Reasons resulting in the collapsed tubing near wellhead in high pressure and high temperature deep well during well testing and measures to prevent the collapsing

Because various reasons, the tubing near wellhead was collapsed during well testing in high pressure and high temperature deep well when the outer pressure was less than collapsing strength. To find the reasons in the abnormally collapse and countermeasures, first the quality of the tubing was checked. It was founded that the collapse was not resulted from the defect of the tubing. Then, force and stress exerted in the tubing was analyzed taking XS2 well as an example. The analysis results were concluded as follows. The collapsing strength of tubing decreased due to the axial tensile, which is seriously at the upper tubing especially. During injecting, the additional axial force that was caused by the temperature effect increased the tubing near wellhead to suffer axial tensile and further reduced the collapsing strength of tubing near wellhead. Reinforcing defect, prohibiting defect tubing to trip in hole, according to the calculation to impose appropriate annular pressure, selecting size nozzle to reverse pumping and controlling the reverse pumping speed and pressure, prohibiting to be opened flow and reducing or releasing the annular pressure can prevent the well testing tubing down-hole being collapsed at the wellhead.

Formability determination of AZ31B tube for IHPF process at elevated temperature

Ring hoop tension test and tube bulging test were carried out at elevated temperatures up to 480 ℃to evaluate the formability of AZ31B extruded tube for internal high pressure forming （IHPF） process. The total elongation along hoop direction and the maximum expansion ratio （MER） of the tube were obtained. The fracture surface after bursting was also analyzed. The results show that the total elongation along hoop direction and the MER value have a similar changing tendency as the testing temperature increases, which is quite different from the total elongation along axial direction. Both the total elongation along hoop direction and the MER value increase to a peak value at about 160 ℃. After that, they begin to decrease quickly until a certain rebounding temperature is reached. From the rebounding temperature, they begin to increase rapidly again. Burnt structure appears on the fracture surface when tested at temperatures higher than 420 ℃. Therefore, the forming temperature of the tested tube should be lower than 420 ℃, even though bigger formability can be achieved at higher temperature.

Primary culture and identification about brain microvascular endothelial cells of rabbits

Objective:To establish a simple and efficient culture method of primary rabbit brain microvascular endothelial cells,provide important carriers and tool cells for the research of related cerebrovascular diseases.Methods:The cerebral cortexes of rabbits were collected aseptic and inoculated after cutting,passing through cell sieve,bovine serum albumin density gradient centrifugation,typeⅡcollagenase digestion,finally inoculated and cultured.The cultured cells were identified by cell morphological observation and angiogenesis experiment.Results:Under the inverted microscope,the cells were short fusiform or polygonal,and grew in clusters and adhere to the wall.After the cells were densely fused,they would be in a typical monolayer flat,“pebbled"mosaic arrangement.Tube formation test had the ability to form tubes structure.Conclusion:This method can successfully separate and cultivate primary rabbit brain microvascular endothelial cells.

Industrial Elaboration by Extrusion of PVC Tubes Loaded with Micronized Dura Palm Kernel Shell Powder

We present in this work how to use the dura palm kernel shell powders as loads for the elaboration by extrusion of PVC tubes. The transformation of dura palm kernel shells into micronized shell powder as well as its characterization was the subject of recent work. We carried out, the formulations by using the industrial scales of precision, the mixtures of the instrants with an industrial machine of mark HENSHLLE N˚2 MAIN 570762, the routine tests by ATG/DSC then by IRTF, the extrusion of the tubes with an extruder twin-screw with 9 rooms of transformation finally the tests of conformity by the observations and the analyses. We obtained for the formulations the dosage of 0%, 4.01%, 12.54%, 23.03%, 32.01%, 38.01%, 51.02% representing the percentage of hull powder in the mixture, the machine mixing gave perfectly homogeneous powders, the routine tests showed that the hull powder keeps all its properties until the end of the shaping whatever the percentage of hulls contained in the PVC, the extrusion gave tubes for each formulation and the conformity tests gave perfectly round tubes of diameter 90 × 82 mm, a coloration going from white grey at 0% to dark black at 51.02% showing the influence of the carbon black and the color of the shell powder according to its proportion. The infrared of the tubes obtained shows for each formulation a variation of the CH2 and CH bonds and a decrease of the −OH bonds. The thermogravimetric analyses and the differential calorimetric analyses of the tubes of each formulation, show each time that the quantity of shell powders in the mixture influences the PVC tubes obtained. Thus, we obtain a variation of the phase temperatures according to the dosage, giving from 108.72˚C to 76.56˚C for the glass transition temperature and from 494.71˚C to 414.56˚C for the melting temperature, at the DSC and a progressive decrease of the mass following the heat absorption with each time 4 phases instead of 5 for the unloaded PVC tubes at the ATG according to the dosage.

Validation of the TASS/SMR-S Code for the Core Heat Transfer Model on the Steady Experimental Conditions

The SMART （System-integrated Modular Advanced ReacTor） which is a 330 MWt advanced integral PWR was developed by the KAERI （Korea Atomic Energy Institute） for electricity generation and seawater desalination. To enhance its safety, the various design concepts were adopted such as the most containing of the RCS （reactor coolant system） components and a PRHRS （passive residual heat removal system）. To ensure the safety and performance of the SMART, a thermal hydraulic evaluation and safety analysis are performed by the TASS/SMR-S code. It uses a one dimensional node/path modeling and point kinetics for the core power simulation. The code also has specific models reflecting the design features of the SMART such as a helical tube and PRHRS heat transfer models. In this study, the validation of the core heat transfer model in the TASS/SMR-S code on the steady conditions was performed with the Bennett＇s heated tube tests and THTF （thermal hydraulic test facility） experiment. From the results of the TASS/SMR-S code calculation, the CHF （critical heat flux） point and the fuel rod surface temperature were predicted conservatively compared to the test results.

Comparison on the Perinatal Complications for Newborns between by IVF-ET and Natural Delivery

This study was conducted to compare the perinatal complications for newborns by In vitro fertilization with embryo transfer(IVF-ET)and natural delivery.Respectively 50 cases of the IVF-ET and 50 cases of the natural delivery were selected from Hospital of Chengde Medical University as research subjects.All the recruited cases were selected with the newborns from April,2021 to April,2022.Defining the IVF-ET as the test group,while the natural delivery as the control group to compare and analyze the perinatal situations and the incidences of complications in both the groups.This study showed that the incidences of pregnancy-induced hypertension,diabetes,multiple pregnancy,premature delivery,and cesarean section in the test group were significantly(p<0.05)higher,than the control group.In addition,the incidences of neonatal respiratory distress syndrome(NRDS)and hyperbilirubinemia of newborns in the test group were statistical(p<0.05)higher,compared to the control group.In contrast,there are no statistically significant differences in terms of hypoglycemia,pneumonia,and neonatal asphyxia incidences between the two groups(p>0.05).Interestingly,there is a significant difference(p<0.05)in the incidences of neonatal cardiac anomalies in both groups,however,no significant differences(p>0.05)were observed in terms of birth defects including hypospadias,the cleft lip and palate,polydactyly,anal atresia,and esophageal atresia in both the groups.In summary,the test tube babies of IVF-ET are more susceptible to complications in their perinatal stage compared with natural delivery newborns,therefore,during the clinical development physicians should strengthen clinical attention and take proactive healthcare management,in order to maintain the health and life of the newborns.

Construction of nanoreactors on TiO_(2)nanotube arrays as a POCT device for sensitive colorimetric detection

With increasing attention to personalized healthcare,miniaturized and easily implementable devices are desired for point-of-care testing(POCT).Herein,hydrophilic patterns were designed on freestanding TiO_(2)nanotube arrays(Ti NTs)as nanoreactors for a naked-eye colorimetric assay.With a high aspect ratio,TiN Ts can provide a long observation length combined with a limited volume.Moreover,by combining the photocatalytic property of TiO_(2)and spatiotemporal controllability of light,hydrophilic nanoreactors were fabricated with minimal volume,and thus the indicator and analyte are limited in a confined void by the hydrophobic surroundings,thus allowing a higher sensitivity for sensing.We believe the proposed sensing platform could provide a promising strategy in developing POCT devices for routine health monitoring.

Dopamine D2 receptors in the dorsomedial prefrontal cortex modulate social hierarchy in male mice

Social hierarchy greatly influences behavior and health.Both human and animal studies have signaled the medial prefrontal cortex(mPFC)as specifically related to social hierarchy.Dopamine D1 receptors(D1Rs)and D2 receptors(D2Rs)are abundantly expressed in the mPFC,modulat-ing its functions.However,it is unclear how DR-expressing neurons in the mPFC regulate social hierarchy.Here,using a confrontation tube test,we found that most adult C57BL/6J male mice could establish a linear social rank after 1 week of cohabitation.Lower rank individuals showed social anxiety together with decreased serum testosterone levels.D2R expression was significantly downregulated in the dorsal part of mPFC(dmPFC)in lower rank individuals,whereas D1R expression showed no significant difference among the rank groups in the whole mPFC.Virus knockdown of D2Rs in the dmPFC led to mice being particularly prone to lose the contests in the confrontation tube test.Finally,simultaneous D2R activation in the subordinates and D2R inhibition in the dominants in a pair switched their dominant-subordinate relationship.The above results indicate that D2Rs in the dmPFC play an important role in social dominance.Our findings provide novel insights into the divergent func-tions of prefrontal D1Rs and D2Rs in social dominance,which may contribute to ameliorating social dysfunctions along with abnormal social hierarchy.

Synthesis of aluminum nanoparticles as additive to enhance ignition and combustion of high energy density fuels

High energy density fuels are critical for hypersonic aerospace propulsion but suffer from difficul- ties of ignition delay and incomplete combustion. This research reports aluminum nanoparticles （A1 NPs） assisted ignition and combustion of high energy density JP-10 fuel. A1NPs with a size of 16 nm were fabricated through a mild and simple method by decomposing AIH3. Et20 with the addition of a surfactant ligand. The uniform size distribu- tion, nanoscaled size and surface ligand make A1 NPs stably suspend in JP-10, with 80% NPs being dispersed in the liquid fuel after six months. A shock tube test shows that the presence of 1 wt-% A1 NPs can significantly shorten ignition delay time at temperature of 1500 to 1750 K, promote the combustion, and enhance energy release of JP-10. This work demonstrates the potential of A1 NPs as ignition and combustion additive for high energy density fuel in hypersonic applications.

Patulous Eustachian tube (PET), a practical overview

Symptoms of patulous Eustachian tube(ET),particularly autophony,can overlap with other conditions,and can arise from a variety of causes.We review the pathophysiology of“speech hyper-resonance syndromes”,and possible mechanisms,including resonances in the tympanic membrane,Eustachian tube and nasopharynx.Treatment can be directed at the eardrum or the ET depending on site of pathology.We review typical presentations,examination findings,and useful clinical tests to distinguish PET from other disorders,and our philosophy of management.

Dr. Chang Min Chueh——Father of Test Tube Babies

CHANG Min Chueh (1908-1991)—the father of test tube babies, was a Chinese-born American scientist and inventor who developed the first oral contraceptives. Dr. Chang was from Dunhou Township, Lanxian County, Shanxi Province. In middle school, he was fascinated with biology. Later he was accepted to the Animal Psychology Department at Qinghua University.