Search results for: feeding tube
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1256

Search results for: feeding tube

1106 An Analysis on Thermal Energy Storage in Paraffin-Wax Using Tube Array on a Shell and Tube Heat Exchanger

Authors: Syukri Himran, Rustan Taraka, Anto Duma

Abstract:

The aim of the study is to improve the understanding of latent and sensible thermal energy storage within a paraffin wax media by an array of cylindrical tubes arranged both in in-line and staggered layouts. An analytical and experimental study was carried out in a horizontal shell-and-tube type system during the melting process. Pertamina paraffin-wax was used as a phase change material (PCM), where as the tubes are embedded in the PCM. From analytical study we can obtain the useful information in designing a thermal energy storage such as : the motion of interface, amount of material melted at any time in the process, and the heat storage characteristic during melting. The use of staggered tubes is proposed as superior to in-line layout for thermal storage. The experimental study was used to verify the validity of the analytical predictions. From the comparisons, the analytical and experimental data are in a good agreement.

Keywords: latent, sensible, paraffin-wax, thermal energy storage, conduction, natural convection

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1105 Analysis of Vortex-Induced Vibration Characteristics for a Three-Dimensional Flexible Tube

Authors: Zhipeng Feng, Huanhuan Qi, Pingchuan Shen, Fenggang Zang, Yixiong Zhang

Abstract:

Numerical simulations of vortex-induced vibration of a three-dimensional flexible tube under uniform turbulent flow are calculated when Reynolds number is 1.35×104. In order to achieve the vortex-induced vibration, the three-dimensional unsteady, viscous, incompressible Navier-Stokes equation and LES turbulence model are solved with the finite volume approach, the tube is discretized according to the finite element theory, and its dynamic equilibrium equations are solved by the Newmark method. The fluid-tube interaction is realized by utilizing the diffusion-based smooth dynamic mesh method. Considering the vortex-induced vibration system, the variety trends of lift coefficient, drag coefficient, displacement, vertex shedding frequency, phase difference angle of tube are analyzed under different frequency ratios. The nonlinear phenomena of locked-in, phase-switch are captured successfully. Meanwhile, the limit cycle and bifurcation of lift coefficient and displacement are analyzed by using trajectory, phase portrait, and Poincaré sections. The results reveal that: when drag coefficient reaches its minimum value, the transverse amplitude reaches its maximum, and the “lock-in” begins simultaneously. In the range of lock-in, amplitude decreases gradually with increasing of frequency ratio. When lift coefficient reaches its minimum value, the phase difference undergoes a suddenly change from the “out-of-phase” to the “in-phase” mode.

Keywords: vortex induced vibration, limit cycle, LES, CFD, FEM

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1104 Food for Thought: Preparing the Brain to Eat New Foods through “Messy” Play

Authors: L. Bernabeo, T. Loftus

Abstract:

Many children often experience phases of picky eating, food aversions and/or avoidance. For families with children who have special needs, these experiences are often exacerbated, which can lead to feelings that negatively impact a caregiver’s relationship with their child. Within the scope of speech language pathology practice, knowledge of both emotional and feeding development is key. This paper will explore the significance of “messy play” within typical feeding development, and the challenges that may arise if a child does not have the opportunity to engage in this type of exploratory play. This paper will consider several contributing factors that can result in a “picky eater.” Further, research has shown that individuals with special needs, including autism, possess a neurological makeup that differs from that of a typical individual. Because autism is a disorder of relating and communicating due to differences in the limbic system, an individual with special needs may respond to a typical feeding experience as if it is a traumatic event. As a result, broadening one’s dietary repertoire may seem to be an insurmountable challenge. This paper suggests that introducing new foods through exploratory play can help broaden and strengthen diets, as well as improve the feeding experience, of individuals with autism. The DIRFloortimeⓇ methodology stresses the importance of following a child's lead. Within this developmental model, there is a special focus on a person’s individual differences, including the unique way they process the world around them, as well as the significance of therapy occurring within the context of a strong and motivating relationship. Using this child-centered approach, we can support our children in expanding their diets, while simultaneously building upon their cognitive and creative development through playful and respectful interactions that include exposure to foods that differ in color, texture, and smell. Further, this paper explores the importance of exploration, self-feeding and messy play on brain development, both in the context of typically developing individuals and those with disordered development.

Keywords: development, feeding, floortime, sensory

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1103 Concentrated Animal Feeding Operations and Planning in the United States: Evidences from North Carolina

Authors: Asmaa Benbaba

Abstract:

This paper aims to reconsider relationships between animal feeding operations (CAFOs) and planning. It stresses the idea of the necessity for a methodological revolution in order to increase the chances for dialogue between different actors and various planning agencies and create possibilities to manage conflicts. The explored case of North Carolina shows limitations in environmental agencies’ actions and methods. It also calls for a more integrated approach among agencies including the local agencies.

Keywords: CAFOs, North Carolina, planning, United States

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1102 Bioresorbable Medicament-Eluting Grommet Tube for Otitis Media with Effusion

Authors: Chee Wee Gan, Anthony Herr Cheun Ng, Yee Shan Wong, Subbu Venkatraman, Lynne Hsueh Yee Lim

Abstract:

Otitis media with effusion (OME) is the leading cause of hearing loss in children worldwide. Surgery to insert grommet tube into the eardrum is usually indicated for OME unresponsive to antimicrobial therapy. It is the most common surgery for children. However, current commercially available grommet tubes are non-bioresorbable, not drug-treated, with unpredictable duration of retention on the eardrum to ventilate middle ear. Their functionality is impaired when clogged or chronically infected, requiring additional surgery to remove/reinsert grommet tubes. We envisaged that a novel fully bioresorbable grommet tube with sustained antibiotic release technology could address these drawbacks. In this study, drug-loaded bioresorbable poly(L-lactide-co-ε-caprolactone)(PLC) copolymer grommet tubes were fabricated by microinjection moulding technique. In vitro drug release and degradation model of PLC tubes were studied. Antibacterial property was evaluated by incubating PLC tubes with P. aeruginosa broth. Surface morphology was analyzed using scanning electron microscopy. A preliminary animal study was conducted using guinea pigs as an in vivo model to evaluate PLC tubes with and without drug, with commercial Mini Shah grommet tube as comparison. Our in vitro data showed sustained drug release over 3 months. All PLC tubes revealed exponential degradation profiles over time. Modeling predicted loss of tube functionality in water to be approximately 14 weeks and 17 weeks for PLC with and without drug, respectively. Generally, PLC tubes had less bacteria adherence, which were attributed to the much smoother tube surfaces compared to Mini Shah. Antibiotic from PLC tube further made bacteria adherence on surface negligible. They showed neither inflammation nor otorrhea after 18 weeks post-insertion in the eardrums of guinea pigs, but had demonstrated severe degree of bioresorption. Histology confirmed the new PLC tubes were biocompatible. Analyses on the PLC tubes in the eardrums showed bioresorption profiles close to our in vitro degradation models. The bioresorbable antibiotic-loaded grommet tubes showed good predictability in functionality. The smooth surface and sustained release technology reduced the risk of tube infection. Tube functional duration of 18 weeks allowed sufficient ventilation period to treat OME. Our ongoing studies include modifying the surface properties with protein coating, optimizing the drug dosage in the tubes to enhance their performances, evaluating their functional outcome on hearing after full resoption of grommet tube and healing of eardrums, and developing animal model with OME to further validate our in vitro models.

Keywords: bioresorbable polymer, drug release, grommet tube, guinea pigs, otitis media with effusion

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1101 Performance Analysis of a Shell and Tube Heat Exchanger in the Organic Rankine Cycle Power Plant

Authors: Yogi Sirodz Gaos, Irvan Wiradinata

Abstract:

In the 500 kW Organic Rankine Cycle (ORC) power plant in Indonesia, an AFT (according to the Tubular Exchanger Manufacturers Association – TEMA) type shell and tube heat exchanger device is used as a pre-heating system for the ORC’s hot water circulation system. The pre-heating source is a waste heat recovery of the brine water, which is tapped from a geothermal power plant. The brine water itself has 5 MWₜₕ capacities, with average temperature of 170ᵒC, and 7 barg working pressure. The aim of this research is to examine the performance of the heat exchanger in the ORC system in a 500 kW ORC power plant. The data for this research were collected during the commissioning on the middle of December 2016. During the commissioning, the inlet temperature and working pressure of the brine water to the shell and tube type heat exchanger was 149ᵒC, and 4.4 barg respectively. Furthermore, the ΔT for the hot water circulation of the ORC system to the heat exchanger was 27ᵒC, with the inlet temperature of 140ᵒC. The pressure in the hot circulation system was dropped slightly from 7.4ᵒC to 7.1ᵒC. The flow rate of the hot water circulation was 80.5 m³/h. The presentation and discussion of a case study on the performance of the heat exchanger on the 500 kW ORC system is presented as follows: (1) the heat exchange duty is 2,572 kW; (2) log mean temperature of the heat exchanger is 13.2ᵒC; (3) the actual overall thermal conductivity is 1,020.6 W/m².K (4) the required overall thermal conductivity is 316.76 W/m².K; and (5) the over design for this heat exchange performance is 222.2%. An analysis of the heat exchanger detailed engineering design (DED) is briefly discussed. To sum up, this research concludes that the shell and tube heat exchangers technology demonstrated a good performance as pre-heating system for the ORC’s hot water circulation system. Further research need to be conducted to examine the performance of heat exchanger system on the ORC’s hot water circulation system.

Keywords: shell and tube, heat exchanger, organic Rankine cycle, performance, commissioning

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1100 Flow of a Second Order Fluid through Constricted Tube with Slip Velocity at Wall Using Integral Method

Authors: Nosheen Zareen Khan, Abdul Majeed Siddiqui, Muhammad Afzal Rana

Abstract:

The steady flow of a second order fluid through constricted tube with slip velocity at wall is modeled and analyzed theoretically. The governing equations are simplified by implying no slip in radial direction. Based on Karman Pohlhausen procedure polynomial solution for axial velocity profile is presented. An expressions for pressure gradient, shear stress, separation and reattachment points and radial velocity are also calculated. The effect of slip and no slip velocity on velocity, shear stress, pressure gradient are discussed and depicted graphically. It is noted that when Reynolds number increases velocity of the fluid decreases in both slip and no slip conditions. It is also found that the wall shear stress, separation and reattachment points are strongly effected by Reynolds number.

Keywords: approximate solution, constricted tube, non-Newtonian fluids, Reynolds number

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1099 Species Diversity of Migratory Birds along Boat Touring Routes in Klong Kone Sub-District, Muang District, Samut Songkram Province, Thailand

Authors: P. Chitman, N. Charoenpokaraj

Abstract:

This research aims to study the species, feeding behavior and activity characteristics of birds which reap benefits from the research area in boat touring routes in Klong Kone Sub-district, Muang District, Samut Songkram Province, Thailand from October 2013 – May 2014. The results from the survey of birds on all three routes found that there are 11 families and 22 species. Route 1 (Klong Kone canal) had the most species, 20 species. According to feeding behavior, there were insectivorous, piscivorous and aquatic invertebrate feeder birds. Activity characteristics of birds which reap benefits from the research were finding food, nesting and raise nestlings along boat touring routes.

Keywords: bird species diversity, boat touring routes, Samut Songkram, feeding behavior

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1098 Optimizing Design Parameters for Efficient Saturated Steam Production in Fire Tube Boilers: A Cost-Effective Approach

Authors: Yoftahe Nigussie Worku

Abstract:

This research focuses on advancing fire tube boiler technology by systematically optimizing design parameters to achieve efficient saturated steam production. The main objective is to design a high-performance boiler with a production capacity of 2000kg/h at a 12-bar design pressure while minimizing costs. The methodology employs iterative analysis, utilizing relevant formulas, and considers material selection and production methods. The study successfully results in a boiler operating at 85.25% efficiency, with a fuel consumption rate of 140.37kg/hr and a heat output of 1610kW. Theoretical importance lies in balancing efficiency, safety considerations, and cost minimization. The research addresses key questions on parameter optimization, material choices, and safety-efficiency balance, contributing valuable insights to fire tube boiler design.

Keywords: safety consideration, efficiency, production methods, material selection

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1097 The Soft and Hard Palate Cleft’s Impact on the Auditory Tube Function

Authors: Fedor Semenov

Abstract:

One of the most widespread facial bones’ malformations – the congenital palatoschisis – significant impact on drainage and ventilation of the middle ear through the incorrect work of soft palate muscles, which results in recurrent middle ear inflammation and subsequently leads to the hearing dysfunction. The purpose of this research is to evaluate the auditory tube function and hearing condition before the operative treatment (uranoplasty) and after 3 and 12 months. 42 patients aged from 6 months to 17 years who had soft and hard palate cleft and B and C type tympanogram were included in that study. The examination includes otoscopy, pure tone audiometry (for patients older than 8 years – 11 patients), tympanometry. According to the otoscopy results all the patients were divided into two groups: those who had a retracted eardrum and those who had a normal one. The results of pure tone audiometry showed that there were six patients with an air-bone gap of more than 10 dB and the five with normal audiograms. According to the results of this research, uranoplasty demonstrated strongly positive effects on the auditory tube function: normalization of eardrum view upon otoscopy was observed in 64% of children with a retracted eardrum three month after surgery and 85 % twelve months. The quantity of patients with A-type of tympanogram improved in 25 children out of 41 in 3 month and in 35 out of 41 in twelve months after operation. While before the operative treatment, six patients older than 8 years had had an air-bone gap of more than 10 dB; only two of them still had it in 12 months, and the others’ audiograms were normal. To sum it up, the uranoplasty showed a significant contribution in the restoration of auditory tube functioning. Some patients had signs of auditory dysfunction even after the operative treatment. That group of children needs further treatment by an otorhinolaryngologist.

Keywords: auditory tube dysfunction, palatoschisis, uranoplasy, otitis

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1096 An Energy and Economic Comparison of Solar Thermal Collectors for Domestic Hot Water Applications

Authors: F. Ghani, T. S. O’Donovan

Abstract:

Today, the global solar thermal market is dominated by two collector types; the flat plate and evacuated tube collector. With regards to the number of installations worldwide, the evacuated tube collector is the dominant variant primarily due to the Chinese market but the flat plate collector dominates both the Australian and European markets. The market share of the evacuated tube collector is, however, growing in Australia due to a common belief that this collector type is ‘more efficient’ and, therefore, the better choice for hot water applications. In this study, we investigate this issue further to assess the validity of this statement. This was achieved by methodically comparing the performance and economics of several solar thermal systems comprising of; a low-performance flat plate collector, a high-performance flat collector, and an evacuated tube collector coupled with a storage tank and pump. All systems were simulated using the commercial software package Polysun for four climate zones in Australia to take into account different weather profiles in the study and subjected to a thermal load equivalent to a household comprising of four people. Our study revealed that the energy savings and payback periods varied significantly for systems operating under specific environmental conditions. Solar fractions ranged between 58 and 100 per cent, while payback periods range between 3.8 and 10.1 years. Although the evacuated tube collector was found to operate with a marginally higher thermal efficiency over the selective surface flat plate collector due to reduced ambient heat loss, the high-performance flat plate collector outperformed the evacuated tube collector on thermal yield. This result was obtained as the flat plate collector possesses a significantly higher absorber to gross collector area ratio over the evacuated tube collector. Furthermore, it was found for Australian regions operating with a high average solar radiation intensity and ambient temperature, the lower performance collector is the preferred choice due to favorable economics and reduced stagnation temperature. Our study has provided additional insight into the thermal performance and economics of the two prevalent solar thermal collectors currently available. A computational investigation has been carried out specifically for the Australian climate due to its geographic size and significant variation in weather. For domestic hot water applications were fluid temperatures between 50 and 60 degrees Celsius are sought, the flat plate collector is both technically and economically favorable over the evacuated tube collector. This research will be useful to system design engineers, solar thermal manufacturers, and those involved in policy to encourage the implementation of solar thermal systems into the hot water market.

Keywords: solar thermal, energy analysis, flat plate, evacuated tube, collector performance

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1095 An Exploration of Health Promotion Approach to Increase Optimal Complementary Feeding among Pastoral Mothers Having Children between 6 and 23 Months in Dikhil, Djibouti

Authors: Haruka Ando

Abstract:

Undernutrition of children is a critical issue, especially for people in the remote areas of the Republic of Djibouti, since household food insecurity, inadequate child caring and feeding, unhealthy environment and lack of clean water, as well as insufficient maternal and child healthcare, are underlying causes which affect. Nomadic pastoralists living in the Dikhil region (Dikhil) are socio-economically and geographically more vulnerable due to displacement, which in turn worsens the situation of child stunting. A high prevalence of inappropriate complementary feeding among pastoral mothers might be a significant barrier to child growth. This study aims to identify health promotion intervention strategies that would support an increase in optimal complementary feeding among pastoral mothers of children aged 6-23 months in Dikhil. There are four objectives; to explore and to understand the existing practice of complementary feeding among pastoral mothers in Dikhil; to identify the barriers in appropriate complementary feeding among the mothers; to critically explore and analyse the strategies for an increase in complementary feeding among the mothers; to make pragmatic recommendations to address the barriers in Djibouti. This is an in-depth study utilizing a conceptual framework, the behaviour change wheel, to analyse the determinants of complementary feeding and categorize health promotion interventions for increasing optimal complementary feeding among pastoral mothers living in Dikhil. The analytical tool was utilized to appraise the strategies to mitigate the selected barriers against optimal complementary feeding. The data sources were secondary literature from both published and unpublished sources. The literature was systematically collected. The findings of the determinants including the barriers of optimal complementary feeding were identified: heavy household workload, caring for multiple children under five, lack of education, cultural norms and traditional eating habits, lack of husbands' support, poverty and food insecurity, lack of clean water, low media coverage, insufficient health services on complementary feeding, fear, poor personal hygiene, and mothers' low decision-making ability and lack of motivation for food choice. To mitigate selected barriers of optimal complementary feeding, four intervention strategies based on interpersonal communication at the community-level were chosen: scaling up mothers' support groups, nutrition education, grandmother-inclusive approach, and training for complementary feeding counseling. The strategies were appraised through the criteria of effectiveness and feasibility. Scaling up mothers' support groups could be the best approach. Mid-term and long-term recommendations are suggested based on the situation analysis and appraisal of intervention strategies. Mid-term recommendations include complementary feeding promotion interventions are integrated into the healthcare service providing system in Dikhil, and donor agencies advocate and lobby the Ministry of Health Djibouti (MoHD) to increase budgetary allocation on complementary feeding promotion to implement interventions at a community level. Moreover, the recommendations include a community health management team in Dikhil training healthcare workers and mother support groups by using complementary feeding communication guidelines and monitors behaviour change of pastoral mothers and health outcome of their children. Long-term recommendations are the MoHD develops complementary feeding guidelines to cover sector-wide collaboration for multi-sectoral related barriers.

Keywords: Afar, child food, child nutrition, complementary feeding, complementary food, developing countries, Djibouti, East Africa, hard-to-reach areas, Horn of Africa, nomad, pastoral, rural area, Somali, Sub-Saharan Africa

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1094 Research on Users' Obesity and Office Tower Core-Tube Design from the Perspective of Physical Activities

Authors: Ming Ma, Zhenyu Cai, Rui Li

Abstract:

People are more vulnerable to health problems than ever before, such as overweight and obesity due to the change of built environment. In the high-rise buildings, the core-tube layout is closely associated with user’s physical activities which will affect human’s health in a long-term. As for the white-collars who spends the amount of time working in the office tower, using staircase seems to provide an opportunity for them to increase the physical activities in the workplaces. This paper is aiming to find out the specific relationship between health and core-tube in the office tower through analyzing the correlation between staircase’s layout and user’s health. The variables of staircase’s layout are consisted of two indicators: plan layout and space design, including nine factors while health variable is applying BIM as the only main factor. 14 office towers in downtown Shanghai are selected as the research samples because of its typical users’ pattern and similar core-tube layout. In the result, it is obvious that the users from these 14 cases have higher BMI than average partly because that the staircases are mainly designed for emergency and fire instead of daily use. After the regression and correlation analysis of the variables of health and staircases, it’s found that users’ BMI is significantly associated with the factors of floor guide-signs and distance from lobby to the staircase. In addition, the factors of comfort level of staircase such as width and daylighting have a certain correlation with users’ BMI.

Keywords: office tower, staircase, design, obesity, physical activity

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1093 Primary Fallopian Tube Carcinoma: A Case Report

Authors: Mary Abigail T. Ty, Mary Jocelyn Yu-Laygo, Jocelyn Z. Mariano

Abstract:

This is a case of L.S.T., a 61 year old, G6P4 (3124) who presented with a one month history of intermittent, brownish, watery, non foul smelling vaginal discharge. There were no other accompanying symptoms. On rectovaginal examination, a palpable adnexal mass on the left was appreciated, with the lower border measuring 3 cm. The mass was non-tender, had irregular borders and solid areas. On transvaginal sonography, it revealed a left pelvic mass measuring 3 x 4 x 2 cm, with a Sassone score of 9. It had vascularization. The primary consideration was Ovarian Newgrowth, probably malignant in nature. CA-125 results were slightly elevated at 43.2 u/ml (NV: 0-35 u/ml). After intraoperative evaluation, the left fallopian tube was converted into a 9 x 4.5 x 3 cm bulbous cystic mass with solid areas. On cut section, the ampullary portion of the fallopian tube contained necrotic and friable looking tissues. Specimen was sent for frozen section and results revealed adenocarcinoma of the left fallopian tube. Patient subsequently underwent complete surgical staging with unremarkable post-operative course. The Surg Ico pathologic diagnosis was G6P4 (3124) Fallopian tube serous cystadenocarcinoma stage 1. The mean incidence of PFTC is 3.6 per million women yearly. This is associated with a generally low survival rate. The primary diagnosis is very difficult to establish because only 0–10% of patients suffering from PFTC are diagnosed pre-operatively. Symptoms play a very important role in the discovery of this disease, because there will be no presentation to the hospital without symptoms. The most common of which may be vaginal bleeding, abdominal pain, a palpable mass and ascites. A conglomerate of manifestations may be encountered, but not at all times. This is termed hydrops tubae profluens where there is presence of colicky pain with relief from intermittent passage of serosanguinous vaginal discharge. The significance of this report is to emphasize the rarity of the case and how the dilemma in the diagnosis is almost always present despite ancillary procedures.

Keywords: fallopian tube carcinoma, prognosis, rare, risk factors

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1092 Fathers' Knowledge and Attitude towards Breastfeeding: A Cross Sectional Study

Authors: Jacqueline R. Llamas, Agnes Regal

Abstract:

Objective: To determine the breastfeeding knowledge and attitudes of fathers seen at the University of Santo Tomas Hospital. Design: Cross-sectional design. Setting: University of Santo Tomas Hospital (USTH). Participants: 156 fathers who were accompanying their wives/children at the USTH. Findings: Outcome of the Iowa Infant Feeding Attitude Scale showed fathers to be generally unbiased whether their child be fed breast milk or milk formula. About 85% agreed that breast milk is the ideal food for babies, 79% believed that breastfed babies are healthier than formula fed and 55% of them do not believe that breast milk lacks iron. About 80% agreed that it is easily digested, 87% are aware of the economical value and 57% agreed of its convenience. Breastfeeding support was noted when 55% of the fathers would encourage mothers to breastfeed so as not to miss the joys of motherhood, 91% believed that breastfeeding increased mother-infant bonding. About 57% do not feel left out whenever the mothers breastfeed. However, 46.6% support the decision of their wives to switch to formula feeding once they go back to work, 42% only find breastfeeding in public to be acceptable and 57% will not allow breast feeding to mothers who drink alcohol. Conclusion: In the study, although fathers’ attitude toward breastfeeding is unbiased towards breastfeeding or formula feeding, the majority of the fathers appreciate breastfeeding and its benefits. Also, how the father’s level of education, age, profession, household income and number of children had an effect on their attitude towards breastfeeding.

Keywords: father, breastfeeding, breast milk, knowledge

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1091 Empirical Heat Transfer Correlations of Finned-Tube Heat Exchangers in Pulsatile Flow

Authors: Jason P. Michaud, Connor P. Speer, David A. Miller, David S. Nobes

Abstract:

An experimental study on finned-tube radiators has been conducted. Three radiators found in desktop computers sized for 120 mm fans were tested in steady and pulsatile flows of ambient air over a Reynolds number range of  50 < Re < 900. Water at 60 °C was circulated through the radiators to maintain a constant fin temperature during the tests. For steady flow, it was found that the heat transfer rate increased linearly with the mass flow rate of air. The pulsatile flow experiments showed that frequency of pulsation had a negligible effect on the heat transfer rate for the range of frequencies tested (0.5 Hz – 2.5 Hz). For all three radiators, the heat transfer rate was decreased in the case of pulsatile flow. Linear heat transfer correlations for steady and pulsatile flow were calculated in terms of Reynolds number and Nusselt number.

Keywords: finned-tube heat exchangers, heat transfer correlations, pulsatile flow, computer radiators

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1090 Design and Manufacture of Removable Nosecone Tips with Integrated Pitot Tubes for High Power Sounding Rocketry

Authors: Bjorn Kierulf, Arun Chundru

Abstract:

Over the past decade, collegiate rocketry teams have emerged across the country with various goals: space, liquid-fueled flight, etc. A critical piece of the development of knowledge within a club is the use of so-called "sounding rockets," whose goal is to take in-flight measurements that inform future rocket design. Common measurements include acceleration from inertial measurement units (IMU's), and altitude from barometers. With a properly tuned filter, these measurements can be used to find velocity, but are susceptible to noise, offset, and filter settings. Instead, velocity can be measured more directly and more instantaneously using a pitot tube, which operates by measuring the stagnation pressure. At supersonic speeds, an additional thermodynamic property is necessary to constrain the upstream state. One possibility is the stagnation temperature, measured by a thermocouple in the pitot tube. The routing of the pitot tube from the nosecone tip down to a pressure transducer is complicated by the nosecone's structure. Commercial-off-the-shelf (COTS) nosecones come with a removable metal tip (without a pitot tube). This provides the opportunity to make custom tips with integrated measurement systems without making the nosecone from scratch. The main design constraint is how the nosecone tip is held down onto the nosecone, using the tension in a threaded rod anchored to a bulkhead below. Because the threaded rod connects into a threaded hole in the center of the nosecone tip, the pitot tube follows a winding path, and the pressure fitting is off-center. Two designs will be presented in the paper, one with a curved pitot tube and a coaxial design that eliminates the need for the winding path by routing pressure through a structural tube. Additionally, three manufacturing methods will be presented for these designs: bound powder filament metal 3D printing, stereo-lithography (SLA) 3D printing, and traditional machining. These will employ three different materials, copper, steel, and proprietary resin. These manufacturing methods and materials are relatively low cost, thus accessible to student researchers. These designs and materials cover multiple use cases, based on how fast the sounding rocket is expected to travel and how important heating effects are - to measure and to avoid melting. This paper will include drawings showing key features and an overview of the design changes necessitated by the manufacture. It will also include a look at the successful use of these nosecone tips and the data they have gathered to date.

Keywords: additive manufacturing, machining, pitot tube, sounding rocketry

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1089 Modeling of Full Range Flow Boiling Phenomenon in 23m Long Vertical Steam Generator Tube

Authors: Chaitanya R. Mali, V. Vinod, Ashwin W. Patwardhan

Abstract:

Design of long vertical steam generator (SG) tubes in nuclear power plant involves an understanding of different aspects of flow boiling phenomenon such as flow instabilities, flow regimes, dry out, critical heat flux, pressure drop, etc. The knowledge of the prediction of local thermal hydraulic characteristics is necessary to understand these aspects. For this purpose, the methodology has been developed which covers all the flow boiling regimes to model full range flow boiling phenomenon. In this methodology, the vertical tube is divided into four sections based on vapor fraction value at the end of each section. Different modeling strategies have been applied to the different sections of the vertical tube. Computational fluid dynamics simulations have been performed on a vertical SG tube of 0.0126 m inner diameter and 23 m length. The thermal hydraulic parameters such as vapor fraction, liquid temperature, heat transfer coefficient, pressure drop, heat flux distribution have been analyzed for different designed heat duties (1.1 MW (20%) to 3.3 MW (60%)) and flow conditions (10 % to 80 %). The sensitivity of different boiling parameters such as bubble departure diameter, nucleation site density, bubble departure frequency on the thermal hydraulic parameters was also studied. Flow instability has been observed at 20 % designed heat duty and 20 % flow conditions.

Keywords: thermal hydraulics, boiling, vapor fraction, sensitivity

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1088 Effects of Position and Cut-Out Lengths on the Axial Crushing Behavior of Aluminum Tubes: Experimental and Simulation

Authors: B. Käfer, V. K. Bheemineni, H. Lammer, M. Kotnik, F. O. Riemelmoser

Abstract:

Axial compression tests are performed on circular tubes made of Aluminum EN AW 6060 (AlMgSi0.5 alloy) in T66 state. All the received tubes have the uniform outer diameter of 40mm and thickness of 1.5mm. Two different lengths 100mm and 200mm are used in the analysis. After performing compression tests on the uniform tube, important crashworthy parameters like peak force, average force, crush efficiency and energy absorption are measured. The present paper has given importance to increase the percentage of crush efficiency without decreasing the value energy absorption of a tube, so a circumferential notch was introduced on the top section of the tube. The effects of position and cut-out lengths of a circumferential notch on the crush efficiency are well explained with relative deformation modes and force-displacement curves. The numerical simulations were carried on the software tool ANSYS/LS-DYNA. It is seen that the numerical results are reasonably good in agreement with the experimental results. 

Keywords: crash box, Notch triggering, energy absorption, FEM simulation

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1087 Structural Behavior of Composite Hollow RC Column under Combined Loads

Authors: Abdul Qader Melhm, Hussein Elrafidi

Abstract:

This paper is dealing with studying the structural behavior of a steel-composite hollow reinforced concrete (RC) column model under combined eccentric loading. The composite model consists of an inner steel tube surrounded via a concrete core with longitudinal and circular transverse reinforcement. The radius of gyration according to American and Euro specifications be calculated, in order to calculate the thinnest ratio for this type of composite column model, in addition to the flexural rigidity. Formulas for interaction diagram is given for this type of model, which is a general loading conditions in which an element is exposed to an axial load with bending at the same time. The structural capacity of this model, elastic, plastic loads and strains will be computed and compared with experimental results. The total eccentric axial load of the column model is calculated based on the effective length KL available from several relationships provided in the paper. Furthermore, the inner tube experiences buckling failure after reaching its maximum strength will be investigated.

Keywords: column, composite, eccentric, inner tube, interaction, reinforcement

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1086 Mixed Convection Heat Transfer of Copper Oxide-Heat Transfer Oil Nanofluid in Vertical Tube

Authors: Farhad Hekmatipour, M. A. Akhavan-Behabadi, Farzad Hekmatipour

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In this paper, experiments were conducted to investigate the heat transfer of Copper Oxide-Heat Transfer Oil (CuO-HTO) nanofluid laminar flow in vertical smooth and microfin tubes as the surface temperature is constant. The effect of adding the nanoparticle to base fluid and Richardson number on the heat transfer enhancement is investigated as Richardson number increases from 0.1 to 0.7. The experimental results demonstrate that the combined forced-natural convection heat transfer rate may be improved significantly with an increment of mass nanoparticle concentration from 0% to 1.5%. In this experiment, a correlation is also proposed to predict the mixed convection heat transfer rate of CuO-HTO nanofluid flow. The maximum deviation of both correlations is less than 14%. Moreover, a correlation is presented to estimate the Nusselt number inside vertical smooth and microfin tubes as Rayleigh number is between 2´105 and 6.8´106 with the maximum deviation of 12%.

Keywords: mixed convection, heat transfer, nanofluid, vertical tube, microfin tube

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1085 Design, Fabrication, and Study of Droplet Tube Based Triboelectric Nanogenerators

Authors: Yana Xiao

Abstract:

The invention of Triboelectric Nanogenerators (TENGs) provides an effective approach to the sustainable power of energy. Liquid-solid interfaces-based TENGs have been researched in virtue of less friction for harvesting energy from raindrops, rivers, and oceans in the form of water flows. However, TENGs based on droplets have rarely been investigated. In this study, we have proposed a new kind of droplet tube-based TENG (DT-TENG) with free-standing and reformative grating electrodes. Both straight and curved DT-TENGs were designed, fabricated, and evaluated, including straight tubes TENG with 27 electrodes and curved tubes TENG of 25cm radius curvature- at the inclination of 30°, 45° and 60° respectively. Different materials and hydrophobicity treatments for the tubes have also been studied, together with a discussion on the mechanism and applications of DT-TENGs. As different types of liquid discrepant energy performance, this kind of DT-TENG can be potentially used in laboratories to identify liquid or solvent. In addition, a smart fishing float is contrived, which can recognize different levels of movement speeds brought about by different weights and generate corresponding electric signals to remind the angler. The electric generation performance when using a PVC helix tube around a cylinder is similar in straight situations under the inclination of 45° in this experiment. This new structure changes the direction of a water drop or flows without losing kinetic energy, which makes utilizing Helix-Tube-TENG to harvest energy from different building morphologies possible.

Keywords: triboelectric nanogenerator, energy harvest, liquid tribomaterial, structure innovation

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1084 Clinico-Microbiological Study of S. aureus from Various Clinical Samples with Reference to Methicillin Resistant S. aureus (MRSA)

Authors: T. G. Pathrikar, A. D. Urhekar, M. P. Bansal

Abstract:

To find out S. aureus from patient samples on the basis of coagulase test. We have evaluated slide coagulase (n=46 positive), tube coagulase (n=48 positive) and DNase test (n=44, positive) , We have isolated and identified MRSA from various clinical samples and specimens by disc diffusion method determined the incidence of MRSA 50% in patients. Found out the in vitro antimicrobial susceptibility pattern of MRSA isolates and also the MIC of MRSA of oxacillin by E-Test.

Keywords: cefoxitin disc diffusion MRSA detection, e – test, S. aureus devastating pathogen, tube coagulase confirmation

Procedia PDF Downloads 494
1083 Investigation on Scattered Dose Rate and Exposure Parameters during Diagnostic Examination Done with an Overcouch X-Ray Tube in Nigerian Teaching Hospital

Authors: Gbenga Martins, Christopher J. Olowookere, Lateef Bamidele, Kehinde O. Olatunji

Abstract:

The aims of this research are to measure the scattered dose rate during an X-ray examination in an X-ray room, compare the scattered dose rate with exposure parameters based on the body region examined, and examine the X-ray examination done with an over couch tube. The research was carried out using Gamma Scout software installation on the computer system (Laptop) to record the radiation counts, pulse rate, and dose rate. The measurement was employed by placing the detector at 900 to the incident X-ray. Proforma was used for the collection of patients’ data such as age, sex, examination type, and initial diagnosis. Data such as focus skin distance (FSD), body mass index (BMI), body thickness of the patients, the beam output (kVp) were collected at Obafemi Awolowo University, Ile-Ife, Western Nigeria. Total number of 136 patients was considered during this research. Dose rate range between 14.21 and 86.78 µSv/h for the plain abdominal region, 85.70 and 2.86 µSv/h for the lumbosacral region,1.3 µSv/yr and 3.6 µSv/yr in the pelvis region, 2.71 µSv/yr and 28.88 µSv/yr for leg region, 3.06 µSv/yr and 29.98 µSv/yr in hand region. The results of this study were compared with those of other studies carried out in other countries. The findings of this study indicated that the number of exposure parameters selected for each diagnostic examination contributed to the dose rate recorded. Therefore, these results call for a quality assurance program (QAP) in diagnostic X-ray units in Nigerian hospitals.

Keywords: X-radiation, exposure parameters, dose rate, pulse rate, number of counts, tube current, tube potential, diagnostic examination, scattered radiation

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1082 Exclusive Breast Feeding Practices in Bangladesh

Authors: Md. Ashikur Rahman

Abstract:

Optimal breastfeeding practice is essential to reducing childhood morbidity and mortality and helps to achieve Millennium Development Goal (MDG). A cross-sectional study was conducted in a rural area in Dhaka district to explore the barrier to optimal breastfeeding practices. The population of this study constitutes all nursing mothers having children aged 0-6 months, and they were selected purposively. The study adopted a structured and in-depth interview procedure consisting of open and closed-ended questions. Four hundred rural nursing mothers constituted the sample of the structured interview, while 15 were involved in the in-depth interview. Among the respondent's majority (67%) were in the age group 17-25 years, with a mean age of 24.44 years. Most (39.5%) of the mothers were housewives with a secondary level of education (46.5%). About 32% of mothers started breastfeeding within one hour after birth. But delayed initiation was reported in 31.5% of mothers, whereas 36.8% of mothers forgot the exact time of initiation of breastfeeding. The main reason not to practice colostrum was mothers tried to breastfeed, but there was no milk, stated 13.8% of mothers. In addition, about one-third (34.3%) of the respondents practiced pre-lacteal feeding, and among them, 12.8% introduced sugar with water. Reasons given by the mothers for bottle-feeding was that baby was not satisfied with breast milk only; 22.0% of mothers indicated this cause. The main influence to take formula milk by their mother and mothers-in-law was stated by 18.8% of mothers. Some mothers stated that major constraints to EBF were the perception of not having enough milk (25.5 %) and babies crying seems to be hungry (8.8%). One-third of the mothers (31.5%) felt uncomfortable during breastfeeding. Access to antenatal and postnatal counseling in the study area also was a key obstacle to optimal breastfeeding practices. In a qualitative survey, some mothers believed that there was no difference between breast milk and formula milk. Colostrum feeding, pre-lacteal feeding, early initiation of breastfeeding, and exclusive breastfeeding were strongly associated with family type, family member, birth order, religion, husbands' occupation, delivery attendants and delivery type, postnatal care, and health care facilities. To reduce the barriers to the successful practice of exclusive breastfeeding, there is a need for a grass-roots approach to educating and counseling nursing mothers with identifying factors influencing or discouraging the optimal practice.

Keywords: exclusive, breast feeding, practices, Bangladesh

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1081 The Possibility of Increase UFA in Milk by Adding of Canola Seed in Holstein Dairy Cow Diets

Authors: H. Mansoori Yarahmadi, A. Aghazadeh, K. Nazeradl

Abstract:

This study was done to evaluate the effects of feeding canola seed for enrichment of UFA and milk performance of early lactation dairy cows. Twelve multi parous Holstein cows (635.3±18 kg BW and 36±9 DIM) were assigned to 1 of 3 treatments: 1- Control (CON) without canola seed, 2- 7.5% raw canola seed (CUT), and 3- 7.5% Heat-treated canola seed (CHT) of the total ration. Diets contained same crude protein, but varied in net energy. Diets were composed by basis of corn silage and alfalfa. Cows were milked twice daily for 4 wk. The inclusion of canola seed did not alter DM intake, weight gain, or body condition score of cows. Milk fat from CHT cows had greater proportions of UFA and MUFA (P < 0.05). Feeding CUT increased PUFA without significant difference. Milk fat from CHT had a greater proportion of C18 UFA and tended to have a higher proportion of other UFA. FCM milk yields, milk fat and protein percentages and total yield of these components were similar between treatments. Milk urea nitrogen was lower in cows fed CON and CHT. Feeding canola seed to lactating dairy cows resulted in milk fat with higher proportions of healthful fatty acids without adverse affecting milk yield or milk composition.

Keywords: canola seed, fatty acid, dairy cow, milk

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1080 Phase Diagram Including a Negative Pressure Region for a Thermotropic Liquid Crystal in a Metal Berthelot Tube

Authors: K. Hiro, T. Wada

Abstract:

Thermodynamic properties of liquids under negative pressures are interesting and important in fields of scienceand technology. Here, phase transitions of a thermotropic liquid crystal are investigatedin a range from positive to negative pressures with a metal Berthelot tube using a commercial pressure transducer.Two co-existinglines, namely crystal (Kr) – nematic (N), and isotropic liquid (I) - nematic (N) lines, weredrawn in a pressure - temperature plane. The I-N line was drawn to ca. -5 (MPa).

Keywords: Berthelot method, liquid crystal, negative pressure, phase transitions

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1079 Effect of Relaxation Techniques on Immunological Properties of Breast Milk

Authors: Ahmed Ali Torad

Abstract:

Background: Breast feeding maintains the maternal fetal immunological link, favours the transmission of immune-competence from the mother to her infant and is considered an important contributory factor to the neo natal immune defense system. Purpose: This study was conducted to investigate the effect of relaxation techniques on immunological properties of breast milk. Subjects and Methods: Thirty breast feeding mothers with a single, mature infant without any complications participated in the study. Subjects will be recruited from outpatient clinic of obstetric department of El Kasr El-Aini university hospital in Cairo. Mothers were randomly divided into two equal groups using coin toss method: Group (A) (relaxation training group) (experimental group): It will be composed of 15 women who received relaxation training program in addition to breast feeding and nutritional advices and Group (B) (control group): It will be composed of 15 women who received breast feeding and nutritional advices only. Results: The results showed that mean mother’s age was 28.4 ± 3.68 and 28.07 ± 4.09 for group A and B respectively, there were statistically significant differences between pre and post values regarding cortisol level, IgA level, leucocyte count and infant’s weight and height and there is only statistically significant differences between both groups regarding post values of all immunological variables (cortisol – IgA – leucocyte count). Conclusion: We could conclude that there is a statistically significant effect of relaxation techniques on immunological properties of breast milk.

Keywords: relaxation, breast, milk, immunology, lactation

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1078 Modelling of Solidification in a Latent Thermal Energy Storage with a Finned Tube Bundle Heat Exchanger Unit

Authors: Remo Waser, Simon Maranda, Anastasia Stamatiou, Ludger J. Fischer, Joerg Worlitschek

Abstract:

In latent heat storage, a phase change material (PCM) is used to store thermal energy. The heat transfer rate during solidification is limited and considered as a key challenge in the development of latent heat storages. Thus, finned heat exchangers (HEX) are often utilized to increase the heat transfer rate of the storage system. In this study, a new modeling approach to calculating the heat transfer rate in latent thermal energy storages with complex HEX geometries is presented. This model allows for an optimization of the HEX design in terms of costs and thermal performance of the system. Modeling solidification processes requires the calculation of time-dependent heat conduction with moving boundaries. Commonly used computational fluid dynamic (CFD) methods enable the analysis of the heat transfer in complex HEX geometries. If applied to the entire storage, the drawback of this approach is the high computational effort due to small time steps and fine computational grids required for accurate solutions. An alternative to describe the process of solidification is the so-called temperature-based approach. In order to minimize the computational effort, a quasi-stationary assumption can be applied. This approach provides highly accurate predictions for tube heat exchangers. However, it shows unsatisfactory results for more complex geometries such as finned tube heat exchangers. The presented simulation model uses a temporal and spatial discretization of heat exchanger tube. The spatial discretization is based on the smallest possible symmetric segment of the HEX. The heat flow in each segment is calculated using finite volume method. Since the heat transfer fluid temperature can be derived using energy conservation equations, the boundary conditions at the inner tube wall is dynamically updated for each time step and segment. The model allows a prediction of the thermal performance of latent thermal energy storage systems using complex HEX geometries with considerably low computational effort.

Keywords: modelling of solidification, finned tube heat exchanger, latent thermal energy storage

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1077 Simulation of the Asphaltene Deposition Rate in a Wellbore Blockage via Computational Fluid Dynamic

Authors: Xiaodong Gao, Pingchuan Dong, Qichao Gao

Abstract:

There has been lots of published work focused on asphaltene deposited on the smooth pipe under steady conditions, while particle deposition on the blockage wellbores under transient conditions has not been well elucidated. This work attempts to predict the deposition rate of asphaltene particles in blockage tube through CFD simulation. The Euler-Lagrange equation has been applied during the flow of crude oil and asphaltene particles. The net gravitational force, virtual mass, pressure gradient, saffman lift, and drag forces are incorporated in the simulations process. Validation of CFD simulation results is compared to the benchmark experiments from the previous literature. Furthermore, the effect of blockage location, blockage length, and blockage thickness on deposition rate are also analyzed. The simulation results indicate that the maximum deposition rate of asphaltene occurs in the blocked tube section, and the greater the deposition thickness, the greater the deposition rate. Moreover, the deposition amount and maximum deposition rate along the length of the tube have the same trend. Results of this study are in the ability to better understand the deposition of asphaltene particles in production and help achieve to deal with the asphaltene challenges.

Keywords: asphaltene deposition rate, blockage length, blockage thickness, blockage diameter, transient condition

Procedia PDF Downloads 202