Cross-Sectional Texture Gradients in Interstitial Free Steels Processed by Accumulated Roll Bonding

2005 ◽  
Vol 105 ◽  
pp. 233-238 ◽  
Author(s):  
Ana Carmen C. Reis ◽  
Leo Kestens
Keyword(s):  
Plane Strain ◽  
True Strain ◽  
Orientation Imaging Microscopy ◽  
Lamellar Microstructure ◽  
Annealing Treatment ◽  
Rolled Sheet ◽  
Interstitial Free ◽  
Cross Sectional ◽  
Roll Bonding ◽  
Significant Difference

An interstitial-free steel was severely plastically deformed in an accumulative roll bonding (ARB) experiment with 10 consecutive passes applied at 480°C. Nominal reductions of 50% per pass and an intermediate annealing treatment of 5 min. at 520°C were employed. A total true strain of evM = 8.00 was applied, which corresponds to an accumulated reduction of 99.9%. The evolution of texture and microstructure was monitored by means of orientation imaging microscopy. A lamellar microstructure, characteristic of severely rolled sheet materials, was observed even after the highest strains. The average lamellar width was determined as a function of rolling strain. Under the experimental limitations in terms of spatial resolution, no significant difference was observed between the average lamellar width in the mid-section and near the surface of the sheet. Texture analysis revealed a conventional cross-sectional gradient with plane strain rolling components in the mid-layers and shear components in the subsurface regions. Although these different strain modes did not affect the microstructure in terms of the average lamellar spacing, an effect was observed on the average aspect ratio of the grains. This was much higher in the sheared (surface) layers than in the plane strain compressed (centre) areas. The surface structure did not have an effect, though, on the bulk microstructural evolution in spite of the specific nature of the ARB process during which the surface layer of one pass reappears in the mid-section of the next pass.

Lamellar Subdivision during Accumulative Roll Bonding of a Titanium Interstitial Free Steel

2005 ◽  
Vol 495-497 ◽  
pp. 351-356 ◽  
Author(s):  
Ana Carmen C. Reis ◽  
Leo Kestens ◽  
Yvan Houbaert
Keyword(s):  
Shear Strain ◽  
Accumulative Roll Bonding ◽  
Rolling Direction ◽  
Orientation Imaging Microscopy ◽  
Lamellar Microstructure ◽  
Composite Sample ◽  
Interstitial Free ◽  
High Angle ◽  
Roll Bonding ◽  
Interstitial Free Steel

Titanium alloyed interstitial free steel was processed by means of accumulative roll bonding (ARB) in order to obtain an ultrafine grained structure. Ten consecutive rolling passes were applied at 480°C with a nominal reduction of 50% per pass and an intermediate annealing treatment of 5 min. at 500°C. A total true strain was obtained of evM = 8.0 which corresponds to an accumulated reduction of 99.9%. Orientation imaging microscopy was used to evaluate textures and microstructures. A pronounced lamellar structure was observed until the 5th pass with an incidence of high angle grain boundaries predominantly parallel to the rolling direction. After the 6th pass (evM = 4.8) an increased fragmentation perpendicular to the rolling direction starts to develop in spite of the lamellar microstructure with an average spacing of approximately 1 µm. From the 7th pass onwards (evM ≥ 5.6) a random high angle grain boundary distribution develops which results in a more equi-axed ultrafine microstructure after the 9th pass (evM = 7.2) with an average grain width of 200 nm. As the rolling is carried out without lubrication, the surface areas display a slightly more fragmented structure than the midlayer sections and typical shear texture components are present in these surface zones (<110>//ND and <211>//ND fibre). Although the sheets are stacked upon each other after each subsequent pass, the shear strain microstructural and textural features are rapidly decomposed in the midlayer in each subsequent rolling pass which is clearly revealed by the cross sectional orientation scan on the composite sample. Hence it cannot be concluded that the surface shear strain significantly contributes to the grain fragmentation in the bulk volume of the composite sample.

Evaluation of stored energy after accumulative roll bonding of an interstitial-free steel by means of orientation microscopy data

2005 ◽  
Vol 38 (4) ◽  
pp. 668-674 ◽  
Author(s):  
K. Lee ◽  
A. C. C. Reis ◽  
G. Kim ◽  
L. Kestens
Keyword(s):  
Accumulative Roll Bonding ◽  
Cellular Network ◽  
Boundary Energy ◽  
Orientation Imaging Microscopy ◽  
Radius Of Curvature ◽  
Interstitial Free ◽  
Stored Energy ◽  
Roll Bonding ◽  
Local Boundary ◽  
Von Mises

The stored energy of warm-rolled interstitial-free steels, produced in an accumulative roll bonding process, is evaluated by using the textural and microstructural information contained in orientation imaging microscopy (OIM) scans which were measured after accumulated von Mises strains (∊vM) of 0.8, 1.6, 2.4 and 4.0, respectively. It is assumed that the plastic strain energy is stored in a cellular network of local boundaries of low and high misorientations. The presence of intracellular dislocations which do not contribute to a local crystal orientation gradient is ignored in the present analysis. On the basis of the Read–Shockley equation, the local misorientation can be associated with a local boundary energy which can be expressed as a local stored energy by taking into account the radius of curvature of the cellular network. The validity of this procedure was verified by comparing the integrated average stored energy of the sample with the Vickers hardness data, which produced a reasonable correspondence. The present analysis also allowed the calculation of the stored energy distribution in the areas of the orientation representation space which were sufficiently populated by sample crystal orientations,i.e.the γ fibre (〈111〉||ND) of the present deformation texture. The distribution of stored energy along this fibre displayed a maximum on the {111}〈211〉 texture component, particularly after a von Mises strain of 1.6, whereas the {111}〈110〉 component displayed a local minimum of stored energy after ∊vM= 2.4 and 4.0.

Personal Audio System: Hearing Symptoms, Habits, and Sound Pressure Levels Measured in Real Ear and a Manikin

2020 ◽  
Vol 63 (6) ◽  
pp. 2016-2026
Author(s):  
Tamara R. Almeida ◽  
Clayton H. Rocha ◽  
Camila M. Rabelo ◽  
Raquel F. Gomes ◽  
Ivone F. Neves-Lobo ◽  
...  
Keyword(s):  
Sound Pressure ◽  
Daily Basis ◽  
Cross Sectional Study ◽  
Normal Hearing ◽  
Chi Square ◽  
Cross Sectional ◽  
The Real ◽  
Significant Difference ◽  
Sound Pressure Levels ◽  
Audio System

Purpose The aims of this study were to characterize hearing symptoms, habits, and sound pressure levels (SPLs) of personal audio system (PAS) used by young adults; estimate the risk of developing hearing loss and assess whether instructions given to users led to behavioral changes; and propose recommendations for PAS users. Method A cross-sectional study was performed in 50 subjects with normal hearing. Procedures included questionnaire and measurement of PAS SPLs (real ear and manikin) through the users' own headphones and devices while they listened to four songs. After 1 year, 30 subjects answered questions about their usage habits. For the statistical analysis, one-way analysis of variance, Tukey's post hoc test, Lin and Spearman coefficients, the chi-square test, and logistic regression were used. Results Most subjects listened to music every day, usually in noisy environments. Sixty percent of the subjects reported hearing symptoms after using a PAS. Substantial variability in the equivalent music listening level (Leq) was noted ( M = 84.7 dBA; min = 65.1 dBA, max = 97.5 dBA). A significant difference was found only in the 4-kHz band when comparing the real-ear and manikin techniques. Based on the Leq, 38% of the individuals exceeded the maximum daily time allowance. Comparison of the subjects according to the maximum allowed daily exposure time revealed a higher number of hearing complaints from people with greater exposure. After 1 year, 43% of the subjects reduced their usage time, and 70% reduced the volume. A volume not exceeding 80% was recommended, and at this volume, the maximum usage time should be 160 min. Conclusions The habit of listening to music at high intensities on a daily basis seems to cause hearing symptoms, even in individuals with normal hearing. The real-ear and manikin techniques produced similar results. Providing instructions on this topic combined with measuring PAS SPLs may be an appropriate strategy for raising the awareness of people who are at risk. Supplemental Material https://doi.org/10.23641/asha.12431435

Parent’s Experiences from the Treatment of their Children at the Physic Children’s Surgery Clinic in Skopje.

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
M. Trajchevska ◽  
A. Lleshi ◽  
S. Gjoshev ◽  
A. Trajchevski
Keyword(s):  
Health Care ◽  
Health Status ◽  
Independent Predictor ◽  
Demographic Data ◽  
Parental Satisfaction ◽  
Pediatric Care ◽  
Simple Random Sample ◽  
Significant Independent Predictor ◽  
Cross Sectional ◽  
Significant Difference

Background: The respect of the needs and wishes of the patients is in the focus of the human health system. The experience of the parents in terms of child’s health care may be used as an indicator of quality of the health care. Material and methods: The research is a quantitative analytical cross-sectional study. In accordance with the inclusion and exclusion criteria, simple random sample of 207 parents / guardians is covered, whose children in the period of three months, had been hospitalized in the hospital department JZUU Pediatric Surgery Clinic in Skopje.It was used a two parted questionnaire. The first part is a standardized questionnaire (Parent Experience of Pediatric Care - PECP), and the second part concerns the general socio-demographic data of the parent/guardian. Statistical evaluation was performed using appropriate statistical programs (Statistics for Windows 7,0 and SPSS 17.0). Results: In accordance with the age of the parents, the survey respondents were divided into two groups: a) age ≤ 33 years - 107 (51.69%) and b) age> 33 years - 100 (48.31%).Significant independent predictor of parental satisfaction from the receipt of their child to the clinic research confirms the age of the parent under / over 33 years due to 4.1% of the change in satisfaction (R2 = 0,041). Parents generally believe that their children's room of the clinic is "good", without significant difference between parental satisfaction from both age groups (Mann-Whitney U Test Z = -0,9613 p = 0,3364). Significant independent predictor of parental satisfaction from the room of their child improves the health status after treatment due to 6% of the change in satisfaction (R2 = 0,060). Parents generally believe that testing and treatment of their children in the clinic was "very good" and an independent significant predictor is to improve the health status after the treatment - 7,8% (R2 = 0,078). Conclusions: Regardless of the generally good parental satisfaction about health care for their children, it is necessary to continuously monitor the status of the clinic in order to consider the possible deficiencies and needs of intervention.

AWARENESS ABOUT INDOOR AIR POLLUTION IN GENERAL POPULATION OF RAWALPINDI AND ISLAMABAD

2018 ◽  
Vol 8 (2) ◽  
pp. 80-83
Author(s):  
Nadia Tariq ◽  
Tamkeen Jaffry ◽  
Rahma Fiaz ◽  
Abdul Majid Rajput ◽  
Sadaf Khalid
Keyword(s):  
Air Pollution ◽  
General Population ◽  
Indoor Air ◽  
Indoor Air Pollution ◽  
Economic Status ◽  
Educational Status ◽  
Epidemiological Studies ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Significant Difference

Background: Indoor air pollutants are increasingly being associated with respiratory illnesses leading to high degree of morbidity and mortality. There are not sufficient epidemiological studies from Pakistan which assess level of awareness of indoor air pollution resulting in respiratory diseases in population. Methods: This cross sectional survey was carried out on general population of Rawalpindi/Islamabad. Sample size was 223 study subjects selected by non-probability convenient sampling. Knowledge of the study subjects was determined with regard to indoor air pollution, its effects on health and different sources of indoor air pollution with the help of a questionnaire. The influence of age, gender, educational status and socio economic status on the level of awareness was also analyzed. Results: Out of total 223 participants, 115 were males and108 females. Participants aware of indoor air pollution were 91.5% and adequate awareness about its sources was 80.7%. Those who knew indoor air pollution is detrimental to health were 95.1%. Awareness about building construction dust as source of indoor air pollution was maximum (84.8%). There was significant difference in awareness among participants with different monthly incomes and educational status and also between males and females. Conclusion: This study concludes that general population of Rawalpindi/Islamabad has fairly good awareness about sources of indoor air pollution. Use of harmful material causing indoor air pollution should be limited or substituted with better ones where possible.

Estimation of Trace Elements in Gingival Crevicular Fluid and Serum-Comparative Study in Healthy and Periodontitis

2017 ◽  
Vol 9 (5) ◽  
Author(s):  
Bhagavathami Meenaksh ◽  
Chitraa R. Chandran ◽  
Aravindhan Thathchari Ranganathan ◽  
Kavindapadi Venkateswaran Rama ◽  
Valarmathy Srinivasan
Keyword(s):  
Trace Elements ◽  
Inductively Coupled Plasma ◽  
Gingival Crevicular Fluid ◽  
Serum Zinc ◽  
Cross Sectional Study ◽  
Serum Copper ◽  
Cross Sectional ◽  
Inductively Coupled ◽  
Significant Difference ◽  
Copper Zinc

Background: This study aims to determine and compare the levels of trace elements copper, zinc, selenium and chromium in GCF and serum of patients with periodontitis and healthy individuals. Methods: This cross sectional study includes 24 study subjects recruited from the patients reporting to the Department of Periodontics , Tagore Dental College Chennai. All the selected patients were subjected to a clinical examination done by a single examiner. The estimation of trace elements Copper, Zinc, Selenium and Chromium in GCF and serum is performed using Perkin Elmer optima 5300 Inductively Coupled Plasma Emission Spectrometer (ICPOES). Results: GCF and serum copper levels showed no significant difference in both periodontitis and healthy groups . Selenium levels tend to be the same in both groups. Serum zinc levels are more in periodontitis patients than healthy subjects (p less than 0.01). GCF chromium levels are found to be more in patients with periodontitis than healthy. Conclusions : More research is therefore needed to monitor the role of these trace elements C with an increased sample size to ascertain whether they are associated with a reduced risk of periodontitis.

Clinical-Reported Outcomes Of Deferoxamine Versus Deferasirox In The Treatment Of Homozygous BetaThalassemia

2018 ◽  
Vol 9 (SPL1) ◽  
Author(s):  
Zeina A Munim Al-Thanoon ◽  
Zeina A Munim Al-Thanoon ◽  
Mustafa Basil ◽  
Nasih A Al-Kazzaz
Keyword(s):  
Serum Ferritin ◽  
Iron Chelation ◽  
Iron Chelator ◽  
Beta Thalassemia ◽  
Control Group ◽  
Current Standard ◽  
Cross Sectional ◽  
Significant Difference ◽  
Multiple Blood ◽  
Group 2

Iron chelation therapy with deferoxamine (DFO),the current standard for the treatment of iron overload in patients with betathalassemia,requires regular subcutaneous or intravenous infusions. This can lead to reduced quality of life and poor adherence,resulting in increased morbidity and mortality in iron-overloaded patients with beta-thalassemia. Deferasirox (DFX) is an orally administered iron chelator that has been approved for use in many countries. The requirement of an effective,well tolerated iron chelator with a less demanding mode of administration has led to the development of deferasirox. The present study was aimed to compare the satisfaction and compliance with deferoxamine versus deferasirox (Exjade®),a novel oral iron chelator in patients with transfusion - dependent beta- thalassemia. A cross-sectional,single-center investigation study was carried out in the Thalassemia Center of Ibn-Atheer Teaching Hospital in Nineveh province,Iraq. One hundred and eight thalassemic patients aged between 2- 20 years old having received multiple blood transfusions and a serum ferritin greater than 1500 ng/ml. Patients were randomised into two groups. Group 1 received deferoxamine at a dose of 20-50mg/kg/day and group 2 received deferasirox at the dose of 10-30 mg/kg/day. Another 56 apparently healthy volunteers were used as a control group. The assessment of chelation was done during the period between November 2013 and February 2014 by measurement of serum ferritin. Satisfaction and compliance was assessed by using a special questionnaire prepared by the researcher. Out of the 108 thalassemic patients enrolled there was no discontinuation in treatment with the two drugs under study. The serum ferritin did not change significantly in any of the chelation groups. In comparison with the patients who were treated with DFO,those receiving DFX reported a significantly higher rate of compliance and satisfaction (P < 0.05). However,no significant difference was observed between the two groups regarding their satisfaction (P > 0.05).Compliance with deferasirox (50 %) was more than that with deferoxamine (20 %). Satisfaction with deferoxamine was significantly lower than deferasirox (p= 0.00).

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.

Postpartum Depression and Its Associated Factors among Women in Bandar Abbas City

2018 ◽  
Vol 7 ◽  
Author(s):  
Arefeh Shahi
Keyword(s):  
Postpartum Depression ◽  
Associated Factors ◽  
Parental Education ◽  
Unwanted Pregnancy ◽  
Routine Care ◽  
Cross Sectional Study ◽  
Vulnerable Groups ◽  
Cross Sectional ◽  
Significant Difference ◽  
Bandar Abbas

Background: Postpartum depression with a different incidence of 40- 45% in different societies, which it has adverse effects on the health of mothers and their child, given the negative effects of maternal depression and its harmful effects on the baby and the quality of family life. So, this study was performed with the aim to determine postpartum depression and its associated factors in Bandar Abbas city. Materials and Methods: A descriptive cross-sectional study was conducted in 2015 after obtaining consent from mothers by the census. A total of 343 mothers was examined for depression who referred to Bandar Abbas health centers in the 2nd and 4th months after childbirth. The data collection tools included demographic information and Postpartum Depression Edinburgh questionnaires. Finally, the statistical analyses were performed using SPSS (version 22.0) software and data were analyzed using the Independent t-test, Mann Whitney, Chi-square, and Fisher exact tests.Result: Totally, 68 (19.8%) of samples were in the second month and 54 (15.7%) in the fourth month after delivery had postpartum depression. The incidence of depression in the four months was 6.6%. There was a significant difference between depression and income, parental education, father’s use of cigarette and abnormalities of the infant (P <0.001). There was no significant difference between other factors such as gestational age, infant sex, birth weight, unwanted pregnancy, and type of delivery. Conclusion: Regarding the prevalence of this disorder, it seems that postpartum depression screening planning should be considered during child routine care as an essential component, especially for vulnerable groups.

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