Novel measurement tool and model for aberrant urinary stream in 3D printed urethras derived from human tissue

Background An estimated 10% of male adults have split or dribbled stream leading to poor hygiene, embarrassment, and inconvenience. There is no current metric that measures male stream deviation. Objective To develop a novel method to measure spray in normal and abnormal anatomical conformations. Design, setting, and participants We developed a novel platform to reliably describe spray. We used cadaveric tissues and 3D Printed models to study the impact of meatal shape on the urinary stream. Cadaveric penile tissue and 3D printed models were affixed to a fluid pump and used to simulate micturition. Dye captured on fabric allowed for spray detection. Outcome measurements and statistical analysis Spray pattern area, deviation from normal location, and flowrates were recorded. Computational fluid dynamic models were created to study fluid vorticity. Results and limitations Obstructions at the penile tip worsened spray dynamics and reduced flow. Ventral meatotomy improved flowrate (p<0.05) and reduced spray (p<0.05) compared to tips obstructed ventrally, dorsally or in the fossa navicularis. 3D models do not fully reproduce parameters of their parent cadaver material. The average flowrate from 3D model was 10ml/sec less than that of the penis from which it was derived (p = 0.03). Nonetheless, as in cadavers, increasing obstruction in 3D models leads to the same pattern of reduced flowrate and worse spray. Dynamic modeling revealed increasing distal obstruction was correlated to higher relative vorticity observed at the urethral tip. Conclusions We developed a robust method to measure urine spray in a research setting. Dynamic 3D printed models hold promise as a methodology to study common pathologies in the urethra and corrective surgeries on the urine stream that would not be feasible in patients. These novel methods require further validation, but offer promise as a research and clinical tool.

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The 360 Lab

10.5194/egusphere-egu21-10189 ◽

2021 ◽

Author(s):

Josh Wolstenholme ◽

Christopher Skinner

Keyword(s):

3D Models ◽

Flood Management ◽

Face To Face ◽

Management Interventions ◽

3D Printed ◽

Face To Face Learning ◽

Personal Resilience ◽

Individual Ability ◽

Interactive 3D ◽

The Impact

Flooding is a major risk to lives and properties globally and this risk is increasing because of several factors, not least the increase of sea level and changes to patterns of precipitation due to climate change. Whilst flood management interventions can reduce the risk and the impact of flooding, it is not possible, and never will be possible, to stop flooding completely and this necessitates a public that is informed and equipped to take actions to increase their personal resilience.Successful learning in Geosciences requires 3D thinking yet many of the tools used by educators are 2D visualisations, relying on the student&#8217;s individual ability and imagination. There has been an increasing use of interactive 3D visualisations, particularly of geological outcrops, yet the methods used to produce these either rely on expensive equipment or processing using high-specification machines. The 360 Lab uses new functionality offered by state-of-the-art tablets to rapidly capture high-resolution 3D scenes of flood management interventions, for example, woody dams.The 3D scenes were used to create interactive models of the flood management features, allowing people to get, virtually, &#8216;hands-on&#8217; and explore them. The 3D models are fully compatible with virtual reality headsets. Guided tours of schemes have been developed to be used by schools, showing how features are installed and providing a focus to discuss how they work and how effective they might be.&#160; This overcomes challenges to accessing such locations, including location, budget, accessibility, and Covid-19 related restrictions. Future developments include using the rapid scans to create 3D printed models of features for face-to-face learning and scaled experiments.

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Quantification of the Effect of Water Temperature on the Fall Rate of Expendable Bathythermographs

Journal of Atmospheric and Oceanic Technology ◽

10.1175/jtech-d-15-0216.1 ◽

2016 ◽

Vol 33 (6) ◽

pp. 1271-1284 ◽

Cited By ~ 4

Author(s):

John P. Abraham ◽

Rebecca Cowley ◽

Lijing Cheng

Keyword(s):

Water Temperature ◽

Dynamic Models ◽

Fluid Dynamic ◽

Correction Method ◽

Rate Coefficients ◽

Rate Equations ◽

Measured Temperature ◽

Fall Rate ◽

Influence Of Water ◽

The Impact

AbstractA very large portion of the historical information on ocean temperatures has been measured using expendable bathythermograph (XBT) devices. For decades, these devices provided the majority of global information. It is, therefore, important to quantify their accuracy and identify biases in this important historical dataset. Here, calculations are made of the influence of water temperature on the rate of descent of the XBT devices into the ocean waters. In colder regions, the larger viscosity of the water is expected to cause a greater drag force on the device, which would slow the descent. It was found through computational fluid dynamic models that the impact of temperature and viscosity on the probe descent is approximately 2.2% for water temperatures that range from 0° to 27°C. Probe-specific temperature-dependent fall rate equations were applied to 269 collocated XBT/conductivity–temperature–depth (CTD) measurements from two different research cruises. It was found that the probe-specific descent equations were an improvement over the uncorrected method. Next, in an effort to automate the process, the fall rate coefficients were related to the topmost measured temperature in the water column. With this relationship, comparisons were made between the probe-specific descent calculations and 2937 high-resolution XBT–CTD pairs. It was found that again, the new methodology outperformed the standard fall rate equation. The new method was also compared with an independent correction method that was previously published. It was found that both new methods were improvements upon the industry-standard fall rate calculation. Subsequent calculations using the top-100-m water temperature were performed and were found to be statistically insignificant compared to the proposed simplified method.

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Monetary policy and the effect of the transfer of oil prices to inflation

Voprosy Ekonomiki ◽

10.32609/0042-8736-2020-8-41-50 ◽

2020 ◽

pp. 41-50

Author(s):

Ph. S. Kartaev ◽

I. D. Medvedev

Keyword(s):

Monetary Policy ◽

Inflation Targeting ◽

Dynamic Models ◽

Oil Prices ◽

Oil Price ◽

Oil Price Shocks ◽

Negative Effects ◽

Price Shocks ◽

Policy Regime ◽

The Impact

The paper examines the impact of oil price shocks on inflation, as well as the impact of the choice of the monetary policy regime on the strength of this influence. We used dynamic models on panel data for the countries of the world for the period from 2000 to 2017. It is shown that mainly the impact of changes in oil prices on inflation is carried out through the channel of exchange rate. The paper demonstrates the influence of the transition to inflation targeting on the nature of the relationship between oil price shocks and inflation. This effect is asymmetrical: during periods of rising oil prices, inflation targeting reduces the effect of the transfer of oil prices, limiting negative effects of shock. During periods of decline in oil prices, this monetary policy regime, in contrast, contributes to a stronger transfer, helping to reduce inflation.

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Fiber energy efficiency Part I: Extended entropy model

Nordic Pulp & Paper Research Journal ◽

10.3183/npprj-2014-29-02-p322-331 ◽

2014 ◽

Vol 29 (2) ◽

pp. 322-331 ◽

Cited By ~ 1

Author(s):

Anders Karlström ◽

Karin Eriksson

Keyword(s):

Energy Efficiency ◽

Temperature Profile ◽

Dynamic Models ◽

Fluid Dynamic ◽

Multiscale Model ◽

Process Conditions ◽

Entropy Model ◽

Refining Zone ◽

Energy Balances ◽

Flat Zone

Abstract This is the first in a series of papers presenting the development of a comprehensive multiscale model with focus on fiber energy efficiency in thermo mechanical pulp processes. The fiber energy efficiency is related to the defibration and fibrillation work obtained when fibers and fiber bundles interact with the refining bars. The fiber energy efficiency differs from the total refining energy efficiency which includes the thermodynamical work as well. Extracting defibration and fibrillation work along the radius in the refining zone gives information valuable for fiber development studies.Models for this process must handle physical variables as well as machine specific parameters at different scales. To span the material and energy balances, spatial measurements from the refining zone must be available. In this paper, measurements of temperature profile and plate gaps from a full-scale CD-refiner are considered as model inputs together with a number of process variables. This enables the distributed consistency in the refining zone as well as the split of the total work between the flat zone and the CD-zone to be derived. As the temperature profile and the plate gap are available in the flat zone and the CD-zone at different process conditions it is also shown that the distributed pulp dynamic viscosity can be obtained. This is normally unknown in refining processes but certainly useful for all fluid dynamic models describing the bar-to-fiber interactions. Finally, it is shown that the inclusion of the machine parameters will be vital to get good estimates of the refining conditions and especially the split between the thermodynamical work and the defibration/fibrillation work.

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Bone tissue engineering in the greater omentum with computer-aided design/computer-aided manufacturing scaffolds is enhanced by a periosteum transplant

Regenerative Medicine ◽

10.2217/rme-2020-0115 ◽

2020 ◽

Author(s):

Hendrik Naujokat ◽

Klaas Loger ◽

Juliane Schulz ◽

Yahya Açil ◽

Jörg Wiltfang

Keyword(s):

Bone Formation ◽

Bone Tissue ◽

Computer Aided Design ◽

Bone Tissue Regeneration ◽

Histological Evaluation ◽

Greater Omentum ◽

Collagen Membrane ◽

Computer Aided ◽

3D Printed ◽

The Impact

Aim: This study aimed to evaluate two different vascularized bone flap scaffolds and the impact of two barrier membranes for the reconstruction of critical-size bone defects. Materials & methods: 3D-printed scaffolds of biodegradable calcium phosphate and bioinert titanium were loaded with rhBMP-2 bone marrow aspirate, wrapped by a collagen membrane or a periosteum transplant and implanted into the greater omentum of miniature pigs. Results: Histological evaluation demonstrated significant bone formation within the first 8 weeks in both scaffolds. The periosteum transplant led to enhanced bone formation and a homogenous distribution in the scaffolds. The omentum tissue grew out a robust vascular supply. Conclusion: Endocultivation using 3D-printed scaffolds in the greater omentum is a very promising approach in defect-specific bone tissue regeneration.

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Quality Control in 3D Printing: Accuracy Analysis of 3D-Printed Models of Patient-Specific Anatomy

Materials ◽

10.3390/ma14041021 ◽

2021 ◽

Vol 14 (4) ◽

pp. 1021

Author(s):

Bernhard Dorweiler ◽

Pia Elisabeth Baqué ◽

Rayan Chaban ◽

Ahmed Ghazy ◽

Oroa Salem

Keyword(s):

Wall Thickness ◽

Large Scale ◽

Fused Deposition Modeling ◽

Vascular Anatomy ◽

3D Models ◽

Patient Specific ◽

Stl File ◽

Fused Deposition ◽

3D Printed ◽

The Mean

As comparative data on the precision of 3D-printed anatomical models are sparse, the aim of this study was to evaluate the accuracy of 3D-printed models of vascular anatomy generated by two commonly used printing technologies. Thirty-five 3D models of large (aortic, wall thickness of 2 mm, n = 30) and small (coronary, wall thickness of 1.25 mm, n = 5) vessels printed with fused deposition modeling (FDM) (rigid, n = 20) and PolyJet (flexible, n = 15) technology were subjected to high-resolution CT scans. From the resulting DICOM (Digital Imaging and Communications in Medicine) dataset, an STL file was generated and wall thickness as well as surface congruency were compared with the original STL file using dedicated 3D engineering software. The mean wall thickness for the large-scale aortic models was 2.11 µm (+5%), and 1.26 µm (+0.8%) for the coronary models, resulting in an overall mean wall thickness of +5% for all 35 3D models when compared to the original STL file. The mean surface deviation was found to be +120 µm for all models, with +100 µm for the aortic and +180 µm for the coronary 3D models, respectively. Both printing technologies were found to conform with the currently set standards of accuracy (<1 mm), demonstrating that accurate 3D models of large and small vessel anatomy can be generated by both FDM and PolyJet printing technology using rigid and flexible polymers.

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Towards real-time fire data synthesis using numerical simulations

Journal of Fire Sciences ◽

10.1177/0734904121993449 ◽

2021 ◽

pp. 073490412199344

Author(s):

Wolfram Jahn ◽

Frane Sazunic ◽

Carlos Sing-Long

Keyword(s):

Real Time ◽

Computational Fluid Dynamic ◽

Dynamic Models ◽

Fluid Dynamic ◽

Near Field ◽

Computing Time ◽

Temperature Correction ◽

Dynamic Simulations ◽

Conservation Of Energy ◽

Fire Scenarios

Synthesising data from fire scenarios using fire simulations requires iterative running of these simulations. For real-time synthesising, faster-than-real-time simulations are thus necessary. In this article, different model types are assessed according to their complexity to determine the trade-off between the accuracy of the output and the required computing time. A threshold grid size for real-time computational fluid dynamic simulations is identified, and the implications of simplifying existing field fire models by turning off sub-models are assessed. In addition, a temperature correction for two zone models based on the conservation of energy of the hot layer is introduced, to account for spatial variations of temperature in the near field of the fire. The main conclusions are that real-time fire simulations with spatial resolution are possible and that it is not necessary to solve all fine-scale physics to reproduce temperature measurements accurately. There remains, however, a gap in performance between computational fluid dynamic models and zone models that must be explored to achieve faster-than-real-time fire simulations.

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Buoyancy control in ammonoid cephalopods refined by complex internal shell architecture

Scientific Reports ◽

10.1038/s41598-021-87379-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

David J. Peterman ◽

Kathleen A. Ritterbush ◽

Charles N. Ciampaglio ◽

Erynn H. Johnson ◽

Shinya Inoue ◽

...

Keyword(s):

Surface Tension ◽

Water Retention Capacity ◽

Functional Explanation ◽

Retention Capacity ◽

Biomechanical Stress ◽

Liquid Retention ◽

3D Printed ◽

Functional Explanations ◽

Hydrophilic Coatings ◽

The Impact

AbstractThe internal architecture of chambered ammonoid conchs profoundly increased in complexity through geologic time, but the adaptive value of these structures is disputed. Specifically, these cephalopods developed fractal-like folds along the edges of their internal divider walls (septa). Traditionally, functional explanations for septal complexity have largely focused on biomechanical stress resistance. However, the impact of these structures on buoyancy manipulation deserves fresh scrutiny. We propose increased septal complexity conveyed comparable shifts in fluid retention capacity within each chamber. We test this interpretation by measuring the liquid retained by septa, and within entire chambers, in several 3D-printed cephalopod shell archetypes, treated with (and without) biomimetic hydrophilic coatings. Results show that surface tension regulates water retention capacity in the chambers, which positively scales with septal complexity and membrane capillarity, and negatively scales with size. A greater capacity for liquid retention in ammonoids may have improved buoyancy regulation, or compensated for mass changes during life. Increased liquid retention in our experiments demonstrate an increase in areas of greater surface tension potential, supporting improved chamber refilling. These findings support interpretations that ammonoids with complex sutures may have had more active buoyancy regulation compared to other groups of ectocochleate cephalopods. Overall, the relationship between septal complexity and liquid retention capacity through surface tension presents a robust yet simple functional explanation for the mechanisms driving this global biotic pattern.

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Online Reviews and Product Sales: The Role of Review Visibility

Journal of theoretical and applied electronic commerce research ◽

10.3390/jtaer16040038 ◽

2021 ◽

Vol 16 (4) ◽

pp. 638-669

Author(s):

Miriam Alzate ◽

Marta Arce-Urriza ◽

Javier Cebollada

Keyword(s):

Decision Making ◽

Dynamic Models ◽

Generalized Method Of Moments ◽

Online Reviews ◽

Consumer Decision Making ◽

Product Sales ◽

The Impact ◽

The Relationship ◽

The Empirical Analysis

When studying the impact of online reviews on product sales, previous scholars have usually assumed that every review for a product has the same probability of being viewed by consumers. However, decision-making and information processing theories underline that the accessibility of information plays a role in consumer decision-making. We incorporate the notion of review visibility to study the relationship between online reviews and product sales, which is proxied by sales rank information, studying three different cases: (1) when every online review is assumed to have the same probability of being viewed; (2) when we assume that consumers sort online reviews by the most helpful mechanism; and (3) when we assume that consumers sort online reviews by the most recent mechanism. Review non-textual and textual variables are analyzed. The empirical analysis is conducted using a panel of 119 cosmetic products over a period of nine weeks. Using the system generalized method of moments (system GMM) method for dynamic models of panel data, our findings reveal that review variables influence product sales, but the magnitude, and even the direction of the effect, vary amongst visibility cases. Overall, the characteristics of the most helpful reviews have a higher impact on sales.

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