scholarly journals Potential Reduction of Peripheral Local SAR for a Birdcage Body Coil at 3 Tesla Using a Magnetic Shield

2021 ◽  
Vol 9 ◽  
Author(s):  
C.C. van Leeuwen ◽  
B.R. Steensma ◽  
S.B. Glybovski ◽  
M.F.J. Lunenburg ◽  
C. Simovski ◽  
...  
Keyword(s):  
Eddy Currents ◽  
Periodic Structures ◽  
Ring Resonators ◽  
Scale Model ◽  
Birdcage Coil ◽  
Magnetic Shield ◽  
Body Regions ◽  
Body Coil ◽  
Local Sar ◽  
The Right

The birdcage body coil, the standard transmit coil in clinical MRI systems, is typically a shielded coil. The shield avoids interaction with other system components, but Eddy Currents induced in the shield have an opposite direction with respect to the currents in the birdcage coil. Therefore, the fields are partly counteracted by the Eddy currents, and large coil currents are required to reach the desired B1+ level in the subject. These large currents can create SAR hotspots in body regions close to the coil. Complex periodic structures known as metamaterials enable the realization of a magnetic shield with magnetic rather than electric conductivity. A magnetic shield will have Eddy currents in the same direction as the coil currents. It will allow generating the same B1+ with lower current amplitude, which is expected to reduce SAR hotspots and improve homogeneity. This work explores the feasibility of a birdcage body coil at 3 T with a magnetic shield. Initially, we investigate the feasibility by designing a scale model of a birdcage coil with an anisotropic implementation of a magnetic shield at 7 T using flattened split ring resonators. It is shown that the magnetic shield destroys the desired resonance mode because of increased coil loading. To enforce the right mode, a design is investigated where each birdcage rung is driven individually. This design is implemented in a custom built birdcage at 7 T, successfully demonstrating the feasibility of the proposed concept. Finally, we investigate the potential improvements of a 3 T birdcage body coil through simulations using an idealized magnetic shield consisting of a perfect magnetic conductor (PMC). The PMC shield is shown to eliminate the peripheral regions of high local SAR, increasing the B1+ per unit maximum local SAR by 27% in a scenario where tissue is present close to the coil. However, the magnetic shield increases the longitudinal field of view, which reduces the transmit efficiency by 25%.

scholarly journals Layanan Informasi Berbasis Pohon Karier untuk Meningkatkan Pemahaman Perencanaan Karier Siswa

2021 ◽  
Vol 2 (1) ◽  
pp. 12-19
Author(s):  
Sukma Gita Lestari ◽  
Ramtia Darma Putri ◽  
Nurlela
Keyword(s):  
Job Search ◽  
Quantitative Research ◽  
Career Planning ◽  
Information Services ◽  
Scale Model ◽  
Search Process ◽  
Career Plans ◽  
Group Design ◽  
Quasi Experimental ◽  
The Right

Problems that are often encountered in career planning are students who choose the wrong career because they are forced to follow the wishes of their parents so that careers that are in accordance with the child's wishes, talents, and abilities are ignored. The intervention of parents who tend to dominate their desires in children's studies is considered the right decision, while children are considered still unable to determine attitudes and make decisions to plan their careers. Some of the difficulties that arise during the job search process often occur because individuals do not have a clear career planning direction. In addition, job providers are also more selective in finding and selecting prospective employees. The purpose of this study is to determine whether the use of career tree-based information services can improve students' understanding of career planning or not. This study uses quantitative research with a Quasi-Experimental design experimental research method. The Quasi-Experimental form used in this study is the Pretest Posttest Group Design with a sample of 35 people. The instrument used in this study used a Likert scale model. The results showed that career tree-based information services can improve students' understanding of career plans. Students can understand clearly and with a strong passion to determine their own career by referring to various information obtained through the career

scholarly journals Students’ Sexual Identity Based on Interest, Style and Behavior

2020 ◽  
Vol 4 (1) ◽  
pp. 51
Author(s):  
Neviyarni Neviyarni ◽  
Netrawati Netrawati ◽  
Riska Ahmad ◽  
Wiwi Delfita
Keyword(s):  
Sexual Identity ◽  
Random Sampling ◽  
Sampling Technique ◽  
Quantitative Approach ◽  
Scale Model ◽  
Counseling Services ◽  
Opposite Sex ◽  
Identity Based ◽  
The Right ◽  
And Behavior

The right sexual identity, if a person is interested to the opposite sex. In fact, there are still some students who are known as homosexual. This article is aimed to define the sexual identity of students based on behavior, style and interest. This study utilized quantitative approach with descriptive type. The populations of the research were students of Universitas Negeri Padang 2017 and 2018 generation in amount of 15.752, and sample counted were 385 students (by using Taro Yamane formula and continued with Multistage Random Sampling Technique. The researcher employed instrument which isSexual Identity scale, model Gutman. After being analyzed with descriptive technique, the researcher got result that generally students tended to identify their sexual identity as heterosexual based on interest, behavior, and style. Counselor is hoped to be able to help students whom are identified as homosexual to the right direction(heterosexual) by giving counseling services needed by sexual identity.

Burnout and its Association with Musculoskeletal Pain among Primary Care Providers

2017 ◽  
Vol 61 (1) ◽  
pp. 1010-1014 ◽  
Author(s):  
Xuanxuan Zhang ◽  
Mark C. Schall ◽  
Richard Sesek ◽  
Sean Gallagher ◽  
Jesse Michel
Keyword(s):  
Primary Care ◽  
Musculoskeletal Pain ◽  
Healthcare Providers ◽  
Primary Care Providers ◽  
Care Providers ◽  
Cross Sectional ◽  
Body Regions ◽  
Increased Risk ◽  
The Right

Burnout is a growing concern among primary care providers (PCPs). The condition may lead to diminished quality of patient care as well as reduced quality of life. Although self-reported musculoskeletal pain is common among healthcare providers, the relationship between burnout and musculoskeletal pain among PCPs has been studied very little. We describe a cross-sectional pilot survey conducted among 38 PCPs (MDs, DOs, PAs, and NPs) in the Midwestern United States. Self-reported feelings of burnout and musculoskeletal pain in different body regions were analyzed using regression models. Results suggested that increasing number of hours worked per day, severity of pain in the neck / shoulder area, and severity of pain in the right wrist were associated with an increased risk of burnout. On the contrary, burnout decreased with increasing age. The findings suggest that additional research is needed to understand the risk factors for burnout among PCPs, particularly during the early stages of their career.

Effects of clothing ease and body postures on the air gap and clothing coverage

2019 ◽  
Vol 31 (4) ◽  
pp. 578-594
Author(s):  
Shitan Wang ◽  
Xiuhua Wang ◽  
Yunyi Wang
Keyword(s):  
Air Gap ◽  
The Body ◽  
Upper Body ◽  
Gap Size ◽  
Lower Body ◽  
Content Type ◽  
Body Postures ◽  
Body Regions ◽  
Gap Models ◽  
The Right

Purpose The purpose of this paper is to determine the effects of clothing ease and body postures on the size and distribution of the air gap as well as the body coverage with the clothing. Design/methodology/approach Visual and quantitative analyses were conducted using a 3D body scanner and Geomagic Software. The air gap size and clothing area factor (fcl) in three test coverall and seven selected postures were calculated and compared. Findings The results indicated that both the clothing ease and body postures had a strong effect on the air gap and clothing coverage, especially the more complex the postures, the wider the range of influence. Nevertheless, these effects varied over body regions, being stronger at the lower body than the upper body. The air gap size at the left side of the body was generally larger than the right side. It was also found that the clothing coverage was linearly correlated with the air gap size and could be employed as an indicator to evaluate clothing protective capabilities. Practical implications The findings suggested that greater attention should be paid to the protection and flexibility at the lower body and asymmetrical distribution of the air gap should be considered in the future air gap modeling. Originality/value The outcomes provided useful information to improve the protective clothing and develop more realistic air gap models to simulate the heat and mass transfer.

Underhood Buoyancy Driven Flow—An Experimental Study

2011 ◽  
Vol 133 (8) ◽  
Author(s):  
Parviz Merati ◽  
Charles Davis ◽  
K.-H. Chen ◽  
J. P. Johnson
Keyword(s):  
Surface Temperature ◽  
Ambient Air ◽  
Engine Block ◽  
Scale Model ◽  
Flow Structures ◽  
Engine Compartment ◽  
Fluid Exchange ◽  
Thermal Measurements ◽  
The Right ◽  
Over The Top

Particle image velocimetry and thermal measurements using thermocouples are used to measure the buoyant flow of a simplified full-scale model of an engine compartment. The engine block surface temperature and exhaust heaters are kept at about 100 and 600°C, respectively. Thermal measurements include enclosure surface temperature, temperature difference on the enclosure wall at midplane, engine block temperatures, and air temperatures under the hood. The highest surface temperatures were concentrated near the top of the enclosure around the exhaust heaters. This effect was due primarily to radiation from the exhaust heaters. Highest measured air temperature was about 300°C immediately above the right exhaust heater. The measured dominant flow structures are two larger counter rotating vortices over the top right side of the engine block and two counter rotating vortices over the top left side. These flow structures weaken considerably during the first 35 min of the transient cool down of the engine block and the exhaust heaters. Colder ambient air is sucked into the engine compartment at the vents near the bottom of the compartment with some exiting as hot air through the top slots. The time scale of the fluid exchange at the vents is in the order of seconds, indicating that this process is occurring very slowly.

scholarly journals Application of Rasch Rating Scale Model to Analysis of Fear of Missing Out a Smartphone

10.32698/0562 ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 50
Author(s):  
Alizamar Alizamar
Keyword(s):  
Rating Scale ◽  
Large City ◽  
Likert Scale ◽  
Scale Model ◽  
Scale Analysis ◽  
Fear Of Missing Out ◽  
Rasch Rating Scale Model ◽  
The Right ◽  
The Rasch Model ◽  
Rating Scale Model

The presence of smartphones is one of the technological advancements that have contributed greatly to changes in social behavior. This led to the inception of the Fear of Missing Out (FoMO) smartphone device. The purpose of this study therefore was to determine the right instrument to measure the FoMO smartphone by analyzing response points obtained from respondents. The study sample consisted of three groups of test subjects, from large city, small town and villages with n values of 226, 248, and 55 respectively. The data in this study were obtained using the 5-point Likert scale politomy data from a Fear of Missing out scale instrument, distributed online. The research data were analyzed using the Rasch model by testing rating scale analysis through Threshold. The results showed that the rating scale answered choices turned into a 3-point Likert scale with those not right, less right, and very right.

Cardiac rupture caused by traffic accident: Case reports and a literature review

2018 ◽  
Vol 86 (3) ◽  
pp. 152-156
Author(s):  
S Zerbo ◽  
E Ventura Spagnolo ◽  
S Salerno ◽  
G Lo Re ◽  
A Guajana ◽  
...  
Keyword(s):  
Traffic Accidents ◽  
Case Reports ◽  
Cardiac Injury ◽  
Soft Tissue Injuries ◽  
Interatrial Septum ◽  
Post Mortem ◽  
Body Regions ◽  
Conventional Autopsy ◽  
Sport Activities ◽  
The Right

The commonest cause of blunt cardiac injuries is from traffic accidents followed by violent falls, sport activities, accidents or a fight but rupture of the heart is rare and lethal. The precise incidence of cardiac injury after a blunt chest trauma is unknown as rates vary greatly in the literature from between 7% and 76% of cases. Autopsy studies have shown that the right ventricle is the most frequently ruptured, followed by the left ventricle, right atrium, intraventricular septum, left atrium and interatrial septum with decreasing frequency. Post-mortem imaging is a rapidly advancing field of post-mortem investigations of trauma victims. The available literature dealing with the comparison of post-mortem computed tomography results with forensic autopsy indicates that conventional autopsy remains superior for the detection of organ and soft tissue injuries in all body regions.

Proportional regulation of body form and cortical organelle pattern in the ciliate Dileptus

1977 ◽  
Vol 24 (1) ◽  
pp. 11-29
Author(s):  
K. Golinska ◽  
J. Kink
Keyword(s):  
Proximal Portion ◽  
Posterior Region ◽  
Body Form ◽  
Ultrastructural Studies ◽  
Regulatory Processes ◽  
Body Regions ◽  
Dileptus Anser ◽  
The Right ◽  
Pattern Regulation

Morphometric and ultrastructural studies of shape and pattern regulation were performed on Dileptus anser. In this ciliate 2 body regions can be distinguished: proboscis and trunk. When a large portion of the trunk is excised, shape regulation occurs and the proper proboscis/trunk ratio is restored through elongation of the remnant of the trunk and shortening of the proboscis. When there is nothing but proboscis left, the trunk is formed from the proximal portion of proboscis and again the right proportion is restored. Regulation of the ciliary pattern is based mainly on resorption of some ciliary elements. The resorption of somatic ciliature is especially intense within narrowing regions, where otherwise overcrowding of cilia would occur. The resorption of oral ciliature was found to occur within an area located at the apex of the proboscis. Oral structures when damaged by cutting may be repaired in situ. Changes in the microfibrillar system of the cell were found during regulation of shape of the posterior region of the cell, as well as during regulation of size of oral structures. Regulatory processes in Dileptus are compared to those known for other ciliates, and possible differences between the regulation of shape and the regulation of pattern are discussed.

Limitations of large‐loop transient electromagnetic surveys in conductive terrains

Geophysics ◽  
1984 ◽  
Vol 49 (7) ◽  
pp. 902-912 ◽  
Author(s):  
Brian R. Spies ◽  
Patricia D. Parker
Keyword(s):  
Decay Constant ◽  
Eddy Currents ◽  
Electrical Contact ◽  
Scale Model ◽  
Geometric Condition ◽  
Model Studies ◽  
Large Loop ◽  
Transient Electromagnetic ◽  
Inductive Effects ◽  
Tem Method

Conventional interpretation aids used in transient electromagnetic (TEM) exploration assume that the anomalous response is due to induction in a simple model such as a plate, sphere, or uniform layer. Estimates of conductivity, depth, and size are based on analyzing the profile shape and transient decay constant. In regions with conductive overburden or conductive bedrock, TEM responses obtained with the large‐loop configuration can often be very dependent upon the location of the transmitter loop, and the results can be easily misinterpreted. A series of scale‐model studies was carried out to investigate the influence of current channeling and gathering phenomena with the large fixed loop and moving single‐loop configurations of the TEM method. Models studied included resistive and step discontinuities in a horizontal conductive slab, and a vertical plate in electrical contact with conductive overburden. Large TEM anomalies can be observed at the edge of a conductive unit, when diffusing eddy currents migrating through surface conductors are channeled and become spatially localized. Current gathering occurs when the diffusing eddy currents are gathered into a locally more conductive zone. The most common geometric condition under which these effects are observed is when a conductor of long strike length is located outside a large transmitter loop. The TEM response is enhanced by channeling and gathering, and it is often stronger than simple inductive effects. Current channeling and current gathering phenomena are relatively unimportant when measurements are made within a large transmitter loop, or when a single‐ or in‐loop configuration is used. It is therefore recommended that multiple transmitter loop locations be used when surveying in conductive terrains with the largeloop configuration, or alternatively that the single‐ or in‐loop configuration be employed for additional geophysical control.

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