scholarly journals Assessment of the Bending Moment Capacity of Naturally Corroded Box-Section Beams

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5766
Author(s):  
Przemysław Fiołek ◽  
Jacek Jakubowski
Keyword(s):  
Failure Modes ◽  
The Body ◽  
Moment Capacity ◽  
Bending Tests ◽  
Box Section ◽  
Corrosion Loss ◽  
Modeling Approach ◽  
The Mean ◽  
Hot Rolled ◽  
Minimum Moment

The steel constructions of mine shaft steelwork are particularly exposed to aggressive environments, which cause large, nonuniform corrosion loss throughout the steel members. A correct assessment of corrosion loss and load-carrying capacity of shaft steelwork is crucial for its maintenance and safe operation. In this article, we present the results of laboratory, numerical, and analytical investigations conducted on naturally corroded steel guides disassembled from shaft steelwork. The steel guides considered had a closed profile formed by welding two hot-rolled channel sections. Laboratory bending tests were carried out on beams with various levels of corrosion loss, corresponding to compact, non-compact, and slender cross sections. Multiple detailed measurements of the thicknesses of naturally corroded walls were used in order to reproduce their nonuniform geometry in finite element (FE) models. The results of numerical simulations of five bending tests showed good agreement with laboratory measurements and replicated the observed failure modes, therefore confirming the applicability of this modeling approach for assessing the moment capacity of highly corroded steel beams when the deteriorated geometry is known. For the purpose of generalization, a series of derived models reflecting the natural corrosion pattern was then developed, and moment capacity statistics were collected through multiple simulations. They showed that the mean moment capacity is determined by the mean wall thickness. However, the minimum moment capacity is strongly affected by corrosion loss variation, particularly for the highly corroded beams. A simplified, analytical modeling approach was also examined, providing fairly good assessments of the mean; however, the minimum moment capacity could not be estimated. This study contributes to the body of knowledge on the mechanical behavior of highly corroded hot-rolled box-section beams.

Evaluation of Salivary Antioxidants and Oxidative Stress Markers in Male Smokers

2019 ◽  
Vol 22 (7) ◽  
pp. 496-501
Author(s):  
Fatemeh Ahmadi-Motamayel ◽  
Parisa Falsafi ◽  
Hamidreza Abolsamadi ◽  
Mohammad T. Goodarzi ◽  
Jalal Poorolajal
Keyword(s):  
Oxidative Stress ◽  
Uric Acid ◽  
Free Radicals ◽  
Antioxidant Capacity ◽  
Cigarette Smoke ◽  
Total Antioxidant Capacity ◽  
The Body ◽  
Total Antioxidant ◽  
The Mean ◽  
And Oxidative Stress

Background: Cigarette smoke free radicals can cause cellular damage and different diseases. All the body fluids have antioxidants which protect against free radicals. Objective: The aim of this study was to evaluate salivary total antioxidant capacity and peroxidase, uric acid and malondialdehyde levels in smokers and a nonsmoking control group. Methods: Unstimulated saliva was collected from 510 males. A total of 259 subjects were current smokers and 251 were non-smokers. The levels of salivary total antioxidant capacity, uric acid, peroxidase and malondialdehyde were measured using standard procedures. Data were analyzed with t test and ANOVA. Results: The smokers were younger and dental hygiene index was higher than healthy nonsmoking controls. The mean total antioxidant capacity in smokers and nonsmokers was 0.13±0.07 and 0.21±011, respectively (P=0.001). Smokers had significantly lower peroxidase and uric acid levels than healthy controls. In addition, the mean malondialdehyde levels in the smokers and nonsmokers were 4.55 ±2.61 and 2.79 ±2.21, respectively (P=0.001). Conclusion: Cigarette smoke produces free radical and oxidative stress, causing many side effects. Salivary antioxidant levels decreased and malondialdehyde levels increased in smokers, indicating the high oxidative stress among smokers compared to nonsmokers. Cigarette smoke had deleterious effects on main salivary antioxidants levels.

Effect of High Plane of Nutrition on Blood Biochemical Profile and Onset of Puberty in Prepubertal HF X Kankrej Crossbred Heifers

2019 ◽  
Vol 15 (02) ◽  
pp. 14-17
Author(s):  
K K Hadiya ◽  
A J Dhami ◽  
D V Chaudhari ◽  
P M Lunagariya
Keyword(s):  
Body Weight ◽  
Treatment Group ◽  
Plasma Levels ◽  
Age Of Onset ◽  
The Body ◽  
Monthly Interval ◽  
Control Group ◽  
Blood Biochemical ◽  
Lower Protein ◽  
The Mean

This study was initiated on 24 prepubertal Holstein x Kankrej crossbred heifers of nearly identical age (7-9 months) and body weight (130-140 kg) at University farm to evaluate the effect of high plane of nutrition on blood biochemical and minerals profile and the age at puberty. Twelve heifers were managed under routine farm feeding (control) and the rest 12 under ideal optimum feeding regime (treatment) that included extra 1 kg concentrate, 30 g min mix and ad-lib dry fodder. The body weight and ovarian ultrasonography together with blood sampling was carried out at monthly interval from 10 to 18 months of age to study the ovarian dynamics and blood biochemical changes. High plane of nutrition to growing heifers was beneficial in reducing the age of onset of puberty (by 2-3 months) compared to routine farm fed group. The mean plasma total protein and cholesterol concentrations showed a rising trend with significant variations from 10 to 16 months of age, where it got mostly stabilized indicating adult profile. The activity of enzymes GOT and GPT also rose gradually and significantly from 10 months till 14-15 months of age, and thereafter it remained more or less static till 18 months of age. The levels of both these enzymes were higher, with lower protein and cholesterol, in control than the treatment group from 15-16 months of age onwards. The mean plasma levels of both calcium and phosphorus increased gradually and significantly with advancing age till 16-17 months of age, with little higher values in supplemented than a control group. The plasma levels of zinc, iron, copper, and cobalt also showed rising trend with significant differences between 10th and 12th-14th months of age, and from 15th to 18th months of age the levels were statistically the same in all the groups with slightly higher values in the treatment group.

scholarly journals Comparative study between fascia lata and temporalis fascia in myringoplasty

2020 ◽  
Vol 36 (1) ◽  
Author(s):  
Ayman Ali Abdel Fattah ◽  
Abdel Hay Rashad Elasy ◽  
Ahmed Helmy Hoseini ◽  
Tarek Abdel Rahman Abdel Hafez
Keyword(s):  
Tympanic Membrane ◽  
Good Alternative ◽  
Fascia Lata ◽  
The Body ◽  
Temporalis Fascia ◽  
Fascia Graft ◽  
Fascia Lata Graft ◽  
Group A ◽  
The Mean ◽  
Group B

Abstract Background Repair of a perforated tympanic membrane (myringoplasty) can facilitate normal middle ear function, resist infection, and help re-establish normal hearing. Autogenous graft materials are the most popular graft materials used in myringoplasty because of their easy acceptability by the body. This study is conducted to compare between temporalis fascia graft and fascia lata graft in myringoplasty for patients with tubo-tympanic dry perforation. Results A total of 60 patients with persistent dry tympanic membrane perforation were included in our study during the period from January 2018 to May 2020. Patients underwent myringoplasty with temporalis fascia (30 patients as group A) or fascia lata (30 patients as group B). Patients were scheduled for follow-up visits concerning graft status, ear discharge, and audiograms. The mean postoperative air-bone gap in group A was 17.5 ± 4 after 1 month and 8.6 ± 6.9 after 3 months, while in group B, the mean postoperative air-bone gap was 17.6 ± 4.9 after 1 month and 9.4 ± 7.5 after 3 months. There was 90% success in graft uptake in group A, while there was 80% success in group B. Conclusion Using temporalis fascia is still the best and most trustworthy technique of myringoplasty compared to fascia lata graft. However, fascia lata can be a good alternative to temporalis fascia especially in cases of revision myringoplasty, ears having large perforation, or near-total perforation where the chances of residual perforation are high because of the limited margin of remnant tympanic membrane overlapping the graft.

scholarly journals Estimation of Motion and Respiratory Characteristics during the Meditation Practice Based on Video Analysis

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3771
Author(s):  
Alexey Kashevnik ◽  
Walaa Othman ◽  
Igor Ryabchikov ◽  
Nikolay Shilov
Keyword(s):  
Respiratory Rate ◽  
Evaluation System ◽  
Body Movement ◽  
Absolute Error ◽  
The Body ◽  
Meditation Practice ◽  
Body Parts ◽  
Mental Health Training ◽  
Negative Thoughts ◽  
The Mean

Meditation practice is mental health training. It helps people to reduce stress and suppress negative thoughts. In this paper, we propose a camera-based meditation evaluation system, that helps meditators to improve their performance. We rely on two main criteria to measure the focus: the breathing characteristics (respiratory rate, breathing rhythmicity and stability), and the body movement. We introduce a contactless sensor to measure the respiratory rate based on a smartphone camera by detecting the chest keypoint at each frame, using an optical flow based algorithm to calculate the displacement between frames, filtering and de-noising the chest movement signal, and calculating the number of real peaks in this signal. We also present an approach to detecting the movement of different body parts (head, thorax, shoulders, elbows, wrists, stomach and knees). We have collected a non-annotated dataset for meditation practice videos consists of ninety videos and the annotated dataset consists of eight videos. The non-annotated dataset was categorized into beginner and professional meditators and was used for the development of the algorithm and for tuning the parameters. The annotated dataset was used for evaluation and showed that human activity during meditation practice could be correctly estimated by the presented approach and that the mean absolute error for the respiratory rate is around 1.75 BPM, which can be considered tolerable for the meditation application.

scholarly journals On the Pathology of the dropsy produced by obstruction of the superior and inferior venœ and the portal vein.— Preliminary communication

1907 ◽  
Vol 79 (532) ◽  
pp. 267-283 ◽  
Keyword(s):  
Blood Pressure ◽  
Arterial Pressure ◽  
Portal Vein ◽  
Mean Arterial Blood Pressure ◽  
Normal Limit ◽  
The Body ◽  
Diastolic Filling ◽  
Arterial Blood ◽  
Preliminary Communication ◽  
The Mean

In August, 1903, I published a paper in the ‘Journal of Pathology’(1) in which I demonstrated a method experimentally producing uncompensated hear disease in an animal, which was compatible with life. This method consisted in diminishing the size of the pericardial sac by stitches, so that the diastolic filling of the heart was impeded. The main symptoms of this condition were dropsy and diminution in the amount of urine excreted. As the immediate result of this interference with the action of the heart, there occurred a rise of pressure throughout the whole systemic venous system extending as far back as the capillaries, and a fall of the mean arterial blood-pressure. Further, I found that the pressure in all the veins fell to the normal limit again within the space of about one hour, and that subsequently when dropsy was being produced, the vanous pressure in all parts of the body was normal, and the arterial pressure had almost recovered itself.

scholarly journals A Multi-Channel Uncertainty-Aware Multi-Resolution Network for MR to CT Synthesis

2021 ◽  
Vol 11 (4) ◽  
pp. 1667
Author(s):  
Kerstin Klaser ◽  
Pedro Borges ◽  
Richard Shaw ◽  
Marta Ranzini ◽  
Marc Modat ◽  
...  
Keyword(s):  
Medical Image Analysis ◽  
Absolute Error ◽  
Magnetic Resonance Images ◽  
The Body ◽  
Whole Body ◽  
Image Size ◽  
Body Images ◽  
Image Translation ◽  
The Mean ◽  
Synthetic Ct

Synthesising computed tomography (CT) images from magnetic resonance images (MRI) plays an important role in the field of medical image analysis, both for quantification and diagnostic purposes. Convolutional neural networks (CNNs) have achieved state-of-the-art results in image-to-image translation for brain applications. However, synthesising whole-body images remains largely uncharted territory, involving many challenges, including large image size and limited field of view, complex spatial context, and anatomical differences between images acquired at different times. We propose the use of an uncertainty-aware multi-channel multi-resolution 3D cascade network specifically aiming for whole-body MR to CT synthesis. The Mean Absolute Error on the synthetic CT generated with the MultiResunc network (73.90 HU) is compared to multiple baseline CNNs like 3D U-Net (92.89 HU), HighRes3DNet (89.05 HU) and deep boosted regression (77.58 HU) and shows superior synthesis performance. We ultimately exploit the extrapolation properties of the MultiRes networks on sub-regions of the body.

scholarly journals Dynamic modeling of nutrient use and individual requirements of lactating sows1

2019 ◽  
Vol 97 (7) ◽  
pp. 2822-2836 ◽  
Author(s):  
Raphaël Gauthier ◽  
Christine Largouët ◽  
Charlotte Gaillard ◽  
Laetitia Cloutier ◽  
Frédéric Guay ◽  
...  
Keyword(s):  
Feed Intake ◽  
Average Daily Gain ◽  
Individual Performance ◽  
Maintenance Cost ◽  
Nutrient Requirements ◽  
Modeling Approach ◽  
Ex Post ◽  
Nutrient Use ◽  
The Mean ◽  
On Farm

AbstractNutrient requirements of sows during lactation are related mainly to their milk yield and feed intake, and vary greatly among individuals. In practice, nutrient requirements are generally determined at the population level based on average performance. The objective of the present modeling approach was to explore the variability in nutrient requirements among sows by combining current knowledge about nutrient use with on-farm data available on sows at farrowing [parity, BW, backfat thickness (BT)] and their individual performance (litter size, litter average daily gain, daily sow feed intake) to estimate nutrient requirements. The approach was tested on a database of 1,450 lactations from 2 farms. The effects of farm (A, B), week of lactation (W1: week 1, W2: week 2, W3+: week 3 and beyond), and parity (P1: 1, P2: 2, P3+: 3 and beyond) on sow performance and their nutrient requirements were evaluated. The mean daily ME requirement was strongly correlated with litter growth (R2 = 0.95; P < 0.001) and varied slightly according to sow BW, which influenced the maintenance cost. The mean daily standardized ileal digestible (SID) lysine requirement was influenced by farm, week of lactation, and parity. Variability in SID lysine requirement per kg feed was related mainly to feed intake (R2 = 0.51; P < 0.001) and, to a smaller extent, litter growth (R2 = 0.27; P < 0.001). It was lowest in W1 (7.0 g/kg), greatest in W2 (7.9 g/kg), and intermediate in W3+ (7.5 g/kg; P < 0.001) because milk production increased faster than feed intake capacity did. It was lower for P3+ (6.7 g/kg) and P2 sows (7.3 g/kg) than P1 sows (8.3 g/kg) due to the greater feed intake of multiparous sows. The SID lysine requirement per kg of feed was met for 80% of sows when supplies were 112 and 120% of the mean population requirement on farm A and B, respectively, indicating higher variability in requirements on farm B. Other amino acid and mineral requirements were influenced in the same way as SID lysine. The present modeling approach allows to capture individual variability in the performance of sows and litters according to farm, stage of lactation, and parity. It is an initial step in the development of new types of models able to process historical farm data (e.g., for ex post assessment of nutrient requirements) and real-time data (e.g., to control precision feeding).

scholarly journals Mechanotendography in Achillodynia shows reduced oscillation variability of pre-loaded Achilles tendon: a pilot study

2020 ◽  
Vol 30 (2) ◽  
pp. 247-257
Author(s):  
Laura Schaefer ◽  
Frank Bittmann
Keyword(s):  
Achilles Tendon ◽  
Rank Correlation ◽  
Achilles Tendinopathy ◽  
The Body ◽  
Mechanical Pressure ◽  
Mechanical Oscillations ◽  
Pressure Impact ◽  
The Subject ◽  
The Mean ◽  
Intrapersonal Variability

The present study focuses on an innovative approach in measuring the mechanical oscillations of pre-loaded Achilles tendon by using Mechanotendography (MTG) during application of a short yet powerful mechanical pressure impact. This was applied on the forefoot from the plantar side in direction of dorsiflexion, while the subject stood on the ball of the forefoot on one leg. Participants with Achilles tendinopathy (AT; n = 10) were compared to healthy controls (Con; n = 10). Five trials were performed on each side of the body. For evaluation, two intervals after the impulse began (0-100ms; 30-100ms) were cut from the MTG and pressure raw signals. The intrapersonal variability between the five trials in both intervals were evaluated using the arithmetic mean and coefficient of variation of the mean correlation (Spearman rank correlation) and the normalized averaged mean distances, respectively. The AT-group showed a significantly reduced variability in MTG compared to the Con-group (from p = 0.006 to p = 0.028 for different parameters). The 95% confidence intervals (CI) of MTG results were disjoint, whereas the 95% CIs of the pressure signals were similar (p = 0.192 to p = 0.601). We suggest from this work that the variability of mechanical tendon oscillations could be an indicative parameter of an altered Achilles tendon functionality.

Submarine Pipeline Installation JIP: Strength and Deformation Capacity of Pipes Passing Over the S-Lay Vessel Stinger

2006 ◽  
Author(s):  
Enrico Torselletti ◽  
Luigino Vitali ◽  
Erik Levold ◽  
Kim J. Mo̸rk
Keyword(s):  
Water Depth ◽  
Failure Modes ◽  
Bending Moment ◽  
External Pressure ◽  
Submarine Pipeline ◽  
Design Guideline ◽  
Moment Capacity ◽  
Sea Bottom ◽  
Major Vessel ◽  
Gas Fields

The development of deep water gas fields using trunklines to carry the gas to the markets is sometime limited by the feasibility/economics of the construction phase. In particular there is a market for using S-lay vessels in water depth larger than 1000m. The S-lay feasibility depends on the applicable tension at the tensioner which is a function of water depth, stinger length and stinger curvature (for given stinger length by its curvature). This means that, without major vessel up-grading and to avoid too long stingers that are prone to damages caused by environmental loads, the application of larger stinger curvatures than presently allowed by current regulations/state of the art is needed. The work presented in this paper is a result of the project “Development of a Design Guideline for Submarine Pipeline Installation” sponsored by STATOIL and HYDRO. The technical activities are performed in co-operation by DNV, STATOIL and SNAMPROGETTI. The scope of the project is to produce a LRFD (Load Resistant Factor Design) design guideline to be used in the definition and application of design criteria for the laying phase e.g. to S and J-lay methods/equipment. The guideline covers D/t from 15 to 45 and applied strains over the overbend in excess of 0.5%. This paper addresses the failure modes relevant for combined high curvatures/strains, axial, external pressure and local forces due to roller over the stinger of an S-lay vessel and to sea bottom contacts, particularly: • Residual pipe ovality after laying, • Maximum strain and bending moment capacity. Analytical equations are proposed in accordance with DNV OS F101 philosophy and design format.

Implications of body condition and seasonality on morphological and functional parameters of testes of Myotis nigricans (Chiroptera: Vespertilionidae)

2018 ◽  
Vol 30 (7) ◽  
pp. 1029
Author(s):  
Marcelo Ferreira ◽  
Aline Soldati ◽  
Sirlene S. S. Rodrigues ◽  
Laércio dos Anjos Benjamin
Keyword(s):  
Light Microscopy ◽  
Body Condition ◽  
Environmental Variables ◽  
Reproductive Strategies ◽  
Leydig Cells ◽  
Dry Season ◽  
The Body ◽  
Reproductive Capacity ◽  
Seminiferous Tubules ◽  
The Mean

The insectivorous bat Myotis nigricans is widely distributed throughout the Neotropics, including Brazil, and has a reproductive biology that is affected by climate and food availability. To evaluate the reproductive capacity of this species, morphofunctional parameters of the testes were correlated with environmental variables and the body condition of individuals captured. After bats had been killed, their testes were removed, fixed in Karnovsky’s fluid for 24 h and embedded in resin for evaluation by light microscopy. The mean annual tubulosomatic index (0.58%) and the percentage of seminiferous tubules in the testes (88.96%) were the highest ever recorded for the Order Chiroptera. The percentage of Leydig cells and volume of the cytoplasm of Leydig cells were higher in the rainy than dry season (80.62 ± 3.19% and 573.57 ± 166.95 μm, respectively; mean ± s.d.). Conversely, the percentage of nuclei of the Leydig cells in the dry season (26.17 ± 3.70%; mean ± s.d.) and the total number of Leydig cells (6.38 ± 1.84 × 109; mean ± s.d.) were higher in the dry season. The results of the present study could help in future conservation of these bats because they provide a better understanding of the bats’ reproductive strategies and how the species can adapt to changes.

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