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Tytuł:
Evaluation of the Finnish Diabetes Risk Score (FINDRISC) for diabetes screening in occupational health care
Autorzy:
Vandersmissen, Godelieve J.
Godderis, Lode
Powiązania:
https://bibliotekanauki.pl/articles/2177344.pdf
Data publikacji:
2015-04-24
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
diabetes mellitus
occupational health
questionnaires
cross-sectional studies
Opis:
Objectives The objective of the study was to investigate the prevalence of undiagnosed dysglycaemia and the risk for type 2 diabetes using the Finnish Diabetes Risk Score (FINDRISC) in the working population of Belgium. Moreover, it was to evaluate performance and applicability of FINDRISC as a screening tool during occupational health surveillance. Material and Methods A cross-sectional analysis was carried out over the years 2010–2011 among 275 healthy employees who underwent a health check including fasting plasma glucose and the FINDRISC questionnaire. The sensitivity, specificity and predictive value of different FINDRISC cut-off values to detect dysglycaemia was revised in the literature and then calculated. Results The prevalence of unknown dysglycaemia was 1.8%. Twelve percent of the employees had a FINDRISC score of 12 to 14 corresponding to a moderate risk of 17% to develop diabetes within the next 10 years, and 5.5% had a score of 15 or more corresponding to a high – very high risk of 33% to 50%. All dysglycaemic individuals had a FINDRISC score of 12 or higher. The sensitivity and specificity for detecting dysglycaemia was respectively 100% and 84.1% for a FINDRISC cut-off value ≥ 12; and 80% and 95.9% for a cut-off value ≥ 15. Conclusions A considerable number of workers had dysglycaemia or was at risk for developing type 2 diabetes. The questionnaire is a reliable, valuable and easy to use screening tool in occupational health surveillance.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2015, 28, 3; 587-591
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prevalence and predictive factors for exclusive breastfeeding in the first 6 months among mothers attending Primary Health Care Centers in Cairo, Egypt
Autorzy:
Emara, Zeinab Abdelhay
Essam Eldin Amin, Ghada
Hamid, Diaa Marzouk Abdel
Allam, Mohamed Farouk
Powiązania:
https://bibliotekanauki.pl/articles/2038152.pdf
Data publikacji:
2021-06-30
Wydawca:
Uniwersytet Rzeszowski. Wydawnictwo Uniwersytetu Rzeszowskiego
Tematy:
breastfeeding
cross sectional
infants formula
primary healthcare
risk factors
Opis:
Introduction. Although most organizations recommend breastfeeding for at least one year due to its well-known beneficial effects, the prevalence of exclusive breastfeeding in many developing countries was quite low. Aim. To identify prevalence and predictive factors affecting exclusive breastfeeding in Primary Healthcare (PHC) Centers in Cairo, Egypt. Material and methods. A cross-sectional study, among mothers attended first six months immunization sessions in three PHC Centers were selected via a convenient sample, A total sample of 180 mothers, 60 from each PHC Center, were subjected to an interview questionnaire. The questionnaire used was previously validated and pre-tested. Data collection took the period from April to August 2019. Comparison between exclusive and nonexclusive breastfeeding according to possible risk factors was done. Results. The frequency of breastfeeding among the participants was 90.6%; however the total exclusive breastfeeding frequency was only 39.4%. Our logistic regression model showed that exclusive breastfeeding decreased with progressive increase in infant’s age (OR 0.74), and mothers with good knowledge about proper practice of breastfeeding adhered more to exclusive breastfeeding (OR 2.51). Also, it showed that, during working hours, mothers who fed their infants other than breast milk adhered less to exclusive breastfeeding (OR 0.19). Conclusion. The prevalence of exclusive breastfeeding is quite low. The predictive factors for exclusive breastfeeding are, younger infant’s age, good knowledge of the mothers about proper practice of breastfeeding, and mothers insisting on breastfeeding during working hours.
Źródło:
European Journal of Clinical and Experimental Medicine; 2021, 2; 145-152
2544-2406
2544-1361
Pojawia się w:
European Journal of Clinical and Experimental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Association between depression, parameters of adiposity and genetic polymorphisms of pro-inflammatory cytokines: IL-1α, IL-1β, IL-2 and IL-6 in subjects over 55 years old
Autorzy:
Adler, Grażyna
Skonieczna-Żydecka, Karolina
Madlani, Agnieszka
Ogonowski, Jarosław
Grochans, Elżbieta
Pierzak-Sominka, Joanna
Brodowski, Jacek
Karakiewicz, Beata
Powiązania:
https://bibliotekanauki.pl/articles/1038807.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
cross sectional study
genetic variants of cytokines
obesity
depression
Opis:
Background. During the last few decades, adiposity has become a relatively common phenomenon worldwide. The available data on the effects of pro-inflammatory factors in both depression and adiposity has been attracting great attention. Aim. We sought to assess the prevalence of -889C>T IL-1α, -31T>C and -511C>T IL-1β, -330T>G IL-2 and -174G>C IL-6 genes and their association with adiposity and depression in Polish subjects. Methods. A cohort study was conducted in 2013/2014, covering a sample of 297 individuals (217 female and 80 male). Anthropometric data was handled using the BIA analysis method, while for genotyping PCR-RFLP techniques were used. Results. A positive correlation between depression and anthropometric parameters: adipose tissue (in kg) and adipose tissue (in %) (R=0.135 and p=0.02, R=0.114 and p<0.05, respectively) was found. No association between studied polymorphisms and depression was observed. Conclusion. Although it was not possible to demonstrate any influence of the studied polymorphisms as the genetic modulator of depression, authors believe that the presented data are noticeable and may provide the basis for future studies on larger groups.
Źródło:
Acta Biochimica Polonica; 2016, 63, 2; 253-259
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determinants of environmental domain of quality of life in economically active population living in Silesian agglomeration, Poland
Autorzy:
Kowalska, Małgorzata
Danso, Felix
Humeniuk, Maria
Kułak, Elżbieta
Arasiewicz, Hubert
Powiązania:
https://bibliotekanauki.pl/articles/2179798.pdf
Data publikacji:
2013-03-01
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
cross-sectional study
quality of life
WHOQOL-BREF questionnaire
Opis:
Objectives: The aim of this paper is to identify the factors that determine the environmental domain of quality of life in economically active adults living in the industrial agglomeration in Poland. Materials and Methods: During the crosssectional epidemiological study conducted among the economically active population aged 45–60, we used a short version of the WHOQOL-BREF questionnaire. Respondents were recruited randomly from selected factories located in the Silesian Agglomeration. The statistical analysis used descriptive and analytical methods available in the Statistica 9.0 software. Results: The results confi rmed the statistically signifi cant association between marital status, type of occupational activity, declared health status, and the environmental domain of quality of life in economically active inhabitants of the Silesian Agglomeration. The best qualities of life in the environmental domain were those of married people, white collars, and persons who declared their health status to be the best. Conclusions: The major determinants of environmental quality of life in economically active population living in the industrial agglomeration include non-occupational factors, such as marital status and current health status, while a signifi cantly better quality of life was associated with being a white-collar worker and not living in the vicinity of the road with heavy traffic. The results may be useful for future planned activities intended to improve the health and the quality of working life.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2013, 26, 1; 132-143
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
GVAR: A Case of Spurious Cross-Sectional Cointegration
Autorzy:
Kłębowski, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/2075401.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
global VAR
GVAR
panel VAR
PVAR
spurious cross-sectional cointegration
Opis:
Global Vector Autoregressive models came to be used quite widely in empirical studies using macroeconomic non-stationary panel data for the global economy. In this paper, it is shown that when the loading matrix of the cointegrating vectors is not block-diagonal and the cross-sectional spillovers of disequilibrium exist, the use of the GVAR model leads to spurious cross-sectional long-run relationships. Moreover, the results of Monte Carlo simulation show that the GVAR model is outperformed by other valid econometric approaches in terms of the maximum likelihood estimator of long-run coefficients, when the cointegrating vectors matrix is block-diagona
Źródło:
Central European Journal of Economic Modelling and Econometrics; 2021, 2; 175-187
2080-0886
2080-119X
Pojawia się w:
Central European Journal of Economic Modelling and Econometrics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The role of cognitive schemata in the development of posttraumatic stress disorder: results of cross-sectional and longitudinal studies
Autorzy:
Dudek, Bohdan
Szymczak, Wiesław
Powiązania:
https://bibliotekanauki.pl/articles/2185476.pdf
Data publikacji:
2011-03-01
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
cross-sectional study
longitudinal study
SOC
PTSD
firefighters
police officers
Opis:
Objective: There are two theories (by Horowitz and by Foa) which attempt at explaining the process of posttraumatic stress disorder (PTSD) development by information dissonance. The purpose of the present study was to verify these theories via cross-sectional and longitudinal studies. Materials and Methods: The study based on a cross-sectional design was performed on a representative group of Polish firefighters. The study using a longitudinal protocol was conducted among police officers. The level of PTSD was assessed using the Questionnaire for PTSD Measurement (K-PTSD). The sense of coherence (SOC) was measured with the Polish adaptation of the Orientation to Life Questionnaire by A. Antonovsky. Results: In the cross-sectional study, the correlation coefficients between K-PTSD and SOC were –0.35 (p < 0.001) in the group of firefighters and –0.47 (p < 0.001) in that of police officers. In the longitudinal study, the relationship between SOC and PTSD symptoms appeared to be curvilinear and had the U-letter shape. Therefore, we used ANOVA for statistical analysis. Unfortunately, the F(2.31) = 1.900 and p > 0.05 indicated that the tendency we observed was not statistically significant. Conclusions: We would like to propose two possible explanations for the difference in the relationships between SOC and PTSD symptoms obtained in the studies employing the cross-sectional and the longitudinal protocols.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2011, 24, 1; 29-35
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Importance of Internet And Online Social Networks in the Spanish Hotel Sector
Autorzy:
Infante-Moro, A.
Infante-Moro, J-C.
Martínez-López, F-J.
García-Ordaz, M.
Powiązania:
https://bibliotekanauki.pl/articles/118135.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Promocji Wiedzy
Tematy:
hotels
online social networks
internet
e-commerce
cross-sectional study
Opis:
This paper is a cross-sectional study on the use of Internet and Online Social Networks in the Spanish hotel sector compared to Spanish companies in other sectors. The conclusions from this extensive survey are that the use of online social networks is more important and is more developed in the hotel sector than in Spanish companies in general. However, although it gives considerable importance to online social networks, the hotel sector needs to revise its rules of usage. The use of new tools such as e-commerce to sell the hotel stays must increase, and marketing efforts should be geared more towards online social networks because the hotel sector is currently losing ground in a market that generates more and more potential clients and sales by the day.
Źródło:
Applied Computer Science; 2016, 12, 1; 75-86
1895-3735
Pojawia się w:
Applied Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Association of sports and physical activity with obesity among teenagers in Poland
Autorzy:
Glinkowska, Bożena
Glinkowski, Wojciech M.
Powiązania:
https://bibliotekanauki.pl/articles/2162035.pdf
Data publikacji:
2018-12-20
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
survey
sport
overweight
children and adolescents
body mass index
cross sectional
Opis:
Objectives The purpose of the study was to assess the relationship between the body mass index and sports and physical activities in an unbiased, simple, random sample of teenagers from mid-northeastern Poland. Material and Methods Children and adolescents aged 10–19 years old were surveyed. The Internet-based survey was conducted to collect information on physical activity, leisure time, studying hours, weight, and height. Results Obesity was found to be low in the study population. The overall prevalence of overweight was not higher than 8%. Only 0.6% of participants were underweight. Overall, 68% of them confirmed participating in sports. Boys were frequently more active than girls (> 70% boys and > 60% girls). Participants mostly played soccer, volleyball, handball, or basketball (30.5%); 7% of them practiced martial arts and 16.5% of them participated in swimming. Sports activity significantly influenced body mass index. Obesity was not related to the lack of participation for physical activity in girls but a significant relationship was observed in boys (p < 0.02). The risk of obesity or overweight for inactive teenagers increased 2-fold (p < 0.01). Conclusions We report the overall participation of teenagers from 2 cities in mid-northeastern Poland in sports and physical activities and demonstrate that the lack of statistically significant differences in the body mass index and obesity and overweight is prevalent among boys and girls. Obesity was significantly related to less physical activity in boys, and the likelihood of obesity or overweight increased in inactive teenagers. Thus, we suggest that the importance of overweight and obesity prevention programs should be emphasized. Int J Occup Med Environ Health 2018;31(6):771–782
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2018, 31, 6; 771-782
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High prevalence of household pesticides and their unsafe use in rural South India
Autorzy:
Chitra, Grace A.
Kaur, Prabhdeep
Bhatnagar, Tarun
Manickam, Ponnaiah
Murhekar, Manoj V.
Powiązania:
https://bibliotekanauki.pl/articles/2179781.pdf
Data publikacji:
2013-04-01
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
household pesticides
mosquito coil
prevalence
cross-sectional survey
Tamil Nadu
India
Opis:
Objective: To estimate the prevalence of usage, unsafe practices and risk perception regarding household pesticides in a rural community of Tamil Nadu, India. Materials and Methods: In a cross-sectional survey we used a pre-tested questionnaire and trained interviewers to collect information on household pesticide use for the past 6 months from any adult member of randomly selected households. Results: Out of 143 households, 95% used at least one household pesticide (95% CI: 93.5-99.5) and 94% used at least one household pesticide specifically for mosquito control. The most commonly used pesticides were mosquito coils (75%), mosquito liquid vaporizers (36%), ant-killing powder (24%) and moth/naphthalene balls (18%). The major non-chemical methods of pest control were rat traps (12%) and mosquito bed nets (7.5%). Out of the mosquito coil users, 61% kept the windows and doors closed while the coil was burning. Out of the moth ball users, 88% left them in the place of use till they fully vaporized. Nearly half of the users did not know that household pesticides were harmful to their health and the health of their children. Conclusions: The use of household pesticides was highly prevalent in this rural community. The prevalence of unsafe practices while handling them was also high. We recommend that the users of household pesticides be educated about the health hazards and about safe practices and non-chemical methods of pest control be promoted.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2013, 26, 2; 275-282
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quality of life in parents of children and adolescents after systemic sting reactions
Autorzy:
Cichocka-Jarosz, E.
Brzyski, P.
Tarczoń, I.
Jedynak-Wąsowicz, U.
Tomasik, T.
Lis, G.
Powiązania:
https://bibliotekanauki.pl/articles/2083218.pdf
Data publikacji:
2019
Wydawca:
Instytut Medycyny Wsi
Tematy:
quality of life
parents
insect sting
Hymenoptera venom allergy
cross-sectional study
Opis:
Introduction and objectives. The study aimed at evaluating the impact of Hymenoptera venom allergy (HVA) in children and adolescents, on their parents’ QoL, taking into account their socio-demographic characteristics. Materials and method. The study sample consisted of 101 parents of children and adolescents aged 9–17 years, with a history of systemic reaction after insect sting who were referred for consultations in the tertiary level allergology department. The mean age of the parents was 39 years (SD=8.1; range 25–65 years); the majority were mothers (68%) and rural inhabitants (62%). QoL in parents of HVA children and adolescents was measured with the Parents of Children with Hymenoptera Venom Allergy Quality of Life Scale, a questionnaire covering 5 dimensions: anxiety, caution, limitations and discomfort, support provided to the child and feeling of safety, each measured on the scale ranging from 1 to 5. Independent predictors of QoL were estimated using the Generalized Linear Model. Results. Parents of urban children and adolescents treated with venom immunotherapy (VIT) up to 3 years (B=-1.37, 95CI= (-2.22;-0.53); p=0.001) and of rural children treated for more than 3 years (B=-0.94, 95CI=(-1.55;-0.33); p=0.003) reported lower anxiety than parents studied at diagnosis. In urban parents, individuals studied at VIT beginning reported a lower feeling of safety (B=-0.63, 95CI=(-1.11;-0.15); p=0.010); those studied up to 3 years of treatment reported a higher feeling of safety (B=0.64, 95CI=(0.11;1.16); p=0.018) than those studied at diagnosis. Contrariwise, in rural parents, those studied at the beginning of immunotherapy reported a higher feeling of safety than those studied at diagnosis (B=0.51, 95CI=(0.13;0.88); p=0.008). Conclusions. The longest VIT duration in children and adolescents with HVA is related to the decreased anxiety of their parents. Parent’s feeling of safety depends on the stage of treatment and place of residence.
Źródło:
Annals of Agricultural and Environmental Medicine; 2019, 26, 2; 315-321
1232-1966
Pojawia się w:
Annals of Agricultural and Environmental Medicine
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Exposure to self-reported occupational noise and diabetes – A cross-sectional relationship in 7th European Social Survey (ESS7, 2014)
Autorzy:
Dzhambov, Angel M.
Powiązania:
https://bibliotekanauki.pl/articles/2161901.pdf
Data publikacji:
2017-06-19
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
noise
diabetes mellitus
occupational exposure
gender differences
white-collar workers
cross sectional
Opis:
Objectives Almost nothing is known about the effect of occupational noise on diabetes, and this is particularly relevant given the wide spread of both noise exposure and diabetes. This study has aimed to determine whether occupational noise exposure is associated with higher risk of diabetes in Europe. Material and Methods This study is based on 7th European Social Survey (ESS7, 2014) – a multi-country population-based questionnaire survey, which covered 28 221 Europeans aged ≥ 15 years old. Data on self-reported noise exposure, diabetes and other sociodemographic and work-related factors was available. The odds of prevalent diabetes were explored using unconditional logistic regression. Results In the total sample (N = 23 486), participants ever exposed to very loud noise had no substantive increase in the odds of diabetes (odds ratio (OR) = 1.01, 95% confidence interval (CI): 0.78–1.32). There were subgroups with non-significantly increased odds: men (OR = 1.12, 95% CI: 0.87–1.45), the elderly (OR = 1.09, 95% CI: 0.91–1.31), ethnic minority members (OR = 1.55, 95% CI: 0.91–2.62), those with secondary education (OR = 1.05, 95% CI: 0.78–1.41) and those living in small cities/towns (OR = 1.07, 95% CI: 0.89–1.29). Low-skilled white-collar workers had OR = 1.34 (95% CI: 1.09–1.64). Among participants employed during the preceding 5 years the odds were OR = 1.24 (95% CI: 0.95–1.61). Conclusions Self-reported occupational noise was not associated with increased odds of prevalent diabetes in the total sample. Sensitivity analyses revealed some subgroups with non-significantly higher odds. Our results suggest that further delve into the relationship between occupational noise and diabetes is feasible and warranted. Int J Occup Med Environ Health 2017;30(4):537–551
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2017, 30, 4; 537-551
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Occupational risks for SARS-CoV-2 infection: the Polish experience
Autorzy:
Sierpiński, Radosław
Pinkas, Jaroslaw
Jankowski, Mateusz
Juszczyk, Grzegorz
Topór-Mądry, Roman
Szumowski, Łukasz
Powiązania:
https://bibliotekanauki.pl/articles/2116419.pdf
Data publikacji:
2020-10-20
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
occupational exposure
public health
quarantine
coronavirus infection
patient isolation
cross-sectional survey
Opis:
ObjectivesThe disease caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), termed COVID-19, is asymptomatic or mild in most cases. These patients do not need treatment in hospital and can be isolated at home. To date, most studies have been conducted among inpatients with severe COVID-19. In this study, the authors surveyed patients with mild COVID-19 who remained in home isolation, and analyzed the sources and occupational risk factors for SARS-CoV-2 infections.Material and MethodsThis cross-sectional study was carried out on April 17–18, 2020, among patients infected with SARS-CoV-2 who remained in home isolation in Poland. Data were acquired through a structured interview that included questions about the isolation course, symptoms, comorbidities, infection source, household characteristics, occupation, and workplace. Data were presented with descriptive statistics.ResultsOf the 4878 patients in home isolation, the authors were able to contact 3313. Of them, 1191 patients declined their invitation, and 2122 agreed to take part. The median age of the patients included in the study was 50 years; 59% were female. Most patients (92%) had not been abroad before the infection. More than half (55%) knew how they became infected; of them, 75% became infected at work. Of all patients, 70% were occupationally active. Nearly half of the occupationally active patients (48%) worked in healthcare, 3% worked in public administration or defense, 3% worked in transportation, and 2% worked in education. Sixty-five percent of the occupationally active patients worked in companies with >100 employees.ConclusionsMost of the patients with COVID-19 in home isolation in Poland were occupationally active, wherein the majority of people who were aware of the source of SARS-CoV-2 infection worked in healthcare. As most of the infected patients worked in companies with >100 employees, which is not a Polish employment pattern, the authors expect that smaller companies may have a lower risk of SARS-CoV-2 infections.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2020, 33, 6; 781-789
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microstructural Analysis of Asymmetric Dilution by Rotating Direct Metal Deposition
Autorzy:
Choi, Byungjoo
Lee, Gwang-Jae
Yeom, Hyun-Ho
Lee, Moon-Gu
Jeon, Yongho
Powiązania:
https://bibliotekanauki.pl/articles/356931.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
rotating direct metal deposition
asymmetric dilution
cross-sectional analysis
microstructure
metallurgical composition
Opis:
In this study, cross-section analysis was performed on a novel rotating direct-metal deposition method capable of preliminary surface treatment and damage repair of cylindrical inner walls. The cross-sectional shape, microstructure, and metallurgical composition were analyzed to verify feasibility. No defects such as porosity or cracks were found in the cross section, but asymmetric dilution was observed because of the non-coaxial powder nozzle. Microstructural coarsening was confirmed over a higher dilution area by high-magnification optical microscope images. As the dilution ratio was increased, hard carbides in the dendrite were bulkdiffused into inter-dendrite spaces, and the toughness was lowered by Fe penetration into the deposit. Therefore, the increased laser heat input can be modulated to the typical dilution by decreasing the laser scanning velocity.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 2; 535-538
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Elastic beam resting on Vlasov elastic foundation and subjected to an external concentrated load
Belka sprężysta spoczywająca na podłożu sprężystym Własowa o wybranych warunkach brzegowych
Autorzy:
Nagirniak, M.
Rusakov, K.
Powiązania:
https://bibliotekanauki.pl/articles/2084076.pdf
Data publikacji:
2021
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
elastic beam
Vlasov foundation
cross-sectional forces
beam deflection
displacement
disappearance function
Opis:
The paper presents the problem of bending of a beam uniformly loaded along its entire length, resting freely on an elastic Vlasov foundation with an additional external load G applied to the ground at a distance a from the beam end. The given example is a special case of a beam resting freely on an elastic foundation, which is present in many cases of building practice. The paper considers an approximate solution for the influence of an additional load G on the deflection and cross-sectional forces of a beam resting freely on Vlasov elastic subsoil. Graphs of a deflection of the beam and of a soil surface layer beyond the limits of the beam, as well as graphs of bending moments and transverse forces in the beam have been presented. The influence of an additional load applied in a distance a on the deflection and cross-sectional forces in the beam has been investigated.
Źródło:
Acta Scientiarum Polonorum. Architectura; 2021, 20, 4; 29-35
1644-0633
Pojawia się w:
Acta Scientiarum Polonorum. Architectura
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prediction of Tunnel Cross-Sectional Area After Blastin
Autorzy:
Nguyen, Chi Thanh
Nguyen, Nghia Viet
Powiązania:
https://bibliotekanauki.pl/articles/25212147.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
ANN
SVR
tunnel
drilling-blasting method
cross-sectional area of tunnel
prediction
tunele
Opis:
In this paper, two methods to predict and calculate the area of the tunnel face after the blasting were used. The first one is an artificial intelligence method using an artificial neural network system (ANN) model, and the second one – the support vector regression (SVR). After building predictive models for the area of the tunnel face after blasting by both methods, on the basis of comparing the results obtained in both methods, the performance of these models was assessed through the root mean square error RMSE and the coefficient of determination R2. RMSE and R2 values of the artificial neural network system (ANN) model were obtained as 0.1473 and 0.903 in training datasets, respectively. These values are 0.1497 and 0.9107 in testing datasets. In the SRV model, RMSE and R2 were equaled to 0.1228 and 0.9331 in training datasets, respectively. These values are 0.1708 and 0.9055, respectively in testing datasets. It can be concluded that artificial intelligence using ANN and SVM models can be used to predict the area of the tunnel face after blasting with high accuracy.
Źródło:
Inżynieria Mineralna; 2023, 2; 39--47
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 34

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