later removed without complication. Discussion Bile leak can be a challenging clinical entity. Endoscopic sphincterotomy with or without stenting reduces intraductal pressure and diverts the flow form the leaking site. Plastic stents are mostly used, however, CSEMS may provide better therapeutic alternative. The large diameter of these stents allows an effective drainage away from the leakage site. Furthermore, placing the stent across the injured site may help to seal it. So far, only plastic stents could be removed safely endoscopically if necessary. The disadvantage of plastic stents, however, is the small internal diameter which predisposes to occlusion by biliary sludge. CSEMS can help overcome this.1443_A.tif Figure 1: bile leak observed1443_B.tif Figure 2: Covered self expanding metallic stent

Operational performance analysis of spiral capsule robot in multiphase fluid

SUMMARYMinimally invasive surgery is a developing direction of modern medicine. With the successful development of controllable capsule endoscopies, capsule robots are very popular in the field of gastrointestinal medicine. At present, the study of intestinal robots is aimed at the pipeline environment of a single-phase liquid flow. But there exist food residues (i.e. solid particles) or liquid foods in the actual intestine, so intestinal fluid should be liquid–solid or liquid–liquid two-phase mixed fluid. For inner spiral capsule robots with different internal diameters and outer spiral capsule robots, using computational fluid dynamics (CFD) method, the operational performance indicators (i.e. axial thrust force, circumferential resisting moment and maximum pressure to pipeline wall) of spiral capsule robots are numerically calculated in the liquid–solid or liquid–liquid two-phase mixed fluid. By the orthogonal experimental optimization method, the optimum design of spiral capsule robots is obtained in the liquid–solid mixed fluid. The experimental verification has been also carried out. The results show that in the liquid–solid two-phase fluid, the axial thrust force and circumferential resisting moment of the spiral capsule robots decrease with the increase of the size or concentration of solid particles. In the same liquid–solid or liquid–liquid mixed fluid, the operational performance indicators of outer spiral robots are much higher than those of inner spiral robots, and the operational performance indicators of inner spiral robots with bigger internal diameters are higher than those with smaller internal diameters. Adding solid particles of high concentration in the pipeline containing liquid will reduce the drive performance of spiral capsule robots, but adding another liquid of high viscosity will improve the drive performance of spiral capsule robots.