The Biomechanics of Erections: Two- Versus One-Compartment Pressurized Vessel Modeling of the Penis

2010 ◽  
Vol 132 (12) ◽  
Author(s):  
Ahmed M. Mohamed ◽  
Arthur G. Erdman ◽  
Gerald W. Timm
Keyword(s):  
Structural Integrity ◽  
Tunica Albuginea ◽  
Compartment Model ◽  
3D Models ◽  
Lateral Force ◽  
The Body ◽  
Physical Models ◽  
Biomechanical Models ◽  
Significant Difference ◽  
External Forces

Previous biomechanical models of the penis simulated penile erections utilizing 2D geometry, simplified 3D geometry or made inaccurate assumptions altogether. These models designed the shaft of the penis as a one-compartment pressurized vessel fixed at one end when in reality it is a two-compartment pressurized vessel in which the compartments diverge as they enter the body and are fixed at two separate anatomic sites. This study utilizes the more anatomically correct two-compartment penile model to investigate erectile function. Simplified 2D and 3D models of the erect penis were developed using the finite element method with varying anatomical considerations for analyzing structural stresses, axial buckling, and lateral deformation. This study then validated the results by building and testing corresponding physical models. Finally, a more complex and anatomically accurate model of the penis was designed and analyzed. When subject to a lateral force of 0.5 N, the peak equivalent von Mises (EVM) stress in the two-compartment model increased by about 31.62%, while in the one-compartment model, the peak EVM stress increased by as high as 70.11%. The peak EVM stress was 149 kPa in the more complex and anatomically accurate penile model. When the perforated septum was removed, the peak EVM stress increased to 455 kPa. This study verified that there is significant difference between modeling the penis as a two- versus a one-compartment pressurized vessel. When subjected to external forces, a significant advantage was exhibited by two corporal based cavernosal bodies separated by a perforated septum as opposed to one corporal body. This is due to better structural integrity of the tunica albuginea when subjected to external forces.

scholarly journals The Biomechanics of Erections: Modeling the Penis as a One-Comparment Pressurized Vessel vs. Modeling it as a Two-Compartments Pressurized Vessel

2009 ◽  
Vol 3 (2) ◽  
Author(s):  
A. Mohamed ◽  
A. Erdman ◽  
G. Timm
Keyword(s):  
Structural Integrity ◽  
Tunica Albuginea ◽  
Three Dimensional ◽  
The Body ◽  
Physical Models ◽  
Von Mises Stress ◽  
Two Dimensional ◽  
Biomechanical Models ◽  
Significant Difference ◽  
The One

Previous biomechanical models of the penis that have attempted to simulate penile erections have either been limited to two-dimensional geometry, simplified three-dimensional geometry or made inaccurate assumptions altogether. Most models designed the shaft of the penis as a one-compartment pressurized vessel fixed at one end, when in reality it is a two-compartments pressurized vessel, in which the compartments diverge as they enter the body and are fixed at two separate points. This study began by designing simplified two-dimensional and three-dimensional models of the erect penis using Finite Element Analysis (FEA) methods with varying anatomical considerations for analyzing structural stresses, axial buckling and lateral deformation. The study then validated the results by building physical models replicating the computer models. Finally a more complex and anatomically accurate model of the penis was designed and analyzed. There was a significant difference in the peak von-Mises stress distribution between the one-compartment pressurized vessel and the more anatomically correct two-compartments pressurized vessel. Furthermore, the two-compartments diverging pressurized vessel was found to have more structural integrity when subject to external lateral forces than the one-compartment pressurized vessel. This study suggests that Mother Nature has favored an anatomy of two corporal cavernosal bodies separated by a perforated septum as opposed to one corporal body, due to better structural integrity of the tunica albuginea when subject to external forces.

scholarly journals INVESTIGATION THE INFLUENCE DIFFERENCE OF THE WAGON’S WHEELS DIAMETERS ON ITS DERAILMENT BY QUASI-DYNAMICS METHOD

2019 ◽  
pp. 608-614
Author(s):  
A. Kuzyshyn
Keyword(s):  
Lateral Force ◽  
The Body ◽  
Rolling Stock ◽  
Wheel Pair ◽  
Rail Head ◽  
Rolling Surface ◽  
Significant Difference ◽  
Negative Effect ◽  
The Difference ◽  
Dynamics Method

In the article the author notes that the horizontal forces arising in the process of pressing the wheel flanges to the working edge of the rail, under certain conditions can be very significant. These forces, in combination with the wheel unloading, caused by the geometric deviation of the track in the plan and profile, can lead to rolling the wheel of the wheelset onto the rail head and, as a consequence, to the stock derailment. Such pressing of the wheel to the rail head in the straight part of the track can occur when faults in the running gears of the wagons: non-parallelism of the axles of the wheel pairs of the bogie frame by the difference in the bases of the side frames, wear of the guide axle-box openings; the difference of the flanges on one wheel pair is more than permissible, wear of the body and bogie bolster center plates, step bearing; a significant difference in the diameters of the wheels of the wheelset caused by the intense wear of the rolling surface of one of them, etc. The article deals with the investigation of the influence of the wheels’ diameters difference of the wheelset on the amount of lateral force for the empty and loaded state of the rolling stock wagon. The results obtained made it possible to conclude that an increase in the wheels’ diameters difference of the wheelset of a loaded wagon of rolling stock leads to more intensive growth of the lateral force, as compared with the exhaust. This is caused by the linear dependence of the lateral force on the mass of the wagon of the rolling stock. However, for both the empty and the loaded wagon, the increase in the lateral force value has a negative effect. In conjunction with the unloading of the wheel it increases the probability of rolling in the wheel of the wheelset on the rail head. Also, an increase in the action of the lateral force from the wheelset on the rail, causes increased wear of the rail, the wheel flange, which is pressed. At the same time, rolling surfaces of an irregular shape are formed on the surface of the other wheel. Therefore, it is important to ensure the maintenance of the wheels of a wheel pair with the smallest difference in its diameters. Key words: rolling stock, diameter difference of wheels, quasi-dynamics method.

Interaction Forces Between the Rider and the 2-Wheeled Vehicle and Biomechanical Models

2013 ◽  
Author(s):  
Marco Bevilacqua ◽  
Alberto Doria ◽  
Mauro Tognazzo
Keyword(s):  
Lateral Force ◽  
Rigid Bodies ◽  
The Body ◽  
Roll Motion ◽  
Interaction Forces ◽  
Trunk Motion ◽  
Biomechanical Models ◽  
Novel Approach ◽  
Passive Response ◽  
Wheeled Vehicles

In two-wheeled vehicles the mass of the rider is a significant part of the total mass of the system and the rider influences the dynamic behavior both by means of the voluntary control actions and by means of the passive response of his body to the oscillations of the vehicle. The passive response of the rider’s body has a particular influence on roll motion, which is typical of two-wheeled vehicles. Roll oscillations generate inertia forces on the rider’s body, which moves with respect to the vehicle. Forces and torques generated by the rider on the handlebars, saddle and foot rests are different from the ones that would be generated if the body was rigidly fixed to the vehicle. Therefore, advanced simulation of two wheeled vehicles requires passive biomechanical models of the rider. This paper proposes a novel approach for the study of the passive response of the rider’s body that is based on measurements in the laboratory of the interaction forces between the rider and the vehicle. A special motorcycle mock-up is developed, it is driven by a hydraulic shaker that generates roll excitation with variable frequency. A system of load cells measures the lateral force and torque between the rider and the motorcycle mock-up. The study is carried out in the frequency domain, the passive response of rider’s body is represented by means of three frequency response functions (FRFs): lateral force FRF and torque FRF are the ratios between the lateral force/torque and the roll input; motion FRF is the ratio between the roll motion of the rider’s trunk and the roll input. The biomechanical models of the rider’s body that are developed in this work are able to simulate its response both in terms of interaction forces and motion. These models are composed by some rigid bodies with lumped stiffness and damping parameters in the articulations and in this way they represent a good compromise between accuracy and complexity. The biomechanical parameters of the models are identified by means of a genetic algorithm that aims to minimize a penalty function based on the difference between the three FRFs predicted by the model and the measured FRFs. Results show that a 5 degree of freedom model of the rider is able to represent the measured behavior both in terms of interaction forces and trunk motion.

Influence of stable iodine on the uptake of the thyroid – model vs. experiment

2001 ◽  
Vol 40 (01) ◽  
pp. 31-37 ◽  
Author(s):  
U. Wellner ◽  
E. Voth ◽  
H. Schicha ◽  
K. Weber
Keyword(s):  
Time Course ◽  
Compartment Model ◽  
The Body ◽  
Iodine Uptake ◽  
Model Calculations ◽  
Physiological Conditions ◽  
Iodine Supply ◽  
Predicted Values ◽  
The Individual ◽  
Stable Iodine

Summary Aim: The influence of physiological and pharmacological amounts of iodine on the uptake of radioiodine in the thyroid was examined in a 4-compartment model. This model allows equations to be derived describing the distribution of tracer iodine as a function of time. The aim of the study was to compare the predictions of the model with experimental data. Methods: Five euthyroid persons received stable iodine (200 μg, 10 mg). 1-123-uptake into the thyroid was measured with the Nal (Tl)-detector of a body counter under physiological conditions and after application of each dose of additional iodine. Actual measurements and predicted values were compared, taking into account the individual iodine supply as estimated from the thyroid uptake under physiological conditions and data from the literature. Results: Thyroid iodine uptake decreased from 80% under physiological conditions to 50% in individuals with very low iodine supply (15 μg/d) (n = 2). The uptake calculated from the model was 36%. Iodine uptake into the thyroid did not decrease in individuals with typical iodine supply, i.e. for Cologne 65-85 μg/d (n = 3). After application of 10 mg of stable iodine, uptake into the thyroid decreased in all individuals to about 5%, in accordance with the model calculations. Conclusion: Comparison of theoretical predictions with the measured values demonstrated that the model tested is well suited for describing the time course of iodine distribution and uptake within the body. It can now be used to study aspects of iodine metabolism relevant to the pharmacological administration of iodine which cannot be investigated experimentally in humans for ethical and technical reasons.

The influence of osteopathic correction on the rate of various rhythms of the body

2019 ◽  
pp. 64-71 ◽  
Author(s):  
A. E. Chernikova ◽  
Yu. P. Potekhina
Keyword(s):  
Heart Rate ◽  
Respiratory Rate ◽  
Age Groups ◽  
Biomechanical Properties ◽  
Dispersion Analysis ◽  
The Body ◽  
Body Tissues ◽  
Age Related ◽  
Significant Difference ◽  
Before And After

Introduction. An osteopathic examination determines the rate, the amplitude and the strength of the main rhythms (cardiac, respiratory and cranial). However, there are relatively few studies in the available literature dedicated to the influence of osteopathic correction (OC) on the characteristics of these rhythms.Goal of research — to study the influence of OC on the rate characteristics of various rhythms of the human body.Materials and methods. 88 adult osteopathic patients aged from 18 to 81 years were examined, among them 30 men and 58 women. All patients received general osteopathic examination. The rate of the cranial rhythm (RCR), respiratory rate (RR) heart rate (HR), the mobility of the nervous processes (MNP) and the connective tissue mobility (CTM) were assessed before and after the OC session.Results. Since age varied greatly in the examined group, a correlation analysis of age-related changes of the assessed rhythms was carried out. Only the CTM correlated with age (r=–0,28; p<0,05) in a statistically significant way. The rank dispersion analysis of Kruskal–Wallis also showed statistically significant difference in this indicator in different age groups (p=0,043). With the increase of years, the CTM decreases gradually. After the OC, the CTM, increased in a statistically significant way (p<0,0001). The RCR varied from 5 to 12 cycles/min in the examined group, which corresponded to the norm. After the OC, the RCR has increased in a statistically significant way (p<0,0001), the MNP has also increased (p<0,0001). The initial heart rate in the subjects varied from 56 to 94 beats/min, and in 15 % it exceeded the norm. After the OC the heart rate corresponded to the norm in all patients. The heart rate and the respiratory rate significantly decreased after the OC (р<0,0001).Conclusion. The described biorhythm changes after the OC session may be indicative of the improvement of the nervous regulation, of the normalization of the autonomic balance, of the improvement of the biomechanical properties of body tissues and of the increase of their mobility. The assessed parameters can be measured quickly without any additional equipment and can be used in order to study the results of the OC.

Effectiveness Of Toilet Training Education On Mother's Behavior And Toddler Age Toilet Training Ability (18-36 Months)

2020 ◽  
Vol 5 (2) ◽  
pp. 49-55
Author(s):  
Hafiko Andresni ◽  
Zahtamal Zahtamal ◽  
Winda Septiani ◽  
Mitra Mitra ◽  
Lita Lita
Keyword(s):  
Sampling Technique ◽  
T Test ◽  
The Body ◽  
Toilet Training ◽  
Wilcoxon Test ◽  
Control Group ◽  
Maternal Knowledge ◽  
Control Group Design ◽  
Significant Difference

ABSTRACT Toilet training is an effort to train children to be able to control and urinate (BAK) and defecate (BAB). Toilet training is one of the main tasks of children at toddler age. Toilet training is one of the main tasks of children in toddler age which is very important to be done to create independence in children in controlling BAK and BAB and children know the parts of the body and their functions. Data in 2012 shows that ± 60% of parents do not teach toilet training to children from an early age. The aim of the study was to find out the effectiveness of toilet training education on maternal behavior and toilet skills in toddler age training (18-36 months). The study was conducted in July-August 2018. This type of quantitative research used the design of the Quasy pretest and posttest experiment with non-equivalent control group design. Samples were 36 mothers and 36 children with purposive sampling technique. Data analysis used Paired t test, Wilcoxon test, Man-Whitney test an Independent t test. The results showed that toilet training education through lecture methods, modules and maze games was more effective than toilet training education through lecture and leaflet methods on children's knowledge and abilities. Conversely, for the role of mothers in supervision there is no significant difference in effectiveness. Health education is recommended in health promotion programs to increase maternal knowledge, the role of mothers and the ability of toilet training children independently. Keywords: Toilet training, Lecture method, Module, Maze game, Leaflet, Knowledge, Role of mother, Children's ability.

In-vivo anti-oxidant screening of Tectona grandis extract

2020 ◽  
Vol 9 (1) ◽  
pp. 1-4
Author(s):  
Tamilarasi G P ◽  
Sabarees G
Keyword(s):  
Biochemical Parameters ◽  
Tectona Grandis ◽  
The Body ◽  
Altered Expression ◽  
Physiological Conditions ◽  
Synthetic Drugs ◽  
Significant Difference ◽  
Anti Oxidant ◽  
Radical Generation

Oxidation is an essential reaction in the human body, which determines the expression of proteins in the body. This results in the altered expression like rapid growth resulting in cancers and other disorders. Many synthetic drugs are available in the market that is effective in limiting the free radical generation and the reaction of radicals with cells. Unfortunately, all those synthetic drugs were found to cause side effects and adverse effects in the body. But given the accuracy of the predictability of the results and administration, this research focuses on testing the anti-oxidant efficiency in rat models testing the biochemical parameters. Investigations have also been done on the anti-oxidant activity of Tectona, but every research was concentrated to prove the anti-oxidant activity only. extract had been tested for anti-oxidant activity by estimating various tissue parameters and it showed better activity. As predicted, there is a significant difference in the and results which can be explained are due to the physiological conditions that exist inside the body.

Perbedaan Penggunaan Antikoagulan K2EDTA DAN K3EDTA Terhadap Hasil Pemeriksaan Indeks Eritrosit

2018 ◽  
Vol 1 (2) ◽  
pp. 114
Author(s):  
Wahdaniah Wahdaniah ◽  
Sri Tumpuk
Keyword(s):  
Screening Test ◽  
Venous Blood ◽  
The Body ◽  
Ethylene Diamine ◽  
P Value ◽  
Cross Sectional ◽  
Significant Difference ◽  
Ethylene Diamine Tetra Acetate ◽  
The Difference ◽  
Index Value

Abstract: Routine blood examination is the earliest blood test or screening test to determine the diagnosis of an abnormality. Blood easily froze if it is outside the body and can be prevented by the addition of anticoagulants, one of which Ethylene Diamine Tetra Acetate (EDTA). Currently available vacuum tubes containing EDTA anticoagulants in the form of K2EDTA and K3EDTA. K3EDTA is usually a salt that has better stability than other EDTA salts because it shows a pH approaching a blood pH of about 6.4. The purpose of this research is to know the difference of erythrocyte index results include MCH, MCV and MCHC using K3EDTA anticoagulant with K2EDTA. This research is a cross sectional design. This study used venous blood samples mixed with K2EDTA anticoagulant and venous blood mixed with K3EDTA anticoagulants, each of 30 samples. Data were collected and analyzed using paired different test. Based on data analysis that has been done on MCH examination, p value <0,05 then there is a significant difference between samples with K3EDTA anticoagulant with K2EDTA to erythrocyte index value. Then on the examination of MCV and MCHC obtained p value <0.05 then there is no significant difference between samples with K3EDTA anticoagulant with K2EDTA to erythrocyte index value.Abstrak: Pemeriksaan darah rutin merupakan pemeriksaan darah yang paling awal atau screening test untuk mengetahui diagnosis suatu kelainan. Darah mudah membeku jika berada diluar tubuh dan bisa dicegah dengan penambahan antikoagulan, salah satunya Ethylene Diamine Tetra Acetate (EDTA). Dewasa ini telah tersedia tabung vakum yang sudah berisi antikoagulan EDTA dalam bentuk  K2EDTA dan  K3EDTA. K3EDTA  biasanya berupa garam yang mempunyai stabilitas yang lebih baik dari garam EDTA yang lain karena menunjukkan pH yang mendekati pH darah yaitu sekitar 6,4. Tujuan dari penelitian ini adalah untuk mengetahui perbedaan hasil indeks eritrosit meliputi MCH, MCV dan MCHC menggunakan antikoagulan K3EDTA dengan K2EDTA. Penelitian ini merupakan penelitian dengan desain cross sectional. Penelitian ini menggunakan sampel darah vena yang dicampur dengan antikoagulan K2EDTA dan darah vena yang dicampur dengan antikoagulan K3EDTA, masing-masing sebanyak 30 sampel. Data dikumpulkan dan dianalisis menggunakan uji beda berpasangan. Berdasarkan analisis data yang telah dilakukan pada pemeriksaan MCH didapatkan nilai p < 0,05 maka ada perbedaan yang signifikan antara sampel dengan antikoagulan K3EDTA dengan K2EDTA terhadap nilai indeks eritrosit. Kemudian pada pemeriksaan MCV dan MCHC didapatkan nilai p < 0,05 maka tidak ada perbedaan yang signifikan antara sampel dengan antikoagulan K3EDTA dengan K2EDTA terhadap nilai indeks eritrosit.

scholarly journals Computer Literacy and Online Learning Attitude toward GSOE Students in Distance Education Programs

2016 ◽  
Vol 6 (3) ◽  
pp. 147 ◽  
Author(s):  
Lung-Yu Li ◽  
Long-Yuan Lee
Keyword(s):  
Online Learning ◽  
Computer Literacy ◽  
Online Courses ◽  
The Body ◽  
Education Management ◽  
Learning Attitude ◽  
Learning Attitudes ◽  
Significant Difference ◽  
Learning Programs ◽  
Managerial Implications

<p>The purpose of this study was to explore graduate students’ competencies in computer use and their attitudes toward online learning in asynchronous online courses of distance learning programs in a Graduate School of Education (GSOE) in Taiwan. The research examined the relationship between computer literacy and the online learning attitudes of these students. Data were collected via a survey through 252 GSOE students in Taiwan. Results revealed a significant positive relationship between computer literacy and online learning attitude among the students. Higher computer literacy was correlated with higher online learning attitude. However, no statistically significant difference was found in online learning attitude by gender or by age group. Suggestions and managerial implications were discussed in the study, and would provide contribution both to the body of knowledge in the filed of education management.</p>

scholarly journals Digital 3D models of theropods for approaching body-mass distribution and volume

2021 ◽  
Author(s):  
Matías Reolid ◽  
Francisco J. Cardenal ◽  
Jesús Reolid
Keyword(s):  
Body Length ◽  
Heat Dissipation ◽  
Volume Ratio ◽  
3D Models ◽  
The Body ◽  
3D Analysis ◽  
Skull Length ◽  
Knowing That ◽  
Fossil Bones ◽  
Primitive Forms

AbstractThe aim of this work is to obtain diverse morphometric data from digitized 3D models of scientifically accurate palaeoreconstructions of theropods from eight representative families. The analysed polyvinyl chloride (PVC) models belong to the genera Coelophysis, Dilophosaurus, Ceratosaurus, Allosaurus, Baryonyx, Carnotaurus, Giganotosaurus, and Tyrannosaurus. The scanned 3D models were scaled considering different body-size estimations of the literature. The 3D analysis of these genera provides information on the skull length and body length that allows for recognition of major evolutionary trends. The skull length/body length in the studied genera increases according with the size of the body from the smallest Coelophysis with a ratio of 0.093 to ratios of 0.119–0.120 for Tyrannosaurus and Giganotosaurus, the largest study theropods. The study of photogrammetric 3D models also provides morphometric information that cannot be obtained from the study of bones alone, but knowing that all reconstructions begin from the fossil bones, such as the surface/volume ratio (S/V). For the studied theropod genera surface/volume ratio ranges from 35.21 for Coelophysis to 5.55 for Tyrannosaurus. This parameter, closely related to the heat dissipation, help in the characterization of the metabolism of extinct taxa. Accordingly, slender primitive forms of the Early Jurassic (i.e. Coelophysis and Dilophosaurus) had relatively smaller skulls and higher mass-specific metabolic rates than the robust large theropods of the Cretaceous (i.e. Giganotosaurus and Tyrannosaurus). This work presents a technique that, when applied to proper dinosaur models, provides extent and accurate data that may help in diverse study areas within the dinosaur palaeontology and palaeobiology.

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