scholarly journals TWISTING RIGIDITY OF REINFORCED CONCRETE ELEMENTS OF I–BEAM SECTION WITH INCLINED CRACKS

Author(s):  
T.N. Azizov ◽  
◽  
O.M. Orlova ◽  

Abstract. The article shows that to determine the torsional stiffness of the element, you must first cut the reinforcement at the site of the inclined crack. After dissecting the reinforcement, the mutual displacement of the crack edges should be determined. This problem is the main and most difficult in the general problem of determining the torsional stiffness of elements with both normal and inclined cracks. The article is devoted to the solution of this most difficult part of the problem ‒ the determination of the mutual displacement of the banks of the inclined crack of the I-beam element. According to the proposed method, the real element with an inclined crack is replaced by an element with different stiffness in sections. Within an inclined crack, the element has a real slope equal to the slope of the inclined crack. In the area behind the apex of the inclined crack, it is hypothesized that the cross-sectional height of the element varies from a height equal to the height of the zone above the crack to the full cross-sectional height. And change of height occurs according to the law of a straight line. This line is inclined at some angle to the horizontal. It is shown that if we take the angle of inclination of this line equal to 45 degrees, the results are quite accurate. The equivalent section height is defined as the average value between the height above the inclined crack and the total section height. The equivalent torsional stiffness of the element on the section of the sloping line is taken equal to the stiffness of the element with a conditionally constant stiffness at a constant height equal to the equivalent. It is also shown that the calculation according to the proposed method differs from the calculation of an element with a normal crack only in that in the left part in the case of an inclined crack there is a section with a real slope of the section. The rest of the problem is identical. The comparison of calculations by the proposed method with the calculation data in the Lear program using volumetric finite elements is given. The comparison showed a good match of the data.

1990 ◽  
Vol 154 (1) ◽  
pp. 439-461 ◽  
Author(s):  
VANCE A. TUCKER

1. The drag of a bird body mounted on the strut of a drag balance in a wind tunnel is more than the sum of the drags of the isolated strut and the isolated body. The strut changes the air flow around the body and generates additional drag, known as interference drag. This paper describes practical methods for measuring the drag of bird bodies: a strain-gauge drag balance, dimensions for struts made with machine or hand tools, and a procedure for correcting drag measurements for interference drag. 2. Interference drag can be measured by extrapolating a relationship between the drag of isolated struts with different crosssectional sizes and shapes and the drag of a body mounted on those struts. The interference length the length of an isolated strut that produces drag equal to the interference drag is a usefulquantity for predicting interference drag. 3. The relationship mentioned above is a straight line for a model peregrine falcon (Falco peregrinus L.) body mounted on smooth struts struts with convex cross-sectional shapes ranging from streamlined to circular. This finding simplifies the determination of interference drag in three ways: (i) the line can be found from measurements with just two struts a standard strut with low drag and a calibration strut with high drag; (ii) the two struts need not have the same shape for example, the standard strut can be changed to a calibration strut by attaching a spoiler without disturbing the body mounted on the strut and (iii) a single value of interference length (33.1mm) describes smooth struts with a range of shapes and sizes. These struts had drag coefficients between 0.33 and 0.91 at Reynolds numbers between 2100 and 10800. 4. The interference length of a strut supporting the actual falcon body with a feathered surface is not significantly different from that of the strut supporting the model body with a rigid surface. 5. As a hypothesis, interference length (hI, in metres) of a smooth strut varieswith the size of the body mounted on it: hI=0.0365m0.333 where m is the body mass (in kg) of the intact bird.


Author(s):  
T.B. Ball ◽  
W.M. Hess

It has been demonstrated that cross sections of bundles of hair can be effectively studied using image analysis. These studies can help to elucidate morphological differences of hair from one region of the body to another. The purpose of the present investigation was to use image analysis to determine whether morphological differences could be demonstrated between male and female human Caucasian terminal scalp hair.Hair samples were taken from the back of the head from 18 caucasoid males and 13 caucasoid females (Figs. 1-2). Bundles of 50 hairs were processed for cross-sectional examination and then analyzed using Prism Image Analysis software on a Macintosh llci computer. Twenty morphological parameters of size and shape were evaluated for each hair cross-section. The size parameters evaluated were area, convex area, perimeter, convex perimeter, length, breadth, fiber length, width, equivalent diameter, and inscribed radius. The shape parameters considered were formfactor, roundness, convexity, solidity, compactness, aspect ratio, elongation, curl, and fractal dimension.


2020 ◽  
Vol 2 (2) ◽  
pp. 08-15
Author(s):  
Rahma Triyana ◽  
Salmi Salmi

Malaria is one of the health problems in Indonesia, especially West Sumatra. Determination of the description of Malaria disease in an area is needed to determine the spread and severity of the disease. This study aims to determine the frequency distribution according to age, sex and place of residence, description of the types of Plasmodium causes of Malaria and hematological features in Malaria patients at Siti Rahmah Padang Hospital in 2018. This type of research is a descriptive observational study with an approach or design cross section (cross sectional). The frequency distribution of Malaria sufferers in Siti Rahmah Padang Hospital in 2018 according to the highest age was in the age group 21-30 years as many as 28 cases (36.8%), the highest sex among men was 46 (60.5%) and the highest number of residences was found in Koto Tangah sub-district there were 31 cases (40.8%). The type of Plasmodium found in Malaria cases in Siti Rahmah Padang Hospital in 2018 was P. vivax (73 cases (96.05%)) and P. falciparum (3 cases (3.95%)). The results of laboratory tests on Hb, hematocrit, platelet and leukocyte levels in Malaria positive patients in Siti Rahmah Padang Hospital in 2018 were in the normal range.


2020 ◽  
Vol 2 (2) ◽  
pp. 08-15
Author(s):  
Rahma Triyana Y ◽  
Salmi Salmi

Malaria is one of the health problems in Indonesia, especially West Sumatra. Determination of the description of Malaria disease in an area is needed to determine the spread and severity of the disease. This study aims to determine the frequency distribution according to age, sex and place of residence, description of the types of Plasmodium causes of Malaria and hematological features in Malaria patients at Siti Rahmah Padang Hospital in 2018. This type of research is a descriptive observational study with an approach or design cross section (cross sectional). The frequency distribution of Malaria sufferers in Siti Rahmah Padang Hospital in 2018 according to the highest age was in the age group 21-30 years as many as 28 cases (36.8%), the highest sex among men was 46 (60.5%) and the highest number of residences was found in Koto Tangah sub-district there were 31 cases (40.8%). The type of Plasmodium found in Malaria cases in Siti Rahmah Padang Hospital in 2018 was P. vivax (73 cases (96.05%)) and P. falciparum (3 cases (3.95%)). The results of laboratory tests on Hb, hematocrit, platelet and leukocyte levels in Malaria positive patients in Siti Rahmah Padang Hospital in 2018 were in the normal range.


2020 ◽  
Vol 0 (4) ◽  
pp. 19-24
Author(s):  
I.M. UTYASHEV ◽  
◽  
A.A. AITBAEVA ◽  
A.A. YULMUKHAMETOV ◽  
◽  
...  

The paper presents solutions to the direct and inverse problems on longitudinal vibrations of a rod with a variable cross-sectional area. The law of variation of the cross-sectional area is modeled as an exponential function of a polynomial of degree n . The method for reconstructing this function is based on representing the fundamental system of solutions of the direct problem in the form of a Maclaurin series in the variables x and λ. Examples of solutions for various section functions and various boundary conditions are given. It is shown that to recover n unknown coefficients of a polynomial, n eigenvalues are required, and the solution is dual. An unambiguous solution was obtained only for the case of elastic fixation at one of the rod’s ends. The numerical estimation of the method error was made using input data noise. It is shown that the error in finding the variable crosssectional area is less than 1% with the error in the eigenvalues of longitudinal vibrations not exceeding 0.0001.


2017 ◽  
pp. 35-44
Author(s):  
Dinh Toan Nguyen

Background: Studies show that diabetes mellitus is the greatest lifestyle risk factor for dementia. Appropriate management and treatment of type 2 diabetes mellitus could prevent the onset and progression of mild cognitive impairment to dementia. MoCA test is high sensitivity with mild dementia but it have not been used and studied widespread in Vietnam. Aim: 1. Using MoCA and MMSE to diagnose dementia in patients with type 2 diabetes mellitus. 2. Assessment of the relationship between dementia and the risk factors. Methods: cross-sectional description in 102 patients with type 2 diabetes mellitus. The Mini-Mental State Examination(MMSE) and the Montreal Cognitive Assessment (MoCA) were used to assess cognitive function. The diagnosis of dementia was made according to Diagnostic and Statistical Manual of Mental Disorders. Results: The average value for MoCA in the group of patients with dementia (15.35 ± 2.69) compared with non-dementia group (20.72 ± 4.53). The sensitivity and specificity of MoCA were 84.8% and 78.3% in identifying individuals with dementia, and MMSE were 78.5% and 82.6%, respectively. Using DSMIV criteria as gold standard we found MoCA and MMSE were more similar for dementia cases (AUC 0.871 and 0.890). The concordance between MoCA and MMSE was moderate (kappa = 0.485). When considering the risk factors, the education,the age, HbA1c, dyslipidemia, Cholesterol total related with dementia in the type 2 diabetes. Conclusion: MoCA scale is a good screening test of dementia in patients with type 2 diabetes mellitus.When compared with the MMSE scale, MoCA scale is more sensitive in detecting dementia. Key words: MoCA, dementia, type 2 diabetes mellitus, risk factors


2016 ◽  
pp. 7-11
Author(s):  
Vinh Phu Hoang ◽  
Tam Vo ◽  
Van Tien Le ◽  
Thi Hoai Huong Vo

Objective: To review disorders elements of the metabolic syndrome in patients with end-stage chronic renal failure on dialysis cycle. Materials and methods: A cross sectional descriptive study of 85 patients including end-stage chronic renal failure in dialysis cycle from 5/2015 - 9/2016 at the Department of Artificial Kidney, Hue Central Hospital. Results: The prevalence of metabolic syndrome in dialysis patients was 37.65%. The prevalence of abdominal obesity was 30.6%; The prevalence of hypertension was 72.9%, the average value systolic blood pressure and diastolic blood pressure were 142.24 ± 27.53, 80.35 ± 12.48 mmHg; The prevalence of hyperglycemia was 28%, the average value blood glucose was 4.9 ± 1.19 mmol/l; The prevalence of triglyceride increase was 34.1%, the average value triglyceride was 1.59 ± 0.84 mmol/l. The prevalence of HDL-C increase was 47.1%, the average value HDL-C was 1.24 ± 0.33 mmol/l. Conclusion: The prevalence of metabolic syndrome in dialysis patients is very high, in which hypertension and HDL disturbances are the highest. Key words: chronic renal failure, dialysis, metabolic syndrome


1968 ◽  
Vol 51 (4) ◽  
pp. 752-755
Author(s):  
Edward L Pratt ◽  
Morris E Auerbach

Abstract Raceophenidol in feed at concentration levels intended for growth promotion of poultry can be estimated by a curvature inversion measurement related to the ultraviolet spectrum of derived p-methylsulfonylbenzaldehyde. The drug can be accurately measured at the 0.0005% level. Collaborative studies on the method showed an average value of 94 ± 10% of claim. The method is recommended for adoption as official, first action.


2015 ◽  
Vol 72 (2) ◽  
pp. 123-131 ◽  
Author(s):  
Marko Igic ◽  
Nebojsa Krunic ◽  
Ljiljana Aleksov ◽  
Milena Kostic ◽  
Aleksandra Igic ◽  
...  

Background/Aim. The vertical dimension of occlusion is a very important parameter for proper reconstruction of the relationship between the jaws. The literature describes many methods for its finding, from the simple, easily applicable clinically, to quite complicated, with the use of one or more devices for determination. The aim of this study was to examine the possibility of determining the vertical dimension of occlusion using the vocals ?O? and ?E? with the control of values o btained by applying cognitive functions. Methods. This investigation was performed with the two groups of patients. The first group consisted of 50 females and 50 males, aged 18 to 30 years. In this group the distance between the reference points (on top of the nose and chin) was measured in the position of the mandible in the vertical dimension of occlusion, the vertical dimension at rest and the pronunciation of the words ?OLO? and ?ELE?. Checking the correctness of the particular value for the word ?OLO? was also performed by the phonetic method with the application of cognitive exercises when the patients counted from 89 to 80. The obtained difference in the average values i n determining the vertical dimension of occlusion and the ?OLO? and ?ELE? in the first group was used as the reference for determining the vertical dimension of occlusion in the second group of patients. The second group comprised of 31 edentulous persons (14 females and 17 males), aged from 54 to 85 years who had been made a complete denture. Results. The average value obtained for the vertical dimension of rest for the entire sample was 2.16 mm, for the word ?OLO? for the entire sample was 5.51 mm and for the word ?ELE? for the entire sample was 7.47 mm. There was no statistically significant difference between the genders for the value of the vertical dimension at rest, ?ELE? and ?OLO?. There was a statistically significant difference between the values f or the vertical dimension at rest, ?OLO? and ?ELE? for both genders. There was a statistically significant correlation between the value for the vertical dimension at rest, ?OLO? and ?ELE?, for both groups of subjects. Conclusion. Determining the vertical dimension of occlusion requires 5.5 mm subtraction from the position of the mandible in pronunciation of the word ?OLO? or 7.5 mm in pronunciation of the word ?ELE?.


Author(s):  
Katharina Kerschan-Schindl ◽  
Ursula Föger-Samwald ◽  
Andreas Gleiss ◽  
Stefan Kudlacek ◽  
Jacqueline Wallwitz ◽  
...  

Summary Background Circulating serum sclerostin levels are supposed to give a good estimation of the levels of this negative regulator of bone mass within bone. Most studies evaluating total serum sclerostin found different levels in males compared to females and in older compared to younger subjects. Besides an ELISA detecting total sclerostin an ELISA determining bioactive sclerostin has been developed. The aim of this study was to investigate serum levels of bioactive sclerostin in an Austrian population-based cohort. Methods We conducted a cross-sectional observational study in 235 healthy subjects. Using the bioactive ELISA assay (Biomedica) bioactive sclerostin levels were evaluated. Results Serum levels of bioactive sclerostin were higher in men than in women (24%). The levels correlated positively with age (r = 0.47). A positive correlation could also be detected with body mass index and bone mineral density. Conclusion Using the ELISA detecting bioactive sclerostin our results are consistent with data in the literature obtained by different sclerostin assays. The determination of sclerostin concentrations in peripheral blood thus appears to be a robust parameter of bone metabolism.


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