Volumetric Efficiency Improvement by Overflow in Rolling Piston Compressor

The rotary compressor with rolling piston is a widely used compressor with less clearance volume, while it is minimized from normal scale to meso or micro scale, the input and exit ports dimension is limited by port requirement and lead to a certain clearance volume, therefore, keeping or improving its volume efficiency is an important issue. Although rolling piston compressor is a kind of compact structure compressor, the existence of the clearance volume is inevitable in a compressor, the more the clearance volume, the lower the volumetric efficiency of compressor. The overflow is a method to improve the volumetric efficiency of a compressor which had been discussed in wankel compressor, in the overflowing process the clearance space with high pressure is connected directly with the space with lower pressure, mostly that is in the moment, one of the chambers in the rotary compressor is at the end of the exhaust process, and another chamber is at the sucking stage or the initial compression process. The gas pressure in the clearance volume is visibly higher than that in the compression chamber. The high-pressure gas in the clearance volume flows into the compression cylinder via a certain way; this flow considerably increases the pressure in the compression cylinder and decreases the pressure in the clearance volume. Thus, the intake and exhaust times means to be extended, and the volumetric efficiency and the cooling capacity of the compressor can be substantially enhanced. In this paper, we introduce the effect of input and exit dimensions on the volume efficiency of rolling piston compressor, and the overflow design on a rolling piston compressor that fully uses the high-pressure gas in the clearance volume, and discuss its effect on the performance of a compressor by theoretical analyses. Usually, the coefficient of performance of a vapor refrigeration cycle with the compressor overflow has a certain decrease compared with the conventional compressor, but the volumetric efficiency of the compressor with overflow and the cooling capacity of the thermodynamic cycle recesses are visibly higher than those of the conventional compressor in terms of the same operation and dimension parameters. The overflow has beneficial effect on miniaturizing the compresso

Multiple synchronous primary malignancies induced by benzene exposure: a case report

<p>Abstract</p> <p>Background</p> <p>Chronic exposure to high concentrations of benzene is usually associated with the development of haematological diseases. However, solid tumors induced by benzene exposure are less frequent.</p> <p>Case presentation</p> <p>We present an unusual case of triple synchronous primary malignancies most likely induced by occupational benzene exposure in a male patient. This spray painter was diagnosed as chronic aplastic anemia in his 21 years old after exposing to high concentration of benzene for three years. Then he was treated with glucocorticoid for four years. 40 years later, this patient developed three synchronous primary neoplasms with three different histologies including a basaloid squamous cell carcinoma of the esophagus, primary hepatocellular carcinoma, and well-differentiated squamous cell carcinoma of the gum.</p> <p>Conclusion</p> <p>This case reminds us that the occurrence of solid tumors should be monitored in workers with occupational history linked with a high concentration exposure to benzene, though it's rarely happened.</p

Gab2 deficiency suppresses high-fat diet-induced obesity by reducing adipose tissue inflammation and increasing brown adipose function in mice.

Obesity is caused by a long-term imbalance between energy intake and consumption and is regulated by multiple signals. This study investigated the effect of signaling scaffolding protein Gab2 on obesity and its relevant regulation mechanism. Gab2 knockout (KO) and wild-type (WT) mice were fed with a standard diet (SD) or high-fat diet (HFD) for 12 weeks. The results showed that the a high-fat diet-induced Gab2 expression in adipose tissues, but deletion of Gab2 attenuated weight gain and improved glucose tolerance in mice fed with a high-fat diet. White adipose tissue and systemic inflammations were reduced in HFD-fed Gab2 deficiency mice. Gab2 deficiency increased the expression of Ucp1 and other thermogenic genes in brown adipose tissue. Furthermore, the regulation of Gab2 on the mature differentiation and function of adipocytes was investigated in vitro using primary or immortalized brown preadipocytes. The expression of brown fat-selective genes was found to be elevated in differentiated adipocytes without Gab2. The mechanism of Gab2 regulating Ucp1 expression in brown adipocytes involved with its downstream PI3K (p85)-Akt-FoxO1 signaling pathway. Our research suggests that deletion of Gab2 suppresses diet-induced obesity by multiple pathways and Gab2 may be a novel therapeutic target for the treatment of obesity and associated complications

Dynamic in Static:Hybrid Visual Correspondence for Self-Supervised Video Object Segmentation

Conventional video object segmentation (VOS) methods usually necessitate a substantial volume of pixel-level annotated video data for fully supervised learning. In this paper, we present HVC, a \textbf{h}ybrid static-dynamic \textbf{v}isual \textbf{c}orrespondence framework for self-supervised VOS. HVC extracts pseudo-dynamic signals from static images, enabling an efficient and scalable VOS model. Our approach utilizes a minimalist fully-convolutional architecture to capture static-dynamic visual correspondence in image-cropped views. To achieve this objective, we present a unified self-supervised approach to learn visual representations of static-dynamic feature similarity. Firstly, we establish static correspondence by utilizing a priori coordinate information between cropped views to guide the formation of consistent static feature representations. Subsequently, we devise a concise convolutional layer to capture the forward / backward pseudo-dynamic signals between two views, serving as cues for dynamic representations. Finally, we propose a hybrid visual correspondence loss to learn joint static and dynamic consistency representations. Our approach, without bells and whistles, necessitates only one training session using static image data, significantly reducing memory consumption ($\sim$16GB) and training time ($\sim$\textbf{2h}). Moreover, HVC achieves state-of-the-art performance in several self-supervised VOS benchmarks and additional video label propagation tasks

Discovery of Epichloë as novel endophytes of Psathyrostachys lanuginosa in China and their alkaloid profiling

The Epichloë genus represents a significant group of above-ground endophytes extensively researched for their potential applications in agriculture and ecology. Additionally, Epichloë species synthesize bioactive alkaloids, which generally cause health problems in livestock and have detrimental effects on the performance of insect herbivores. Psathyrostachys lanuginosa serves as a valuable forage grass for livestock owing to its high nutritional value and resilience in adverse environmental conditions. Nevertheless, to date, no reports have documented Epichloë as endophytes of P. lanuginosa. In this study, four strains (PF5, PF9, QG2, and QG4) were isolated and identified through morphological, molecular, and phylogenetic analyses as endophytes of P. lanuginosa. Morphological analysis indicated colony characteristics and conidia features consistent with symbiotic Epichloë, with no significant differences observed in growth rates or conidia dimensions among the four strains. Phylogenetic analysis confirmed all strains as E. bromicola. Additionally, alkaloid biosynthetic genes were detected, revealing differences in the potential synthesis of peramine and indole diterpenoid alkaloids among strains from different geographic origins. However, all four E. bromicola strains exhibited similar potential for synthesizing ergot alkaloids, but not loline alkaloids. Overall, this study identified P. lanuginosa as a novel host for E. bromicola and provided insights into the alkaloid profiles of these strains, laying a solid foundation for the scientific and rational utilization of Epichloë resources

Characteristic Compounds Identification and Authenticity Evaluation of Heptapleurum Honey

In order to clarify the characteristic compounds and establish the authenticity evaluation method of heptapleurum honey, high-performance liquid chromatography coupled with quadrupole-time-of-flight tandem mass spectrometry (HPLC-Q/TOF-MS/MS) was used to qualitative and quantitative analysis of characteristic compounds in heptapleurum honey. Five compounds were identified including 4-(1'-cyclodiethyl ether-3'-butanediol)-3,5,5-trimethyl-2-cyclohexenone (Unedone B), 3,4,5-trimethoxy cinnamyl alcohol, 4-(1'2'-dihydroxy-3'epoxypropane) -3,5,5-2-cyclohexenone (Unedone C), trans, trans abscisic acid, and cis, trans abscisic acid. Notably, 3,4,5-trimethoxy cinnamyl alcohol was first found in honey, and it could be a marker of heptapleurum honey. Moreover, 10 raw heptapleurum honey samples with different geographic origins were collected to establish HPLC fingerprint. The authenticity of six commercial heptapleurum honey samples were evaluated by combining characteristic compound with HPLC fingerprint. The results demonstrated that three brands of sample were genuine pure heptapleurum honey, two brands of sample might be mixed with other honeys. A brand sample did not contain characteristic compound and were significantly different with the standard fingerprints of heptapleurum honey. It was inferred that the sample was not heptapleurum honey. This study provides theoretical reference for the authenticity evaluation of heptapleurum honey

Flux coupled tunable superconducting resonator

We present a design and implementation of frequency-tunable superconducting resonator. The resonance frequency tunability is achieved by flux-coupling a superconducting LC-loop to a current-biased feedline; the resulting screening current leads to a change of the kinetic inductance and shift in the resonance frequency. The thin film aluminum resonator consists of an interdigitated capacitor and thin line inductors forming a closed superconducting loop. The magnetic flux from the nearby current feedline induces Meissner shielding currents in the resonator loop leading to change in the kinetic part of the total inductance of the resonator. We demonstarte continuous frequency tuning within 160 MHz around the resonant frequency of 2.7 GHz. We show that: (1) frequency upconversion is achieved when kHz AC modulation signal is superimposed onto the DC bias resulting in sidebands to the resonator tone; (2) three-wave mixing is attained by parametrically pumping the nonlinear kinetic inductance using a strong RF pump signal in the feedline. The simple architecture is amenable to large array multiplexing and on-chip integration with other circuit components. The concept could be applied in flux magnetometers, upconverters, and parametric amplifiers operating above 4 Kelvin cryogenic temperatures when alternative high critical temperature material with high kinetic inductance is used

34. 上肢のentrapment neuropathy手術例について(第520回千葉医学会例会 整形外科例会)

<p>No.8 nozzle assembly; flow rate 15 L/s; ambient pressure 30 MPa; ambient temperature = jet temperature = 373 K. In cross sections, dimensionless radius is the distance from the inner wall to the measure point divided by the total length between inner and outer wall. The tangential velocity has large gradients near both sides of inner and outer walls.</p

Vibration model and frequency characteristics of the piezoelectric transducer in airflow-induced acoustic generator

Piezoelectric transducers, which convert airflow induced vibrational energy into electrical energy, can be applied to self-powered supply and auxiliary power supply for various aircraft electronic systems. Micro-ringtone airflow piezoelectric generator, designed by the principle of airflow induced acoustic, is one kind among them. The vibrating piezoelectric generator, is usually mounted on the aircraft during the flight. The incoming airflow produces hydrodynamic acoustic source, which is the vibration source of the piezoelectric generator, actively vibrates the piezoelectric plate to convert energy. According to the vibration theory, a one-dimensional vibration model of piezoelectric generator with fixed peripheral pressure, under hydrodynamic excitation is established. The vibration and frequency characteristics of the piezoelectric transducers are analyzed by measuring the sound pressure and the piezoelectric generator voltage. Theoretical analysis and experimental results show that the frequency of hydrodynamic acoustic source is slightly lower than that of piezoelectric generator’s natural frequency. Maximum output power is obtained when the inflow speed is in the range of 128 m/s-148 m/s, the corresponding hydrodynamic acoustic source frequency is 6.9 %-8.7 % lower than the natural frequency of the piezoelectric generator. Excitation force Fex and the displacements of piezoelectric plate are in same frequency. But Fex is ahead of phase angle ψ than the displacement of piezoelectric plate