Response of Buried District Heating Pipelines Under Relative Axial Movements

2014 ◽  
Author(s):  
Michael Huber ◽  
Dharma Wijewickreme
Keyword(s):  
Urban Areas ◽  
Test Chamber ◽  
District Heating ◽  
Cost Effective ◽  
Full Scale ◽  
Cross Sectional ◽  
Pullout Resistance ◽  
Pull Out ◽  
Full Scale Tests ◽  
Soil Pipe

District heating (DH) systems are commonly used in urban areas to distribute thermal energy from central heat sources. Buried pipes, with a composite cross-sectional construction, are used transport a heated medium, usually water. These pipes expand and contract radially and axially due to changing water temperatures, invoking soil-pipe interaction situations during operation, and potentially leading to significant pipeline material strains. A series of full-scale tests were undertaken to specifically investigate the influence of thermal expansion on axial pullout resistance using DH pipes buried in sand in a full-scale soil-pipe interaction test chamber. During testing, the pipe is filled with water that is subjected to temperature changes to simulate field conditions. Axial pipe pull-out tests were conducted after applying a given “heating history” with axial pullout force and displacements recorded. The work leads to better understanding of soil-pipe interaction mechanisms generating currently scarce data needed for robust and cost-effective designs of DH pipe systems.

Failure of X52 Wrinkled Pipelines Subjected to Monotonic Axial Deformation

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Y. Zhang ◽  
S. Das
Keyword(s):  
Parametric Study ◽  
Numerical Study ◽  
Numerical Technique ◽  
Small Diameter ◽  
Full Scale ◽  
Thickness Ratio ◽  
Axial Deformation ◽  
Cross Sectional ◽  
Full Scale Tests ◽  
Internal Pressures

This study was undertaken to investigate and understand the behavior of a wrinkled energy pipeline when subjected to sustained monotonic axial compressive deformation. This study involved both experimental and numerical investigations. Two full-scale laboratory tests with moderate and high internal pressures on X52 grade steel pipes with a diameter-to-thickness ratio of 45 show that this pipeline is extremely ductile and did not rupture under axisymmetric compressive axial deformation. However, they fail due to the excessive cross-sectional deformation and the final deformed shape looks like an accordion due to the formation of multiple wrinkles. Subsequently, a detailed parametric study using a numerical technique was undertaken to determine the failure condition and failure mode of this pipeline for various realistic internal pressures and diameter-to-thickness ratios. A nonlinear finite element method was used for the numerical study. The numerical model was validated with the data obtained from the two full-scale tests. The parametric study shows that the X52 linepipe loses its integrity due to the rupture in the pipe wall if the internal pressure is low and/or if the pipe has a small diameter-to-thickness ratio. This paper presents and discusses the results obtained both from the experimental and numerical parametric studies.

Field Full Scale Tests on Longitudinal Pipeline-Soil Interaction

1998 ◽  
Author(s):  
Andrea Cappelletto ◽  
Roberto Tagliaferri ◽  
Gianmario Giurlani ◽  
Giuseppe Andrei ◽  
Giuseppe Furlani ◽  
...  
Keyword(s):  
Practical Implication ◽  
Field Measurements ◽  
Burial Depth ◽  
Direct Shear Tests ◽  
Static Interaction ◽  
Pull Out ◽  
Stress Relieving ◽  
Full Scale Tests ◽  
Different Diameters ◽  
Soil Pipe

Recent research on longitudinal pipe-soil interaction shows that traditional analysis models are inadequate and too conservative, especially when cohesive soils are involved. The practical implication for SNAM, whose network extends over the entire Italian territory where slow ground movements inducing longitudinal soil-pipe interaction are frequent, is that the management of the gas pipeline has to rely mainly on field measurements. The correct assessment of the interaction forces was therefore included as an important part of a wider research program, whose aim is to perform pipe risk analysis by which the structural vulnerability for some SNAM typical scenarios can be quantified as a function of such parameters as the pipe section geometry, the type of soil, the burial depth, the length of pipeline section involved and the magnitude of the soil imposed displacements. Experimental activities specifically regarding longitudinal, static, interaction problems were carried out; in particular pull-out tests were performed on two out of use pipelines, having two different diameters: 8” and 24”. For each site, four different test conditions were investigated where type and compaction state of the material surrounding the pipe varies. The behaviour of the pipe embedded in the original clayey backfill was compared to that observed after such fill was excavated and replaced around the pipe, to simulate conditions after standard stress relieving works. Different fills where then used, made of either granular soil or granulite; this latter was used in order to ascertain the possible benefits of using light artificial materials to mitigate soil-pipe interaction phenomena. Site testing was accompanied by a careful geotechnical investigation both in the field and in laboratory that included direct shear tests of interfaces using coated steel pipe specimens. A comparison between the results obtained and the existing state of the art is presented. This comparison allowed to verify the effectiveness of some interpretative models, and in particular the convenience of adopting effective stress based models rather than pure cohesive ones (i.e. total stress), even in the case of clayey soils.

scholarly journals Risk assessment for diabetes among adult population in urban field practice area of a government medical college in north coastal Andhra Pradesh

2020 ◽  
Vol 7 (4) ◽  
pp. 1454
Author(s):  
B. Dhanalaxmi Lolach Balaga ◽  
K. V. Phani Madhavi ◽  
B. Devi Madhavi
Keyword(s):  
High Risk ◽  
Urban Areas ◽  
Adult Population ◽  
Cost Effective ◽  
High Risk Population ◽  
Cross Sectional ◽  
Screening Programs ◽  
Medical College ◽  
Field Practice ◽  
Study Participants

Background: The rising prevalence of diabetes in developing countries is closely associated with industrialization and socioeconomic development. The major determinants of diabetics in these countries are population growth, age structure, and urbanization, prevalence of obesity because of increased intake of junk food, lack of physical activity, and stress among urban dwellers. Diabetes is increasingly concentrated in the urban areas. Hence, the present study was undertaken. To assess the risk of developing diabetes among urban adults >20 years using a Simplified Indian diabetes risk score.Methods: A community based cross-sectional study was carried out in Allipuram, an urban field practice area of Department of Community Medicine, Andhra Medical College, Visakhapatnam. The study was conducted among adults >20 years of age in a sample of 400 adults chosen by simple random sampling technique after obtaining informed consent. The sample size was calculated using 4PQ/L2 with 3% absolute precision (p=9% from previous studies). The study was done for 2 months (October 15th to December 15th 2019).Results: Majority 158 (39.5%) of study participants are at high risk and 198(49.5%) are at medium risk of developing Diabetes in future. Majority 276 (93.3%) of the study participants do not have family history of diabetes.Conclusions: IDRS is a simple, useful and cost-effective tool for prioritizing and identifying medium and high-risk population for developing diabetes and to subject them for screening of diabetes and making screening programs more cost effective in resource limited settings.

scholarly journals A community based study to assess the validity of Indian diabetic risk score, among urban population of North Central India

2017 ◽  
Vol 4 (6) ◽  
pp. 2101 ◽  
Author(s):  
Anil Kumar Agarwal ◽  
Ghanshyam Ahirwar ◽  
Priyesh Marskole ◽  
A. K. Bhagwat
Keyword(s):  
Diabetes Mellitus ◽  
High Risk ◽  
Risk Score ◽  
Urban Areas ◽  
Central India ◽  
Cost Effective ◽  
Community Based ◽  
Cross Sectional ◽  
Face To Face ◽  
Patients With Diabetes

Background: The prevalence of diabetes mellitus is growing rapidly worldwide and India has earned the dubious distinction of being the diabetic capital of the world and had 69.2 million (8.7%) people living with diabetes.1 Unfortunately over half of these people remain undiagnosed as diabetes. IDRS is a cost effective and simple tool for screening of undiagnosed diabetic individuals in the community. The objective of the study was to estimate prevalence of undiagnosed high risk subjects of diabetes mellitus to validate IDRS as effective tool for diagnosis of diabetes in urban areas of Gwalior City.Methods: In community based cross-sectional observational study house to house survey was conducted and face to face interview had done by predesigned questionnaire, which was based on IDRS variables for those persons of age more than 20 and not known to diabetes previously.Results: In present study 55 (8.94%) out of 615 respondents were diagnosed as a newly diabetic cases. We found that at IDRS score of ≥60 has a sensitivity of 45.5% and specificity of 88.0%.Conclusions: This study provides a use of Indian diabetes risk score for identifying undiagnosed high risk for patients with diabetes in Indian population and could make screening programmes more cost effective. 

scholarly journals Hygiene practices and awareness regarding Milk borne diseases (MBD) among dairy workers in unorganized urban settings of Bhubaneswar, Odisha, India

2021 ◽  
Vol 33 (3) ◽  
pp. 466-474
Author(s):  
Snigdha Singh ◽  
Sonali Kar ◽  
Alpana Mishra ◽  
Dipti Pattnaik
Keyword(s):  
Urban Areas ◽  
Cost Effective ◽  
Emerging Diseases ◽  
Living Conditions ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Urban Settings ◽  
Hygiene Practices ◽  
Fresh Milk ◽  
Dairy Workers

Background: Dairy work is thought to be predominantly a rural occupation. However, due to preferences we see a lot of urban residents consume fresh milk and hence, few people even in the urban areas take up cattle rearing as a cost effective profession. In the midst of much talked re-emerging diseases, caused by close habitation of animals and man, it would be very relevant to see living conditions of these populations and their hygiene practices in a space compromised scenario. In urban settings, they stay in close proximity and due to socioeconomic conditions, dairy workers in do not have appropriate amenities to tend on the cattle,clean or even scope for proper waste disposal. This in nutshell, leads to a disease enabling environment and the study aims at reviewing these living conditions. Besides, an assessment of health conditions of the dairy workers, their awareness regarding the milk borne diseases(MBD) was done. The findings helped generate recommendations for improvement of the profession and ultimately the quality of the milk. Objectives:1) Assess the hygiene practices during the stages of milk collection, storage and transport of milk among the sampled dairy workers from urban unorganized settings of Bhubaneswar. 2) Assess awareness of these workers regarding milk borne diseases. Methodology: This cross?sectional survey was part of a larger study and was conducted in unorganized sector of dairy workers in Bhubaneswar. 60 dairy households were surveyed and from each household, 2 members actively involved in dairy work were selected.The study tool was a semi structured, mixed questionnaire. The questionnaire had 3 sections; A was regarding household information(General sociodemographic details and Housing conditions for 60 HHs); B was to elicit the hygiene status of dairy workers(n=120) during each step of their work, their milk handling details during milk collection, storage and transportation; C had questions to assess the awareness of dairy worker regarding MBD. Results: Hygiene practices were very dismal at all points like milking,storage and transportation. Only 5.0% dairy households practised cleaning udder twice- prior to and after milking. Only 35% households kept the milk storage containers covered. 44.2% workers agreed that “MBD” is a community health problem. On general examination, pallor and icterus was found among workers. This strongly brings out that this group not only have the potential to be infected by zoonotic diseases, but can also transmit it to through the milk they are selling. A felt need is assessed for these workers in terms of creating standards of hygiene practices of cattle and milk handling and also impart them training on improving their occupational practices.

KEJADIAN PENYAKIT HIPERTENSI DAN INDEKS MASSA TUBUH PADA PEREMPUAN YANG TINGGAL DI PEDESAAN DAN PERKOTAAN

2019 ◽  
pp. 127-136
Author(s):  
Venti Agustina
Keyword(s):  
Blood Pressure ◽  
Body Mass Index ◽  
Body Mass ◽  
Rural Women ◽  
Urban Areas ◽  
Stage I ◽  
Normal Body Mass Index ◽  
Cross Sectional ◽  
Normal Body ◽  
Stadium I

Hipertensiadalah penyebab kematian utama di Indonesia. Kematian akibat hipertensi lebih banyak terjadi di perkotaan dibandingkan di desa. Tingginya kejadian hipertensi dipengaruhi oleh faktor yang dapat dikontrol (obesitas,berat badan lebih, konsumsi garam berlebih,aktivitas fisik rendah, perokok, dan konsumsi alkohol) dan faktor yang tidak dapat dikontrol (genetik, usia, dan jenis kelamin). Penelitian bertujuan memberikan gambarandistribusi tekanan darah dan indeks massa tubuh (IMT) pendudukperempuan di kota maupun di desa.Desain penelitian adalah deskriptif kuatitatif dengan pendekatan cross sectional. Data primer didapatkan melalui pengukuran tekanan darah, tinggi badan dan berat badan. Penelitian dilakukan di Desa Kutowinangun Kidul, Kecamatan Tingkir,Salatiga yang mewakili penduduk perempuan di perkotaan dan Desa Batur, Kecamatan Getasan, Kabupaten Semarangyang mewakili penduduk perempuan pedesaan. Adapun jumlah sampel masing-masing 66 respondendan 72responden. Hasil penelitian menunjukkan bahwa kejadian penyakit hipertensi, resiko obese dan obese lebih didominasi oleh respondendi perkotaan dibandingkan di pedesaan dengan rentang usia di atas 46 tahun. Respondendi desa dengan indeks massa tubuh normal cenderung mengalami pre-hipertensi (8,3%) dan hipertensi stadium I (6,9%) sementararesponden dengan resiko obese dan obese cenderung mengalami hipertensi stadium I (1,4%).Respondendi kota dengan indeks massa tubuh normal cenderung mengalami pre hipertensi (6,06%), hipertensi stadium I (4,5%) dan II (7,5%). Responden dengan resiko obese cenderung mengalami hipertensi stadium I (4,5%), dan responden dengan obese I dan II cenderung mengalami pre-hipertensi (4,5%).   Hypertension is the leading cause of death in Indonesia. Deaths due to hypertension are more common in urban areas than in villages. The high incidence of hypertension is influenced by factors that can be controlled (obesity, overweight, excessive salt consumption, low physical activity, smokers, and alcohol consumption) and factors that cannot be controlled (genetic, age, and sex). The study aimed to provide an overview of blood pressure distribution and body mass index (BMI) of female residents in cities and villages. The study design was descriptive quantitative with a cross sectional approach. Primary data was obtained through measurements of blood pressure, height and weight. The study was conducted in Kutowinangun Kidul Village, Tingkir Subdistrict, Salatiga representing women in urban areas and Batur Village, Getasan Subdistrict, Semarang Regency, representing rural women. The number of samples was 66 respondents and 72 respondents respectively. The results showed that the incidence of hypertension, the risk of obese and obese was more dominated by respondents in urban areas than in rural areas with ages above 46 years. Respondents in villages with normal body mass index tended to experience pre-hypertension (8.3%) and stage I hypertension (6.9%) while respondents with obese and obese risk tended to experience stage I hypertension (1.4%). Respondents in cities with normal body mass index tended to experience pre-hypertension (6.06%), stage I hypertension (4.5%) and II (7.5%). Respondents with obese risk tended to experience stage I hypertension (4.5%), and respondents with obese I and II tended to experience pre-hypertension (4.5%).

HIV INFECTION AND SOME RELATED FACTORS IN FEMALE MASSAGE THERAPISTS IN QUANG NGAI PROVINCE

2015 ◽  
pp. 57-60
Author(s):  
Xuan Chuong Tran ◽  
Thi Thanh Hoa Le ◽  
Ngoc Van Nguyen ◽  
Thanh Nguyen
Keyword(s):  
Hiv Infection ◽  
Urban Areas ◽  
Risk Groups ◽  
Sexual Contact ◽  
Related Factor ◽  
Related Factors ◽  
Cross Sectional ◽  
Keywords Hiv ◽  
Study Results ◽  
Massage Therapists

Background: HIV/AIDS is still a dangerous infection in Vietnam and in the world. Studying of HIV infection and related factors in high risk groups, including female massage therapists is therefore very important. Aims: 1. To study the HIV infection in female massage therapists in Quang Ngai province. 2. To fine some related factors to HIV infection. Patients and methods: Female massage therapists working in Quang Ngai province. Cross-sectional, descriptive study. Results: The rate of HIV infection was 0.99%. Group older than 22 years old had higher rate of infection than group under 22 years old (1.80% vs 0.69%). The girls from urban areas or not using condom had higher rate of infection than group from rural or not using condom (1.57% vs 0.47% and 7.32% vs. 0.57%). Most of HIV infected belong to single or divorce groups. Conclusions: The rate of HIV infection in female massage therapists in Quang Ngai province was 0.99%. The HIV infection related factor was not using condom in sexual contact. Keywords: HIV, female massage therapists, Quang Ngai

scholarly journals Local Heating Networks with Waste Heat Utilization: Low or Medium Temperature Supply?

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 954 ◽  
Author(s):  
Hanne Kauko ◽  
Daniel Rohde ◽  
Armin Hafner
Keyword(s):  
Low Temperature ◽  
Heat Pump ◽  
Urban Areas ◽  
Waste Heat ◽  
Local Heating ◽  
District Heating ◽  
Heat Pumps ◽  
Hot Water ◽  
Local Network ◽  
Medium Temperature

District heating enables an economical use of energy sources that would otherwise be wasted to cover the heating demands of buildings in urban areas. For efficient utilization of local waste heat and renewable heat sources, low distribution temperatures are of crucial importance. This study evaluates a local heating network being planned for a new building area in Trondheim, Norway, with waste heat available from a nearby ice skating rink. Two alternative supply temperature levels have been evaluated with dynamic simulations: low temperature (40 °C), with direct utilization of waste heat and decentralized domestic hot water (DHW) production using heat pumps; and medium temperature (70 °C), applying a centralized heat pump to lift the temperature of the waste heat. The local network will be connected to the primary district heating network to cover the remaining heat demand. The simulation results show that with a medium temperature supply, the peak power demand is up to three times higher than with a low temperature supply. This results from the fact that the centralized heat pump lifts the temperature for the entire network, including space and DHW heating demands. With a low temperature supply, heat pumps are applied only for DHW production, which enables a low and even electricity demand. On the other hand, with a low temperature supply, the district heating demand is high in the wintertime, in particular if the waste heat temperature is low. The choice of a suitable supply temperature level for a local heating network is hence strongly dependent on the temperature of the available waste heat, but also on the costs and emissions related to the production of district heating and electricity in the different seasons.

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