Side Milling of Helical End Mill Oscillated in Axial Direction with Ultrasonic Vibration

2019 ◽  
Vol 13 (1) ◽  
pp. 22-31 ◽  
Author(s):  
Hiroyasu Iwabe ◽  
Mitunori Hiwatashi ◽  
Masahiko Jin ◽  
Hidenari Kanai ◽  
◽  
...  
Keyword(s):  
Cutting Force ◽  
Ultrasonic Vibration ◽  
Axial Direction ◽  
Mean Value ◽  
Machined Surface ◽  
Cross Sectional ◽  
Side Milling ◽  
Chip Area ◽  
The Mean ◽  
Conventional Machining

This paper is focused on the cutting performance in the side milling of a small-size end mill with vibrations generated by an ultrasonic vibration spindle apparatus in the axial direction with a helix edge. In side milling with ultrasonic vibration in the rotational direction, the mean value of the cross-sectional chip area per cutting time decreases owing to the frequent repetition of the cutting and non-cutting phases. As a result, the cutting force decreases and provides an optimal cutting performance as compared to that in conventional side milling. First, the cross-sectional chip area is calculated using three-dimensional computer aided design (CAD) with its mean value relative to the cutting time. The ultrasonic vibration spindle apparatus is then attached to the machine spindle, and cutting tests are performed for conventional and ultrasonic vibration machining. Next, the flank wear, surface roughness, cutting force, and residual stress are measured. The results obtained from the cutting tests of the two machining methods are compared. The main results are as follows: (1) A comparison of the flank wears of conventional machining and ultrasonic vibration machining shows that the former is larger than the latter. The maximum flank wear increases as the cutting length increases for both the machining methods. (2) The maximum height of the machined surface in ultrasonic vibration machining is larger than that in conventional machining because of the marks caused by ultrasonic vibration. (3) The mean cross-sectional chip area relative to the cutting time decreases with ultrasonic vibration machining and the tool deformation decreases with a decrease in the mean cutting force relative to the cutting time. (4) With ultrasonic vibration machining, residual stress is generated on the machined surface not only in the feed direction but also in the axial direction because of the repetitive sliding actions in the axial direction of the flank of the cutting edge.

scholarly journals Dietary acrylamide intake by potato crisps consumers: A case of Nairobi County

2020 ◽  
Vol 5 (1) ◽  
pp. 871-878
Author(s):  
George Ooko Abong ◽  
Jackline Akinyi Ogolla ◽  
Michael Wandayi Okoth ◽  
Bruno De Meulenaer ◽  
Jackson Ntongai Kabira ◽  
...  
Keyword(s):  
Probabilistic Approach ◽  
Mean Value ◽  
Mitigation Measures ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Potato Crisps ◽  
Flame Ionization ◽  
Consumption Data ◽  
Dietary Acrylamide ◽  
The Mean

AbstractThe levels of acrylamide intake because of potato crisps consumption remains unknown in Kenyan context. This study assessed the exposure to acrylamide because of consumption of potato crisps in Nairobi, Kenya. A cross-sectional survey was carried out among 315 crisps consumers in Nairobi, and consumption patterns were collected using a pre-tested structured 7-day recall questionnaire. A total of 43 branded and 15 unbranded potato crisps samples were purchased in triplicates of 100 g and acrylamide was quantified using a gas chromatograph with a flame ionization detector. Consumption data were combined with the data on acrylamide contents from which dietary acrylamide intake was calculated using a probabilistic approach based on @Risk TopRank 6 risk analysis software for excel. The mean estimated acrylamide intake was 1.57 µg/kg body weight (BW) per day while the 95th (P95) percentile was 5.1 µg/kg BW per day, with margins of exposures (MOE) being 197 and 61, respectively. The intake of acrylamide was significantly (P < 0.05) higher in unbranded crisps with a mean value of 2.26 and 95th percentile of 6.54 µg/kg BW per day, MOE being 137 and 47, respectively. There were extremely lower MOE indicating higher exposure to acrylamide by the consumers mainly because of the higher acrylamide contents in potato crisps, and hence the need for mitigation measures.

scholarly journals Oral contraceptive among risk factors for women with ischemic stroke

2021 ◽  
Vol 12 (1) ◽  
pp. 548
Author(s):  
Carla S. PALUDO ◽  
Amanda SACHETTI ◽  
Maiara S. PAIXÃO
Keyword(s):  
Risk Factors ◽  
Ischemic Stroke ◽  
Oral Contraceptive ◽  
Oral Contraceptives ◽  
Contraceptive Use ◽  
Cross Sectional Study ◽  
Mean Value ◽  
Northern Region ◽  
Cross Sectional ◽  
The Mean

Objective: To evaluate the frequency of use of oral contraceptives and other risk factors among women with ischemic stroke seen at a hospital in the northern region of the state of Rio Grande do Sul. Methods: Prospective, cross-sectional study. The population was characterized by patients admitted with a diagnosis of ischemic stroke during a period from March to August 2019 and the sample by female patients found in the population. The data were collected through an individual interview using a questionnaire developed by the researchers and tabulated for further analysis. All analyzes were performed using the statistical program Bioestat 5.0, considering p = 0.05. Results: In the characterization of the sample, an average age of 68.2 years was observed. The occurrence of gender was 52.4% for women. The mean hospital stay was 12.2 ± 8.91 days. Outcome of hospital discharge was 89.1%. The mean value of body mass index was 25 ± 4.89 kg / m², with an average of 27.4 kg / m² in patients who used oral contraceptives and 25.23 kg / m² in patients who did not use oral contraceptives. The sample had a 34.5%incidence of oral contraceptive use. The average age of those who used oral contraceptives was 62.4 years and of the patients who did not use it was 70.3 years. Conclusion: The study showed a high use of oral contraceptives in the sample, with percentage values very close to other factors evaluated, thus showing itself as a probable risk factor for the development of ischemic stroke.

scholarly journals Facteurs Épidémiologiques et Pronostiques Associés Aux Étiologies Des Hémorragies Digestives Hautes au CHU Campus de Lomé

2021 ◽  
Vol 17 (34) ◽  
pp. 44
Author(s):  
Aklesso Bagny ◽  
Lidawu Roland-Moise Kogoe ◽  
Laconi Yeba Kaaga ◽  
Late Mawuli Lawson-Ananissoh ◽  
Debehoma Redah ◽  
...  
Keyword(s):  
Teaching Hospital ◽  
Cross Sectional Study ◽  
Mean Value ◽  
Peptic Ulcers ◽  
Gi Bleeding ◽  
Cross Sectional ◽  
Hémorragies Digestives ◽  
Upper Gi Bleeding ◽  
Upper Gi ◽  
The Mean

Objectif : Décrire les aspects épidémiologique, clinique et pronostique associés aux étiologies des hémorragies digestives hautes au CHU Campus de Lomé Patients et méthode: Etude transversale à collecte rétrospective, à visée descriptive et analytique menée du 1er Janvier 2014 au 31 Décembre 2019. Le seuil de significativité était retenu pour p<0,05. Résultats: Deux cent cinquante et un patients avaient été inclus. L’hémorragie était d’origine hypertensive portale chez 69 patients (27,71%) ; ulcéreuse gastro-duodénale chez 100 patients (39,84%). Chez 25 patients (9,96%), la fibroscopie oesogastroduodénale était normale. Une rupture de varices oesophagiennes était retrouvée chez 98,55% des patients présentant une hypertension portale. Les ulcères gastroduodénaux représentaient 54,94% des hémorragies digestives hautes d’origine non hypertensive portale. La valeur moyenne du score de Rockall était de 4(±1) chez les patients présentant une hémorragie d’origine hypertensive et de 3(±1) chez les patients avec hémorragie non hypertensive portale (p<0,001). La valeur moyenne du score de Glasgow-Blatchford était de 10(±3) chez les patients présentant une hémorragie d’origine hypertensive et 9(±3) chez les patients avec hémorragie digestive haute d’origine non hypertensive (p<0,001). La récidive hémorragique et le décès étaient survenus chez les patients présentant un saignement d’origine hypertensive portale dans respectivement 54,84% (p<0,001) et 71,42% (p<0,001). Conclusion: Les lésions inflammatoires aiguës et chroniques représentent la première étiologie des hémorragies digestives hautes dans le service d’Hépato-gastroentérologie du CHU Campus. Ces hémorragies sont associées à la prise de médicaments gastrotoxiques et à un moindre risque de récidive hémorragique et de décès. Objective: To describe epidemiological et prognostic outcomes associated with etiologies upper gastrointestinal bleeding in Campus Teaching Hospital of Lome Patients and method: Cross-sectional study with retrospective collection, descriptive and analytical aim carried out from January 1, 2014 to December 31, 2019. Results: Two hundred and one patients were included. The hemorrhage was of portal hypertensive origin in 69 patients (27.71%); peptic ulcer in 100 patients (39.84%). In 25 patients (9.96%), the oesogastroduodenal fibroscopy was normal. Ruptured esophageal varices were found in 98.55% of patients with portal hypertension. Peptic ulcers accounted for 54.94% of upper GI bleeding of non-portal hypertensive origin. The mean value of the Rockall score was 4(±1) in patients with hemorrhage of hypertensive origin and 3(±1) in patients with non-portal hypertensive hemorrhage (p<0.001). The mean Glasgow-Blatchford score was 10(±3) in patients with hemorrhage of hypertensive origin and 9(±3) in patients with upper GI hemorrhage of nonhypertensive origin (p<0.001). Hemorrhagic recurrence and death occurred in patients with bleeding of hypertensive origin in 54.84% (p<0.001) and 71.42% (p<0.001) respectively. Conclusion: Acute and chronic inflammatory lesions represent the first etiology of upper GI bleeding in the Gastroenterology Department of the Campus Teaching Hospital of Lome. These hemorrhages are associated with the use of gastrotoxic drugs and with a lower risk of recurrence of hemorrhage and death.

scholarly journals Prevalence and predictors of dyslipidemia on HAART and HAART naive HIV positive clients attending Debre Tabor Hospital, Debre Tabor, Ethiopia

2021 ◽  
Author(s):  
Anemut Tilahun Mulu ◽  
Getachew Yideg Yitbarek ◽  
Fitalew Tadele Admasu ◽  
Chalachew Yenew Denekew ◽  
Biruk Demissie Melese
Keyword(s):  
Venous Blood ◽  
Cross Sectional Study ◽  
Mean Value ◽  
Anthropometric Measurement ◽  
Hiv Positive ◽  
Cross Sectional ◽  
Immunodeficiency Virus ◽  
Debre Tabor ◽  
The Mean ◽  
Cd4 Cell

Abstract Background: HAART has been reported to be associated with a number of side effects in human immunodeficiency virus patients among which dyslipidemia is a common metabolic disorder. Methods: A facility based comparative cross-sectional study among 228 HIV positive persons was conducted from July to August 2020. Socio-demographic and clinical data were collected using structured questionnaires. Fasting venous blood sample was drawn for Lipid profiles and CD4 cell determination. Anthropometric measurement was done. Data was analyzed using SPSS version 22 for windows. Result: A total of 228 HIV patients were enrolled in the study. Prevalence of dyslipidemia in HAART naive and on HAART HIV positive persons was 61(53.5%) and 84 (73.7%), respectively. The prevalence of TC≥200 mg/dl was 50% and 30%; HLD-c<40 mg/dl was 43.8% and 36%; LDL-c≥130mg/dl was 48.3% and 28.1%; and TG≥150 mg/dl 59.6% and 39% among on HAART and HAART naïve, respectively. Age greater than 40 years (AOR = 3.27, 95% C.I: 1.47 - 7.25), blood pressure ≥ 140/90 (AOR = 16.13, 95% C.I: 5.81 - 44.75), being on HAART (AOR = 2.73, 95 % C.I: 1.35 - 5.53) and body mass index > 25kg/m2 (AOR = 1.92, 95 % C.I: 1.20 - 4.81) were identified as determinants of dyslipidemia. Conclusion: The mean value of lipid profile was significantly higher among HIV positive clients on HAART as compared to those HAART naïve HIV positive clients.

scholarly journals Factors influencing the dental caries in pregnant women: a cross-sectional study

2021 ◽  
Vol 10 (1) ◽  
pp. e32810111226
Author(s):  
Gabriela Bohrer Bolsson ◽  
Jessica Klöckner Knorst ◽  
Marília Cunha Maroneze ◽  
Maísa Casarin ◽  
Patrícia Pasquali Dotto ◽  
...  
Keyword(s):  
Dental Caries ◽  
Pregnant Women ◽  
Basic Research ◽  
Cross Sectional Study ◽  
Mean Value ◽  
Sectional Study ◽  
Cross Sectional ◽  
The Mean ◽  
The City ◽  
Santa Maria

Objective: To assess factors associated with the average number of dental caries in pregnant women. Method: Basic research design: This cross-sectional study was performed between January 2017 and December 2018 in Santa Maria, Brazil. Clinical setting and participants: Multistage random sampling resulted in the recruitment of 256 pregnant women from public health centers across the city. Clinical exams and semi-structured questionnaires including demographic, socioeconomic and behavioral questions were performed by trained interviewers. Main outcome measure: The experience of dental caries was evaluated through the mean value of the Decay, Missing, and Filled Surface Index (DMFS) by 4 trained and calibrated examiners. Multilevel Poisson regression models were used to evaluate the influence of different variables on the average number of dental caries. Rate ratio (RR) and respective 95% confidence intervals were calculated (CI 95%). Results: The prevalence of untreated dental caries was 62.7% in the sample, while the mean DMFS index was 10.27 (± 10.92). Women who smoked during pregnancy had a higher mean DMFS (RR 1.41; 95% CI 1.25-1.57). Furthermore, pregnant women who had poor self-ratings of oral health had a higher average DMFS (RR 1.21; 95% CI 1.10-1.32). Conclusions: The results showed that older age, ethnicity, fewer years in education and the presence of dental plaque resulted in higher means of DMFS.

scholarly journals Secular trends in weight, height and weight for height among children under 7 years in nine cities of China, 1975–2015: results from five repeated cross-sectional surveys

BMJ Open ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. e029201 ◽  
Author(s):  
Ya Qin Zhang ◽  
Hui Li ◽  
Hua Hong Wu ◽  
Xin Nan Zong
Keyword(s):  
Outcome Measures ◽  
Mean Value ◽  
Secular Trends ◽  
Healthy Children ◽  
Sample Sizes ◽  
Older Children ◽  
Cross Sectional ◽  
The Mean ◽  
Increasing Trends ◽  
Over Time

ObjectiveTo analyse the secular trends in mean value and distribution of weight, height and weight for height in children under 7 years in developed regions in China.DesignFive repeated cross-sectional surveys were conducted using the same methods at the same sites during 1975–2015.SettingNine cities in northern, central and southern regions of China.PopulationHealthy children under 7 years; the sample sizes were 94 496 in 1975, 79 177 in 1985, 79 152 in 1995, 69 760 in 2005 and 83 583 in 2015.Main outcome measuresWeight and height were measured by the same methods in the five surveys.ResultsThe increasing trends in the mean value of weight, height and weight for height were observed and their distribution was found to have shifted upwards. There were unbalanced increments in various centiles and the relative increments in the 3rd centile of height for children under 7 years were larger than those in the 50th and 97th centiles. Although the relative increments in the 3rd centile of weight for children under 2 years were larger than those in the 50th and 97th centiles, the increments in the 97th centile for children older than 2 years became the largest compared with other centiles. The changes in each centile of weight for height were similar with those of weight. The annual increments of height and weight increased over time and were more significant between birth and 2 years of age for height and between ages 4 years and 6 years for weight. The per-decade increments in 1975–1985, 1985–1995 and 1995–2005 became larger, while those in 2005–2015 slowed down.ConclusionsThe rapid increasing trends of weight, height and weight for height had slowed down since 2005 in developed regions of China. The relative increments in the low centile of height were more significant, while the high centile of weight and weight for height increased more significantly in older children.

High-Quality Machining of Edges of Thin-Walled Plates by Tilt Side Milling Based on an Analytical Force-Based Model

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Gongyu Liu ◽  
Jiaqiang Dang ◽  
Weiwei Ming ◽  
Qinglong An ◽  
Ming Chen ◽  
...  
Keyword(s):  
Cutting Force ◽  
Tilt Angle ◽  
Chip Thickness ◽  
Assessment Model ◽  
Force Model ◽  
High Quality ◽  
Machined Surface ◽  
Side Milling ◽  
Thin Walled ◽  
Milling Force Model

The milling of thin-walled workpieces is a common process in many industries. However, the machining defects are easy to occur due to the vibration and/or deformation induced by the poor stiffness of the thin structures, particularly when side milling the edges of plates. To this problem, an attempt by inclining the tool to a proper tilt angle in milling the edges of plates was proposed in this paper, in order to decrease the cutting force component along the direction of the lowest stiffness of the plates, and therefore to mitigate the machining vibration and improve the machined surface quality effectively. First, the milling force model in consideration of the undeformed chip thickness and the tool-workpiece engagement (TWE) was introduced in detail. Then, a new analytical assessment model based on the precisely established cutting force model was developed so as to obtain the optimum tool tilt angle for the minimum force-induced defects after the operation. Finally, the reliability and correctness of the theoretical force model and the proposed assessment model were validated by experiments. The methodology in this paper could provide practical guidance for achieving high-quality machined surface in the milling operation of thin-walled workpieces.

scholarly journals Skinfold Thickness Measurement in Term Nigerian Neonates: Establishing Reference Values

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Olanike Abosede Olutekunbi ◽  
Adaobi Uzoamaka Solarin ◽  
Idowu Odunayo Senbanjo ◽  
Elizabeth Aruma Disu ◽  
Olisamedua Fidelis Njokanma
Keyword(s):  
Birth Weight ◽  
Reference Values ◽  
Reference Population ◽  
Skinfold Thickness ◽  
Thickness Measurement ◽  
Mean Value ◽  
Cross Sectional ◽  
Mean Values ◽  
The Mean ◽  
Thickness Measurements

Skin fold thickness (SFT) measurement is a reliable, cheap, simple, noninvasive method of body fat estimation at all ages including the neonatal period.Objective. To determine reference values of biceps, triceps, subscapular, and suprailiac skinfold thickness measurements in term Nigerian newborns.Method. A prospective cross-sectional study over a six-month period (Dec 2010–May 2011) was carried out on term and healthy neonates delivered between 37 and 41 weeks. The anthropometric measurements were taken within the first 48 hours of life including the skinfold thickness. The skinfold thickness measurements were taken at four sites, namely, triceps, biceps, subscapular, and suprailiac, using Harpenden skinfold calipers. The mean of two readings was recorded.Result. A total of one thousand one hundred and sixty-eight neonates were studied. The birth weight ranged between 2000 g and 5000 g with a mean birth weight of the neonates at3259±470 g. The mean birth weight of the males (3339±0.45) was significantly higher than that of females (3200±0.44) (p<0.0001). Female neonates had higher mean values of triceps, subscapular, and suprailiac skinfold thickness (p<0.001, resp.) while male neonates had higher mean value of biceps skinfold thickness (p=0.008). Females also had higher mean values of the sum of skinfold thicknesses at all four sites and the sum at the two truncal sites at every stratified gestational age.Conclusions. The sex specific percentile chart developed for skinfold thickness measurements can be used to detect deviation from the reference population such that infants who are at risk of nutritional or health problems are identified early, and intervention is instituted promptly.

scholarly journals IgM Anti PGL-1 Antibody Level in Patients with Leprosy: A Comparative Study between Ear Lobes Capillary and Median Cubital Vein Blood Samples

2018 ◽  
Vol 6 (8) ◽  
pp. 1346-1348
Author(s):  
Khairina Nasution ◽  
Kristina Nadeak ◽  
Syahril Rahmat Lubis
Keyword(s):  
Blood Sample ◽  
Filter Paper ◽  
Cross Sectional Study ◽  
Mean Value ◽  
Cross Sectional ◽  
Blood Samples ◽  
Significant Difference ◽  
Median Cubital Vein ◽  
The Mean ◽  
Antibody Levels

BACKGROUND: To establish the diagnosis of leprosy accurately, additional examination such as serologic examination with ELISA is required. There are considerations about taking a blood sample from the earlobe region.AIM: To determine the differences in IgM anti-PGL-1 antibody levels from earlobe capillary and median cubital vein blood sample in leprosy patients.METHODS: An observational analytic study using a cross-sectional study involving 30 patients with leprosy. ELISA examination of earlobe blood samples with filter paper, and the median cubital vein blood samples with filter paper and conventional methods were performed to determine IgM anti-PGL-1 antibody levels.RESULTS: The mean value of IgM anti PGL-1 antibody levels from earlobe blood samples with filter paper (1476.62 μ/ml) was relatively similar with median cubital vein blood samples with conventional method (1476.77 μ/ml), but the mean value of IgM anti PGL-1 antibody levels from median cubital vein blood samples with filter paper (1210.37 μ/ml) was lower from other methods. However, there was no statistically significant difference between them.CONCLUSION: There are no significant differences between the mean levels of IgM anti-PGL-1 antibody from earlobe and the median cubital vein blood samples.

scholarly journals COMPARISON OF RETINAL NERVE FIBER LAYER THICKNESS BETWEEN EMMETROPES AND HIGH MYOPES

2019 ◽  
Vol 3 (9) ◽  
Author(s):  
Neha Yadav
Keyword(s):  
High Myopia ◽  
Thickness Measurement ◽  
Mean Value ◽  
Analysis Of Covariance ◽  
Field Analysis ◽  
P Value ◽  
Fiber Layer ◽  
Cross Sectional ◽  
Rnfl Thickness ◽  
The Mean

Background: The present study aims to compare RNFL thickness of high myopes of > - 6D and compare with emmetropic patients, so as to interpret and distinguish the physiological changes of high myopia from accompanying diseases in such individuals. Methods: This was a prospective cross-sectional study. All subjects underwent a full ophthalmic examination, refraction and visual field analysis. Optical coherence tomography was used for RFNL thickness measurement. The mean peripapillary RNFL thickness between groups was compared using both analysis of variance and analysis of covariance. Results: The mean value of average RNFL thickness in both groups was found to be 85.40 in group 1 and 99.34 in group 2. P value was 0.0001, showing that there was significant statistical difference between both the groups and average RNFL thickness was thinner in myopic group. Conclusion: RNFL was found to be significantly thin in high myopia. Keywords: RNFL thickness, Myopia, Emmetropes

Sign in / Sign up

Export Citation Format

Share Document