bluuebunny/crossref_metadata_2025 huggingface dataset:
HLA class I depletion by citric acid, and irradiation of apheresis platelets for transfusion of refractory patients
Authors: Mirlashari Mohammad Reza , Vetlesen Annette , Nissen‐Meyer Lise Sofie H. , Naper Christian , Tjønnfjord Geir Erland , Njerve Ida Unhammer , Ezligini Farshid , Landmark Brynjar Fowels , Meinke Stephan , Sandgren Per , Höglund Petter , Hetland Geir
Published: February 2021

Background

Patients can form antibodies to foreign human leukocyte antigen (HLA) Class I antigens after exposure to allogeneic cells. These anti‐HLA class I antibodies can bind transfused platelets (PLTs) and mediate their destruction, thus leading to PLT refractoriness. Patients with PLT refractoriness need HLA‐matched PLTs, which require expensive HLA typing of donors, antibody analyses of patient sera and/or crossmatching. An alternative approach is to reduce PLT HLA Class I expression using a brief incubation in citric acid on ice at low pH.

Methods and Materials

Apheresis PLT concentrates were depleted of HLA Class I complexes by 5 minutes incubation in ice‐cold citric acid, at pH 3.0. Surface expression of HLA Class I complexes, CD62P, CD63, phosphatidylserine, and complement factor C3c was analyzed by flow cytometry. PLT functionality was tested by thromboelastography (TEG).

Results

Acid treatment reduced the expression of HLA Class I complexes by 71% and potential for C3c binding by 11.5‐fold compared to untreated PLTs. Acid‐treated PLTs were significantly more activated than untreated PLTs, but irrespective of this increase in steady‐state activation, CD62P and CD63 were strongly upregulated on both acid‐treated and untreated PLTs after stimulation with thrombin receptor agonist peptide. Acid treatment did not induce apoptosis over time. X‐ray irradiation did not significantly influence the expression of HLA Class I complexes, CD62P, CD63, and TEG variables on acid treated PLTs.

Conclusion

The relatively simple acid stripping method can be used with irradiated apheresis PLTs and may prevent transfusion‐associated HLA sensitization and overcome PLT refractoriness.
Multicenter observational study evaluating the impact of platelet transport bags on product wastage
Authors: Kron Amie , Vijenthira Shangari , Pendergrast Jacob , Modi Dimpy , McLaren Alyson , MacDonald Anna , Armali Chantal , Cserti‐Gazdewich Christine , Smith Erica , Quest Graeme , Gabanowicz Katie , Lieberman Lani , Aseltine Laura , Sani Luarne , Roche Margaret , DeOliviera Maria , Yu Philip , Fazari Sandra , Patel Sneha , Lin Yulia , Kelly Zofia , Callum Jeannie
Published: February 2021

Background

Platelets are the most commonly discarded blood product in Canada, with the most common cause of in‐date product loss being improper storage. Transport containers to maintain temperature and extend acceptable return time may represent a method to reduce wastage. The objective of this study was to evaluate the impact of a validated Platelet Transport Bag (PTB) on platelet wastage.

Study Design and Methods

Thirty‐six hospitals with the highest platelet discards were invited to participate in a before–after observational study. Hospitals were instructed to utilize a validated 4‐h PTB for clinical situations where immediate transfusion was not planned. Five hospitals audited in‐date platelet discards from July 2018 to November 2019 to characterize wastage causes. In‐date platelet discard data 12 months before and after the start date for each site were analyzed to determine changes in wastage.

Results

Of 36 hospital sites, 16 agreed to participate. Pre‐ and postdiscards were 277 and 301, respectively, for all sites combined. There were no significant before–after change in wastage rate (+0.05%, p = .51). Fifty discards were included in the detailed audit; the most common reasons were return to the blood bank after more than 60 min outside a PTB (n = 17, 34%) and return in a red cell cooler (n = 10, 20%).

Conclusion

Implementation of PTB did not improve wastage. Common causes of in‐date discards were return after 1 h outside of a PTB and placement in a red cell cooler in error. Further research is required to investigate potential strategies to mitigate in‐date platelet wastage.
Minimally invasive ethyl cellulose ethanol ablation in domesticated cats with naturally occurring head and neck cancers: Six cats
Authors: Lai Yen‐Hao Erik , Morhard Robert , Ramanujam Nirmala , Nolan Michael W.
Published: February 2021

It is difficult to retain tumoricidal doses of ethanol in large or unencapsulated tumours without causing intoxication or damaging surrounding tissue. Ethyl cellulose‐ethanol ablation (ECEA) overcomes this limitation by trapping ethanol intratumorally. To evaluate the safety of ECEA and to develop a clinically feasible workflow, a single‐arm pilot study was performed in cats with lingual/sublingual squamous cell carcinoma (SCC). Six cats underwent intratumoral injection of 6% ethyl cellulose in ethanol. Subjects were observed overnight. There was mild bleeding and transient hyperthermia, and injection site pain and swelling that improved with anti‐inflammatory drugs. Serum ethanol was minimally elevated; the mean concentration peaked 1 hour after injection (129 +/− 15.1 nM). Cats were rechecked at weeks 1 and 2; booster treatments were given in cats (n = 3) with stable quality of life and partial response to therapy. Recheck examinations were then performed monthly. The longest tumour dimension increased in each animal (progressive disease via cRECIST); however, estimated tumour volume was reduced in 3 of 6 cats, within 1 week of ECEA. All cats were euthanized (median survival time 70 days) because of local tumour progression and/or lingual dysfunction that was likely hastened by ECEA. ECEA is not a viable treatment for feline lingual/sublingual SCC; tumour volume was effectively reduced in some cats, but the simultaneous loss of lingual function was poorly tolerated. Further optimization may make ECEA a useful option for SCC at other oral sites in the cat, and for head and neck malignancies in other species.
Comparison of needle arthroscopy, traditional arthroscopy, and computed tomography for the evaluation of medial coronoid disease in the canine elbow
Authors: Hersh‐Boyle Rebecca A. , Chou Po‐Yen , Kapatkin Amy S. , Spriet Mathieu , Filliquist Barbro , Garcia Tanya C. , Marcellin‐Little Denis J.
Published: February 2021

Objective

To evaluate the diagnostic value of still images of needle arthroscopy (SNAR), still images of traditional arthroscopy (STAR), and computed tomography (CT) to diagnose medial coronoid process (MCP) pathology.

Study design

Prospective clinical trial.

Animals

Dogs (n = 17) presented for evaluation of elbow dysplasia.

Methods

For each case, two SNAR and STAR images of the MCP were reviewed independently and in random order by three board‐certified surgeons. Computed tomographic images were reviewed by one board‐certified radiologist. Reviewers were blinded to surgical and clinical findings. Surgical findings from real‐time TAR with palpation were used as the gold standard. Receiver operating characteristic (ROC) curves and concordance statistics tests for the diagnostic accuracy of MCP fissure, MCP fragment, medial compartment condition, and cartilage score were calculated.

Results

Images of 27 elbows joints were reviewed. For MCP fissure detection, areas under the ROC curves for CT (0.84), STAR (0.73), and SNAR (0.57) did not differ. For the detection of MCP fragment, STAR had a larger area under the ROC curve (0.93) compared with SNAR (0.74,P = .015) and CT (0.54,P < .001). Still images of TAR and SNAR had comparable concordance for cartilage score (0.80 and 0.77, respectively) and medial compartment pathology (0.80 and 0.73, respectively).

Conclusion

Still images of NAR, STAR, and CT had similar diagnostic value to identify MCP fissures. Still images of TAR was superior to SNAR and CT to identify MCP fragments.

Clinical significance

The diagnostic accuracy of SNAR varied on the basis of the coronoid lesion being evaluated.
Effect of bupivacaine concentration and formulation on canine chondrocyte viability in vitro
Authors: Rengert Roger , Snider Darren , Gilbert Peter J.
Published: February 2021

Objective

To quantitate bupivacaine concentration and formulation effects on chondrocyte viability in vitro.

Study design

Controlled laboratory study.

Sample population

Primary canine chondrocyte isolates.

Methods

Cell passage 3 and 4 canine chondrocytes were exposed to 0.9% saline; canine chondrocyte growth medium; 0.4, 0.5, 0.6, 1.5, 2.5, 3.5, or 5 mg/mL preservative‐free standard formulation bupivacaine (SFB); or 13.3 or 6.65 mg/mL liposomal encapsulated bupivacaine (LEB) for 1 hour. Chondrocyte viability and clonogenicity were quantitated with 3‐(4,5‐dimethylthiazol‐2‐31 yl)‐2,5‐diphenyltetrazolium bromide (MTT) and clonogenic assays, respectively. Differences among concentrations and formulations were assessed with Kruskal‐Wallis and Dwass‐Steel‐Critchlow‐Fligner post hoc tests.

Results

Growth medium had the highest cell viability based on MTT metabolism. Similarly, all LEB concentration groups had higher cell viability compared with SFB concentration cells treated with 3.5 or 5 mg/mL SFB (P < .03). Among SFB concentrations, cell viability was higher at 0.6 mg/mL compared with at 2.5 mg/mL or greater (P < .03). Cell clonogenicity was not significantly different between saline, culture medium, or 0.5 mg/mL SFB. Clonogenicity was lower with all tested LEB concentrations compared with saline or medium (P < .02).

Conclusion

In vitro toxicity of SFB on canine chondrocytes is concentration dependent. Liposomal encapsulated bupivacaine may have time‐dependent effects resulting in chondrotoxicity.

Clinical significance

Clinically relevant concentrations of SFB after a single injection may not result in chondrotoxic effects in vitro. Liposomal encapsulated bupivacaine should not be used in the articular environment.
A cluster epidemic of influenza A(H1N1)pdm09 virus infection in four captive cheetahs (Acinonyx jubatus)
Authors: Usui Tatsufumi , Ueda Miya , Azumano Akinori , Nomura Mika , Arima Toru , Murata Koichi , Ito Toshihiro , Yamaguchi Tsuyoshi
Published: February 2021

In January 2019, four cheetahs (Acinonyx jubatus) kept at a Japanese zoo intermittently showed respiratory signs following the incidence of seasonal influenza in animal caregivers. Respiratory materials (saliva, sputum and food tray swabs) were non‐invasively collected from the four cheetahs. Although we were unable to isolate the virus, the NP gene of influenza A virus was detected in three of the cheetahs but not in the fourth cheetah that had nearly recovered. From a food tray swab which tested weakly positive by a commercial influenza detection kit, we were able to obtain the whole‐genome sequence of the influenza A virus. Analysis of the genome, A/cheetah/Kanagawa/2/2019(H1N1), revealed that the virus was closely related to influenza A(H1N1)pdm09 viruses isolated from humans in Japan in the 2018–2019 winter. Production of haemagglutinin inhibition (HI) antibodies (64–128 HI) against an A(H1N1)pdm09 virus in plasma samples confirmed infection of all four cheetahs. The animals continued to produce antibodies for at least 314 days after disease onset. These findings strongly suggest that reverse zoonotic transmission of A(H1N1)pdm09 virus occurred from human to cheetah and subsequently from cheetah to cheetah in the zoo. We also show that specimens can be safely and non‐invasively collected from non‐domesticated animals and used to investigate respiratory infectious diseases.
DEBUNKING ARGUMENTS GAIN LITTLE FROM COGNITIVE SCIENCE OF RELIGION
Authors: Launonen Lari
Published: February 2021

Cognitive science of religion (CSR) has inspired a number of debunking arguments against god‐belief. They aim to show that the belief‐forming processes that underlie belief in god(s) are unreliable. The debate surrounding these arguments gives the impression that CSR offers new scientific evidence that threatens the rationality of religious belief. This impression, however, is partly misleading. A close look at a few widely discussed debunking arguments shows, first, that CSR theories as such are far from providing sufficient empirical evidence that the belief‐forming processes behind god‐belief are unreliable. Thus, appealing solely to CSR theories makes a debunking argument weak. Second, there are strong arguments that also invoke CSR, but these gain their strength primarily from more familiar claims about evolutionary epistemology and religious diversity. What CSR actually does in these arguments is providing an explanation of why people might believe in gods even if gods did not exist. But explaining is not debunking.
A Theoretical Investigation of the Maximum-Lift Coefficient
Authors: von Kármán Th. , Millikan Clark B.
Published: February 2021

In the present paper the application of a laminar boundary-layer theory, previously developed by the authors, to the problem of the maximum-lift coefficient of airfoils is discussed. The calculations are carried through in detail for a first approximation, called a single-roof profile, to the potential velocity distribution over the upper surface of an airfoil. The results indicate a large variation in Clmax with turbulence but the quantitative dependence on Reynolds’ number and turbulence is not satisfactory. The calculations are then repeated for a so-called double-roof profile which approximates to the flow over the upper surface of an N.A.C.A. 2412 airfoil. These results are compared with those obtained from an experimental investigation on the same airfoil. The agreement is considered to indicate that for moderate values of R and Clmax the phenomenon of the maximum-lift coefficient is controlled by a contest between the separation and transition points of the laminar boundary layer over the nose of the airfoil. The difficulties involved in extending the theory to larger values of R, or to airfoils whose Cl vs. α curves are not approximately linear up to the stall, are mentioned.
A Numerical Study on Channel Deformation and Springback Using Tool Rollers
Authors: Nikhare Chetan P.
Published: February 2021

A sudden increase in the usage of automotive vehicles results in sudden increases in the fuel consumption which results in an increase in air pollution. To cope up with this challenge federal government is implying the stricter environmental regulation to decrease air pollution. To save from the environmental regulation penalty vehicle industry is researching innovation which would reduce vehicle weight and decrease the fuel consumption. Thus, the innovation related to light-weighting is not only an option anymore but became a mandatory necessity to decrease fuel consumption. To achieve this target, the industry has been looking at fabricating components from high strength to ultra-high strength steels or lightweight materials. With the usage of advanced high strength steels, the lightweight was achieved by reducing a gage thickness without compromising the strength aspect. However due to their high strength property often challenges occurred are higher machine tonnage requirement, sudden fracture, geometric defect, etc. The geometric defect comes from the elastic recovery of a material, which is also known as a springback. Springback is commonly known as a manufacturing defect due to the geometric error in the part, which would not be able to fit in the assembly without secondary operation or compensation in the forming process. It is learned that the springback of the material increases with an increase in the material strength and/or decrease in material thickness. In advanced high strength steels, higher strength and lower gage thickness options make the part prone to higher springback. Due to these many challenges with the materials and their properties which affect the springback, other research routes involved are innovative forming processes which would reduce the springback such as applying electricity through the material after forming and before the release of the load, performing warm or hot forming, die compensation, etc. One such innovative and patented process which is studied in the paper is using rollers in the tool i.e., in die and punch during the forming process. In this paper, the 2D channel strip of the aluminum 2024 high strength and thin material will be used in the bending processes. The process will be simulated in ABAQUS finite element software. First, the conventional channel bending process will be performed and springback will be analyzed as compared to the desired shape. Then the tool rollers will be implied to the die and punch corner radius and then the channel bending process will be performed and springback will be analyzed. The roller rotations will be set constant in this study, but the motion i.e., clockwise or counterclockwise in both die and punch will be studied on the springback of the channel. In addition, the no rotation of the roller effect on the springback will be studied and results will be compared. Further the maximum stress before and after springback and the stress distribution all cases will be analyzed and presented.
Mechanical and System Simulation Modeling and Analysis of Surge Relief Valve
Authors: Zhou Hao , Yang Changqun , Yuan Jun , Zhao Shengdun , Chen Yuyang , Dong Peng , Dong Guodong , Wang Yongfei
Published: February 2021

Surge pressure relief valve is widely used in oil transportation. When water hammer occurs in the pipeline, the valve shall be opened in time to release the high pressure so as to ensure the safety of the oil pipeline. This paper discusses the structure and principle of the surge relief valve. Combined with the working process, the stress and working state of the main valve and the pilot valve are analyzed. The mechanical model of the pilot valve is established. This paper focuses on the analysis of the parameters affecting the closing process of the main valve. The relevant laws of the structure and performance parameters of the pilot valve to the main valve closing are obtained. The model of relief valve is modeled and simulated in detail by the AMESim software. The dynamic characteristics of the surge relief valve are analyzed and the correctness of the main parameters and rules that affect the main valve closing is verified by using the model. According to the analysis and simulation results, the friction force of the pilot valve can only affect whether the two valves can close normally. The closing time of the main valve is inversely proportional to the diameter of the inlet pressure orifice. In the normal operating range, the closing time of main valve gradually increases with the diameter of outlet pressure pipes, but does not change with the length of outlet pressure pipes.
Development of a Novel Modular Robot for Vertical Pipeline Climbing
Authors: Gharib Mohamed , Alnouri Leen , Alsulaiti Abdulrahman , Buhendi Ibrahim , Al-Hamidi Yasser
Published: February 2021

Crude oil pipelines are always at risk of failing as a result of cracking or corrosion. Failing pipelines can be hazardous to personnel, damaging to the environment, and extremely costly. This makes it essential that all pipelines have a schedule of inspection and maintenance. Robots that inspect pipelines from the outside are preferable to ones that work from the inside, because they can undertake inspections without causing any disruption to production processes and can be put to work at any point of the pipeline. Nevertheless, external robots and associated machinery have several challenges and limitations.

This research proposes the design, fabrication, and testing of a novel climbing robot that incorporates a drone-like means of propulsion. The purpose of this robot will be to undertake detection of external defects and to monitor the health of the horizontal and vertical pipelines. This climbing mobile robot is intended to assist the production of new system that will improve pipeline longevity using a minimum of energy and needing little human control. The robot proposed is a modular one, capable of motion on vertical pipes, exhibiting flexibility where there are bends in pipes, can adapt itself to different diameters of pipe, and employs a robust quadcopter propulsion mechanism. The robot itself exists without inspection techniques; it can carry a payload of modules that are incorporated into the design that are able to scan pipelines for inspection. The suggested design has a number of features that will help it to work efficiency, including the ability to carry multiple payloads, the ability to cope with both vertical and curved pipes, the ability to adapt to different sizes of pipe, being able to move autonomously, and being able to transport health monitoring systems.

In this paper, a literature survey is presented to show the different types of climbing robots. Compared to the developed robots in literature, the proposed robot is novel in the concept and design. The design of the robot components is discussed in details and the robot prototype is illustrated. This paper focuses on the new mechanical designs for the robot and prototype workability. The robot consists of multiple modules, to include payload modules, suspension modules, and propulsion modules. The suggested innovative design is economical and can be easily installed. Several industries would be very interested in this type of novel reliable means of inspecting pipelines. Future work is presented to show the continuity of the proposed robot development.
An Active Control Methodology to Improve Pulsatile Turbocharger Operating Conditions and Performance
Authors: Song Yue , Ding Shuiting , Xu Zheng , Du Farong , Zhou Yu
Published: February 2021

As a critical component of an Internal Combustion Engine (ICE), a turbocharger suffers highly pulsatile airflow from the exhaust pipe, which determines the turbocharger performance is very different from that under steady and quasi-steady conditions. Faced with the theoretical and computational challenges associated with the optimization of the inlet and outlet conditions of the turbocharger, this paper presents an active control methodology (ACM) to improve turbocharger operating conditions and performance based on the redistribution of air mass flow and fuel flow. Considering the poor-efficiency of constant pressure turbocharging system and high structural-dependent pulse turbocharging system, the ACM proposes 3 essential steps: extract partial compressed air from the compressor outlet, then heat the compressed air with the appropriate amount of fuel in a burner and finally supply the high-pressure and high-temperature gas to the turbine inlet. These three control steps are executed in every cycle of the engine operating period, which can achieve cycle-level active control for turbine inlet compressor outlet conditions and finally achieve the purpose of overall performance amelioration for turbocharger and engine. In this paper, a two-cylinders two-stroke turbocharged diesel engine with this active control system (ACS) is modeled using 1-D modeling software to validate the effectiveness of the methodology. System performance simulations are conducted with exemplifications of control strategies and 5 different extraction pipe diameters in the 1-D simulation model. Results show that 7mm is the optimal pipe size for the ACS corresponding to the adapted control strategies, which is supported by the 62.5% wider surge margin of the compressor and better instantaneous performance of the turbine. The presented ACM combines the features of high energy utilization for pulse exhaust and stable operating conditions for the turbocharger, which can achieve a wider surge margin and better engine performance. This paper provides an initial and rather unique insight for designing and optimizing the high-performance turbocharging system for engines.
Particle Image Velocimetry As Applied to Inlet Flow Field of a Turbocharger Compressor at Varying Rotational Speeds With Emphasis on Surge
Authors: Banerjee Deb , Dehner Rick , Selamet Ahmet , Miazgowicz Keith
Published: February 2021

Turbocharger surge remains an area of concern for the automotive industry as it limits the permissible operating range on the compressor map, while also adversely impacting the compressor’s pressure rise, efficiency, and acoustics. The present study uses Stereoscopic Particle Image Velocimetry (SPIV) to investigate the flow field at the inlet of an automotive turbocharger compressor without a recirculating channel. Experiments were carried out at four different speeds, including 80, 100, 120, and 140 krpm, which represent a substantial portion of the compressor map. The mass flow rates investigated ranged from choke to deep surge, thus spanning the entire mass flow regime at each rotational speed. The current work aims to characterize how the compressor inlet velocity field varies with rotational speed, with a specific emphasis on surge. The qualitative nature of the flow field (radial dependence of axial and tangential velocity profiles), over the choke to mild surge range, was observed to be nearly independent of rotational speed for comparable operating conditions (for example, comparison of mild surge at different rotational speeds). A quantitative comparison of the velocity profiles at the choke or mild surge operating points showed an increase in the velocity magnitudes with increasing rotational speed. The flow field at deep surge, however, was observed to change substantially from 80 krpm to 140 krpm. At 80 krpm, the character of the flow field at different times (at different points on the surge cycle) was observed to be similar: the core flow near the center of the duct was always directed into the impeller, whereas the reversed flow occupied an annular region near the periphery in nearly all time instances. However, as the rotational speed was increased to 140 krpm, the variation in the flow field at different instances within a deep surge cycle increased. At 140 krpm, the negative flow rate (where the cross-sectional average flow is directed out of the inducer back into the inlet duct) portion of the surge cycle was still similar to the overall surge flow field at 80 krpm, but over a substantial part of the positive flow rate (cross-sectional average flow is directed into the impeller) portion of the surge cycle, there was no sign of reversed flow within the visualization domain. As the rotational speed was increased, the surge loop (obtained by combining the PIV and pressure transducer data) extended over a wider portion of the compressor map with higher maximum (positive) and minimum (negative) flow rates, along with higher amplitude pressure fluctuations. The mean amplitude of mass flow rate and pressure ratio fluctuations at deep surge increased in nearly a quadratic fashion with rotational speed. The deep surge frequency did not change substantially over the range of rotational speeds examined in this study.
Investigation of Pressure Losses and Flow Fluctuations in an Intercept Valve Assembly of an Intermediate-Pressure Turbine Part
Authors: Slama Vaclav , Mrozek Lukas , Rudas Bartolomej , Simurda David , Hala Jindrich , Radnic Tomas
Published: February 2021

A new design of an intercept valve assembly of the intermediate-pressure turbine part of greater power output is investigated in terms of pressure losses and flow fluctuations by using measurement on an experimental valve model. In addition, numerical simulations are used to further clarify measured phenomena. For such valve assemblies, it is important to exactly predict pressure losses and avoid danger of vibrations, which are caused by undesirable flow fluctuations, in order to guarantee valve’s efficiency and operational reliability. For this type of valve, it is especially important for turbine operations in partial loads (off-design conditions). Measurements were carried out in the Aerodynamic laboratory of the Institute of Thermomechanics of the Czech Academy of Sciences (IT) in a modular aerodynamic tunnel. Numerical simulations were carried out in the Doosan Skoda Power Company (DSP) by using a package of ANSYS software tools. The experimental valve model is a scaled model of a real valve assembly. It consists of an inlet pipeline, a stop valve and a control valve including its diffuser and outlet pipeline. Measured regimes were defined by a mass flow rate and a control valve cone lift which can be precisely changed. In order to investigate pressure loses, total and static pressures at valve characteristic locations were measured by using Prandtl probes and wall static pressure taps. In order to measure pressure fluctuations, Kulite fast response pressure transducers were used. They were situated near the valve throat where the flow fluctuations, which are strongly related to a flow separation, are the most visible and influential. Measurement results are compared with numerical results and locations with a flow separation were found. In order to reduce this phenomenon, different valve seat angles were also tested. As a result, a valve design could be optimized and, for a pressure loss prediction, a pressure loss model for this new intercept valve assembly could be created. Therefore, pressure losses in similar valve assemblies can be predicted with required accuracy for each new turbine where modern intercept valves are used. This helps to increase steam turbine efficiency and reduce fuel consumption. Based on pressure fluctuations results, operating conditions at which dangerous flow instabilities occur were identified. It was concluded that there is an operating condition border where the flow field starts to be unstable. As a result, the areas of safe and dangerous operating conditions can be predicted so that the operational reliability of the valve can be guaranteed.
Design Strategy for Fixed Sunroof System
Authors: Huang Hailing , Zhang Yuxiang , Sui Hua
Published: February 2021

Fixed Sunroof System (FSS), which consists of a large size heat-strengthened roof panel glass, locating components, encapsulation, etc., is replacing traditional metal roof panel on vehicle to achieve weight reduction as well as providing a broad vision above passengers. As a result of the roof panel glass surface area and curvature, FSS could not be self-fixed on vehicle bodyside outer by means of its locating components currently and a tooling fixture is needed when the fixed sunroof be assembled to vehicle. Meanwhile, varied status of the interferences between FSS and vehicle outer or inner sheet metal may introduce additional loading forces while assembling. That could involve perceived quality issues on its appearance. At the same time, safety performance of FSS also leads a critical role on replacing traditional metal roof panel. This paper is aimed to present a comprehensive design strategy for FSS to achieve self-fixed to vehicle sheet metal as well as robust and sufficient assembly process. For the part of self-location, the concepts are divided to two major directions: location pins’ layout and pins’ structure. A reasonable layout and a new-developed structure of the location clip are essential to make sure the operators could see the clips clearly when assembly, which also conducive to avoid over-positioning. In addition, the fixed sunroof cannot be a naked glass because of appearance reason and seal function requirement. The relationship between loading force and encapsulation’s structure, material and interference volume distributed on the FSS should be established with the purpose of optimizing assembly process and improving interference performance.

This study also develops into detail by experimental and finite element analysis method to figure out the contribution on loading force from encapsulation’s structure, material and interference volume. Moreover, the strength of the FSS can be taken depends on is manufacture process and the shape of the glass. The key elements in manufacture process and the feasibility of further optimization can be identified by means of theoretical in the formation of glass stress. The effect of the fixed sunroof on entire vehicle can be estimated by FE analysis. This paper combines the traditional process with these new-optimized elements, which creates a new manufacture process to achieve a heat-strengthened roof panel glass with lager surface and high rigidity taking the reference of the production process in windshield and backlite. A detection method on glass strength and stiffness can also be figured out during the study in this new manufacture process.
Construction-Scale Concrete Additive Manufacturing and its Application in Infrastructure Energy Storage
Authors: Atkins Celeste , Betters Emma , Boulger Alex , Chesser Phillip , Heineman Jesse , Hun Diana , Lapsa Melissa , Loy Amy , Roschli Alex , Vaughan Joshua , Wang Peter , Post Brian
Published: February 2021

Construction is filled with labor intensive, hazardous, and often wasteful processes. It is also an enormous industry, so improvements in efficiency could have a tremendous economic impact. Construction-scale additive manufacturing is one path toward achieving those improvements. In this paper, a construction-scale additive manufacturing system, called Sky-BAAM, is presented. In addition to possibly leading to more energy-efficient construction practices, leveraging additive manufacturing in construction opens the solution space to more energy efficient building design. One such design, the EMPOWER wall, is also presented in this paper. The exterior of the wall is shaped to maximize heat transfer, while acting as form work for an internal energy-storage system. This allows energy to be stored in the wall during off-peak times and retrieved during peak periods.
Numerical Analysis on the Stability Conditions of an Electrohydrodynamic Jet
Authors: Cândido Sílvio , Páscoa José C.
Published: February 2021

The Taylor cone jet is a well-known electrohydrodynamic flow (EHD), usually produced by applying an external electric field to a capillary liquid. The generation of this kind of flow involves a multi-phase and a multi-physics process and its stability has a specific operation window. This operating window is intrinsically dependent on the flow rate and magnitude of the applied electric voltage. In case high voltages are applied to the jet it can atomize and produce an electrospray. Our work presents a numerical study of the process of atomization of a Taylor cone jet using computational fluid dynamics (CFD). The study intents to assess the limit conditions of operation and the applied voltage needed to stabilize an electrospray. The numerical model was implemented within OpenFOAM, where the multi-phase hydrodynamics equations are solved using a volume-of-fluid (VOF) approach. This method is coupled with the Maxwell equations governing an electrostatic field, in order to incorporate the electric body forces into the incompressible Navier-Stokes equations. The leaky-dielectric model is used and, therefore, the interface between the two phases is subject to the hydrodynamic surface tension and electric stress (Maxwell stress). This allows a leakage of charge though the phase due to ohmic conduction. Thus, the permittivity and conductivity of the phases are taken into consideration. A two-fluid system with relevant electric properties can be categorized as, dielectric-dielectric, dielectric-conducting, and conducting-conducting considering the electrical conductivity and permittivities of the participating phases. Due to the usage of the leaky-dielectric model, it is possible to simulate any of this physical situations. By increasing the applied voltage reaches a value where the cone instability is verified, allowing a discussion on this effect. It is demonstrated that to adequately model the process of atomization a fine grid refinement is needed. The validation of the numerical model is made by comparing against diverse experimental data, for the case of a stable jet. The diameter and velocity of the droplet and the electric current of the jet are the main variables that are compared with previous results. The tests were performed with Heptane. The cone and the jet are strongly affected by the flow rate. The dimensionless diameter, as a function of the dimensionless flow rate, agrees with the scaling laws. The model predicts accurate results over a wide range of flow rates with an accuracy of around 10%. The results are obtained using structured meshes.
Hydrogen Fast Fill Modeling and Optimization of Cylinders Lined With Phase Change Material
Authors: Liszka Miroslaw , Fridlyand Aleksandr , Jayaraman Ambalavanan , Bonnema Michael , Sishtla Chakravarthy
Published: February 2021

This work is a continuation of a previous study (IMECE2019-11449) which sought to explore the feasibility and means of successfully modeling the hydrogen fast filling process of cylinders lined with phase change material (PCM) entirely in CFD software. The first focus of this work was to address the simplistic approach of how the liner temperature was modelled in the previous study. Previously, the entire liner was assigned a single temperature which was obtained and updated through the lumped heat capacity method. This meant that the hotter gas at the end of the cylinder opposite the inlet was in contact with a liner at a temperature lower than could realistically be expected. This was remedied by splitting the liner into four sections. Two sections were used for the curved portions at each end of the cylinder, and the straight wall section was split into two. Each section had its temperature independently calculated through the lumped heat capacity method. A temperature difference on the order of a ten degrees Celsius was observed between the different sections of the liner prior to latent heating beginning. The mass averaged temperature of the hydrogen inside the cylinder obtained with the sectioned wall case matched that obtained with the single wall temperature almost exactly, less than a degree difference.

Despite the unexpected findings of the average hydrogen temperature not changing much when the wall is split into sections, this approach was still taken with all the cases completed in this study. The liner could be split into a greater amount of sections than four, but this was considered unnecessary due to the findings regarding the overall hydrogen temperature. Four sections were considered adequate and used to model the temperature gradient along the wall or liner. The effect of gravity on the filling process was also explored based on the orientation of the cylinder. This required completing three-dimensional simulations to accurately simulate buoyancy driven flow in horizontally mounted cylinders.

All the simulations were completed with ANSYS Fluent 2019 R1 without the use of additional software to handle the heat transfer involving the PCM. All simulations were completed with the coupled pressure-based solver and K-Omega SST turbulence model. The gas properties were obtained from tables generated from NIST properties (REFPROP) available within ANSYS Fluent to limit the amount of error in the accumulated mass within the cylinder due to inaccurate gas properties. The initial conditions for the gas and liner temperatures were 25°C and 100 bar for the gas pressure. A constant mass flow rate of 0.02174 kg/s at a temperature 0°C were used as the initial conditions for the inlet hydrogen gas.
Simulation of a Hydraulic Pulsation Dampener Used for Pulsation Reduction Induced by Vibrations in a Hydraulic System
Authors: Von Dolln William , Duan Shanzhong (Shawn)
Published: February 2021

To reduce vibration-induced pulsations, various devices have been developed, including diaphragm chamber system or gas bladder, non-intrusive fluid wave actuator and fluid filled also known as reflection-type dampeners. However, they are not suitable used in a hydraulic system powered by a triplet piston pump. For example, pulsation dampeners incorporating gas bladders are effective, but there are a number of drawbacks. Loss of gas charge, incorrect gas charge or volume/mass ratio, elastomeric rupture, narrow range of pressure operation and pump speeds, routine maintenance, ineffective location and branch connection instead of in-line configuration are all integrity issues which the industry faces. In addition to having a structural integrity issue, branch connected devices do not perform as efficiently as in-line devices. If a pulsation dampener is responsible for safeguarding critical equipment or systems, premature rupture of a gas bladder can be catastrophic.

This paper introduces a dynamic model and mathematical formulations of a spherical liquid pulsation dampener (U.S. patent number 3731709) that is commonly used to reduce harmful pulsations induced by a triplet piston pump source in fluid power systems. Based on the mathematically proven formulations, computer simulations and optimization procedures were developed in MATLAB to validate the model. Simulation results were then compared with field testing data to numerically verify the model and formulations. For the sake of simplicity, in this paper the pulsation dampener is in conjunction with a three-piston horizontal pump referred to as a triplex pump. The foundation of the simulation is based on a transfer function developed by electrohydraulic analogy resulting in a resistance-impedance-based model. This model takes into consideration all the components of the pulsation dampener and allows for a detailed relationship to its primary function of reducing magnitude spikes. After nonlinear impedances were linearized, MATLAB codes were able to recreate pressure pulsations before and after the pulsation dampener was applied to the system. This allowed for a comparison with field testing data, including mean pressures and range of pressure changes. The mean pressure values examined included 6.08 MPa, 15.20 MPa and 30.40 MPa. The key characteristics to properly analyze the comparison. The wave representing the pressure change over time via MATLAB and that of the field testing were consistent in pulsation reduction. With the validity of the transfer function confirmed, a meta-heuristic approach was utilized to find optimized dimensions of the pulsation dampener while maintaining the desired magnitude reduction. This method can be used to hone the precise dimensions for a variety of functions and even further reduce pulsations.
Lifestyle-Integrated Functional Exercise for People With Dementia: A Pilot Study
Authors: Almeida Sara , Paixão Cátia , Gomes da Silva Madalena , Marques Alda
Published: February 2021

The objective of this study was to explore the feasibility and preliminary effectiveness of the Lifestyle-Integrated Functional Exercise for People with Dementia (LiFE4D) on health-related physical fitness, cognitive function, physical activity, and respiratory and upper limb functions. A randomized controlled pilot study was conducted (control group: usual care; experimental group: usual care and LiFE4D). The feasibility of LiFE4D was determined considering recruitment, protocol acceptability, adherence, and safety. Measures of health-related physical fitness, cognitive function, physical activity, and respiratory and upper limb functions were assessed at the baseline and 3 months. Twelve participants (8 [66.7%] female, 82 [72.2–84] years) were included, six per group. Recruitment was challenging. LiFE4D was acceptable with excellent adherence and no major adverse events. Cardiorespiratory endurance (effect size = 1.64, 95% confidence interval [CI; 0.33, 2.95]) and balance (effect size = 1.46, 95% CI [0.19, 2.73]) improved after LiFE4D. LiFE4D seems to be feasible and safe, and it shows potential to significantly improve the health-related physical fitness of people with dementia.
Climate impacts of U.S. forest loss span net warming to net cooling
Authors: Williams Christopher A. , Gu Huan , Jiao Tong
Published: February 2021

Avoiding deforestation in the United States cools in some places but warms in others.
Optimized gene expression from bacterial chromosome by high-throughput integration and screening
Authors: Saleski Tatyana E. , Chung Meng Ting , Carruthers David N. , Khasbaatar Azzaya , Kurabayashi Katsuo , Lin Xiaoxia Nina
Published: February 2021

Pathway gene expression from the chromosome is optimized by a method of random site integrations and high-throughput screening.
The 2.4 Å cryo-EM structure of a heptameric light-harvesting 2 complex reveals two carotenoid energy transfer pathways
Authors: Gardiner Alastair T. , Naydenova Katerina , Castro-Hartmann Pablo , Nguyen-Phan Tu C. , Russo Christopher J. , Sader Kasim , Hunter C. Neil , Cogdell Richard J. , Qian Pu
Published: February 2021

The structure of a heptameric LH2 antenna complex reveals energy transfer pathways and basic assembly principles.
Biomimetic and flexible piezoelectric mobile acoustic sensors with multiresonant ultrathin structures for machine learning biometrics
Authors: Wang Hee Seung , Hong Seong Kwang , Han Jae Hyun , Jung Young Hoon , Jeong Hyun Kyu , Im Tae Hong , Jeong Chang Kyu , Lee Bo-Yeon , Kim Gwangsu , Yoo Chang D. , Lee Keon Jae
Published: February 2021

Biomimetic piezoelectric mobile acoustic sensor is fabricated for exceptional accuracy of AI-based biometric authentication.
Age control of the first appearance datum for Javanese
Homo erectus
in the Sangiran area
Authors: Matsu’ura Shuji , Kondo Megumi , Danhara Tohru , Sakata Shuhei , Iwano Hideki , Hirata Takafumi , Kurniawan Iwan , Setiyabudi Erick , Takeshita Yoshihiro , Hyodo Masayuki , Kitaba Ikuko , Sudo Masafumi , Danhara Yugo , Aziz Fachroel
Published: February 2021

Dating the arrival of the first hominins in Java

The World Heritage archaeological site at Sangiran on the island of Java in Indonesia has major importance for the understanding of human arrival and evolution in Asia. However, the timing of the first appearance of
Homo erectus
at the site has been controversial. Using a combination of dating techniques for hominin-bearing sediments, Matsu'ura
et al.
resolved the arrival of
H. erectus
at ∼1.3 million years ago (see the Perspective by Brasseur). This dating suggests that the earliest hominins in Sangiran are at least 200,000 years younger than has been thought and may represent an important step to the resolution of the controversy.

Science
, this issue p.
210
; see also p.
147
Hydrophobic zeolite modification for in situ peroxide formation in methane oxidation to methanol
Authors: Jin Zhu , Wang Liang , Zuidema Erik , Mondal Kartick , Zhang Ming , Zhang Jian , Wang Chengtao , Meng Xiangju , Yang Hengquan , Mesters Carl , Xiao Feng-Shou
Published: February 2021

Confining peroxide to make methanol

In principle, hydrogen peroxide would be an efficient oxidant for the conversion of methane to methanol under mild conditions. In practice, however, it is currently too expensive to produce the peroxide ahead of time for this purpose. Jin
et al.
report a catalyst system that generates and concentrates hydrogen peroxide for immediate reaction with methane. A hydrophobically coated zeolite keeps the peroxide close to the gold and palladium active site, where incoming methane is then selectively oxidized to methanol.

Science
, this issue p.
193
Observation of hydrogen trapping at dislocations, grain boundaries, and precipitates
Authors: Chen Yi-Sheng , Lu Hongzhou , Liang Jiangtao , Rosenthal Alexander , Liu Hongwei , Sneddon Glenn , McCarroll Ingrid , Zhao Zhengzhi , Li Wei , Guo Aimin , Cairney Julie M.
Published: February 2021

An anti-embrittlement roadmap

Hydrogen is important for energy applications such as fuel cells but tends to diffuse into materials and make them more susceptible to fracture. Chen
et al.
tackled the challenge of identifying the exact location of hydrogen atoms in two common steels. The light weight and high mobility of hydrogen creates serious problems with conventional techniques. The authors used cryo-transfer atom probe tomography to show that hydrogen is pinned to various interfaces in the steels. This direct look into hydrogen trapping should help with the development of materials that are more resistant to hydrogen embrittlement.

Science
, this issue p.
171