bluuebunny/crossref_metadata_2025 huggingface dataset:
Modelling of asymmetric nanojets in coronal loops
Authors: Pagano P. , Antolin P. , Petralia A.
Published: September 2021

Context. Observations of reconnection jets in the solar corona are emerging as a possible diagnostic for studying highly elusive coronal heating. Such jets, and in particular those termed nanojets, can be observed in coronal loops and have been linked to nanoflares. However, while models successfully describe the bilateral post-reconnection magnetic slingshot effect that leads to the jets, observations reveal that nanojets are unidirectional or highly asymmetric, with only the jet travelling inward with respect to the coronal loop’s curvature being clearly observed.

Aims. The aim of this work is to address the role of the curvature of the coronal loop in the generation and evolution of asymmetric reconnection jets.

Methods. We first use a simplified analytical model in which we estimate the post-reconnection tension forces based on the local intersection angle between the pre-reconnection magnetic field lines and their post-reconnection retracting length towards new equilibria. Second, we use a simplified numerical magnetohydrodynamic (MHD) model to study how two opposite propagating jets evolve in curved magnetic field lines.

Results. Through our analytical model, we demonstrate that in the post-reconnection reorganised magnetic field, the inward directed magnetic tension is inherently stronger (by up to three orders of magnitude) than the outward directed one and that, with a large enough retracting length, a regime exists where the outward directed tension disappears, leading to no outward jet at large, observable scales. Our MHD numerical model provides support for these results, proving also that in the subsequent time evolution the inward jets are consistently more energetic. The degree of asymmetry is also found to increase for small-angle reconnection and for more localised reconnection regions.

Conclusions. This work shows that the curvature of the coronal loops can play a major role in the asymmetry of the reconnection jets and that inward directed jets are more likely to occur and are more energetic than the corresponding outward directed ones.
Rubber agroforestry system in Indonesia: Past, present, and future practices
Authors: Agustina D.S. , Oktavia Fetrina
Published: September 2021

Indonesia is the second largest rubber producing country after Thailand. The area of rubber in 2018 was about 3.7 million hectares with the total production of 3.6 million tons. Among those areas, 88.13% were owned by smallholders, and the rest belongs to private estate (5.16%) and government estate (6.7%). Productivity is still become the problem at smallholders’ level. Some efforts have been conducted in order to improve the productivity of smallholders. The concept of agroforestry has become increasingly relevant in recent days as they introduced new commercial opportunities to smallholders. Agroforestry, with its multiple environmental and economic benefits, can help the agriculture and forestry sectors find innovative solutions to present-day problems: including low profitability, environmental impacts, and negative public perception This paper presents the implementation of rubber agroforestry system at the smallholders’ level since the past, current situation and future scenario for agroforestry in order to support the sustainability of rubber smallholders.
Research review on design method of ice protection system for civil aircraft based on ice-tolerant concept
Authors: Zhao Binbin , Li Xianping , Li Jie , Chen Haixin , Ai Jianliang
Published: September 2021

Icing is an important disaster-causing factor which threatens the flight safety of civil aircraft and a major safety issue of concern for the airworthiness. The design of icing protection system based on ice-tolerant concept can minimize the impact of icing on aerodynamic characteristics and fully utilize the potential of flight performance, which is the frontier direction of current icing protection research for civil aircraft. This paper aims at the requirements of civil aircraft flight safety design and airworthiness certification. The design method of civil aircraft icing protection system based on the concept of ice-tolerant capacity is analyzed from two aspects. One is the capacity of ice-tolerant for aircraft frame, the other one is the design of ice-tolerant with active control. The optimum design strategy of wing in aerodynamic performance considering icing loss is refined and the design idea of ice-tolerant protection control system based on flight control law reconstruction is formed. The change from passive flight safety of icing to active safety design of icing can effectively improve the survivability and safety of civil aircraft under icing weather conditions.
Multi-objective aerodynamic optimization of flying-wing configuration based on adjoint method
Authors: Liu Xiaodong , Zhang Peiliang , He Guanghong , Wang Yongen , Yang Xudong
Published: September 2021

In order to solve the multi-objective multi-constraint design in aerodynamic design of flying wing, the aerodynamic optimization design based on the adjoint method is studied. In terms of the principle of the adjoint equation, the boundary conditions and the gradient equations are derived. The Navier-Stokes equations and adjoint aerodynamic optimization design method are adopted, the optimization design of the transonic drag reduction for the two different aspect ratio of the flying wing configurations is carried out. The results of the optimization design are as follows: Under the condition of satisfying the aerodynamic and geometric constraints, the transonic shock resistance of the flying wing is weakened to a great extent, which proves that the developed method has high optimization efficiency and good optimization effect in the multi-objective multi-constraint aerodynamic design of the flying wing.
Underwater image enhancement method with non-uniform illumination based on Retinex and ADMM
Authors: Liu Weidong , Li Jiyu , Zhang Wenbo , Li Le
Published: September 2021

In order to solve the image blurring and distortion problem caused by underwater non-uniform and low illumination, this paper proposes an underwater image enhancement algorithm based on the Retinex theory and the Alternating Direction Method of Multipliers (ADMM). Firstly, the L component of the original image in the Lab space is extracted as the initial illumination map, and an Augmented Lagrange Multiplier (ALM) framework is constructed based on the ADMM to optimize the initial illumination map in order to obtain an accurate illumination image. In addition, the illumination map is further corrected in the luminance region with the Gamma Correction. Secondly, combined with the color constancy characteristics in the Retinex theory, the reflected image of the object is obtained. Finally, the bilateral filter is picked to suppress the underwater noise and obtain a more detailed enhanced image. The experimental results show that the underwater image enhancement algorithm can effectively solve the non-uniform illumination problem caused by natural light or artificial light source and improve the underwater image quality, thus having a better performance than other algorithms.
Effects of probes with different structures on the flow field and measurement results of imported compressors
Authors: Zheng Guanghua , Shui Fei , Hu Jinxin , Liu Xin , Xiao Huazhong
Published: September 2021

In this paper, the measurement accuracy of two different types of total pressure probe and total temperature probe in turboshaft engine compressor inlet channel and the influence of these two probes on the flow field through numerical simulation was studied. At the same time, the influence of the probe structure and installation position on probe measurement results under three typical working conditions of cruise, maximum continuous and takeoff was analyzed. The simulation results showed that the higher the engine inlet flow rate, the greater the measurement error of the probe. Comparing with the total temperature probe, the total pressure probe measurement accuracy is more influenced by the flow rate. The velocity uniformity is less affected by the engine operating conditions and is mainly related to the structure of the inserted probes. The closer the total pressure probe to the support plate, the greater the measurement error. The probe installation position has a small effect on the total pressure loss coefficient at the outlet.
Optimization of correlate subquery based on distributed database
Authors: Zhang Chenyu , Liu Wenjie , Pang Tianze , Yue Yantao
Published: September 2021

Subquery is widely used in database. It can be divided into related subquery and non-related subquery according to whether it is dependent on the table of the parent query. For related subqueries, it is necessary to take a tuple from the parent query before executing the subquery, that is, the content of the subquery needs to be repeatedly operated. Disk access costs of this strategy is very big, in the distributed database, because of data communication overhead, in the parent query yuan set is too low efficiency, therefore, for the class sub queries, on the basis of the optimization of the existing query strategy, combining with the characteristics of distributed database, put forward by the subquery on to join queries, eliminate redundant clauses in the subquery, eliminate accumulation function method based on distributed database query optimization strategy, and the effectiveness of the present optimization strategy is verified by experiment.
An efficient algorithm for solving the constellation-to-ground region coverage problem based on longitude strip division
Authors: Song Zhiming , Liu Haidong , Chen Xiaoyu , Wang Maocai
Published: September 2021

Aiming at the constellation-to-ground region coverage problem, an efficient solution method called the longitude strip method is proposed. By dividing the ground region into several longitude strips, the latitude range of each strip is computed according to the region. Similarly, concerning the coverage area of the satellite, the latitude range of each strip is also calculated. On this basis, the coverage rate can be obtained by comprehensive statistics. Additionally, the upper and lower bounds for problems of continuous coverage and accumulative coverage are solved. Numerical simulation experiments show the proposed algorithm has higher accuracy and it is also efficient in resolving the ground area with arbitrary shapes.
Speed of Movement, Fatness, and the Change in Cardiometabolic Risk
Factors in Children
Authors: Shang Xianwen , Li Yanping , Xu Haiquan , Zhang Qian , Liu Ailing , Ma Guansheng
Published: September 2021

We aimed to examine speed of movement and its interactive association with
fatness to changes in cardiometabolic risk factors over one year in
children. The analysis included 8345 children aged 6–13 years.
Cardiometabolic risk score was computed by summing Z-scores of waist
circumference, the average of systolic and diastolic blood pressure, fasting
glucose, high-density lipoprotein cholesterol (multiplied by −1),
and triglycerides. Both high baseline and improvement in speed of movement
were associated with favourable changes in percent body fat, lipids, and
cardiometabolic risk score. Percentages of the association between baseline
speed of movement and changes in cardiometabolic risk score, triglycerides,
and high-density lipoprotein cholesterol explained by baseline BMI were
24.6% (19.6–29.1%), 26.2%
(19.7–31.1%), and 12.5% (9.6–15.4%),
respectively. The corresponding number for percent body fat was
47.0% (40.4–54.1%), 43.3%
(36.7–51.7%), and 29.8%
(25.0–34.6%), respectively. Speed of movement mediated the
association between fatness and cardiometabolic risk factors. Improved speed
of movement was associated with a lower increase in blood pressure in obese
children only. Speed of movement is a strong predictor of changes in
cardiometabolic risk factors. Fatness and speed of movement are
interactively associated with cardiometabolic risk factors. Speed of
movement may attenuate the positive association between fatness and blood
pressure.
Sportkardiologie 2021 – was gibt es Neues?
Authors: Most Astrid , Bauer Pascal
Published: September 2021

Was ist neu?

Sport bei kardiovaskulären Risikofaktoren und im Alter Falls Personen mit kardiovaskulären Risikofaktoren oder im Alter von ≥ 65 Jahren eine intensive sportliche Belastung planen, wird ihnen zur Risikominimierung des sportassoziierten plötzlichen Herztods eine kardiale Vorsorgeuntersuchung empfohlen. Zur individuellen Risikoeinordnung sollte beim Vorliegen von kardiovaskulären Risikofaktoren der ESC-Score Verwendung finden.

Sport bei kardiovaskulären Erkrankungen Die erstmalig erschienenen Leitlinien der European Society of Cardiology (ESC) „Sportkardiologie und körperliche Aktivität bei Patienten mit kardiovaskulärer Erkrankung“ (2020) 1 geben umfassende Trainingsempfehlungen zur Ausübung von Freizeit- und Leistungssport für Patienten mit kardiovaskulären Erkrankungen. Dabei ist eine kardiale Eingangsuntersuchung zur individuellen Risikostratifizierung als Basis der Trainingsberatung unumgänglich. Nur in Ausnahmefällen wird von einer sportlichen Betätigung (passager) abgeraten.

Sport, COVID-19 und Herz COVID-19 kann zu kardialen Schäden führen, wobei diese selten auch bei asymptomatischen und milden Krankheitsverläufen beobachtet wurden. Vor Wiederaufnahme intensiver sportlicher Aktivitäten sollte, in Abhängigkeit von Krankheitsschwere und Symptomatik, die Sporttauglichkeit überprüft und dann individuell das weitere Vorgehen bezüglich des Trainingsaufbaus festgelegt werden.
Mit Mut und Kreativität durch die Pandemie
Authors: Rebecca Runge Laura
Published: September 2021

Aufgrund der Corona-Pandemie hat sich auch in der Psychiatrie vieles verändert. Wie können Pflegende ihre Patienten durch diese schwierigen Zeiten begleiten, ihnen Struktur und Ablenkung bieten?
Einfluss der Ernährung auf den Verlauf von Autoimmunerkrankungen
Authors: Römmele Petra
Published: September 2021

Patienten mit Autoimmunerkrankungen haben einen hohen Leidensdruck und suchen nach Therapieansätzen. Die Ernährung ist ein Teil des Lebensstils, mit dem man den Verlauf von Autoimmunerkrankungen beeinflussen kann. Wenngleich die Studienbasis für viele Fragen noch lückenhaft ist, so lassen sich doch einige Prinzipien für eine Ernährung bei Autoimmunerkrankungen ableiten. Der Beitrag thematisiert übergeordnete Erkenntnisse zur Ernährung sowie die spezifische Wirkung einzelner Nährstoffe am Beispiel der Hashimoto-Thyreoiditis.
A Semantic-Based Framework for Verbal Autopsy to Identify the Cause of Maternal Death
Authors: Durrani Muhammad I. A. , Naz Tabbasum , Atif Muhammad , Khalid Numra , Amelio Alessia
Published: September 2021

Objective Verbal autopsy is a technique used to collect information about a decedent from his/her family members using questionnaires, conducting interviews, making observations, and sampling. In substantial parts of the world, particularly in Africa and Asia, many deaths are unrecorded. In 2017, globally pregnant women were dying daily around 810 and 295,000 in a year because of pregnancy-related problems, pointed out by World Health Organization. Identifying the cause of a death is a complex process which requires in-depth medical knowledge and practical experience. Generally, medical practitioners possess different knowledge levels, set of abilities, and problem-solving skills. Additionally, the medical negligence plays a significant part in further worsening the situation. Accurate identification of the cause of death can help a government to take strategic measures to focus on, particularly increasing the death rate in a specific region.

Methods This research provides a solution by introducing a semantic-based verbal autopsy framework for maternal death (SVAF-MD) to identify the cause of death. The proposed framework consists of four main components as follows: (1) clinical practice guidelines, (2) knowledge collection, (3) knowledge modeling, and (4) knowledge codification. Maternal ontology for the framework is developed using Protégé knowledge editor. Resource description framework application programming interface (API) for PHP (RAP) is used as a Semantic Web toolkit along with Simple Protocol and RDF Query Language (SPARQL) is used for querying with ontology to retrieve data.

Results The results show that 92% of maternal causes of deaths assigned using SVAF-MD correctly matched manual reports already prepared by gynecologists.

Conclusion SVAF-MD, a semantic-based framework for the verbal autopsy of maternal deaths, assigns the cause of death with minimum involvement of medical practitioners. This research helps the government to ease down the verbal autopsy process, overcome the delays in reporting, and facilitate in terms of accurate results to devise the policies to reduce the maternal mortality.
A “Congenitally Adapted” TFCC Tear in Radial Longitudinal Deficiency: Case Report and Review of Literature
Authors: Oestreich Kerstin , Lindau T.R.
Published: September 2021

We present a case of chronic wrist pain in a 14-year-old child with mild radial longitudinal deficiency and radiographic carpal collapse due to the absence of the scaphoid. Wrist arthroscopy demonstrated synovitis and a tear to the TFCC, which would be called “degenerative,” according to the Palmer classification. This was debrided, and the patient is still asymptomatic at long-term follow-up. Review of the literature found one paper with a similar observation in a 17-year-old adolescent. We propose that paediatric “degenerative” tears ought to be called “congenitally adapted” tears.
Mutations of PHOX2B Gene in Patients of Obesity Hypoventilation Syndrome in Central India
Authors: Tyagi Ankita , Goyal Abhishek , Chaware Prashant , Rathinam Bertha A.D.
Published: September 2021

Background Paired-like homeobox 2B (PHOX2B) gene on chromosome 4p12 codes for a transcription factor having a role in the formation of noradrenergic neuronal circuits. Its mutations have been linked to congenital central hypoventilation syndrome (CCHS). The clinical presentation of both, obesity hypoventilation syndrome (OHS) and CCHS in adults (named late-onset central hypoventilation syndrome), is quite similar. Because of this symptomatic similarity, multifactorial causation of OHS, the mutation of PHOX2B gene was studied in patients with OHS in this study.

Methods A hospital-based cross-sectional study was performed on patients diagnosed with OHS. The deoxyribonucleic acid was extracted from 2 mL of venous blood and was further amplified, specific to exon 3. The amplified products were cast and run in 2% agarose gel and then subjected to Sanger sequencing.

Results Thirty patients of OHS (21 male; 9 female) were enrolled in the present study, average age being 51.7 years. The Sanger sequencing of the samples revealed no apparent areas of deletions and no apparent mutations.

Conclusion Primers for exon 3 were used for amplification in thermocycler, as exon 3 is the most frequently mutated exon for PHOX2B gene, as per existing literature. The entire gene needs to be studied for mutations and the sample size needs to be increased.
Improving the Quality of Venous Blood Sampling Procedure (Phlebotomy): Avoiding Tourniquet Use
Authors: Freitas Francisco , Alves Mónica
Published: September 2021

Background Phlebotomy guidelines discourage tourniquet use whenever possible. We assessed phlebotomists' capability of not using the tourniquet in venous blood sampling, hypothesizing it to be equal to 50% of the patients attended, and identifying the most frequent venipuncture site.

Materials and Methods We assigned two phlebotomists of the same age (41 years) and experience (20 years) to record 10 phlebotomy days, the first with prioritized and the latter with nonprioritized patients. Each acquired daily data for the number of attended patients, age, gender, frequency of nontourniquet usage, and punctured vein. To test our work hypothesis we used the two-tailed single sample t-test. Differences between age-group means and nontourniquet use means by each phlebotomist were tested by two-tailed t-test for independent means.

Results In 10 phlebotomy days, 683 patients were attended (males 43.2%). We found no statistically significant difference between age-group means. The combined capability of nontourniquet use was 50.5%, which did not differ from our null hypothesis, but the difference in individual group means was statistically significant, the means being 33% and 66.9% (prioritized vs. nonprioritized). The medial cubital vein was the most prone to be punctured (77.7%).

Conclusion Performing phlebotomies without tourniquet was possible in at least half of the attended patients, though it was more limited in specific group populations.
Theory and application of the vector pair correlation function for real-space crystallographic analysis of order/disorder correlations from STEM images
Authors: Funni Stephen D. , Yang Zi Jin , Cabral Matthew J. , Ophus Colin , Chen Xiang M. , Dickey Elizabeth C.
Published: September 2021

Deviations of local structure and chemistry from the average crystalline unit cell are increasingly recognized to have a significant influence on the properties of many technologically important materials. Here, we present the vector pair correlation function (vPCF) as a new real-space crystallographic analysis method, which can be applied to atomic-resolution scanning transmission electron microscopy (STEM) images to quantify and analyze structural order/disorder correlations. Our STEM-based vPCFs have several advantages over radial PCFs and/or 3D pair distribution functions from x-ray total scattering: vPCFs explicitly retain crystallographic orientation information, are spatially resolved, can be applied directly on a sublattice basis, and are suitable for any material that can be imaged with STEM. To show the utility of our approach, we measure partial vPCFs in Ba5SmSn3Nb7O30 (BSSN), a tetragonal tungsten bronze (TTB) structured complex oxide. Many TTBs are known to be classical or relaxor ferroelectrics, and these properties have been correlated with the presence of superlattice ordering. BSSN, specifically, exhibits relaxor behavior and an incommensurate structural modulation. From the vPCF data, we observe that, of the cation sites, only the Ba (A2) sublattice is structurally modulated. We then infer the local modulation vector and reveal a marked anisotropy in its correlation length. Finally, short-range correlated polar displacements on the B2 cation sites are observed. This work introduces the vPCF as a powerful real-space crystallography technique, which enables direct, robust quantification of short-to-long range order on a sublattice-specific basis and is applicable to a wide range of complex material types.
Magnetic lifting triboelectric nanogenerators (ml-TENG) for energy harvesting and active sensing
Authors: Matin Nazar Ali , Egbe King-James Idala , Jiao Pengcheng , Wang Yuzhou , Yang Yang
Published: September 2021

Triboelectric nanogenerators (TENG) have been reported with the advantages of high adaptability and easy integration in recent years, which, however, have been facing with the challenge of effective stimuli in different applications. In this study, we develop magnetic lifting triboelectric nanogenerators (ml-TENG) for energy harvesting and active sensing under cyclic loading, such as traffic. The ml-TENG take advantage of magnetic force to provide repulsive force to trigger for relative displacement between the electrode and dielectric layers in the sliding mode. Experimental and numerical studies are conducted to investigate the electrical performance of the ml-TENG under cyclic loading. The open-circuit voltage of 4 V and output power of 340 µW per capsule are obtained. In the end, we develop a self-powered velocity active sensing system using the ml-TENG, and the field test is conducted to obtain the maximum open-circuit voltage of 7.2 V at the velocity of 15 km/h. The reported ml-TENG provide a powerful tool to develop active sensing systems for real-world applications, such as velocity detection.
Long-term survival of large relocated
Authors: Buckee Joanna , Blount Craig
Published: September 2021

In August 2009, eight large Porites corals were relocated prior to dredging works at Cocos (Keeling) Islands. In March 2020, relocated colonies were found to have survived and grown, demonstrating that large Porites colonies growing on unconsolidated substrates can be relocated successfully if moved swiftly to a similar habitat to their source.
A steady-state N balance approach for sustainable smallholder farming
Authors: Yin Yulong , Zhao Rongfang , Yang Yi , Meng Qingfeng , Ying Hao , Cassman Kenneth G. , Cong Wenfeng , Tian Xingshuai , He Kai , Wang Yingcheng , Cui Zhenling , Chen Xinping , Zhang Fusuo
Published: September 2021

Significance

Smallholder farmers in China tend to overuse N fertilizer as an “insurance” to avoid yield loss. Better management can be achieved but lack resources to adopt advanced technologies that improve N use efficiency. Our study proposes a simplified but effective N management approach without sampling. This new approach based on steady-state N balance could significantly reduce N fertilizer use while maintaining or even increasing yields compared to the local farmers’ practice. Demonstrations in Chinese cereal production indicate the potential of the new N management approach to become an effective tool for policy guidance and to contribute to global N sustainability.
Simulation of the Deformation and Contact of Scrolls in the Scroll Compressor
Authors: Wang C , Zhang S , Cheng J M , Lei B W , Du Y J , Wu J H
Published: September 2021

The control of the clearances in a scroll compressor is crucial to ensure the reliability and efficiency of compressor, especially for the compressors without radial compliance mechanism. In this study, the fluid-solid-thermal simulation is conducted to get the temperature field, the pressure load distribution on scroll wraps. Then, the influences of the temperature, pressure and the inertial force on the deformation of scroll wraps are investigated. On these bases, the variation of gap size and potential contact between scroll wraps is analysed under various orbiting radii. It is shown that the deformation caused by temperature is more significant than the pressure and inertial force. The contact occurs even though orbiting follows the theoretical orbiting radius due to the positive radial deformation of scroll wrap and negative radial deformation of inner wall of fixed scroll.
Force assisted discharge valve for piston compressors
Authors: Dür L , Egger A , Lang M , Almbauer R
Published: September 2021

Due to the enormous number of domestic refrigeration appliances worldwide and the associated high overall energy demand of the cooling sector, manufacturers are required to develop more efficient cooling devices. For this reason, variable speed compressors are increasingly being used in order to better match refrigeration demand and supplied cooling capacity. However, variable speed operation is associated with challenges concerning the valve dynamics. Valve oscillation as well as opening and closing delays reduce the energy efficiency (COP) of the compressor.

The underlying study is about a simulation based potential analysis of a novel force assisted discharge valve to improve the valve dynamics of a small hermetic reciprocating compressor for domestic refrigeration. Discharge valve and valve support mechanism are modelled by a 1d-spring-damper-mass multi-body system and implemented in an existing in-house compressor simulation model.

Systematic methods of statistical design of experiments (DOE) are applied not only to improve the COP but also to generate a robust valve behaviour which is largely independent of the operating conditions of the compressor. The findings of the force assisted discharge valve are basically transferable to any other piston compressor with flutter valves.
2D transient analysis of suction process for coupled vane compressor
Authors: Poh W C , Elhadidi B , Ooi K T
Published: September 2021

Although CFD has been widely applied to the study of positive displacement compressors, the primary challenge remains in the generation of solution domain of complicated geometry and accurate handling of the deformation of the working chamber during the compressor operation. In this paper, a 2D transient CFD simulation employing the overset mesh method is performed on the Coupled Vane Compressor (CVC) with air as the working fluid. Initial results revealed the presences of flow reversal and circulation zones at the suction channel resulting in the reduction of effective suction flow area. This has significantly reduced the mass intake. Proposed modification to the suction channel design has resulted in an increase of mass flow rate of 6.97% when operating at 1500rpm. Simulation approach, results and design modification are presented and discussed in this paper.
Modeling and comparison of different capacity modulation strategies with focus on seasonal performance
Authors: Inampudi S , Botticella F , Elbel S
Published: September 2021

Over the past few years, demand for energy efficient HVAC systems has been increasing rapidly, and this trend is likely to continue in the future. There are various modulation technologies that can respond to load variations by switching between capacity levels (tandem, two-stage compressors), PWM control (digital scroll), speed modulation (variable-speed). These technologies can be compared using a single number figure of merit, IPLV. SI which expresses part-load efficiency based on weighted operation at various partial capacities. A model is proposed for a water chiller application having a nominal cooling capacity of 8kW. System performance has been calculated using a 10-coefficient compressor model provided by the manufacturer and the most well-known correlations for heat transfer and pressure drop in a brazed plate heat exchanger. Model validation is performed with experimental data obtained in a parallel experimental investigation. Single-speed and two-stage compressor have a comparable IPLV. SI while a variable-speed compressor has 20% higher IPLV. SI.
Theoretical Study on the Performance of Air Cooler in Cold Storage
Authors: Dong Lin , He Zhilong
Published: September 2021

Air cooler is the most common air cooling and conditioning equipment that used in frozen and cold storage. However, neither application-oriented or production-oriented enterprises have a sufficient understanding about the performance of air cooler, which will restrict its performance enhancement and technological innovation to some extent. Therefore, this paper conducts a theoretical study on the performance of air cooler to guide the optimal design of air cooler. The distributed parameter model of the air cooler is first established along with some sub-models calculating the structural parameters, the physical properties of the wet air, the heat transfer coefficient and the flow resistance on the refrigerant side and the air side. Then, the proposed models are integrated to calculate the performance of air cooler under the effect of different structural parameters, such as fin spacing, fin thickness, tube spacing, outer tube diameter and finned tube materials. Results show that choosing the relatively smaller fin spacing and outer tube diameter, the larger tube spacing and finned tube materials with high thermal conductivity would contribute to the performance improvement of the air cooler, while the effect of the fin thickness is very small. However, the occupied volume, cost and processing difficulty should also be considered for enterprises in the design stage.
CFD Simulation and Experimental studying of a Dry Screw Vacuum Pump
Authors: Ma K , Guo B , Zhou Y , Wang Y B
Published: September 2021

Dry screw vacuum pumps are widely used in semiconductor, microelectronics and food industries due to their oil-free characteristics in the vacuum chamber during operation. The performance of screw vacuum pumps is usually predicted by one-dimensional numerical simulation or empirical methods. However, the above method cannot obtain the distribution of the fluid flow field inside the vacuum pump. In this paper, a three-dimensional model is established based on the experimental dry screw vacuum pump. The internal flow field of the dry screw vacuum pump was simulated by computational fluid dynamics (CFD) software using structured dynamic grid. The flow characteristics of the fluid inside the vacuum pump were analyzed. The distribution of the pressure field and velocity field inside the compressor is obtained. Comparing the P-θ indicator diagram and the performance parameters of the vacuum pump with the experimental results. It was found that the results of the three-dimensional numerical simulation were more consistent with the trends of the experimental data. On this basis, the flow field characteristics and performance of the vacuum pump are analyzed and the flow field of the vacuum pump can be better understood.
Research on motion and friction of rolling piston in rotary compressor
Authors: Xu J , Yu B , Yang O X , Ding S P , Zhao H H
Published: September 2021

Based on the Reynolds equation of mixed lubrication, the dynamic model of rolling piston was established, and the axis locus, rotation velocity, sliding velocity at vane tip, and friction loss of the piston were numerically solved. The analysis results indicated that the numeric results of sliding velocity at vane tip are in good agreement with the experimental results. In addition, the influences of crankshaft rotation speed, working condition, piston density and compression structure parameters on motion and friction were analyzed. Taking the ratio of piston rotation velocity and revolution velocity (λ) as evaluation index, whether λ conforms to cosine curve can judge the motion state between piston and vane. The results show that there is not only sliding state but also rolling state between piston and vane tip, and keeping rolling state is helpful to reduce friction loss. The design schemes of lighter piston, thicker vane and larger height-diameter ratio cylinder are proposed to keep rolling state in a wider rotation speed range and smaller pressure difference condition, thereby improving the annual operating efficiency of R32 rotary compressor.
Design Improvements of Vane Bearing Compressor
Authors: Hu YS , Wei H J , Xu J , Wan P K , Ren L P , Fu Z
Published: September 2021

A variant of vane bearing compressor with double rolling bearing had been introduced two years ago (Hu and Xu, 2019). In order to solve the problems of complex assembly process and abnormal wear in the vane bearing compressor with double rolling bearing, this paper presents a type of improved vane bearing compressor with single rolling bearing. The improved vane bearing compressor integrates the rolling bearings and the cylinder into a rolling bearing cylinder unit. The suction t and discharge ports are placed on the end face of the main bearing. With these improvements, the number of the end face friction pairs of rolling bearing inner ring is reduced by half, the number of parts is reduced accordingly, and the assembly process is thus made simpler than that with double rolling bearing. This paper introduces the operational characteristics and makes a series of structure optimization to improve the performance of the improved vane bearing compressor with single rolling bearing. The energy efficiency of the improved vane bearing compressor with single rolling bearing is found to be 5% higher than that with the double rolling bearing.
Lubricant Options for Screw Compressors Using Alternative Refrigerants
Authors: Karnaz J
Published: September 2021

Environmental concerns have created need to find replacements for HFC and in some cases HCFC refrigerants used in screw compressor applications. Like most refrigerant changes it becomes necessary to assess the best lubricant option in order to maintain system reliability and performance. Regardless of the magnitude of the changes it allows opportunity to appraise alternative lubricant chemistries that are different from what was used in the past.

This paper will investigate various alternative refrigerants being evaluated for screw compressor applications. Choices will be presented that not only maintain what was seen in the past but also offers potential to advance application ranges while using of a single lubricant with various operational designs. As always needed when evaluating lubricants and refrigerants, information on the interaction properties along with stability and material compatibility will be presented. Comparisons will be made to legacy data operation and potential improvements will be presented that are available when using combinations of alternative refrigerants and lubricants.
Hydrodynamic response time of magnetorheological fluid in valve mode: an initial study
Authors: Kubík Michal , Šebesta Karel
Published: September 2021

The transient behaviour of magnetorheological (MR) damper is a very important parameter affecting the performance of this technology in modern semi-actively controlled suspension systems. Currently, the transient behaviour of the MR damper is limited by dynamics of the MR fluid (MRF) itself. The significant part of MRF response time is a hydrodynamic response time which is connected with transient rheology and development of velocity profile in the slit gap. In this paper, the method for measuring the hydrodynamic response time of MRF operating in valve mode is presented. The hydrodynamic response time of MRF-132DG achieved value of τ90 = 0.78 ms for H = 17.5 kA/m a value of τ90 = 0.65 ms for H = 34 kA/m for given geometry of gap. The difference between model and experiment is lower in higher yield stresses of MRF.
Waist Circumference Measurement for Prediction of Preeclampsia: A Population-Based Cohort Study
Authors: Pétursdóttir Maack Heidrun , Sundström Poromaa Inger , Segeblad Birgitta , Lindström Linda , Jonsson Maria , Junus Katja , Wikström Anna-Karin
Published: September 2021

Background

Identifying women at high risk for preeclampsia is essential for the decision to start treatment with prophylactic aspirin. Prediction models have been developed for this purpose, and these typically incorporate body mass index (BMI). As waist circumference (WC) is a better predictor for metabolic and cardiovascular outcomes than BMI in nonpregnant populations, we aimed to investigate if WC is a BMI-independent predictor for preeclampsia and if the addition of WC to a prediction model for preeclampsia improves its performance.

Methods

We used a population-based cohort of 4,696 women with WC measurements taken in the first trimester. The influence of WC on the risk of developing preeclampsia was evaluated by multivariable logistic regression. We generated receiver operating characteristic curves and calculated the area under the curve (AUC) to evaluate the usefulness of WC measurements for prediction of preeclampsia.

Results

Women who developed preeclampsia had greater early pregnancy WC than women who did not (85.8 ± 12.6 vs. 82.3 ± 11.3 cm, P < 0.001). The risk of preeclampsia increased with larger WC in a multivariate model, adjusted odds ratio 1.02 (95% confidence interval 1.01–1.03). However, when adding BMI into the model, WC was not independently associated with preeclampsia. The AUC value for preeclampsia prediction with BMI and the above variables was 0.738 and remained unchanged with the addition of WC to the model.

Conclusions

Large WC is associated with a higher risk of preeclampsia, but adding WC to a prediction model for preeclampsia that already includes BMI does not improve the model’s performance.
Interactive effects of phosphorus fertilization and salinity on plant growth, phosphorus and sodium status, and tartrate exudation by roots of two alfalfa cultivars
Authors: Su Rui , Zhang Zekun , Chang Chao , Peng Qi , Cheng Xiao , Pang Jiayin , He Honghua , Lambers Hans
Published: September 2021

Background and Aims

Soil phosphorus (P) deficiency and salinity are constraints to crop productivity in arid and semiarid regions. Salinity may weaken the effect of P fertilization on plant growth. We investigated the interactive effects of soil P availability and salinity on plant growth, P nutrition and salt tolerance of two alfalfa (Medicago sativa) cultivars.

Methods

A pot experiment was carried out to grow two cultivars of alfalfa in a loess soil under a combination of different rates of added P (0, 40, 80 and 160 mg P kg−1 soil as monopotassium phosphate) and sodium chloride (0, 0.4, 0.8 and 1.6 g NaCl kg−1 soil). Plant biomass, concentrations of P ([P]), sodium ([Na]) and potassium ([K]) were determined, and rhizosheath carboxylates were analysed.

Key Results

There were significant interactions between soil P availability and salinity on some, but not all, of the parameters investigated, and interactions depended on cultivar. Plant growth and P uptake were enhanced by P fertilization, but inhibited by increased levels of salinity. Increasing the salinity resulted in decreased plant P-uptake efficiency and [K]/[Na]. Only soil P availability had a significant effect on the amount of tartrate in the rhizosheath of both cultivars.

Conclusions

Increased salinity aggravated P deficiency. Appropriate application of P fertilizers improved the salt tolerance of alfalfa and increased its productivity in saline soils.
Explainable nucleus classification using Decision Tree Approximation of Learned Embeddings
Authors: Amgad Mohamed , Atteya Lamees A , Hussein Hagar , Mohammed Kareem Hosny , Hafiz Ehab , Elsebaie Maha A T , Mobadersany Pooya , Manthey David , Gutman David A , Elfandy Habiba , Cooper Lee A D
Published: September 2021

Motivation

Nucleus detection, segmentation and classification are fundamental to high-resolution mapping of the tumor microenvironment using whole-slide histopathology images. The growing interest in leveraging the power of deep learning to achieve state-of-the-art performance often comes at the cost of explainability, yet there is general consensus that explainability is critical for trustworthiness and widespread clinical adoption. Unfortunately, current explainability paradigms that rely on pixel saliency heatmaps or superpixel importance scores are not well-suited for nucleus classification. Techniques like Grad-CAM or LIME provide explanations that are indirect, qualitative and/or nonintuitive to pathologists.

Results

In this article, we present techniques to enable scalable nuclear detection, segmentation and explainable classification. First, we show how modifications to the widely used Mask R-CNN architecture, including decoupling the detection and classification tasks, improves accuracy and enables learning from hybrid annotation datasets like NuCLS, which contain mixtures of bounding boxes and segmentation boundaries. Second, we introduce an explainability method called Decision Tree Approximation of Learned Embeddings (DTALE), which provides explanations for classification model behavior globally, as well as for individual nuclear predictions. DTALE explanations are simple, quantitative, and can flexibly use any measurable morphological features that make sense to practicing pathologists, without sacrificing model accuracy. Together, these techniques present a step toward realizing the promise of computational pathology in computer-aided diagnosis and discovery of morphologic biomarkers.

Availability and implementation

Relevant code can be found at github.com/CancerDataScience/NuCLS

Supplementary information

Supplementary data are available at Bioinformatics online.
AlphaMap: an open-source Python package for the visual annotation of proteomics data with sequence-specific knowledge
Authors: Voytik Eugenia , Bludau Isabell , Willems Sander , Hansen Fynn M , Brunner Andreas-David , Strauss Maximilian T , Mann Matthias
Published: September 2021

Integrating experimental information across proteomic datasets with the wealth of publicly available sequence annotations is a crucial part in many proteomic studies that currently lacks an automated analysis platform. Here, we present AlphaMap, a Python package that facilitates the visual exploration of peptide-level proteomics data. Identified peptides and post-translational modifications in proteomic datasets are mapped to their corresponding protein sequence and visualized together with prior knowledge from UniProt and with expected proteolytic cleavage sites. The functionality of AlphaMap can be accessed via an intuitive graphical user interface or—more flexibly—as a Python package that allows its integration into common analysis workflows for data visualization. AlphaMap produces publication-quality illustrations and can easily be customized to address a given research question.

Availability and implementation

AlphaMap is implemented in Python and released under an Apache license. The source code and one-click installers are freely available at https://github.com/MannLabs/alphamap.

Supplementary information

Supplementary data are available at Bioinformatics online.
MuWU: Mutant-seq library analysis and annotation
Authors: Stöcker Tyll , Altrogge Lena , Marcon Caroline , Win Yan Naing , Hochholdinger Frank , Schoof Heiko
Published: September 2021

Motivation

Insertional mutagenesis allows for the creation of loss-of-function mutations on a genome-wide scale. In theory, every gene can be ‘knocked out’ via the insertion of an additional DNA sequence. Resources of sequence-indexed mutants of plant and animal model organisms are instrumental for functional genomics studies. Such repositories significantly speed up the acquisition of interesting genotypes and allow for the validation of hypotheses regarding phenotypic consequences in reverse genetics. To create such resources, comprehensive sequencing of flanking sequence tags using protocols such as Mutant-seq requires various downstream computational tasks, and these need to be performed in an efficient and reproducible manner.

Results

Here, we present MuWU, an automated Mutant-seq workflow utility initially created for the identification of Mutator insertion sites of the BonnMu resource, representing a reverse genetics mutant collection for functional genetics in maize (Zea mays). MuWU functions as a fast, one-stop downstream processing pipeline of Mutant-seq reads. It takes care of all complex bioinformatic tasks, such as identifying tagged genes and differentiating between germinal and somatic mutations/insertions. Furthermore, MuWU automatically assigns insertions to the corresponding mutated seed stocks. We discuss the implementation and how parameters can easily be adapted to use MuWU for other species/transposable elements.

Availability and implementation

MuWU is a Snakemake-based workflow and freely available at https://github.com/tgstoecker/MuWU.

Supplementary information

Supplementary data are available at Bioinformatics online.