scholarly journals Understanding the Characteristics of Pedestrians when Passing Obstacles of Different Sizes: An Experimental Study

2021 ◽  
Vol 6 ◽  
Author(s):  
Abdullah N Alhawsawi ◽  
Majid Sarvi ◽  
Emad Felemban ◽  
Abbas Rajabifard ◽  
Jianyu Wang
Keyword(s):  
Experimental Study ◽  
Flow Rate ◽  
High Speed ◽  
The Body ◽  
Agent Based ◽  
Significant Difference ◽  
Speed Level ◽  
Collective Movements ◽  
The Right ◽  
Insight Into

The aim of this study is to understand the collective movements of individuals and to observe how individuals interact within a physical environment in a crowd dynamic, which has drawn the attention of many researchers. We conducted an experimental study to observe interactions in the collective motions of people and to identify characteristics of pedestrians when passing obstacles of different sizes (bar-shaped, 1.2 m, 2.4 m, 3.6 m and 4.8 m), going through one narrow exit and employing three different flow rates in walking and running conditions. According to the results of our study, there were no differences in collision-avoidance behaviour of pedestrians when walking or running. The pedestrians reacted early to the obstacles and changed the direction in which they were walking by quickly turning to the left or to the right. In terms of the speed of the pedestrians, the average velocity was significantly affected while performing these tasks, decreasing as the size of the obstacle increased; therefore, the size of obstacles will affect flow and speed levels. Travel time was shorter when participants were in the medium-flow rate experiments. In terms of the distance of each individual’s travel, our data showed that there was no significant difference in all the flow rate experiments for both speed levels. Our results also show that when the pedestrians crossed an obstacle, the lateral distance averaged from 0.3 m to 0.7 m, depending on the flow rate and speed level. We then explored how the body sways behaved while avoiding obstacles. It is observed that the average sway of the body was less in the high-speed conditions compared to the low-speed conditions – except for the HF & 4.8 m experiment. These results are expected to provide an insight into the characteristics of the behaviour of pedestrians when avoiding objects, and this could help enhance agent-based models.

scholarly journals Spray mist reduction by means of a high-volume evacuation system—Results of an experimental study

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257137
Author(s):  
Martin Koch ◽  
Christian Graetz
Keyword(s):  
Experimental Study ◽  
Flow Rate ◽  
High Speed ◽  
Statistical Tests ◽  
Mouth Opening ◽  
High Volume ◽  
Worst Case ◽  
Significant Difference ◽  
Tooth Preparation ◽  
Evacuation System

Objectives High-speed tooth preparation requires effective cooling to avoid thermal damage, which generates spray mist, which is a mixture of an aerosol, droplets and particles of different sizes. The aim of this experimental study was to analyze the efficacy of spray mist reduction with an intraoral high-volume evacuation system (HVE) during simulated high-speed tooth preparation for suboptimal versus optimal suction positions of 16 mm sized cannulas and different flow rates of the HVE. Material and methods In a manikin head, the upper first premolar was prepared with a dental turbine, and generated particles of 5–50 microns were analyzed fifty millimeters above the mouth opening with the shadow imaging technique (frame: 6.6×5.3×1.1 mm). This setup was chosen to generate a reproducible spray mist in a vertical direction towards an imaginary operator head (worst case scenario). The flow rate (FR) of the HVE was categorized into five levels (≤120 l/min up to 330 l/min). The number of particles per second (NP; p/s) was counted, and the mass volume flow of particles per second (MVF; μg/s*cm3) was calculated for 10 sec. Statistical tests were nonparametric and two-sided (p≤0.05). Results With increasing flow rate, the NP/MVF values decreased significantly (eta: 0.671/0.678; p≤0.001). Using a suboptimally positioned cannula with an FR≤160 l/min, significantly higher NP values (mean±SD) of 731.67±54.24 p/s (p≤0.019) and an MVF of 3.72±0.42 μg/s*cm3 (p≤0.010) were measured compared to those of the optimal cannula position and FR≥300 l/min (NP/MVF: 0/0). No significant difference in NP and MVF was measurable between FR≥250 l/min and FR>300 l/min (p = 0.652, p = 0.664). Conclusion Within the limitations of the current experimental study, intraoral high-flow rate suction with ≥300 l/min with an HVE effectively reduced 5–50 μm sized particles of the spray mist induced by high-speed tooth preparation with a dental turbine.

Venom flow in rattlesnakes: mechanics and metering

2001 ◽  
Vol 204 (24) ◽  
pp. 4345-4351
Author(s):  
Bruce A. Young ◽  
Krista Zahn
Keyword(s):  
Functional Morphology ◽  
Delivery System ◽  
Flow Rate ◽  
High Speed ◽  
Distal Portion ◽  
Retrograde Flow ◽  
Crotalus Atrox ◽  
Direct Recording ◽  
Significant Difference ◽  
Digital Videography

SUMMARY The functional morphology of venom injection in Crotalus atrox was explored using high-speed digital videography combined with direct recording of venom flow using perivascular flow probes. Although venom flow was variable, in most strikes the onset of venom flow was coincidental with fang penetration, and retrograde flow (venom suction) was observed prior to fang withdrawal. The duration of venom flow was consistently less than the duration of fang penetration. The occurrence of retrograde flow, ‘dry bites’ (which accounted for 35 % of the strikes) and unilateral strikes all support a hypothesis for venom pooling in the distal portion of the venom-delivery system. No significant difference in temporal or volumetric aspects of venom flow were found between defensive strikes directed at small and large rodents. With the species and size of target held constant, the duration of venom flow, maximum venom flow rate and total venom volume were all significantly lower in predatory than in defensive strikes.

scholarly journals Morphometry of human tricuspid valve: A cadaveric study

2020 ◽  
Vol 11 (3) ◽  
pp. 4487-4491
Author(s):  
Kirti Chaudhary ◽  
Amey Dhatrak ◽  
Brij Raj Singh ◽  
Ujwal Gajbe
Keyword(s):  
Tricuspid Valve ◽  
The Body ◽  
Muscle Pathology ◽  
Male And Female ◽  
Unidirectional Flow ◽  
Significant Difference ◽  
Tissue Flaps ◽  
The Right ◽  
Cardiac Surgeons ◽  
Formalin Fixed

The cardiovascular system consists of a pump represented by the heart and blood vessels, which provide the route by which blood circulates to all parts of the body. William Harvey, in the 17th century, discovered that blood is pumped away from the heart, but it all returns to the heart after circulating in the body. A right ventricular function can be compromised by pressure or stress, often secondary to the right heart valve or muscle pathology. The valves maintain unidirectional flow and permit increased pressure to develop in the chambers. The tricuspid valve consists of three tissue flaps. It separates the right atria and the right ventricle. To measure morphometric measurements of an individual leaflet of the tricuspid valve of cadaveric human hearts. The material for the present study comprised of 50 formalin-fixed adult human hearts (35 males and 15 females) which were obtained from the Department of Anatomy from various medical colleges in Maharashtra. Statistical significant difference was found for the height of anterior and posterior leaflets between male and female hearts. The length of the septal leaflet was also found to be statistically significant between male and female hearts. The study will be helpful for cardiac surgeons in providing data for tricuspid valve complex, leaflets, cords and papillary muscles.

scholarly journals Evaluation of the Diagnostic Advantage of Intraoral D and E Film for Detecting Interproximal Caries

2004 ◽  
Vol 5 (4) ◽  
pp. 58-70 ◽  
Author(s):  
Abdolrahim Davari ◽  
Fatemeh Ezoddini Ardakani ◽  
Daryoush Goodarzipour ◽  
Koorosh Goodarzipour
Keyword(s):  
High Speed ◽  
The Body ◽  
Diagnostic Image ◽  
Proximal Caries ◽  
Diagnostic Quality ◽  
Type D ◽  
Film Type ◽  
Significant Difference ◽  
Normal Speed ◽  
A Minor

Abstract Clinicians strive to reduce the exposure of patients to X-ray radiation in an effort to decrease its harmful effects on the body. A potential strategy for achieving this goal is the use of high-speed films that require less exposure to radiation to generate a diagnostic image. There are two film types commonly used in intraoral radiography: high speed or “Ekta-speed” film (Type E) and normal speed or Ultra-speed film (Type D). Type E film requires nearly half of the exposure time that is required by Type D films to produce an acceptable diagnostic image; however, the diagnosis quality and usability of these film types are under question. The purpose of this research is to compare the diagnostic quality of Type E with Type D film when used to diagnose proximal caries. In this study 40 pairs of extracted maxillary premolar teeth were chosen and divided into four groups of 10 pairs. Cavities were made on proximal surfaces at different depths (0.5, 1, 1.5, and 2 mm) for each group. Bitewing radiographs were then taken on each pair of teeth using Type E film and then again using Type D film. Radiographs were evaluated by two oral radiologists and two operative dentistry specialists who recorded the perceived diagnostic depth of the prepared cavities. Our data showed both Type D and E films are suitable for use in diagnosing proximal caries, and despite a minor discrepancy between them no significant difference was found with regard to their value in diagnosing proximal caries. Citation Ardakani FE, Davari A, Goodarizpour D, et. al. Evaluation of the Diagnostic Advantage of Intraoral D and E Film for Detecting Interproximal Caries. J Contemp Dent Pract 2004 November;(5)4:058-070.

scholarly journals PRE AND POSTPRANDIAL THERMOGRAPHIC PROFILE OF GREEN IGUANAS (IGUANA IGUANA)

2016 ◽  
Vol 73 (2) ◽  
pp. 425
Author(s):  
Simona Rusu ◽  
Zdenek Knotek ◽  
Radu Lacatus ◽  
Ionel Papuc
Keyword(s):  
Heat Transfer ◽  
Body Temperature ◽  
Temperature Difference ◽  
The Body ◽  
Significant Difference ◽  
Before And After ◽  
Significant Temperature ◽  
Green Iguanas ◽  
The Right ◽  
Head Temperature

Abstract The body temperature of 10 clinically healthy green iguanas (Iguana iguana) was measured using a thermographic camera (FLIR E6, Flir Systems Sweden) before and after the food was offered. For each animal there were performed a total of 6 measurements (3 before feeding and 3 after the food was offered). The purpose of this experiment was to observe the thermographic pattern of the body before and after the feeding, since herbivore reptiles tend to bask after the feeding to increase the body temperature that will help them afterwards digest the food. The animals were housed in individual vivariums with every animal having a basking spot available. The pictures were taken outside the vivarium in an adjacent room. The animals were handled with gloves and transported in a cardboard box in order to avoid heat transfer between the handler and the iguana that would have produced thermal artefacts. Each individual was placed on a table on a styrofoam slate, again, to avoid the heat transfer between the table and the animal`s body. For each animal a total of 4 pictures were taken (up, front, left and right). The pictures were analysed with the FLIR Tools program that is provided by the manufacturer and 3 temperatures were taken into consideration (the head temperature, body temperature on the right side and body temperature on the left side). The temperatures were compared between them and with the temperature of the vivariums that consisted of the average between the temperature in 3 different spots (basking spot, the feeding bowl site and the coldest spot) measured with an infrared thermometer GM300 (Benetech, China). The temperature of the body was dependent on the vivarium temperature and it was a significant temperature difference between the measurements before the feeding and after the feeding. Also we discovered a significant difference between the head temperature and the body temperature on the left side before the feeding that disappeared after the animals ate. There was also a significant difference between the temperature on right side and on left side of the animals both before and after the feeding. No significant temperature difference was observed between the head and the right side of the body neither before nor after the feeding.

scholarly journals Research on the Deposition Characteristics of Integrated Prefabricated Pumping Station

Symmetry ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 760
Author(s):  
Kai Wang ◽  
Jianbin Hu ◽  
Houlin Liu ◽  
Zixu Zhang ◽  
Li Zou ◽  
...  
Keyword(s):  
Deposition Rate ◽  
Flow Rate ◽  
High Speed ◽  
Particle Diameter ◽  
High Speed Photography ◽  
Pump Operation ◽  
Pumping Station ◽  
Movement Trajectories ◽  
Pump Station ◽  
The Right

Based on the discrete phase model (DPM) solid–liquid two-phase flow model and MATLAB image processing technology, an integrated prefabricated pumping station was taken as the research object to study deposition characteristics under different flow rates, different particle diameters, and different liquid levels. Considering the incomplete symmetry of the internal flow of the prefabricated pumping station, deposition characteristics of the prefabricated pumping station under single/double pumps were also analyzed. Double pumps were symmetrically distributed in the integrated prefabricated pump station, and the movement trajectories of particles at the bottom of the pump pit under the closing inlet valve were measured through the use of a high-speed photography experiment. Results showed that with the increase of the flow rate, the deposition rate of the separated prefabricated pumping station decreased. With an increase of the particle diameter, the movement of particles was farther away from the vertical barrier weir. In the range of particle diameter of 6 to 10 mm, the deposition rate decreased with the increase of the particle diameter. With the increase of the liquid level, the deposition rate decreased, first, and then increased again. In the case of the single pump operation, the deposition rate of the right pump operation was smaller than that of the left pump operation. The variation of the deposition rate when the right pump operated was basically the same as that when the dual pumps operated. The movement path of particle N1 was longer. With the decrease of the flow rate and the increase of the particle diameter, the following feature of the particle decreased, and it was easier to impact the walls and edges, which caused long-term deposition. The research results could provide some suggestions for the design of anti-deposition performance of prefabricated pumping station.

Body Segment Contributions to Javelin Throwing during Final Thrust Phases

1994 ◽  
Vol 10 (2) ◽  
pp. 166-177 ◽  
Author(s):  
Mero Antti ◽  
Paavo V. Komi ◽  
Tapio Korjus ◽  
Enrique Navarro ◽  
Robert J. Gregor
Keyword(s):  
High Speed ◽  
Olympic Games ◽  
Center Of Mass ◽  
The Body ◽  
Body Segment ◽  
Male And Female ◽  
Body Center ◽  
Joint Center ◽  
The Right ◽  
Release Speed

This study investigated body segment contributions to javelin throwing during the last thrust phases. A 3-D analysis was performed on male and female javelin throwers during the finals of the 1992 Olympic Games in Barcelona. The subjects were videotaped from the right sight of the throwing area by two NAC high-speed cameras operating at 100 frames per second. Both men’s and women’s grip of javelin and body center of mass displayed a curved pathway to the right from the left (bracing) foot during the final foot contact. The position of the body center of mass decreased at the beginning of the final foot contact, but after the decrease period it began to increase. Simultaneously with the increase, the peak joint center speeds occurred in a proper sequence from proximal to distal segments and finally to the javelin at release. Release speed correlated significantly with throwing distance in both male and females.

scholarly journals Right-sided lateralization of skin temperature in healthy young persons

2016 ◽  
Vol 39 (6) ◽  
pp. 121 ◽  
Author(s):  
Havva Demirel ◽  
Arzu Bahar ◽  
Nurcan Gokgoz ◽  
Muzeyyen Arslan ◽  
Senol Dane
Keyword(s):  
Lymph Node ◽  
Immune System ◽  
Skin Temperature ◽  
Healthy Subjects ◽  
The Body ◽  
Node Distribution ◽  
Significant Difference ◽  
Close Relationship ◽  
The Right ◽  
Relationship Of

Purpose: Previous studies reported a peripheral immune asymmetry and lateralization of different paired organ cancers. Because of the close relationship of immune system with body temperature, the aim of the study was to test the possible lateralization of skin temperature. Materials and Methods: Four hundred sixty three healthy subjects (325 women, 138 men) with an average age of 23.62 years (SD = 8.65) participated in this study. All skin temperature measurements were done 8:00-9:00 a.m. Skin temperature was assessed for three different points in skin: axillary, thumb and external auditory. Results: Skin temperature was statistically significantly higher on the right side of the body than on the left side, when measured by axillary and thumb temperatures. But there was no statistically significant difference in external auditory temperature. Conclusion: The asymmetry of skin temperature may result from the peripheral immune asymmetry or the asymmetric lymph node distribution.

scholarly journals Temperature of representative areas of the breast department of the vegetative nervous system as the index of human organism functional state

2017 ◽  
Vol 23 (2) ◽  
pp. 27-33
Author(s):  
S. Goncharevskyi ◽  
M. Makarchuk ◽  
V. Martynyuk
Keyword(s):  
Myocardial Infarction ◽  
Nervous System ◽  
Autonomic Nervous System ◽  
Functional State ◽  
Human Body ◽  
The Body ◽  
Human Organism ◽  
Autonomic Nervous ◽  
Significant Difference ◽  
The Right

Almost all processes in the human body in one way or another connected with the autonomic nervous system. That's why it is real to evaluate the functional state of the person by temperature characteristics of representative points of the autonomic nervous system. Location and information of these points are confirmed by fundamental research. However, simply measuring the temperature at some points may not be sufficient to establish any systematic changes in the human body. The establishment of such changes requires systematic assessment of interdependent significant relationships between these parameters.The main aim of our research was to study effects of myocardial infarction in the thoracic region of the autonomic nervous system. The temperature of representative areas of the thoracic autonomic nervous system we measured by infrared thermometer (Medisana FTO D-53340 , with an accuracy of 0.1 degree Celsius). Statistical analysis was conducted in the packet Statistics 10. The presence of a difference in the temperature coefficients of representative areas (p<0,05). For the left side of the spine characterized by a difference in Th1–Th5 segments, which confirms their diagnosis: Th1 – 0,931,12 (control) and -0,797,49 (experiment), Th2 – 1,571,12 and -0,486,70, Th3 – 1,582611,12325 and -0,663,36, Th4 – 0,85913 0,92611 and -1,74,64, Th5 – 0,923480,75469 and-1,615,73 respectively. For the right side of the thoracic spines: Th6 – 0,850,73 (control) and -0,797,49 (experiment), Th7 – -1,000,79 and -1,370,69, Th8 – -0,960,73 and -0,990,68, Th9 – -0,120,64 and -0,380,83, Th10 – -0,921,14 and -1,031,00, Th11 – -1,691,05 and -1,861,06, Th12- -1,651,15 and -1,961,12 respectively. We found that myocardial infarction is manifested in the thoracic spine. In an experimental group there is significant difference of temperature in all segments. We can also notice asymmetry of temperatue between the right and left side of the spine. In the test group there are a deviation from the normal temperature in the first five thoracic segments on the left side, which confirms their diagnosis. On the right side of the spine there are a deviation in the last seven segments, which may indicate the compensatory mechanisms of regulation of the system. We can observe the temperature asymmetry, which in long-term exposure can negatively affect to the body.

scholarly journals 305 FIRST REPORT OF THE USE OF SEXED SEMEN BY FLOW CYTOMETRY IN BOS INDICUS

2005 ◽  
Vol 17 (2) ◽  
pp. 303
Author(s):  
L. Cattaneo ◽  
A. Galassi ◽  
R. Franco ◽  
A. Duarte ◽  
K. Mello ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
High Speed ◽  
Bos Indicus ◽  
Field Trials ◽  
The Body ◽  
Chi Square ◽  
Female Fetus ◽  
Mato Grosso ◽  
Significant Difference ◽  
Sexed Semen

The only method of sexing sperm that works in any practical sense is measuring DNA content of individual sperm by flow cytometry, and sorting them based on that information (Schenk and Seidel 2002 J. Anim. Sci. 80 (Suppl. 1), 188). This is, also, the first reference of the use of sexed semen in Brazil. The objective of this experiment was to compare the fertility of sexed and non-sexed conventional semen in Bos indicus purebreeds. Ejaculates from eight Nelore bulls were collected by artificial vagina, diluted, and stained with Hoeschst 33342 (Schenk et al. 1999 Theriogenology 52, 1375–1391). A high-speed flow cytometer (SX-MOFLO®, DakoCytomation, Inc., Fort Collins, CO, USA) was used for sorting X sperm. Sexed semen was then packaged at 3 million total sperm in 0.25-mL straws and frozen. The average estimated purity obtained by resort analysis of one straw per batch was 91.5%. An aliquot of each ejaculate was frozen unsexed at a concentration of 50 × 106 sperm/mL in 0.5-mL straws (control). A total of 283 Nelore heifers were synchronized with two doses of PGF2α 12 days apart and inseminated in the body of the uterus 12 h after heat detection. Field trials were carried out in four different states in Brazil: Minas Gerais (MG), Mato Grosso (MT), Mato grosso do Sul (MS), Rondônia (RO). Pregnancy diagnosis and fetal sex determination were performed by ultrasound 30 and 60 days post-AI, respectively. Data were analyzed by chi-square and Monte Carlo methods. There was no significant difference (P < 0.05) in pregnancy rate between sexed and non-sexed semen (see Table 1). At the time of abstract submission, of 41 pregnant heifers from sexed semen confirmed by ultrasound, 40 had a female fetus (97%). These results indicate that sexing semen by flow cytometry could be a very important tool to accelerate the genetic gain in Bos indicus cattle. Brazil has the largest commercial herd in the world and, therefore, a great potential to incorporate this technology that is now available in the country. Table 1.

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