scholarly journals 3D Sugar Printing of Networks Mimicking the Vasculature

Micromachines ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 43 ◽  
Author(s):  
Andreas M. A. O. Pollet ◽  
Erik F. G. A. Homburg ◽  
Ruth Cardinaels ◽  
Jaap M. J. den Toonder
Keyword(s):  
Particle Image ◽  
Fibre Diameter ◽  
Vessel Diameter ◽  
The Body ◽  
Flow Profile ◽  
Cross Sectional ◽  
Network Geometry ◽  
Image Velocimetry ◽  
Sugar Glass

The vasculature plays a central role as the highway of the body, through which nutrients and oxygen as well as biochemical factors and signals are distributed by blood flow. Therefore, understanding the flow and distribution of particles inside the vasculature is valuable both in healthy and disease-associated networks. By creating models that mimic the microvasculature fundamental knowledge can be obtained about these parameters. However, microfabrication of such models remains a challenging goal. In this paper we demonstrate a promising 3D sugar printing method that is capable of recapitulating the vascular network geometry with a vessel diameter range of 1 mm down to 150 µm. For this work a dedicated 3D printing setup was built that is capable of accurately printing the sugar glass material with control over fibre diameter and shape. By casting of printed sugar glass networks in PDMS and dissolving the sugar glass, perfusable networks with circular cross-sectional channels are obtained. Using particle image velocimetry, analysis of the flow behaviour was conducted showing a Poisseuille flow profile inside the network and validating the quality of the printing process.

scholarly journals Quality of Life in Patients with Psoriasis Seen in the Department of Dermatology, Antananarivo, Madagascar

2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Fandresena Arilala Sendrasoa ◽  
Naina Harinjara Razanakoto ◽  
Volatantely Ratovonjanahary ◽  
Onivola Raharolahy ◽  
Irina Mamisoa Ranaivo ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Negative Impact ◽  
Young Patients ◽  
The Body ◽  
University Hospital ◽  
Medical Decision ◽  
Cross Sectional ◽  
The Difference ◽  
The Impact

Background. Psoriasis is a chronic, inflammatory, and multifactorial dermatosis that impairs quality of life (QoL). Health-related QoL has become an important element in medical decision-making along with the effectiveness and the harmlessness of the treatments. Objective. To assess the impact of psoriasis in the QoL of patients with psoriasis by using the DLQI scales. Methods. A cross-sectional study from January to June 2018 was conducted in the Department of Dermatology of the University Hospital Joseph Raseta Befelatanana, Antananarivo, Madagascar, including patients more than 18 years old with mild to severe psoriasis. The severity of psoriasis was assessed using the “Psoriasis Area and Severity Index (PASI)”. QoL of patients with psoriasis was evaluated by using the DLQI scales. Results. 80 patients were included, their mean age was 36.5 years, and the male to female was 1.5 : 1. The mean DLQI score was 13.8. Symptoms, feelings, and psychic were the most altered dimensions. QoL was impaired in young patients, single, having medium level education. Even though patients with disease duration more than 5 years had higher DLQI score than other patients, the difference was not statistically significant (p=0.36). Furthermore, the clinical presentation of psoriasis did not influence the patient’s QoL (p=0.73). Patients with nail involvement had QoL impaired but the difference with another localization was not statistically significant (p=0.2). The quality of life was influenced by body area involved. The higher the body surface area involved, the more QoL is impaired (p=0.002). Furthermore, the higher the PASI, the more QoL is altered (p=0.002). Conclusion. Psoriasis has a negative impact in the quality of life in Malagasy patients with psoriasis, especially in younger and single patients. Worse quality of life is correlated to severity of psoriasis.

Investigation of Cross-Sectional Velocity Field Near the Inducer Plane of a Turbocharger Compressor Using 2D Particle Image Velocimetry

2019 ◽  
Author(s):  
Deb Banerjee ◽  
Rick Dehner ◽  
Ahmet Selamet ◽  
Keith Miazgowicz ◽  
Todd Brewer ◽  
...  
Keyword(s):  
Particle Image Velocimetry ◽  
Velocity Field ◽  
Flow Field ◽  
Mass Flow ◽  
Particle Image ◽  
Tangential Velocity ◽  
Cross Sectional ◽  
Flow Rates ◽  
Blade Passage ◽  
Image Velocimetry

Abstract Understanding the velocity field at the inlet of an automotive turbocharger is critical in order to suppress the instabilities encountered by the compressor, extend its map and improve the impeller design. In the present study, two-dimensional particle image velocimetry experiments are carried out on a turbocharger compressor without any recirculating channel to investigate the planar flow structures on a cross-sectional plane right in front of the inducer at a rotational speed of 80 krpm. The objective of the study is to investigate the flow field in front of a compressor blade passage and quantify the velocity distributions along the blade span for different mass flow rates ranging from choke (77 g/s) to deep surge (13.6 g/s). It is observed that the flow field does not change substantially from choke to about 55 g/s, where flow reversal is known to start at this speed from earlier measurements. While the tangential velocity is less than 8 m/s, the radial velocity increases along the span to 17–20 m/s near the tip at high flow rates (55–77 g/s). As the mass flow rate is reduced below 55 g/s, the radial component starts decreasing and the tangential velocity increases rapidly. From about 5 m/s at 55 g/s, the tangential velocity at the blade tip exceeds 50 m/s at 50 g/s and reaches a maximum of about 135 m/s near surge. These time-averaged distributions are similar for different angular locations in front of the blade passage and do not exhibit any substantial azimuthal variation.

scholarly journals The ocellate river stingray (Potamotrygon motoro) exploits vortices of sediment to bury into the substrate

2019 ◽  
Author(s):  
S.G. Seamone ◽  
D.A. Syme
Keyword(s):  
Particle Image ◽  
Dorsal Surface ◽  
Ventral Surface ◽  
The Body ◽  
Effective Control ◽  
Posterior Portion ◽  
Dorsal Midline ◽  
Pectoral Fins ◽  
Image Velocimetry ◽  
Sediment Flow

ABSTRACTParticle image velocimetry and video analysis were employed to discern and describe the mechanism used by the stingray Potamotrygon motoro to bury into the substrate. P. motoro repeatedly and rapidly pumped the body up and down while folding the posterior portion of the pectoral fins up and over, drawing water in and suspending sediment beneath the pectoral disc. As the fins folded up and over, vortices of fluidized sediment travelled along the ventral surface of the fins toward the fin tips, and were then directed onto the dorsal surface of the fins and towards the dorsal midline of the fish, where they dissipated and the sediment settled over the dorsal surface of the ray. As displacement and speed of the body pumping and finbeat motions increased, the speed of the sediment translating across the dorsal surface increased, and accordingly, sediment coverage of the dorsal surface increased. Mean sediment coverage was 82.5% ± 3.0 S.E.M, and appeared to be selectively controlled, whereby the pectoral fins tended to bury more than the body, head and tail, and the body more than the head and the tail. In the most vigorous burying events, vortices of sediment shed from each fin collided at the midline and annihilated, reorienting the sediment flow and sending jets of sediment towards the head and the tail, covering these locations with sediment. Hence, this study demonstrates that the mechanism of burying employed by P. motoro permits effective control of sediment vortices and flows to modulate the extent of burying.

scholarly journals ANALISIS KEPATUHAN MENJALANI HEMODIALISA DENGAN KUALITAS HIDUP PASIEN GAGAL GINJAL KRONIK

2021 ◽  
Vol 5 (2) ◽  
pp. 8
Author(s):  
Riris Andriati ◽  
Fenita Purnama Sari Indah ◽  
Aisyah Aisyah
Keyword(s):  
Quality Of Life ◽  
The Body ◽  
Primary Data ◽  
P Value ◽  
Chi Square ◽  
Cross Sectional ◽  
Hemodialysis Unit ◽  
Chi Square Test ◽  
The Relationship

Compliance with hemodialysis therapy is one of the important things to note, if the patient is not compliant, it can cause a buildup of harmful substances in the body and if left unchecked, it can lead to death. The purpose of this study was to determine the relationship between adherence to undergo hemodialysis therapy with the quality of life of patients with chronic renal failure in the Hemodialysis Unit of the Jakarta Hajj Hospital. This research method is a quantitative study using primary data (questionnaires) and using cross-sectional research. Data collected by using questionnaires. The number of samples were 54 people who were in the hajodialysis unit at the Jakarta Hajj Hospital for the past three months. The results of the study of 54 respondents who have moderate compliance there are 11 people (20.4%), and good compliance a number of 43 people (79.%), in general patients obedient. While from the aspect of quality of life, there were 6 respondents (11.1%) who experienced less quality of life, 35 people had a moderate quality of life (75.%) and 13 people (24.1%) had a good quality of life, in general the quality of life of patients was moderate. After analyzing the relationship between adherence to undergo hemodialysis with quality of life using the Chi Square test p value = 0.468˃0.05, meaning that Ho is accepted, so it can be concluded that there is no relationship between adherence to hemodialysis with the quality of life of patients at Jakarta Hajj Hospital .ABSTRAKKepatuhan menjalani terapi hemodialisa merupakan salah satu hal yang penting untuk diperhatikan, jika pasien tidak patuh dapat menyebabkan terjadinya penumpukan zat-zat berbahaya dalam tubuh dan apabila hal tersebut dibiarkan maka dapat mengakibatkan kematian. Tujuan penelitian untuk mengetahui hubungan antara kepatuhan menjalani terapi hemodialisa dengan kualitas hidup pasien gagal ginjal kronik di Unit Hemodialisa RS Haji Jakarta. Metode penelitian ini merupakan penelitian kuantitatif dengan menggunakan data primer (kuisioner) dan memakai metode penelitian cross-sectional. Data yang dikumpulkan dengan cara menggunakan kuisioner. Jumlah sampel  sebanyak 54 orang yang berada di unit hemodialisa Rumah Sakit haji Jakarta selama tiga bulan terakhir. Hasil penelitian dari 54 responden yang memiliki kepatuhan sedang terdapat 11 orang (20.4 %), dan kepatuhan baik sejumlah 43 orang (79.6 %), secara umum pasien patuh. Sementara dari aspek kualitas hidup diperoleh  responden  yang  mengalami  kualitas  hidup  kurang sejumlah 6 orang (11.1%), kualitas hidup sedang sejumlah 35 orang (75.%)  dan  kualitas  hidup  baik  13 orang  (24.1%), secara umum kualitas hidup pasien sedang. Setelah dilakukan analisa hubungan antara kepatuhan menjalani hemodialisa dengan kualitas hidup dengan menggunakan uji Chi Square diperoleh p value = 0.468˃0.05,  artinya Ho diterima, sehingga dapat disimpulkan tidak ada hubungan antara kepatuhan menjalani hemodialisa dengan kualitas hidup pasien di Rumah Sakit Haji Jakarta.

Fleece characters and their influence on wool production per unit area of skin in Merino sheep

1958 ◽  
Vol 9 (3) ◽  
pp. 363 ◽  
Author(s):  
SSY Young ◽  
RE Chapman
Keyword(s):  
Unit Area ◽  
Fibre Diameter ◽  
Fibre Volume ◽  
Cross Sectional Area ◽  
The Body ◽  
Sectional Area ◽  
Cross Sectional ◽  
Fibre Density ◽  
Wool Production ◽  
Staple Length

The variations in fleece characters and the dependence of wool production per unit area of skin on these characters were studied with 15 sheep in both a medium and a strong-wool strain of Merino. Small but significant differences in staple length and fibre diameter were found between regions on the body, whereas differences in density were large. The variation in density was about three times as large as those in staple length and fibre diameter. Distinct dorsoventral and anteroposterior gradients over the body existed for fibre density, but not for staple length and fibre diameter. The influences of the fleece characters on wool production per unit area were somewhat different in the two strains, and changed with level of production. Among the medium-wool sheep, fibre density had the largest effect on production, with staple length less and mean fibre cross-sectional area least. Among the strong-wool sheep, length was more important than density, which in turn was more important than fibre cross-sectional area. The combined data indicated that as mean wool weight per unit area increased, the influence of density rose to a maximum and then diminished, whereupon mean fibre volume became the main contributor to wool weight. For different positions on the body of individual sheep, the dependence of wool production per unit area on the fleece characters was found to be similar in the two strains. Fibre density had the major effect in determining the level of production, whereas the influences of staple length and fibre area were negligible.

Particle Image Velocimetry Measurements in a Two-Pass 90 Degree Ribbed-Wall Parallelogram Channel

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Tong-Miin Liou ◽  
Shyy-Woei Chang ◽  
Shu-Po Chan ◽  
Yu-Shuai Liu
Keyword(s):  
Particle Image Velocimetry ◽  
Secondary Flow ◽  
Particle Image ◽  
Separation Bubble ◽  
Channel Height ◽  
Mean Velocity ◽  
Cross Sectional ◽  
Local Flow ◽  
Image Velocimetry ◽  
Sharp Turn

A parallelogram channel has drawn very little or no attention in the open literature although it appears as a cross-sectional configuration of some gas turbine rotor blades. Particle image velocimetry (PIV) is presented of local flow structure in a two-pass 90 deg ribbed-wall parallelogram channel with a 180 deg sharp turn. The channel has a cross-sectional equal length, 45.5 mm, of adjacent sides and two pairs of opposite angles are 45 deg and 135 deg. The rib height to channel height ratio is 0.1. All the measurements were performed at a fixed Reynolds number, characterized by channel hydraulic diameter of 32.17 mm and cross-sectional bulk mean velocity, of 10,000 and a null rotating number. Results are discussed in terms of the distributions of streamwise and secondary-flow mean velocity vector, turbulent intensity, Reynolds stress, and turbulent kinetic energy of the cooling air. It is found that the flow is not periodically fully developed in pitchwise direction through the inline 90 deg ribbed straight inlet and outlet leg. Pitchwise variation of reattachment length is revealed, and comparison with reported values in square channels is made. Whether the 180 deg sharp turn induced separation bubble exists in the ribbed parallelogram channel is also documented. Moreover, the measured secondary flow results inside the turn are successively used to explain previous heat transfer trends.

scholarly journals A Study of the Factors Related to Cardiopulmonary Resuscitation Physical Fatigue and the Quality of Resuscitation

2017 ◽  
Vol 34 (1) ◽  
pp. 43-53 ◽  
Author(s):  
Mojtaba Rad ◽  
Mostafa Rad
Keyword(s):  
Cardiopulmonary Resuscitation ◽  
Onset Time ◽  
Cross Sectional Study ◽  
Sampling Procedure ◽  
The Body ◽  
Work Place ◽  
Physical Fatigue ◽  
Cross Sectional ◽  
University Degree

Summary Effective chest compression is an important factor playing a key role in the cardiac arrest patient survival. An understanding of the factors causing an early physical fatigue can help to improve the quality of CPR operations in hospitals. Therefore, this study aimed to assess the factors relevant to the onset time of physical fatigue and resuscitation quality during cardiopulmonary resuscitation (CPR) provision by Iranian nurses. The present cross-sectional study was performed on 194 subjects selected based on a stratified random sampling procedure from different hospital wards. The participants were required to perform CPR operations on a manikin. As they were performing CPR, the time and the quality of compressions were measured by a chronometer and visual analogue fatigue scale, respectively. The rescuers themselves reported the onset time of physical fatigue. Statistical analyses run on the collected data revealed that the majority of participants experienced extreme physical fatigue after a two-minute CPR operation. Moreover, about 71.2% of the participants managed to provide compressions over five centimeters deep. Finally, the physical fatigue experienced by the participants was meaningfully correlated with the body weight, sex, university degree, and work place of the participants (p < 0.05). Since the findings of the present study showed that various factors including the sex, weight, height, university degree, and the work place of the rescuer were significantly correlated with the onset time of physical fatigue experienced during CPR operation, it is recommended that male nurses with greater height and weight be employed in the rescue teams in ICU wards. Moreover, it seems mandatory for the nurses currently working in such teams in hospitals to improve their physical fitness through doing aerobics on a regular basis so that they may experience less fatigue during their CPR operations in future.

scholarly journals Time-resolved vortex wake of a common swift flying over a range of flight speeds

2010 ◽  
Vol 8 (59) ◽  
pp. 807-816 ◽  
Author(s):  
P. Henningsson ◽  
F. T. Muijres ◽  
A. Hedenström
Keyword(s):  
High Speed ◽  
Particle Image ◽  
Digital Particle Image Velocimetry ◽  
Transverse Plane ◽  
The Body ◽  
Vortex Wake ◽  
Vertical Force ◽  
Time Resolved ◽  
Longitudinal Plane ◽  
Image Velocimetry

The wake of a freely flying common swift ( Apus apus L.) is examined in a wind tunnel at three different flight speeds, 5.7, 7.7 and 9.9 m s −1 . The wake of the bird is visualized using high-speed stereo digital particle image velocimetry (DPIV). Wake images are recorded in the transverse plane, perpendicular to the airflow. The wake of a swift has been studied previously using DPIV and recording wake images in the longitudinal plane, parallel to the airflow. The high-speed DPIV system allows for time-resolved wake sampling and the result shows features that were not discovered in the previous study, but there was approximately a 40 per cent vertical force deficit. As the earlier study also revealed, a pair of wingtip vortices are trailing behind the wingtips, but in addition, a pair of tail vortices and a pair of ‘wing root vortices’ are found that appear to originate from the wing/body junction. The existence of wing root vortices suggests that the two wings are not acting as a single wing, but are to some extent aerodynamically detached from each other. It is proposed that this is due to the body disrupting the lift distribution over the wing by generating less lift than the wings.

In Situ PLIF and Particle Image Velocimetry Measurements of the Primary Entrainment Fuel Jet in a Naturally Aspirated Water Heater

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
Daniel J. Sherwin ◽  
Jon D. Koch
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Initial Conditions ◽  
Entrainment Rate ◽  
Water Heater ◽  
Cross Sectional ◽  
Mass Entrainment ◽  
Fuel Jet ◽  
Image Velocimetry ◽  
Entire Flow

The time-averaged characteristics of a fuel jet have been measured via acetone planar laser-induced fluorescence (PLIF) and particle image velocimetry (PIV) in the primary mixing region of an operating gas-fired water heater. These measurements allow for experimental characterization of the cross-sectional scalar and velocity fields as well as the estimation of the mass entrainment as the flow enters the burner in a practical system. In these experiments, reasonable results were obtained when only the fuel jet was seeded with acetone or PIV particles rather than the entire flow, thus demonstrating the potential for simplified experimental configurations in some applications where controlling or seeding the entire flow may be difficult. The entrainment characteristics of the fuel jet are compared with benchmarks from literature. The commercial device exhibits a larger mass entrainment rate than is found in typical free jets that have been studied in the literature. This may be a result of the jet's low Reynolds number (9,600) in comparison with other literature studies, and a result of initial conditions.

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