scholarly journals MODELING OF REDUCTION IN THE CROSS-SECTIONAL AREA OF STEEL REINFORCEMENT IN CONCRETE UNDER THE ACTION OF CORROSIVE ENVIRONMENT

2017 ◽  
Vol 21 (1) ◽  
pp. 43-49 ◽  
Author(s):  
G. A. Smolyago ◽  
A. V. Dronov ◽  
N. V. Frolov
Keyword(s):  
Mathematical Model ◽  
Reinforced Concrete ◽  
Steel Reinforcement ◽  
Cross Sectional Area ◽  
Testing Time ◽  
Corrosive Environment ◽  
Sectional Area ◽  
Cross Sectional ◽  
Rc Structures ◽  
The Cross

Process of depassivation of steel in concrete under the action of chloride corrosive environment is considered. Method of durable testing of bended reinforced concrete structures during corrosive period is described. Results of experimental research in steel reinforcement corrosion in reinforced concrete beams under the action of corrosive environment are described in the article. The diagram of corrosive potential changes during the testing time is given in the article. Measurements of corrosion potential were carried out by the corrosion analyzing instrument. Analysis of corrosive potential changes during the testing time was carried out. Main properties and features of chloride corrosion process and damages are considered. Corrosive pits on the surface of the reinforcement bars were studied. Measurements of depth and diameter of the corrosive pits were carried out. Stress-strain diagrams of steel after the corrosive period were obtained. Mathematical model of reduction in the cross-sectional area of steel reinforcement in concrete under the action of corrosive chloride environment is suggested. This model allows to consider effect of concrete cover thickness on depth of corrosion. Comparison of experimental results and theoretical calculations reveals high accuracy of corrosion damage definition by given mathematical model. The ways to use the model are suggested. The given model allows to consider corrosive damages of steel rebars by definition of cross-section area losses and may be used in calculations of strength and deformations of RC structures. It’s possible to use the model for prediction of the remaining strength life of RC structures.

Tensile strength of partially filled FFF printed parts: meta modelling

2017 ◽  
Vol 23 (3) ◽  
pp. 524-533 ◽  
Author(s):  
Shahrain Mahmood ◽  
A.J. Qureshi ◽  
Kheng Lim Goh ◽  
Didier Talamona
Keyword(s):  
Mathematical Model ◽  
Tensile Strength ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Fused Filament Fabrication ◽  
Cross Sectional ◽  
Content Type ◽  
Test Pieces ◽  
Solid Part ◽  
The Cross

Purpose This paper aims to investigate the tensile strength of partially filled fused filament fabrication (FFF) printed parts with respect of cross-sectional geometry of partially filled test pieces. It was reported in the authors’ earlier work that the ultimate tensile strength (UTS) is inversely proportional to the cross-sectional area of a specimen, whereas the number of shells and infill density are directly proportional to the UTS with all other parameters being held constant. Here, the authors present an in-depth evaluation of the phenomenon and a parametric model that can provide useful estimates of the UTS of the printed part by accounting for the dimensions of the solid floor/roof layers, shells and infills. Design/methodology/approach It was found that partially filled FFF printed parts consist of hollow sections. Because of these voids, the conventional method of determining the UTS via the gross cross-sectional area given by A = b × h, where b and h are the width and thickness of the printed part, respectively, cannot be used. A mathematical model of a more accurate representation of the cross-sectional area of a partially filled part was formulated. Additionally, the model was extended to predict the dimensions as well as the lateral distortion of the respective features within a printed part using input values from the experimental data. Findings The result from this investigation shows that to calculate the UTS of a partially filled FFF part, the calculation based on the conventional approach is not sufficient. A new meta-model is proposed which takes into account the geometry of the internal features to give an estimate of the strength of a partially filled printed part that is closer to the value of the strength of the material that is used for fabricating the part. Originality/value This paper investigates the tensile strength of a partially filled FFF printed part. The results have shown that the tensile strength of a partially filled part can be similar to that of a solid part, at a lower cost: shorter printing time and lower material usage. By taking into account the geometries within a printed part, the cross-sectional area can be accurately represented. The mathematical model which was developed would aid end-users to predict the tensile strength for a given set of input values of the process parameters.

scholarly journals Atrophy patterns in isolated subscapularis lesions

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Gernot Seppel ◽  
Andreas Voss ◽  
Daniel J. H. Henderson ◽  
Simone Waldt ◽  
Bernhard Haller ◽  
...  
Keyword(s):  
Muscle Atrophy ◽  
Area Ratio ◽  
Cross Sectional Area ◽  
Control Group ◽  
Sectional Area ◽  
Cross Sectional ◽  
Subscapularis Muscle ◽  
Mri Scans ◽  
The Mean ◽  
The Cross

Abstract Background While supraspinatus atrophy can be described according to the system of Zanetti or Thomazeau there is still a lack of characterization of isolated subscapularis muscle atrophy. The aim of this study was to describe patterns of muscle atrophy following repair of isolated subscapularis (SSC) tendon. Methods Forty-nine control shoulder MRI scans, without rotator cuff pathology, atrophy or fatty infiltration, were prospectively evaluated and subscapularis diameters as well as cross sectional areas (complete and upper half) were assessed in a standardized oblique sagittal plane. Calculation of the ratio between the upper half of the cross sectional area (CSA) and the total CSA was performed. Eleven MRI scans of patients with subscapularis atrophy following isolated subscapularis tendon tears were analysed and cross sectional area ratio (upper half /total) determined. To guarantee reliable measurement of the CSA and its ratio, bony landmarks were also defined. All parameters were statistically compared for inter-rater reliability, reproducibility and capacity to quantify subscapularis atrophy. Results The mean age in the control group was 49.7 years (± 15.0). The mean cross sectional area (CSA) was 2367.0 mm2 (± 741.4) for the complete subscapularis muscle and 1048.2 mm2 (± 313.3) for the upper half, giving a mean ratio of 0.446 (± 0.046). In the subscapularis repair group the mean age was 56.7 years (± 9.3). With a mean cross sectional area of 1554.7 mm2 (± 419.9) for the complete and of 422.9 mm2 (± 173.6) for the upper half of the subscapularis muscle, giving a mean CSA ratio of 0.269 (± 0.065) which was seen to be significantly lower than that of the control group (p < 0.05). Conclusion Analysis of typical atrophy patterns of the subscapularis muscle demonstrates that the CSA ratio represents a reliable and reproducible assessment tool in quantifying subscapularis atrophy. We propose the classification of subscapularis atrophy as Stage I (mild atrophy) in case of reduction of the cross sectional area ratio < 0.4, Stage II (moderate atrophy) in case of < 0.35 and Stage III (severe atrophy) if < 0.3.

The area of eye muscle of beef cattle carcasses

1963 ◽  
Vol 3 (10) ◽  
pp. 249
Author(s):  
RM Seebeck
Keyword(s):  
Beef Cattle ◽  
Cross Sectional Area ◽  
Carcass Weight ◽  
Sectional Area ◽  
Muscle Area ◽  
Cross Sectional ◽  
Eye Muscle ◽  
Angus Cattle ◽  
The Cross

Variations in the cross-sectional area of eye muscle of carcasses cut between the tenth and eleventh ribs were investigated, using 105 Hereford and 51 Angus steers aged 20 months. These cattle consisted of three groups, born in successive years. At constant carcass weight, statistically significant differences in eye muscle area were found between breeds and between years. Breed and year differences were also found in eye muscle area with width and depth of eye muscle constant, so that there are limitations to the estimation of eye muscle area from width and depth measurements. A nomograph is given for estimating eye muscle area from width and depth for Hereford and Angus cattle, when all animals are reared in the same year and environment. The use of eye muscle area as an indicator of weight of carcass muscle is discussed.

Comparison of the Cross Sectional Area, the Loss in Volume and the Mechanical Properties of LAE442 and MgCa0.8 as Resorbable Magnesium Alloy Implants after 12 Months Implantation Duration

2010 ◽  
Vol 638-642 ◽  
pp. 675-680 ◽  
Author(s):  
Martina Thomann ◽  
Nina von der Höh ◽  
Dirk Bormann ◽  
Dina Rittershaus ◽  
C. Krause ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cross Sections ◽  
Degradation Process ◽  
Cross Sectional Area ◽  
Bending Test ◽  
Sectional Area ◽  
Cross Sectional ◽  
Initial Strength ◽  
Three Point Bending ◽  
The Cross

Current research focuses on magnesium based alloys in the course of searching a resorbable osteosynthetic material which provides sufficient mechanical properties besides a good biocompatibility. Previous studies reported on a favorable biocompatibility of the alloys LAE442 and MgCa0.8. The present study compared the degradation process of cylindrical LAE442 and MgCa0.8 implants after 12 months implantation duration. Therefore, 10 extruded implants (2.5 x 25 mm, cross sectional area 4.9 mm²) of both alloys were implanted into the medullary cavity of both tibiae of rabbits for 12 months. After euthanization, the right bone-implant-compound was scanned in a µ-computed tomograph (µCT80, ScancoMedical) and nine uniformly distributed cross-sections of each implant were used to determine the residual implants´ cross sectional area (Software AxioVisionRelease 4.5, Zeiss). Left implants were taken out of the bone carefully. After weighing, a three-point bending test was carried out. LAE442 implants degraded obviously slower and more homogeneously than MgCa0.8. The mean residual cross sectional area of LAE442 implants was 4.7 ± 0.07 mm². MgCa0.8 showed an area of only 2.18 ± 1.03 mm². In contrast, the loss in volume of LAE442 pins was more obvious. They lost 64 % of their initial weight. The volume of MgCa0.8 reduced clearly to 54.4 % which corresponds to the cross sectional area results. Three point bending tests revealed that LAE442 showed a loss in strength of 71.2 % while MgCa0.8 lost 85.6 % of its initial strength. All results indicated that LAE442 implants degraded slowly, probably due to the formation of a very obvious degradation layer. Degradation of MgCa0.8 implants was far advanced.

A method of in-vitro measurement of the cross-sectional area of soft tissues, using ultrasonography

2002 ◽  
Vol 7 (2) ◽  
pp. 247-251 ◽  
Author(s):  
Masahiko Noguchi ◽  
Toshiya Kitaura ◽  
Kazuya Ikoma ◽  
Yoshiaki Kusaka
Keyword(s):  
Soft Tissues ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
The Cross

Intra- and inter-rater reliability for the measurement of the cross-sectional area of ankle tendons assessed by magnetic resonance imaging

2021 ◽  
pp. 028418512110032
Author(s):  
Henrique Mansur ◽  
Guilherme Estanislau ◽  
Marcos de Noronha ◽  
Rita de Cassia Marqueti ◽  
Emerson Fachin-Martins ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Repeated Measures ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Resonance Imaging ◽  
Cross Sectional ◽  
Rater Reliability ◽  
The Cross ◽  
Very High

Background The cross-sectional area (CSA) records make an essential measurement for determining the mechanical properties of tendons, such as stress and strength. However, there is no consensus regarding the best method to record the CSA from different tendons. Purpose To determine intra- and inter-rater reliability for CSA measures from magnetic resonance imaging (MRI) of the following tendons: tibialis anterior; tibialis posterior; fibularis longus and brevis; and Achilles. Material and Methods We designed an observational study with repeated measures taken from a convenience sample of 20 participants diagnosed with acute or chronic ankle sprain. Two independent raters took three separate records from the CSA of ankle tendon images of each MRI slice. The intra-class correlation coefficient (ICC) and 95% limits of agreement (LoA) defined the quality (associations) and magnitude (differences), respectively, of intra- and inter-rater reliability on the measures plotted by the Bland–Altman method. Results Data showed very high intra- and inter-rater correlations for measures taken from all tendons analyzed (ICC 0.952–0.999). It also revealed an excellent agreement between raters (0.12%–2.3%), with bias no higher than 2 mm2 and LoA in the range of 4.4–7.9 mm2. The differences between repeated measures recorded from the thinnest tendons (fibularis longus and brevis) revealed the lowest bias and narrowest 95% LoA. Conclusion Reliability for the CSA of ankle tendons measured from MRI taken by independent rates was very high, with the smallest differences between raters observed when the thinnest tendon was analyzed.

scholarly journals Sequential alterations in the diameters of capillaries in rabbit skeletal muscle following deep transverse friction - a morphometric study

2005 ◽  
Vol 61 (2) ◽  
Author(s):  
M. A. Gregory ◽  
M. N. Deane ◽  
M. Marsh
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Muscle Blood Flow ◽  
Biceps Femoris ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Biceps Femoris Muscle ◽  
Beneficial Effects ◽  
The Cross

Objective: The precise mechanisms by which massage promotes repair in injured soft tissue are unknown. Various authorshave attributed the beneficial effects of massage to vasodilation and increased skin and muscle blood flow. The aim of this study was to determine whether deep transverse friction massage (DTF) causes capillary vasodilation in untraumatised skeletal muscle. Setting: Academic institution.Interventions: Twelve New Zealand white rabbits were anaesthetised and the left biceps femoris muscle received 10 minutes of DTF. Following treatment, wedge biopsies were taken from the musclewithin 10 minutes of treatment (R1 - 4), 24 hours (R5 - 8) and 6 days(R9 - 12) after treatment. To serve as controls, similar biopsies weretaken from the right biceps femoris of animals. The samples were fixed, dehydrated and embedded in epoxy resin.Transverse sections (1µm) of muscle were cut, stained with 1% aqueous alkaline toluidine blue and examined with a light microscope using a 40X objective. Images containing capillaries were captured using an image analyser with SIS software and the cross sectional diameters of at least 60 capillaries were measured from each specimen. Main Outcome Measures: Changes in capillary diameter. Results: The mean capillary diameters in control muscle averaged 4.76 µm. DTF caused a significant immediate increase of 17.3% in cross sectional area (p<0.001), which was not significantly increased by 10.0% after 24 hours (p>0.05). Six days after treatment the cross-sectional area of the treated muscle was 7.6% smaller than the controls. Conclusions: This confirms the contention that DTF stimulates muscle blood flow immediately after treatment and this may account for its beneficial effects in certain conditions. 

Cross-sectional area and mean echogenicity of shoulder and elbow tendons in adult German Shepherd dogs

2013 ◽  
Vol 26 (05) ◽  
pp. 366-371 ◽  
Author(s):  
G. Loprete ◽  
V. Musella ◽  
D. Britti ◽  
J. M. Vilar ◽  
G. Spinella
Keyword(s):  
Cross Sectional Area ◽  
Sectional Area ◽  
Triceps Brachii ◽  
German Shepherd ◽  
Cross Sectional ◽  
Extensor Muscles ◽  
Flexor Carpi Ulnaris ◽  
Triceps Brachii Muscle ◽  
The Cross ◽  
Distal Tendon

SummaryThe aim of this study was to describe the cross-sectional area and mean echogenicity of the main tendons of the shoulder and elbow joints in adult German Shepherd dogs and to determine the effects of sex, weight, and age on these parameters. No previous publications in the veterinary literature have reported information regarding quantitative ultrasonographic tendon measurements in dogs.Thirty German Shepherd dogs were examined: 13 males and 17 females. The cross-sectional area was significantly higher in males than in females (p <0.05) for the distal tendon of the triceps brachii muscle and the tendons of the flexor carpi ulnaris and common digital extensor muscles. The influence of sex on mean echogenicity was not significant. According to age, mean echogenicity was higher in older dogs, while the cross-sectional areas were similar in the two groups. Cross-sectional area and mean echogenicity of the tendons showed a direct increase with an increase in body weight. The data gained from this study can help support the clinician to discriminate between normal and pathological conditions.

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