bluuebunny/crossref_metadata_2025_split huggingface dataset:
Research on the Vapor Injection of Two-stage Rotary Compressor
Authors: Hu Y S , Wei H J , Yu B , Yang O X , Wang J , Wu J 
Published: September 2019

Abstract
In order to understand the vapor injection flow characteristics of two-stage rotary compressor in the course of compression, a mathematical model based on mass conservation equation, energy equation and thermodynamic identity was established and proved by P-V diagram testing results. Some useful conclusions about pressure in the intermediate chamber and mass flow of vapor injection in the course of compression were also given out. The results show that, gas backflow between the intermediate chamber and the vapor injection channel is an important defection of two-stage rotary compressor which can be solved by the application of injection valve in vapor injection channel. The injection valve can obviously reduce the gas backflow and the power loss in the course of compression while increasing the pressure fluctuation in the intermediate chamber. Experiments show that the COP of two-stage rotary compressor with the injection valve increased by over 2% in ASHRAE/T working condition.
The Theoretical and Experimental Research of a Novel Rotary Cylinder Compressor
Authors: Hu Y S , Wei H J , Xu J , Du Z C , Yang S , Ren L P 
Published: September 2019

Abstract
Rotary compressor has been widely used in home air conditioning. The sealing forms of roller-vane and roller-cylinder in rotary compressor are linear sealing, resulting in large leakage and low volumetric efficiency. The performance of the compressor tempestuously reduces with the running frequency decreasing. A novel positive displacement compressor was introduced in this paper: rotary cylinder compressor. The cylinder and shaft rotate around their own axes, and the piston reciprocates relative to them, in order to implement suction and exhaust process. Further, the volume efficiency and mechanical efficiency of rotary cylinder compressor and rotary compressor was analyzed and compared theoretically. The results indicated that the sealing forms of all leaking channels in rotary cylinder compressor are face sealing, which results in less leakage and higher volumetric efficiency than linear sealing. The novel compressor has a significant advantage at the medium and low frequency, and the advantage shows more obvious with the decreasing frequency. Finally, the experimental results of the prototype fully verified the performance advantages of rotary cylinder compressor at volumetric efficiency and electrical efficiency, which was consistent with the theoretical analysis.
Numerical investigation of oil injection in a Roots blower operated as expander
Authors: Casari Nicola , Fadiga Ettore , Pinelli Michele , Suman Alessio , Kovacevic Ahmed , Rane Sham , Ziviani Davide 
Published: September 2019

Abstract
The adoption of positive displacement machines as expanders in Organic Rankine Cycles (ORCs) is increasingly common, especially in the low to medium power range. At the same time, these devices often serve as compressor in Vapor-Compression Refrigeration Systems. In both cases, the application of Computation Fluid Dynamics (CFD) to optimize such machines has become an integrated tool in the design process. As a consequence, several challenges associated with the numerical simulation have to be taken into account. For example, the modeling of the gap represents a challenge for the stability of the numerical analysis. The dynamic of the process, combined with deformations of the clearances and of the working chamber has to be considered with extra care.
To raise the efficiency of the machine, oil is typically injected. Its numerical modeling imply an extra challenge in the simulation of the actual operation of the machine. The present work is mainly focused on the multi-phase nature of the flow, with a particular analysis of the lubricant oil injected. In this work, a two-lobe Roots blower operated as expander has been simulated with the open-source software OpenFOAM-v1812, using the SCORG-V5.2.2. This analysis highlights the areas that are affected the most by the oil presence in order to highlight the sealing effect it provides
Model predictive control of a free piston compressor/expander with an integrated linear motor/alternator
Authors: Gusev Sergei , Ziviani Davide , Paepe Michel De 
Published: September 2019

Abstract
Linear positive displacement machines are becoming increasingly more attractive for applications that are normally known as unconquerable niches of rotary and scroll machines. Free-piston machines are characterized by the absence of a crank mechanism, since there is a direct transformation of electrical energy into the piston movement. From the point of view of manufacturing, these machines benefit from a higher robustness and reliability because of less mechanical components involved and reduced frictional losses associate with a conventional crank mechanism.
However, the major challenge in replacing the rotary machines by linear ones is a lower efficiency at lower speeds which is unavoidable because of the nature of linear motion: continuous operation means a reciprocating movement within a stroke length with significantly long periods of acceleration and deceleration when the speed is far from its optimal value. However, the advantage of free-piston machines is the fact that the motion profile is freely configurable within physical constraints, which provides a possibility to optimize the speed given the efficiency map of particular linear motor.
While the methods and results of the efficiency assessment for rotary machines are widely available, there is a lack of these analyses for linear machines. The current study provides in-depth analyses of a double-coil iron core linear motor also acting as a generator.
Investigation on the Performance Improvement of the Scroll Compressor by DLC Film
Authors: Ji Lantian , He Zhilong , Han Yaoxiang , Chen Weiqing , Xing Ziwen 
Published: September 2019

Abstract
The material property of orbiting scroll surface, mainly affects the life and performance of scroll compressors. Generally, the anodic oxide film (AOF) is used in the surface treatment of the domestic orbiting scroll, which has numerous drawbacks such as poor adhesion of the film-substrate and easy wear failure. In this paper, a process producing the diamond-like carbon film (DLCF) on the surface of an orbiting scroll by unbalanced magnetron sputtering technology was proposed based on the mechanical characteristics of the scroll compressor and the surface treatment method of the orbiting scroll. The friction coefficient, microhardness, film-substrate adhesion and other performances of the AOF and DLCF were analyzed from the data measured by various test facilities. The refrigeration capacity, power and volumetric efficiency of compressors with different coatings were analyzed and compared by tests under different operating conditions with fixed values of refrigerant charge and oil content. The surface morphology of the coatings was then studied by scanning electron microscope to identify the microstructure after the operation. The results showed that a more even and dense surface was obtained by the DLCF compared with the AOF, which improved the wear resistance of the surface. The surface friction coefficient was only 0.11 as the Cr transition layer markedly enhanced the bonding strength. The DLCF displayed more properties of graphite with the thickness of only 0.73 μ m. The volumetric efficiency of the compressor under the nominal operating condition increased by 5.8%.
Comparison between single and cascaded organic Rankine cycle systems accounting for the effects of expansion volume ratio on expander performance
Authors: White M T , Read M G , Sayma A I 
Published: September 2019

Abstract
Compared to single-stage organic Rankine cycle (ORC) systems, cascaded ORC systems, in which a high-temperature topping cycle and low-temperature bottoming cycle are coupled together, could have advantages in terms of removing the potential for sub-atmospheric condensation conditions and improving expander performance as the expansion process is effectively divided across two stages. Moreover, reducing the expansion volume ratio could facilitate the use of volumetric expanders, such as twin-screw expanders, which, in turn, could facilitate two-phase expansion to be utilised in one, or both, of the cycles. The aim of this paper is to compare single-stage and cascaded ORC systems, accounting for the effect of the expander volume ratio on expander performance. To investigate this, thermodynamic models for single-stage and cascaded ORC systems are developed, which include variable efficiency expander models for both radial turbines and twin-screw expanders that can estimate the effect of the expansion volume ratio on the expander isentropic efficiency. Using this model, three different scenarios are compared for different temperature heat-source temperatures, namely: (i) single-stage ORC systems with vapour-phase expansion obtained using a turboexpander; (ii) single-stage ORC systems operating with a twin-screw expander, with the possibility for two-phase expansion; and (iii) cascaded cycles with either vapour- or two-phase expansion. The results from this comparison are used to identify applications where cascaded ORC systems could offer performance benefits.
Investigation of a Thermo-Fluidic Exchange Pump in Trilateral Flash and Organic Rankine Cycles
Authors: Baggley C R , Read M G 
Published: September 2019

Abstract
It is well known that large amounts of energy loss occurs at low temperature states in a wide range of industrial processes., The recovery and reuse of this energy is at the forefront of increasing the overall efficiencies of industrial systems. The aim of this paper is to investigate the effectiveness of using a Thermo-Fluidic Exchange (TFE) pump at low temperature conditions in both a Saturated-Vapour Organic Rankine Cycle (SORC) and a Trilateral Flash Cycle (TFC).
For some low temperature applications, TFCs have been shown to achieve higher net power output than conventional SORCs, due to their ability to extract more heat from the source fluid. This is the subject of current research as a result of advancements made in the design of positive displacement machines for operation as two-phase expanders. Conventional turbines cannot be used for TFCs as they must operate in the vapour phase.
One drawback of the TFC is the higher working fluid mass flow rate required. Depending on the scale of the system, this can potentially cause difficulties with pump selection. A TFE pump uses heat input to the system to increase the pressure and temperature of the working fluid, rather than the work input in a standard mechanical pump. This paper compares the net power output achievable using both mechanical and TFE pumps with SORC and TFC systems. The results suggest that the TFE pump could be a viable option for TFC systems.
Heterogeneity introduced by EHR system implementation in a de-identified data resource from 100 non-affiliated organizations
Authors: Glynn Earl F , Hoffman Mark A 
Published: September 2019

Abstract

Objectives
Electronic health record (EHR) data aggregated from multiple, non-affiliated, sources provide an important resource for biomedical research, including digital phenotyping. Unlike work with EHR data from a single organization, aggregate EHR data introduces a number of analysis challenges.

Materials and Methods
We used the Cerner Health Facts data, a de-identified aggregate EHR data resource populated by data from 100 independent health systems, to investigate the impact of EHR implementation factors on the aggregate data. These included use of ancillary modules, data continuity, International Classification of Disease (ICD) version and prompts for clinical documentation.

Results and Discussion
Health Facts includes six categories of data from ancillary modules. We found of the 664 facilities in Health Facts, 49 use all six categories while 88 facilities were not using any. We evaluated data contribution over time and found considerable variation at the health system and facility levels. We analyzed the transition from ICD-9 to ICD-10 and found that some organizations completed the shift in 2014 while others remained on ICD-9 in 2017, well after the 2015 deadline. We investigated the utilization of “discharge disposition” to document death and found inconsistent use of this field. We evaluated clinical events used to document travel status implemented in response to Ebola, height and smoking history. Smoking history documentation increased dramatically after Meaningful Use, but dropped in some organizations. These observations highlight the need for any research involving aggregate EHR data to consider implementation factors that contribute to variability in the data before attributing gaps to “missing data.”
Obesity as a Risk Factor Among Hospitalized Patients with Infective Endocarditis
Authors: Harris Ché Matthew , Albaeni Aiham , Wright Scott , Norris Keith C 
Published: September 2019

Abstract

Objective
Obesity contributes to diagnostic and management challenges for many hospitalized patients. The impact of obesity on in-hospital outcomes in patients with infective endocarditis has not been studied and was the focus of this investigation.

Method
We used the 2013 and 2014 Nationwide Inpatient Sample to identify adults ≥18 years of age with a principle diagnosis of endocarditis. We divided the sample into 2 groups based on presence of absence of obesity. Multivariate linear and logistic regression analysis was used to compare in-hospital mortality, valvular replacement, length of stay (LOS), and hospitalization charges.

Results
A total of 24 494 adults 18 years and older were hospitalized with infective endocarditis, of which 2625 were classified as obese. Patients with obesity were older (mean age, 57.8 ± 0.3 vs 54.3 ± 0.6 years; P &lt; .01), more likely to be female (50.1% vs 36.1%; P &lt; .01), and had more comorbidities (Charlson comorbidity score ≥ 3, 50.6% vs 28.8%; P &lt; .01). Multivariate regression analysis found no differences between the 2 groups for mortality or repairs or replacements for any valve. On evaluation of resource utilization, patients with obesity had longer average LOS (13.9 days; confidence interval [CI], 12.7–15.1 vs 12.4 days; CI, 12.0–12.8; P = .016) and higher total hospital charges (US $160 789.90; CI, $140.922.40–$180 657.50 vs US $130 627.20; CI, $123 916.70–$137 337.70; P &lt;.01). After adjustment for LOS for total hospital charges, there was no observed difference $11436.26 (CI, -$6649.07–$29521.6; P = .22).

Conclusions
. Obesity does not significantly impact in-hospital mortality or surgical valvular interventions among patients hospitalized with infective endocarditis, but obesity is associated with increased utilization of hospital resources.
Treatment and surveillance of advanced, metastatic iodine-resistant differentiated thyroid cancer
Authors: Ibrahim Eiman Y. , Busaidy Naifa L. 
Published: September 2019

Purpose of review
This review will focus on the management and treatment of metastatic thyroid cancer that is radioactive iodine refractory and review the new drugs and their mechanism of actions as well as their adverse events.

Recent findings
Until recently, there were no efficacious therapeutic modalities for these patients. With advancement in knowledge and research of the molecular aberrations and oncogenic mutations in thyroid cancer as well as further understanding the role of angiogenesis in tumor growth molecular pathogenesis, novel targeted therapies are available for these patients. Some of these drugs have successfully prolonged progression free survival and are now Food and Drug Administration approved. Additional agents are approved for the treatment of other types of cancers and are currently under investigation for differentiated thyroid cancer treatment.

Summary
Differentiated thyroid cancer (papillary and follicular) is the most common endocrine malignancy. It is generally known to have an excellent prognosis and patients are usually cured with the conventional primary treatments including surgery, radioactive iodine, and thyroid stimulating hormone suppression. A minor proportion of patients do not fully recover mainly because they develop radioactive iodine-resistant disease. These patients have few treatment options, which we aimed to describe here.
Designing Peptides on a Quantum Computer
Authors: Mulligan Vikram Khipple , Melo Hans , Merritt Haley Irene , Slocum Stewart , Weitzner Brian D. , Watkins Andrew M. , Renfrew P. Douglas , Pelissier Craig , Arora Paramjit S. , Bonneau Richard 
Published: September 2019

AbstractAlthough a wide variety of quantum computers are currently being developed, actual computational results have been largely restricted to contrived, artificial tasks. Finding ways to apply quantum computers to useful, real-world computational tasks remains an active research area. Here we describe our mapping of the protein design problem to the D-Wave quantum annealer. We present a system whereby Rosetta, a state-of-the-art protein design software suite, interfaces with the D-Wave quantum processing unit to find amino acid side chain identities and conformations to stabilize a fixed protein backbone. Our approach, which we call the QPacker, uses a large side-chain rotamer library and the full Rosetta energy function, and in no way reduces the design task to a simpler format. We demonstrate that quantum annealer-based design can be applied to complex real-world design tasks, producing designed molecules comparable to those produced by widely adopted classical design approaches. We also show through large-scale classical folding simulations that the results produced on the quantum annealer can inform wet-lab experiments. For design tasks that scale exponentially on classical computers, the QPacker achieves nearly constant runtime performance over the range of problem sizes that could be tested. We anticipate better than classical performance scaling as quantum computers mature.
Reactivation of chromosome signalling induces reversal of the meiotic program
Authors: Castellano-Pozo Maikel , Pacheco Sarai , Sioutas Georgios , Jaso-Tamame Angel Luis , Dore Marian H , Martinez-Perez Enrique 
Published: September 2019

AbstractChromosome movements and programmed DNA double-strand breaks (DSBs) promote homologue pairing and initiate recombination at meiosis onset. Meiotic progression involves checkpoint-controlled termination of these events when all homologue pairs achieve synapsis and form crossover precursors. We show that termination of chromosome movement and DSB formation is reversible and is continuously implemented by the synaptonemal complex (SC), which silences chromosome signals that promote CHK-2 activity. Forced removal of the SC or different meiosis-specific cohesin complexes, which are individually required for SC stability, causes rapid CHK-2-dependent reinstallation of the DSB-formation and chromosome-movement machinery. This nuclear reorganization occurs without transcriptional changes, but requires signalling from HORMA protein HTP-1. Conversely, CHK-2 inactivation causes rapid disassembly of the DSB-formation and chromosome-movement machinery. Thus, nuclear organization is constantly controlled by the level of CHK-2 activity. Our results uncover an unexpected plasticity of the meiotic program and show how chromosome signalling integrates nuclear organization with meiotic progression.
Computational modeling reveals a hydrophobic force-induced pore-forming mechanism for cholesterol-dependent cytolysins
Authors: Pang Shichao , Yang Junchen , Wang Jingfang 
Published: September 2019

ABSTRACTDuring the pore-forming process, cholesterol-dependent cytolysins (CDCs) bind to cholesterol-rich membranes and subsequently undergo a series of conformational changes, predominantly involving in the collapse of the protein and the transformation from α helices to β-hairpins to form a large hydrophobic pore. In the current study, we reconstructed a structural model for both the prepore and pore-forming complexes of PFO based on the cryo-EM data of pneumolysin and performed molecular dynamics simulations and free energy calculations to study the conformational changes in the PFO prepore-to-pore conversion. Our simulations indicate that D2 cannot collapse spontaneously due to the hydrogen bonding and pi-pi interactions between domains D2 and D3, which are partially weakened by binding to cell membranes and oligomerization. The free energy landscape for the prepore-to-pore conversion reveals that an additional force is required for the collapse of D2 to overcome an energy barrier of ∼ 24 kcal/mol. Based on these computational results, we proposed a hydrophobic force-induced pore-forming mechanism to explain the pore-forming process of CDCs. In this mechanism, the hydrophobic interactions between the TMHs and membranes are essential for the prepore-to-pore conversion. The hydrophobic force generated by the TMHs-membrane interactions drives the conformational changes in domains D2 and D3. These findings well explain how the conformational changes within two distant domains synergistically occur, and fits well for the previous biophysical and biochemical data.
Defined factors to reactivate cell cycle activity in adult mouse cardiomyocytes
Authors: Judd Justin , Lovas Jonathan , Huang Guo N. 
Published: September 2019

ABSTRACTAdult mammalian cardiomyocytes exit the cell cycle during the neonatal period, commensurate with the loss of regenerative capacity in adult mammalian hearts. We established conditions for long-term culture of adult mouse cardiomyocytes that are genetically labeled with fluorescence. This technique permits reliable analyses of proliferation of pre-existing cardiomyocytes without complications from cardiomyocyte marker expression loss due to dedifferentiation or significant contribution from cardiac progenitor cell expansion and differentiation in culture. Using this system, we took a candidate gene approach to screen for fetal-specific proliferative gene programs that can induce proliferation of adult mouse cardiomyocytes. Using pooled gene delivery and subtractive gene elimination, we identified a novel functional interaction between E2f Transcription Factor 2 (E2f2) and Brain Expressed X-Linked (Bex)/Transcription elongation factor A-like (Tceal) superfamily members Bex1 and Tceal8. Specifically, Bex1 and Tceal8 both preserved cell viability during E2f2-induced cell cycle re-entry. Although Tceal8 inhibited E2f2-induced S-phase re-entry, Bex1 facilitated DNA synthesis while inhibiting cell death. In sum, our study provides a valuable method for adult cardiomyocyte proliferation research and suggests that Bex family proteins may function in modulating cell proliferation and death decisions during cardiomyocyte development and maturation.
Multistable and dynamic CRISPRi-based synthetic circuits
Authors: Santos-Moreno Javier , Tasiudi Eve , Stelling Joerg , Schaerli Yolanda 
Published: September 2019

AbstractGene expression control based on CRISPRi (clustered regularly interspaced short palindromic repeats interference) has emerged as a powerful tool for creating synthetic gene circuits, both in prokaryotes and in eukaryotes; yet, its lack of cooperativity has been pointed out as a potential obstacle for dynamic or multistable circuit construction. Here we use CRISPRi to build prominent synthetic gene circuits in Escherichia coli. We report the first-ever CRISPRi oscillator (“CRISPRlator”), bistable network (toggle switch) and stripe pattern-forming incoherent feed-forward loop (IFFL). Our circuit designs, conceived to feature high predictability and orthogonality, as well as low metabolic burden and context-dependency, allowed us to achieve robust circuit behaviors. Mathematical modeling suggests that unspecific binding in CRISPRi is essential to establish multistability. Our work demonstrates the wide applicability of CRISPRi in synthetic circuits and paves the way for future efforts towards engineering more complex synthetic networks, boosted by the advantages of CRISPR technology.