Empty Tubes Research Articles

Investigation of newly designed Alternate Perforated V-Notch (APVN) twisted tape with heat transfer characteristics

Swirl device is seen as a path to enhance the efficiency of a thermal switch. Swirl device with fabricated form of porosity and v-cuts twisted tape (tt) inner pipe insert helps to augment performance by improving the heat transfer (U) coefficient. This work is related to the thermal performance factor (TPF), friction factor (ff) and Nusselt (NNu) number in the inner tube inserted with a innovative design of Alternate Perforated V-Notch (APVN) tape having twisted ratio 6.25 incorporating porosity amount of Rp = 1.087% and width (w/W) ratio = 0.333, were investigated features to improve heat transfer rate. Enhancement in turbulent generation of the primary flow into the secondary flow with this design. Experiment test was performed on a pipe in pipe tubes of (d) internal diameter of 0.013 m with test section length of 0.9 m. Temperature of the warm water had kept constant at 60 °C within the Reynolds number range of 2246–16,224. The heat exchanger with empty tube (without tt) and the input of normal twisted tape (tt) has been checked. In addition to the investigated range, NNu, ff and TPF in the tube with APVN twisted tape insertion were observed (Rp - ratio) 1.833–2.276, 2.155–4.549 and 1.84–1.778 times more than the values of empty tube. The presented work is very useful in the field of energy conservation through maximum transfer of heat in the industrial process.

Bending behavior of triply periodic minimal surface foam-filled tubes

Foam-filled tubes represent one of the best energy-absorbing components for future crashworthiness applications. Triply Periodic Minimal Surface (TPMS)-filled tubes were investigated under quasi-static and dynamic three-point bending loading conditions. The TPMS-filled tubes enhanced specific energy absorption up to 46% compared to the sum of empty tubes and the core response separately. The validated computational models were used to extend the computational study to investigate graded core of TPMS-filled tubes under bending loading. The study results show that the mechanical response of TPMS-filled tubes can be tuned using different relative densities or/and distributions of relative density of the core.

Study on energy absorption behavior of bionic tube inspired by feather shaft of bean goose

To improve the crashworthiness and energy absorption of the thin-walled tube, micro-CT is used to observe the section of the feather shaft, we extract the “sawtooth” and “semicircle” structure to design five kinds of bionic thin-walled tubes. The simulation results of axial compression and three-point bending show that the bionic tubes have higher energy absorption efficiency than the traditional square tube. At the same time, quasi-static compression experiment is carried out on BFTZ4 bionic tube (the inner sides are “sawtooth”) with the best energy absorption in numerical simulation. The energy absorption of bionic tube is compared with that of traditional square tube, and its crushing behaviors is studied. It is found that the mean load and specific energy absorption of the bionic empty tube are 1.65 times and 1.35 times that of the square empty tube, respectively. The mean load and specific energy absorption of the bionic filled tube are 1.27 times and 1.24 times that of the square filled tube, respectively. This study provides theoretical and experimental basis for the bionic design of crashworthiness.

Apically Extruded Debris during Instrumentation using Different Engine Driven File Systems: A Comparative In Vitro Study

AIM: The aim of the present study was to evaluate and compare the amount of apically extruded debris using three engine driven systems. METHODS: Sixty mandibular premolars with single root were used. The samples were divided into three groups with 20 teeth for each group: group 1 Neolix Neoniti A1 (25, 0.08), group 2 WaveOne GOLD Primary (25.07, red), and group 3 Protaper Next (PTN), using X1 (017/0.04), X2 (025/0.06) files. All files were used to prepare the root canals according to manufacturer instruction. Root canal preparation for each group was done according to manufacturer instructions using 16:1 gear reduction hand piece powered by a torque controlled electric motor. Debris collection was made using apparatus described by Myers and Montgomery. The extruded debris weight was measured by subtracting the weight of the empty Eppendorf tubes from the weight of the debris containing tubes results were statistically analyzed. RESULTS: One-way analysis of variance test revealed that there was statistically significant differences between all the three groups being tested (p < 0.001) showed that apical extrusion of the debris of WaveOne Gold was the least followed by Neolix Neoniti and finally PTN which showed the most apical extrusion of debris with a significant difference between all groups. CONCLUSIONS: WaveOne Gold was found to be the least apical extruded debris system among all groups.

Hepatic enzymes and immunoinflammatory response to Bio-C Temp bioceramic intracanal medication implanted into the subcutaneous tissue of rats

Our purpose was to evaluate the biocompatibility and hepatotoxicity of a new bioceramic intracanal medicament, Bio-C Temp (BIO). The biological properties of BIO were compared with calcium hydroxide-based intracanal medicament (Calen; CAL), used as gold pattern. Polyethylene tubes filled with BIO or CAL, and empty tubes (control group, CG) were implanted into subcutaneous tissue of rats. After 7, 15, 30 and 60 days, the samples were embedded in paraffin for morphological, quantitative and immunohistochemistry analyses. At 7 and 60 days, blood samples were collected for analysis of serum glutamic-oxaloacetic transaminase (GOT) and glutamic-pyruvic transaminase (GPT) levels. The data were submitted to two-way ANOVA and Tukey’s test (p ≤ 0.05). No significant difference was detected in serum GOT and GPT levels among BIO, CAL and CG specimens. In all periods, BIO specimens exhibited lower number of inflammatory cells and immunoexpression of IL-6, a pro-inflammatory cytokine, than CAL specimens. The reduction of these parameters was accompanied by significant increase in the collagen content and in the immunoexpression of IL-10, a cytokine involved in the tissue repair, over time. Our findings indicate that Bio-C Temp is biocompatible and had no hepatotoxicity effect.

Evaluation of dry specimen transport and processing time using an isothermal amplification high-risk human papillomavirus assay

BackgroundDry specimen transport has shown equivalence to traditional liquid transport using a novel high-risk Human papillomavirus assay. Considering that dry transport might cross obstacles during cervical cancer screening in low and middle resource settings, this study was designed evaluate different processing time of dry specimen transport using the same isothermal amplification hrHPV assay. MethodsThere were 564 women between the ages of 30–55 recruited from colposcopy clinic. For each patient, two endocervical samples were collected and placed into empty collection tubes by physician. Samples were stored at room temperature until analyzed for hrHPV using the AmpFire assay at two time points: 2 days and 2 weeks. 511 of the 564 participants with positive hrHPV were provided colposcopy exam and quadrant biopsy. ResultsA total of 1128 endocervical samples from 564 patients were detected by the Ampfire assay. Good agreement was found between two time periods (Kappa ​± ​Standard error ​= ​0.67 ​± ​0.04). Sensitivity (2days/2weeks) for CIN2+ was 95.28% (95% CI: 92.14%–98.42%) vs 90.57% (CI (86.65%–94.49%) and specificity (2days/2weeks) was 22.47% (CI 19.33%–25.61%) vs 28.15% (CI 24.23%–32.07%) respectively. The difference for Ampfire HPV detection in sensitivity for CIN2+ for the two time periods was not significant (P ​= ​0.227), while the difference in specificity for CIN2+ was significant (P ​= ​0.001). The difference in Ct values 29.23 (CI 28.15–30.31) and 29.27 (CI 28.19–30.35) between two time points was not significant (P ​= ​0.164). ConclusionProcessing dry brush specimens can be delayed up to 2 weeks. Using the AmpFire assay platform which supports cervical cancer prevention programs in low-to-middle-income countries (LMICs).

Simultaneous determination of monochloropropanediol esters and glycidyl esters in vegetable oils by acidic transesterification-gas chromatography-mass spectrometry

建立了一种气相色谱-质谱同时测定植物油中3-氯丙二醇酯、2-氯丙二醇酯和缩水甘油酯的方法。称取0.25 g样品,依次加入内标工作液、四氢呋喃和酸性溴化钠溶液,50 ℃水浴反应15 min,加入6 g/L碳酸氢钠溶液终止反应,使用正己烷提取,上层液经氮气吹干后用四氢呋喃溶解。随后加入1.8%(v/v)硫酸-甲醇溶液于40 ℃恒温水浴中反应16 h,加入饱和碳酸氢钠溶液终止反应。样液再经过净化、衍生、提取、氮吹后,以1 mL正己烷定容,过膜,进样测定。采用毛细管气相色谱柱DB-5MS(30 m×0.25 mm×1 μm)分离,程序升温,电子轰击电离(EI)源检测,在选择离子扫描模式下,以保留时间和特征离子信息进行定性分析,内标法定量。结果表明,3-氯丙二醇酯、2-氯丙二醇酯和缩水甘油酯在0.01~0.80 mg/L范围内线性关系良好,相关系数(r2)均在0.999以上,方法的检出限(S/N=3)和定量限(S/N=10)分别为25、25、20 μg/kg和75、75、60 μg/kg。选取4种不同基质类型的样品,在低、中、高3个不同添加水平下的平均回收率为89.0%~98.7%,相对标准偏差(RSD)在2.05%~7.81%之间。采用该方法测定了市售112份植物油样本,其中有84份样本检出3-氯丙二醇酯、2-氯丙二醇酯和缩水甘油酯。与已建立的国家标准方法(GB 5009.191-2016)和行业标准方法(SN/T 5220-2019)相比,该方法所采用的酸性酯交换法可避免副反应(碱性条件下3-氯丙二醇、2-氯丙二醇及3-溴丙二醇向游离态缩水甘油转化)的发生,同时该方法也弥补了国家标准和行业标准无法对3-氯丙二醇酯、2-氯丙二醇酯和缩水甘油酯同时进行测定的缺失。该方法实验操作更高效,结果更准确、重复性更好,对我国植物油中3-氯丙二醇酯、2-氯丙二醇酯和缩水甘油酯污染水平的控制、检测标准的制定和生产工艺的优化具有一定的理论和现实意义。

Compressive Behavior and Analytical Model of Ultra-Early Strength Concrete-Filled FRP Tube With Zero Curing Time

Fiber-reinforced polymer (FRP) has been widely used in civil engineering due to its light weight, high strength, convenient construction, and strong corrosion resistance. One of the important applications of FRP composites is the concrete-filled FRP tube (CFFT), which can greatly improve the compressive strength and ductility of concrete as well as facilitate construction. In this article, the compressive performances of a normal concrete-filled FRP tube (N-CFFT) column with 5-hour curing time and an ultra-early strength concrete-filled FRP tube (UES–CFFT) column with zero curing time were studied by considering the characteristics of rapid early strength improvement of ultra-early strength concrete and the confinement effect of the FRP tube. Monotonic axial compression tests were carried out on 3 empty FRP tubes (FTs) without an internal filler and 6 CFFT (3 N-CFFTs and 3 UES-CFFTs) specimens. All specimens were cylinders of 200 mm in diameter and 600 mm in height, confined by glass fiber–reinforced polymer (GFRP). Test results indicated that the compressive bearing capacity of the specimens increased significantly by adopting the ultra-early strength concrete as the core concrete of the CFFT, although the curing time was zero. It was also shown that the compressive behavior of the UES–CFFT specimens with zero curing time increased significantly than that of the N-CFFT specimens with 5-hour curing time because the former was able to achieve rapid strength enhancement in a very short time than the latter. The ultimate compressive strength of UES–CFFT specimens with zero curing time reached 78.3 MPa, which was 66.2 and 97.2% higher than that of N-CFFT with 5-hour curing time and FT specimens, respectively. In addition, a simple confinement model to predict the strength of UES–CFFT with zero curing time in ultimate condition was introduced. Compared with the existing models, the proposed model could predict the ultimate strength of UES–CFFT specimens with zero curing time with better accuracy.

In-situ observation of the extrusion processes of Acrylonitrile Butadiene Styrene and Polylactic Acid for material extrusion additive manufacturing

In material extrusion (MatEx) additive manufacturing, solid polymer filaments are fed into extruders to generate extrudates that are needed to build 3D plastic parts. There is a finite gap between the inner surface of an extruder and the edge of a filament, which facilitates the insertion and translation of the filament inside the extruder. It is still not clear how this gap is filled during the extrusion. On the other hand, it is important to know this information, for example, to model the distributions of temperature and pressure during the extrusion. In this work, the gap-filling processes of Acrylonitrile Butadiene Styrene (ABS) and Polylactic Acid (PLA) filaments were directly observed through a heated glass tube. The glass tube functioned as the extruder in our case. A criterion was first developed to determine whether the gap was filled at a specific location of the tube. The gap-filling processes were then observed for different combinations of extrusion temperatures and feed rates. ABS and PLA filaments, which consisted of different colors, were custom-made to aid in the observation. Although ABS and PLA were, respectively, amorphous and semi-crystalline polymers, for both materials, we found: i) the gap inside an extruder was filled through three different steps during the initial stage of extrusion; ii) the gap-filling level depended on extrusion temperature and feed rate; and iii) there was no noticeable difference in the gap-filling level when the extrusion started with an empty tube or resumed after the printing had been paused.

Effect of cap gap and welded seam strength on concrete-filled steel tube arch bridge ribs

In this paper, the quantitative analysis is investigated for the concrete-filled steel tube (CFST) ribs strength that contained defects. The friction Coulomb model was used to investigate the interaction between the steel tube and the concrete core. Based on the non-destructive testing data, the finite element analysis is simulated with ABAQUS to obtain the strength of serviced concrete-filled steel tube ribs containing cap gaps and reduced spiral-welded seam strength which is exposed to weak eccentric axial compression. The results show that spiral-welded seam defects have weaker influence on the bearing capacity of CFST than that on empty steel tube. However, they have a significant influence on CFST local yield failure mode. The cap gap defects have effect on the shape of N-ε relationships. For CFSTs with composite defects, welded seam defects weakened local steel tube restrain capacity to concrete, resulting in CFST bending failure.

The efficacy of new neuronal growth factor in the healing of the sciatic nerves in rabbits.

Regeneration of nervous tissue is unpredictable and an ideal growth factor to influence the healing of the injured nerves is not available. A recent study in rats had shown that a new neuronal growth factor (NNGF) was effective in the early healing of the sciatic nerves. The aim of this experimental study is to test the efficacy of NNGF in the healing of iatrogenic division of the sciatic nerves in a larger animal (rabbits). White New Zealand 20 male rabbits of 6 months of age were divided into two groups. Intramuscular ketamine and xylazine were used to anesthetize the animals. The sciatic nerves were divided using scalpel blade 15 and 10/0 Vicryl was used to repair the divided neural tissue. In the study group, 10 mg/kg body weight of NNGF was instilled on the top of the divided nerves and the wound was closed. At 4 weeks, the operated limbs were observed for any trophic skin changes. Nerve conduction studies were carried out using train-of-four-Watch SX, Organon (Ireland) Ltd., and Ireland. The rabbits were put to death humanely and the sciatic nerves were removed and delivered to the pathologist in 2% formalin. The pathologists were blinded about the two groups. Electromyographic study done at 4 weeks showed in the untreated group; the mean twitches 1-T4 was 0.45 ± 0.31% and in the treated group, the average was 77.912 ± 5% (P > 0.001). Microscopic anatomy in the treated group revealed prominent healing by regeneration was evidenced by showing growth of its proximal segments into an empty endoneurial tube which was not seen in the control group. In the control group, the nerves showed no histological element of healing by regeneration. NNGF proves that in a larger animal at 4 weeks profoundly influenced early regeneration of experimentally created divisions of myelinated nerve tissue.

Behavioral, neurochemical, and neuroimmune changes associated with social buffering and stress contagion

Social buffering can provide protective effects on stress responses and their subsequent negative health outcomes. Although social buffering is beneficial for the recipient, it can also have anxiogenic effects on the provider of the social buffering – a phenomena referred to as stress contagion. Social buffering and stress contagion usually occur together, but they have traditionally been studied independently, thus limiting our understanding of this dyadic social interaction. In the present study, we examined the effects of preventative social buffering and stress contagion in socially monogamous prairie voles (Microtus ochrogaster). We tested the hypothesis that this dynamic social interaction is associated with coordinated alterations in behaviors, neurochemical activation, and neuroimmune responses. To do so, adult male prairie voles were stressed via an acute immobilization restraint tube (IMO) either alone (Alone) or with their previously pair-bonded female partner (Partner) in the cage for 1 h. In contrast, females were placed in a cage containing either an empty IMO tube (Empty) or one that contained their pair-bonded male (Partner). Anxiety-like behavior was tested on the elevated plus maze (EPM) following the 60-mins test and brain sections were processed for neurochemical/neuroimmune marker labeling for all subjects. Our data indicate that females in the Partner group were in contact with and sniffed the IMO tube more, showed fewer anxiety-like behaviors, and had a higher level of oxytocin expression in the paraventricular nucleus of the hypothalamus (PVN) compared to the Empty group females. Males in the Partner group had lower levels of anxiety-like behavior during the EPM test, greater activation of corticotropin-releasing hormone expressing neurons in the PVN, lower activation of serotonin neurons in the dorsal raphe, and lower levels of microgliosis in the nucleus accumbens. Taken together, these data suggest brain region- and neurochemical-specific alterations as well as neuroinflammatory changes that may be involved in the regulation of social buffering and stress contagion behaviors.

Biocompatibility assessment of different root-end filling materials implanted subcutaneously in rats: An in vivo study.

Root-end filling materials are used in surgical endodontic treatment to seal the teeth periapically. Ideally, these materials should prevent bacterial leakage by tightly sealing the canal, be biocompatible with the periapical tissues, and preferably stimulate the regeneration of dentin, contributing to the success of treatment. The purpose of this study was to evaluate and compare the biocompatibility of the GuttaFlow® Bioseal cement in relation to MTA Angelus® and Zical® after implantation into the subcutaneous tissue of rats. Eighteen male albino rats were used in the study. Four polyethylene tubes were implanted in the backs of the rats (3 tubes containing the test materials and 1 empty tube as a control). Nine animals were sacrificed at each interval of 7 and 30 days, and the implants were removed with the surrounding tissue. The samples were evaluated for stromal inflammatory response, fibrous tissue formation, vascular reactivity, and the presence of multinucleated giant cells (MNGCs). On day 7, the capsules in all subgroups revealed moderate to severe inflammatory reactions with the presence of inflammatory cells, multiple irregular collagen fibers, dilated blood vessels, and MNGCs. However, on day 30, tissue organization was more evident with a reduction in the inflammatory response. In this time interval, the tissue in contact with GuttaFlow Bioseal showed progressive healing with a wellformed fibrous capsule. Conversely, the tissue close to MTA Angelus revealed a fibrous capsule of limited organization with mild pericapsular fibrosis and vascular congestion. Zical showed a mild to moderate persistent inflammatory reaction and vascular reactivity. The 3 cements demonstrated more severe irritation at the beginning that became milder with time. GuttaFlow Bioseal yielded better tissue organization than MTA Angelus and Zical. Thus, these findings strongly suggest that GuttaFlow Bioseal is a promising material for root-end filling.

First report of the order Mysida (Crustacea) in Antarctic marine ice caves, with description of a new species of Pseudomma and investigations on the taxonomy, morphology and life habits of Mysidetes species.

SCUBA diving explorations of three islands off Dumont d’Urville Station at the coast of Adélie Land, East Antarctica, enabled the observation of marine ice caves. Sampling in this unusual habitat yielded a total of three species of Mysidae, altogether previously poorly known or unknown to science. Pseudommakryotroglodytumsp. nov. is described, based on the structure of the antennal scale, telson and on cornea-like lateral portions set off against the main body of eyeplates. Mysidetesilligi is re-established at species level after almost a century in synonymy. Re-descriptions are provided for M.illigi and M.hanseni, based on types and ice cave materials. Keys to the Southern Ocean species of Pseudomma and to the world-wide species of Mysidetes are given.Phylogenetic trees are provided for the genera Pseudomma and Mysidetes. 18S rDNA sequences of P.kryotroglodytum differ from GenBank sequences of other Pseudomma species. First sequence data are given for species of the genus Mysidetes: 18S differs between the two examined species and COI is quite diverse between and within species.We found previously unknown, probably sensorial structures in these ice cave species: in P.kryotroglodytum, the basal segment of the antennula shows a pit-like depression with striated pad on the bottom and a median cyst, connected with the bottom of the eyeplate cleft. M.illigi shows a female homologue of the appendix masculina bearing a field of modified setae. Subsequent investigations demonstrated these structures also in species from other habitats.The feeding apparatus and stomach contents of the three ice cave species point to brushing of small particles (detritus, microalgae) from available surfaces, such as sediment, rock and the ice surface. Differences in the feeding apparatus are very subtle between the two Mysidetes species. The high content of fat bodies in M.hanseni could help it to survive periods of starvation. The large storage volume of the foregut in P.kryotroglodytum points to the collection of food with low nutritional quality and could help to balance strongly fluctuating food availability.Summer specimens of M.hanseni showed a bimodal frequency of developmental stages in the marsupium and bimodal size-frequency distribution of free-living stages. The females with younger brood (embryos) were, on average, larger and carried more marsupial young than those with older brood (nauplioid larvae). All examined incubating and spent females showed (almost) empty foreguts and empty ovarian tubes, suggesting possible semelparity and death following the release of young. The absence of juveniles and immature females from summer samples suggests that growth and accumulation of fat and yolk occur outside ice caves, while such caves could be used by fattened adults as shelter for brooding. A provisional interpretation proposes a biannual life cycle for M.hanseni, superimposed with shifted breeding schedules, the latter characterised by early breeding and late breeding females, probably in response to harsh physical and trophic conditions along the continental coast of Antarctica.

Flexural strength of composite high-density polyurethane foam filled light gauge square steel tubes

The improved flexural strength of composite high-density Polyurethane (PU) foam (Density 150 kg/m3) filled Light Gauge Square Steel (LGSS) tubes is presented in this paper. 4Point bending tests are conducted on Empty and PU Foam filled LGSS Tubes having b/t ratios of 125,100 and 83.33. Numerical study carried out using ABAQUS software to validate experimental results. Using past theoretical models, moment-rotation graphs are prepared for empty and PUFF tubes. The results define the triaxial crushing strength of PU foam in pure bending zone due to confinement by the steel envelope in pre and post buckling regimes and its influence on the composite bending strength (combined flexure and shear). Various types of composite filled tube beams are selected and ratios of their flexural strengths to their own weights are calculated and compared. Observed highest Strength-to-weight ratio for current research composite filled tubes.

Biological and antimicrobial properties of the association Ambroxol and a water-soluble viscous liquid as a vehicle for a tricalcium silicate-based sealer

This study aimed to investigate the antimicrobial and biological properties of Ambroxol associated with glycerin (GLI), propylene glycol (PG), and polyethylene glycol (PEG) as a possible vehicle for an experimental tricalcium silicate sealer, with the intention of developing a new biomaterial. Mouse undifferentiated dental pulp cells (OD-21) were cultured, and the effects of different association on cell proliferation and inflammatory cytokine production were investigated. Antimicrobial adhesion of Enterococcus faecalis to setting sealers at 2 h was evaluated. Polyethylene tubes containing experimental sealers and empty tubes were implanted into dorsal connective tissues of 12 male 3- to 4-months-old Wistar rats (250–280 g). After 7 and 30 days, the tubes were removed and processed for histological and immunohistochemical analyses. ANOVA followed by Bonferroni correction and ANOVA followed by Tukey test was used for parametric data and Kruskal–Wallis followed by Dunn for nonparametric (p < 0.05). Cell proliferation was dose-dependent, since all association were cytotoxic at higher concentrations; however, Ambroxol–PEG showed significantly higher cytotoxicity than other association (p < 0.05). In addition, irrespective of the association, no cytokine production was observed in vitro. Ambroxol–GLI reduced bacterial viability, whereas Ambroxol–PEG increased (p < 0.05). Histological examination showed no significant difference in the inflammatory response (p > 0.05) and mineralization ability in all association. Additionally, IL-1β and TNF-α were upregulated on Ambroxol–PEG in relation to Control at 07 days (p < 0.05). Ambroxol–GLI was the best vehicle for experimental tricalcium silicate sealer, as it promoted an increase in antimicrobial activity without altering the inflammatory response or mineralization ability.

Performance enhancement of a split air conditioner using porous material inside the evaporator pipes

AbstractIn this experimental study, a porous material is used inside the pipes of the evaporator as the main heat exchanging device in the air conditioning cycle. The used porous material consists of stainless steel balls of different diameters. As a case study, refrigerant R454B, which is a drop‐in replacement to refrigerant R410A, is used as a working fluid in the air conditioner thermodynamic cycle. Four different porosities were used during the experimental tests; 100% (empty tube), 46%, 40%, and 33%. This study investigated the influence of variation of porosity as well as outside air temperature and refrigerant evaporation temperature on the cycle coefficient of performance, evaporation capacity, pressure drop, and power consumption during the compression process. Measured evaporation temperatures and indoor temperatures during tests were in the range of 1.5–12°C and 18–25°C, respectively. The use of porous material in the evaporation heat exchanger resulted in a considerable increase in the cycle evaporation capacity and coefficient of performance. Varying porosity from 100% to 33% resulted in an average percent increase of cycle evaporation capacity and coefficient of performance by 48.8% and 84.3%, respectively. Also, decreasing porosity from 100% to 33% resulted in an average percent increase in power consumption during the compression process by about 27%. An average percent increase of power consumption of compressor by about 25.9% is also reported, when evaporation temperature increased from 1.5°C to 12°C. Increasing outside air temperature from 27.1°C to 39.5°C resulted in decreasing evaporation capacity and coefficient of performance by 35.2% and 34.5%, respectively, and in increasing compressor power consumption by about 14.3%. A considerable pressure drop was recorded during the evaporation process when using porous material. The volumetric evaporation capacity, as well as compressor discharge temperature, are increased by increasing evaporating temperature and by decreasing evaporator porosity. The increase in air ambient temperature resulted in a considerable increase in refrigerant mass flow rate.

Magnetic Flux Circulation in the Saturnian Magnetosphere as Constrained by Cassini Observations in the Inner Magnetosphere

AbstractIn steady state, magnetic flux conservation must be maintained in Saturn’s magnetosphere. The Enceladus plumes add mass to magnetic flux tubes in the inner magnetosphere, and centrifugal force pulls the mass‐loaded flux tubes outward. Those flux tubes are carried outward to the magnetotail where they deposit their mass and return to the mass loading region. It may take days for the magnetic flux to be carried outward to the tail, but the return of the nearly empty flux tubes can last only several hours, with speeds of inward motion around 200 km/s. Using time sequences of Cassini particle count rate, the difference in curvature drift and gradient drift is accounted for to determine the return speed, age, and starting dipole L‐shell of return flux tubes. Determination of this flux‐return process improves our understanding of the magnetic flux circulation at Saturn and provides insight into how other giant planets remove the mass added by their moons.

The SARS-CoV-2 main protease Mpro causes microvascular brain pathology by cleaving NEMO in brain endothelial cells

Coronavirus disease 2019 (COVID-19) can damage cerebral small vessels and cause neurological symptoms. Here we describe structural changes in cerebral small vessels of patients with COVID-19 and elucidate potential mechanisms underlying the vascular pathology. In brains of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected individuals and animal models, we found an increased number of empty basement membrane tubes, so-called string vessels representing remnants of lost capillaries. We obtained evidence that brain endothelial cells are infected and that the main protease of SARS-CoV-2 (Mpro) cleaves NEMO, the essential modulator of nuclear factor-κB. By ablating NEMO, Mpro induces the death of human brain endothelial cells and the occurrence of string vessels in mice. Deletion of receptor-interacting protein kinase (RIPK) 3, a mediator of regulated cell death, blocks the vessel rarefaction and disruption of the blood–brain barrier due to NEMO ablation. Importantly, a pharmacological inhibitor of RIPK signaling prevented the Mpro-induced microvascular pathology. Our data suggest RIPK as a potential therapeutic target to treat the neuropathology of COVID-19.

Live black soldier fly larvae (Hermetia illucens) provisioning is a promising environmental enrichment for pigs as indicated by feed- and enrichment-preference tests

Live black soldier fly larvae (BSFL) could function as environmental enrichment for pigs as they are edible, odorous, manipulable, and destructible, though the interest of pigs in live BSFL is unestablished. In this study, three trials were performed to assess this interest in order to verify the suitability of live BSFL as enrichment. Eight (Trial 1 & 2) and 16 (Trial 3) pairs of weaned pigs were included. In Trial 1, the relative motivation of pigs to consume live BSFL compared to corn, raisins and feed pellets was evaluated in no-choice and subsequent two-choice preference tests including all (combinations of) feed items. In Trial 2, the feed items in the no-choice and two-choice tests were provided in tubes that had to be rooted or pushed to access the feed items. In this trial BSFL, corn, feed pellets, and empty tubes were compared. In Trial 1 & 2 each day had two 15 min tests occurring six hours apart. In Trial 3 the long-term interest in live BSFL provided in the tubes for a 5-day period was compared to feed pellets provided in tubes, to jute sacks, and to rubber balls attached to chains. Tubes with live BSFL or pellets were refilled every morning. The relative interest was determined through intake of feed items and/or time spent interacting with the items, as measured by 1.5- or 1 min scan sampling. In Trial 3, the time spent on oral manipulation of pen mates was also scored through scan sampling. In all trials the interaction with and consumption of live BSFL was significantly higher compared to the other items, indicating a clear preference for live BSFL, and pigs remained engaged with BSFL as long as they were accessible. In Trial 3, interest in live BSFL decreased on day 5 compared to day 1, interest in jute sacks and feed pellets decreased on day 3 compared to day 1, and interest in rubber balls attached to chains was continuously low. Pigs also spent less time on oral manipulation of pen mates when having access to live BSFL, pellets, or jute sacks, compared to rubber balls attached to chains. Overall, pigs showed high and extended interest in live BSFL, confirming their suitability as edible environmental enrichment. Pigs were willing to work for access to live BSFL by rooting and pushing tubes, which can be employed when providing live BSFL as enrichment commercially.