Search results for: distal radius fractures
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 710

Search results for: distal radius fractures

200 Bone Mineral Density in Long-Living Patients with Coronary Artery Disease

Authors: Svetlana V. Topolyanskaya, Tatyana A. Eliseeva, Olga N. Vakulenko, Leonid I. Dvoretski

Abstract:

Introduction: Limited data are available on osteoporosis in centenarians. Therefore, we evaluated bone mineral density in long-living patients with coronary artery disease (CAD). Methods: 202 patients hospitalized with CAD were enrolled in this cross-sectional study. The patients' age ranged from 90 to 101 years. The majority of study participants (64.4%) were women. The main exclusion criteria were any disease or medication that can lead to secondary osteoporosis. Bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry. Results: Normal lumbar spine BMD was observed in 40.9%, osteoporosis – in 26.9%, osteopenia – in 32.2% of patients. Normal proximal femur BMD values were observed in 21.3%, osteoporosis – in 39.9%, and osteopenia – in 38.8% of patients. Normal femoral neck BMD was registered only in 10.4% of patients, osteoporosis was observed in 60.4%, osteopenia in 29.2%. Significant positive correlation was found between all BMD values and body mass index of patients (p < 0.001). Positive correlation was registered between BMD values and serum uric acid (p=0.0005). The likelihood of normal BMD values with hyperuricemia increased 3.8 times, compared to patients with normal uric acid, who often have osteoporosis (Odds Ratio=3.84; p = 0.009). Positive correlation was registered between all BMD values and body mass index (p < 0.001). Positive correlation between triglycerides levels and T-score (p=0.02), but negative correlation between BMD and HDL-cholesterol (p=0.02) were revealed. Negative correlation between frailty severity and BMD values (p=0.01) was found. Positive correlation between BMD values and functional abilities of patients assessed using Barthel index (r=0,44; p=0,000002) and IADL scale (r=0,36; p=0,00008) was registered. Fractures in history were observed in 27.6% of patients. Conclusions: The study results indicate some features of BMD in long-livers. In the study group, significant relationships were found between bone mineral density on the one hand, and patients' functional abilities on the other. It is advisable to further study the state of bone tissue in long-livers involving a large sample of patients.

Keywords: osteoporosis, bone mineral density, centenarians, coronary artery disease

Procedia PDF Downloads 119
199 Simulation and Fabrication of Plasmonic Lens for Bacteria Detection

Authors: Sangwoo Oh, Jaewoo Kim, Dongmin Seo, Jaewon Park, Yongha Hwang, Sungkyu Seo

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Plasmonics has been regarded one of the most powerful bio-sensing modalities to evaluate bio-molecular interactions in real-time. However, most of the plasmonic sensing methods are based on labeling metallic nanoparticles, e.g. gold or silver, as optical modulation markers, which are non-recyclable and expensive. This plasmonic modulation can be usually achieved through various nano structures, e.g., nano-hole arrays. Among those structures, plasmonic lens has been regarded as a unique plasmonic structure due to its light focusing characteristics. In this study, we introduce a custom designed plasmonic lens array for bio-sensing, which was simulated by finite-difference-time-domain (FDTD) approach and fabricated by top-down approach. In our work, we performed the FDTD simulations of various plasmonic lens designs for bacteria sensor, i.e., Samonella and Hominis. We optimized the design parameters, i.e., radius, shape, and material, of the plasmonic lens. The simulation results showed the change in the peak intensity value with the introduction of each bacteria and antigen i.e., peak intensity 1.8711 a.u. with the introduction of antibody layer of thickness of 15nm. For Salmonella, the peak intensity changed from 1.8711 a.u. to 2.3654 a.u. and for Hominis, the peak intensity changed from 1.8711 a.u. to 3.2355 a.u. This significant shift in the intensity due to the interaction between bacteria and antigen showed a promising sensing capability of the plasmonic lens. With the batch processing and bulk production of this nano scale design, the cost of biological sensing can be significantly reduced, holding great promise in the fields of clinical diagnostics and bio-defense.

Keywords: plasmonic lens, FDTD, fabrication, bacteria sensor, salmonella, hominis

Procedia PDF Downloads 251
198 Community Engagement Strategies to Assist with the Development of an RCT Among People Living with HIV

Authors: Joyce K. Anastasi, Bernadette Capili

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Community Engagement Strategies to Assist with the Development of an RCT Among People Living with HIV Our research team focuses on developing and testing protocols to manage chronic symptoms. For many years, our team designed and implemented symptom management studies for people living with HIV (PLWH). We identify symptoms that are not curative and are not adequately controlled by conventional therapies. As an exemplar, we describe how we successfully engaged PLWH in developing and refining our research feasibility protocol for distal sensory peripheral neuropathy (DSP) associated with HIV. With input from PLWH with DSP, our research received National Institutes of Health (NIH) research funding support. Significance: DSP is one of the most common neurologic complications in HIV. It is estimated that DSP affects 21% to 50% of PLWH. The pathogenesis of DSP in HIV is complex and unclear. Proposed mechanisms include cytokine dysregulation, viral protein-produced neurotoxicity, and mitochondrial dysfunction associated with antiretroviral medications. There are no FDA-approved treatments for DSP in HIV. Purpose: Aims: 1) to explore the impact of DSP on the lives of PLWH, 2) to identify patients’ perspectives on successful treatments for DSP, 3) to identify interventions considered feasible and sensitive to the needs of PLWH with DSP, and 4) to obtain participant input for protocol/study design. Description of Process: We conducted a needs assessment with PLWH with DSP. From our needs assessment, we learned from the patients’ perspective detailed descriptions of their symptoms; physical functioning with DSP; self-care remedies tried, and desired interventions. We also asked about protocol scheduling, instrument clarity, study compensation, study-related burdens, and willingness to participate in a randomized controlled trial (RCT) with a placebo and a waitlist group. Implications: We incorporated many of the suggestions learned from the need assessment. We developed and completed a feasibility study that provided us with invaluable information that informed subsequent NIH-funded studies. In addition to our extensive clinical and research experience working with PLWH, learning from the patient perspective helped in developing our protocol and promoting a successful plan for recruitment and retention of study participants.

Keywords: clinical trial development, peripheral neuropathy, traditional medicine, HIV, AIDS

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197 Barnard Feature Point Detector for Low-Contractperiapical Radiography Image

Authors: Chih-Yi Ho, Tzu-Fang Chang, Chih-Chia Huang, Chia-Yen Lee

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In dental clinics, the dentists use the periapical radiography image to assess the effectiveness of endodontic treatment of teeth with chronic apical periodontitis. Periapical radiography images are taken at different times to assess alveolar bone variation before and after the root canal treatment, and furthermore to judge whether the treatment was successful. Current clinical assessment of apical tissue recovery relies only on dentist personal experience. It is difficult to have the same standard and objective interpretations due to the dentist or radiologist personal background and knowledge. If periapical radiography images at the different time could be registered well, the endodontic treatment could be evaluated. In the image registration area, it is necessary to assign representative control points to the transformation model for good performances of registration results. However, detection of representative control points (feature points) on periapical radiography images is generally very difficult. Regardless of which traditional detection methods are practiced, sufficient feature points may not be detected due to the low-contrast characteristics of the x-ray image. Barnard detector is an algorithm for feature point detection based on grayscale value gradients, which can obtain sufficient feature points in the case of gray-scale contrast is not obvious. However, the Barnard detector would detect too many feature points, and they would be too clustered. This study uses the local extrema of clustering feature points and the suppression radius to overcome the problem, and compared different feature point detection methods. In the preliminary result, the feature points could be detected as representative control points by the proposed method.

Keywords: feature detection, Barnard detector, registration, periapical radiography image, endodontic treatment

Procedia PDF Downloads 425
196 Estimation of Source Parameters and Moment Tensor Solution through Waveform Modeling of 2013 Kishtwar Earthquake

Authors: Shveta Puri, Shiv Jyoti Pandey, G. M. Bhat, Neha Raina

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TheJammu and Kashmir region of the Northwest Himalaya had witnessed many devastating earthquakes in the recent past and has remained unexplored for any kind of seismic investigations except scanty records of the earthquakes that occurred in this region in the past. In this study, we have used local seismic data of year 2013 that was recorded by the network of Broadband Seismographs in J&K. During this period, our seismic stations recorded about 207 earthquakes including two moderate events of Mw 5.7 on 1st May, 2013 and Mw 5.1 of 2nd August, 2013.We analyzed the events of Mw 3-4.6 and the main events only (for minimizing the error) for source parameters, b value and sense of movement through waveform modeling for understanding seismotectonic and seismic hazard of the region. It has been observed that most of the events are bounded between 32.9° N – 33.3° N latitude and 75.4° E – 76.1° E longitudes, Moment Magnitude (Mw) ranges from Mw 3 to 5.7, Source radius (r), from 0.21 to 3.5 km, stress drop, from 1.90 bars to 71.1 bars and Corner frequency, from 0.39 – 6.06 Hz. The b-value for this region was found to be 0.83±0 from these events which are lower than the normal value (b=1), indicating the area is under high stress. The travel time inversion and waveform inversion method suggest focal depth up to 10 km probably above the detachment depth of the Himalayan region. Moment tensor solution of the (Mw 5.1, 02:32:47 UTC) main event of 2ndAugust suggested that the source fault is striking at 295° with dip of 33° and rake value of 85°. It was found that these events form intense clustering of small to moderate events within a narrow zone between Panjal Thrust and Kishtwar Window. Moment tensor solution of the main events and their aftershocks indicating thrust type of movement is occurring in this region.

Keywords: b-value, moment tensor, seismotectonics, source parameters

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195 Long-Term Effect of Dialysis Therapy for Osteoporosis and Extra-Osseous Calcification in Chronic Renal Failure

Authors: Itsuo Yokoyama, Rikako Kikuti, Naoko Watabe, Tosinori Asai, Sarai Tsuyoshi

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Introduction: Chronic kidney disease presents significant changes in mineral and bone metabolism, referred to as CKD-MBD. These changes lead to decreased bone mass, heightened bone fragility, fractures, and increased vascular and valvular calcification, ultimately impacting cardiovascular outcomes. Key contributors to these complications in dialysis patients include calcium, phosphate, parathyroid hormone (PTH), fibroblast growth factor 23 (FGF23), and the vitamin D hormonal system. Methods: In our outpatient dialysis clinic, we monitor the long-term effects of vascular calcifications by calculating the volume of calcified areas in the abdominal aorta based on CT scan data. The results revealed a progressive nature of vascular calcification. To extend our study, we measured the volume of calcification in bones (vertebrae and femur) corresponding to Hounsfield units of 200 and 300. The study aims to investigate changes in osteoporosis during a 5-year follow-up period and its relationship with extraosseous calcification. Results and Considerations: While extraosseous calcification demonstrated a generally progressive nature, often resistant to medical treatment, the degree of osteoporotic change varied among patients. The majority exhibited continuous osteoporotic changes, while some showed improvement or minimal changes in bone calcification. Variations in the distribution and magnitude of osteoporotic changes were observed between groups based on the timing of hemodialysis initiation during the study. The former group tended to display more osteoporotic changes, possibly attributed to differences in medication between the groups. Other contributing factors may include the patient's age, duration of dialysis, or causes of renal disease. In conclusion, we emphasize the importance of carefully monitoring calcium and phosphate levels and maintaining adequate dialysis therapy to prevent osteoporosis in dialysis patients.

Keywords: CKD-MBD, dialysis, calcification, kidney

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194 Evaluation of the Urban Landscape Structures and Dynamics of Hawassa City, Using Satellite Images and Spatial Metrics Approaches, Ethiopia

Authors: Berhanu Terfa, Nengcheng C.

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The study deals with the analysis of urban expansion and land transformation of Hawass City using remote sensing data and landscape metrics during last three decades (1987–2017). Remote sensing data from Various multi-temporal satellite images viz., TM (1987), TM (1995), ETM+ (2005) and OLI (2017) were used to examine the urban expansion, growth types, and spatial isolation within the urban landscape to develop an understanding the trends of built-up growth in Hawassa City, Ethiopia. Landscape metrics and built-up density were employed to analyze the pattern, process and overall growth status. The area under investigation was divided into concentric circles with a consecutive circle of 1 km incremental radius from the central pixel (Central Business District) for analysis. The result exhibited that the built-up area had increased by 541.32% between 1987 and 2017and an extension growth types (more than 67 %) was observed. The major growth took place in north-west direction followed by north direction in haphazard manner during 1987–1995 period, whereas predominant built-up development was observed in south and southwest direction during 1995–2017 period. Land scape metrics result revealed that the of urban patches density, total edge and edge density increased, while mean nearest neighbors’ distance decreased showing the tendency of sprawl.

Keywords: landscape metrics, spatial patterns, remote sensing, multi-temporal, urban sprawl

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193 Total Arterial Coronary Revascularization with Aorto-Bifemoral Bipopliteal Bypass: A Case Report

Authors: Nuruddin Mohammod Zahangir, Syed Tanvir Ahmady, Firoz Ahmed, Mainul Kabir, Tamjid Mohammad Najmus Sakib Khan, Nazmul Hossain, Niaz Ahmed, Madhava Janardhan Naik

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The management of combined Coronary Artery Disease and Peripheral Vascular Disease is a challenge and brings with it numerous clinical dilemmas.The 56 year old gentleman presented to our department with significant triple vessel disease with occluded lower end of aorta just before bifurcation and bilateral superficial femoral arteries. Operation was done on 11.03.14. The The Left Internal Mammary Artery (LIMA) and the Right Internal Mammary Artery (RIMA) were harvested in skeletonized manner. The free RIMA was then anastomosed with LIMA to make LIMA-RIMA Y. Cardio Pulmonary Bypass was then established and coronary artery bypass grafts performed. LIMA was anastomosed to the Left Anterior Descending artery. RIMA was anastomosed to Posterior Descending Artery, 1st and 2nd Obtuse Marginal arteries in a sequential manner. Abdomen was opened by midline incision. The infrarenal aorta exposed and was found to be severely diseased. A Vascular Clamp was applied infrarenally, aortotomy done and limited endarterectomy performed. An end-to-side anastomosis was done with upper end of PTFE synthetic Y-graft (14/7 mm) to the infarenal Aorta and the Clamp released. Good flow noted in both limbs of the graft. Patient was then slowly weaned off from Cardio Pulmonary Bypass without difficulty. The distal two limbs of the Y graft were passed to the groin through retroperitoneal tunnels and anastomosed end-to-side with the common femoral arteries. Saphenous vein was interposed between common femoral and popliteal arteries bilaterally through subfascial tunnels in both thigh. On 12th postoperative day he was discharged from hospital in good general condition. Follow up after 3 months of operation the patient is doing good and free of chest pain and claudication pain.

Keywords: total arterial, coronary revascularization, aorto-bifemoral bypass, bifemoro-bipopliteal bypass

Procedia PDF Downloads 446
192 Effects of Intergenerational Social Mobility on General Health, Oral Health and Physical Function among Older Adults in England

Authors: Alejandra Letelier, Anja Heilmann, Richard G. Watt, Stephen Jivraj, Georgios Tsakos

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Background: Socioeconomic position (SEP) influences adult health. People who experienced material disadvantages in childhood or adulthood tend to have higher adult disease levels than their peers from more advantaged backgrounds. Even so, life is a dynamic process and contains a series of transitions that could lead people through different socioeconomic paths. Research on social mobility takes this into account by adopting a trajectory approach, thereby providing a long-term view of the effect of SEP on health. Aim: The aim of this research examines the effects of intergenerational social mobility on adult general health, oral health and functioning in a population aged 50 and over in England. Methods: This study is based on the secondary analysis of data from the English Longitudinal Study of Ageing (ELSA). Using cross-sectional data, nine social trajectories were created based on parental and adult occupational socio-economic position. Regression models were used to estimate the associations between social trajectories and the following outcomes: adult self-rated health, self-rated oral health, oral health related quality of life, total tooth loss and grip strength; while controlling for socio-economic background and health related behaviours. Results: Associations with adult SEP were generally stronger than with childhood SEP, suggesting a stronger influence of proximal rather than distal SEP on health and oral health. Compared to the stable high group, being in the low SEP groups in childhood and adulthood was associated with poorer health and oral health for all examined outcome measures. For adult self-rated health and edentulousness, graded associations with social mobility trajectories were observed. Conclusion: Intergenerational social mobility was associated with self-rated health and total tooth loss. Compared to only those who remained in a low SEP group over time reported worse self-rated oral health and oral health related quality of life, and had lower grip strength measurements. Potential limitations in relation to data quality will be discussed.

Keywords: social determinants of oral health, social mobility, socioeconomic position and oral health, older adults oral health

Procedia PDF Downloads 254
191 Kýklos Dimensional Geometry: Entity Specific Core Measurement System

Authors: Steven D. P Moore

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A novel method referred to asKýklos(Ky) dimensional geometry is proposed as an entity specific core geometric dimensional measurement system. Ky geometric measures can constructscaled multi-dimensionalmodels using regular and irregular sets in IRn. This entity specific-derived geometric measurement system shares similar fractal methods in which a ‘fractal transformation operator’ is applied to a set S to produce a union of N copies. The Kýklos’ inputs use 1D geometry as a core measure. One-dimensional inputs include the radius interval of a circle/sphere or the semiminor/semimajor axes intervals of an ellipse or spheroid. These geometric inputs have finite values that can be measured by SI distance units. The outputs for each interval are divided and subdivided 1D subcomponents with a union equal to the interval geometry/length. Setting a limit of subdivision iterations creates a finite value for each 1Dsubcomponent. The uniqueness of this method is captured by allowing the simplest 1D inputs to define entity specific subclass geometric core measurements that can also be used to derive length measures. Current methodologies for celestial based measurement of time, as defined within SI units, fits within this methodology, thus combining spatial and temporal features into geometric core measures. The novel Ky method discussed here offers geometric measures to construct scaled multi-dimensional structures, even models. Ky classes proposed for consideration include celestial even subatomic. The application of this offers incredible possibilities, for example, geometric architecture that can represent scaled celestial models that incorporates planets (spheroids) and celestial motion (elliptical orbits).

Keywords: Kyklos, geometry, measurement, celestial, dimension

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190 Roll Forming Process and Die Design for a Large Size Square Tube

Authors: Jinn-Jong Sheu, Cang-Fu Liang, Cheng-Hsien Yu

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This paper proposed the cold roll forming process and the die design methods for a 400mm by 400 mm square tube with 16 mm in thickness. The tubular blank made by cold roll forming is 508mm in diameter. The square tube roll forming process was designed considering the layout of rolls and the compression ratio distribution for each stand. The final tube corner radius and the edge straightness in the front end of the tube are to be controlled according to the tube specification. A five-stand forming design using four rolls at each stand was proposed to establish the base reference of square tube roll forming quality. Different numbers of pass and roll designs were proposed and compared to the base design in order to find the feasibility of increase pass number to improve the square tube quality. The proposed roll forming processes were simulated using FEM analysis. The thickness variations of the corner and the edge areas were examined. The maximum loads and the torques of each stand were calculated to study the power consumption of the roll forming machine. The simulation results showed the square tube thickness variations and concavity of the edge are acceptable with the JIS tube specifications for the base design. But the maximum loads and torques are very high. By changing the layout and the number of the rolls were able to obtain better tube geometry and decrease the maximum load and torque of each stand. This paper had shown the feasibility of designing the roll forming process and the layout of dies using FEM simulation. The obtained information is helpful to the roll forming machine design for a large size square tube making.

Keywords: cold roll forming, FEM analysis, roll forming die design, tube roll forming

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189 An Energy-Balanced Clustering Method on Wireless Sensor Networks

Authors: Yu-Ting Tsai, Chiun-Chieh Hsu, Yu-Chun Chu

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In recent years, due to the development of wireless network technology, many researchers have devoted to the study of wireless sensor networks. The applications of wireless sensor network mainly use the sensor nodes to collect the required information, and send the information back to the users. Since the sensed area is difficult to reach, there are many restrictions on the design of the sensor nodes, where the most important restriction is the limited energy of sensor nodes. Because of the limited energy, researchers proposed a number of ways to reduce energy consumption and balance the load of sensor nodes in order to increase the network lifetime. In this paper, we proposed the Energy-Balanced Clustering method with Auxiliary Members on Wireless Sensor Networks(EBCAM)based on the cluster routing. The main purpose is to balance the energy consumption on the sensed area and average the distribution of dead nodes in order to avoid excessive energy consumption because of the increasing in transmission distance. In addition, we use the residual energy and average energy consumption of the nodes within the cluster to choose the cluster heads, use the multi hop transmission method to deliver the data, and dynamically adjust the transmission radius according to the load conditions. Finally, we use the auxiliary cluster members to change the delivering path according to the residual energy of the cluster head in order to its load. Finally, we compare the proposed method with the related algorithms via simulated experiments and then analyze the results. It reveals that the proposed method outperforms other algorithms in the numbers of used rounds and the average energy consumption.

Keywords: auxiliary nodes, cluster, load balance, routing algorithm, wireless sensor network

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188 Spontaneous Generation of Wrinkled Patterns on pH-Sensitive Smart-Hydrogel Films

Authors: Carmen M. Gonzalez-Henriquez, Mauricio A. Sarabia-Vallejos, Juan Rodriguez-Hernandez

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DMAEMA, as a monomer, has been widely studied and used in several application fields due to their pH-sensitive capacity (tertiary amine protonation), being relevant in the biomedical area as a potential carrier for drugs focused on the treatment of genetic or acquired diseases (efficient gene transfection), among others. Additionally, the inhibition of bacterial growth and, therefore, their antimicrobial activity, can be used as dual-functional antifogging/antimicrobial polymer coatings. According to their interesting physicochemical characteristics and biocompatible properties, DMAEMA was used as a monomer to synthesize a smart pH-sensitive hydrogel, namely poly(HEMA-co-PEGDA575-co-DMAEMA). Thus, different mole ratios (ranging from 5:1:0 to 0:1:5, according to the mole ratio between HEMA, PEGDA, and DEAEMA, respectively) were used in this research. The surface patterns formed via a two-step polymerization (redox- and photo-polymerization) were first chemically studied via 1H-NMR and elemental analysis. Secondly, the samples were morphologically analyzed by using Field-Emission Scanning Electron Microscopy (FE-SEM) and Atomic Force Microscopy (AFM) techniques. Then, a particular relation between HEMA, PEGDA, and DEAEMA (0:1:5) was also characterized at three different pH (5.4, 7.4 and 8.3). The hydrodynamic radius and zeta potential of the micro-hydrogel particles (emulsion) were carried out as a possible control for morphology, exploring the effect that produces hydrogel micelle dimensions in the wavelength, height, and roughness of the wrinkled patterns. Finally, contact angle and cross-hatch adhesion test was carried out for the hydrogels supported on glass using TSM-silanized surfaces in order to measure their mechanical properties.

Keywords: wrinkled patterns, smart pH-sensitive hydrogels, hydrogel micelle diameter, adhesion tests

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187 Impact of Hormone Replacement Therapy on Body Composition Analysis of Women during Perimenopause: A Framework for Action

Authors: Varsha Chorsiya, Pooja Aneja, Dhananjay Kaushik, Abhinav Yadav

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Intoduction: Women’s Health Initiatives (WHI) focuses on defining the risks and benefits of strategies that could potentially reduce the incidence of obesity, heart disease, breast cancer and colorectal cancer, and fractures in menopause women. The utility of the present research work determines to find the role of Hormone Replacement Therapy (HRT) in changing the different component of body composition during perimenopause period. Methods: A comparative cross-sectional study included 30 subjects, aged between 40 and 50 years which were assigned into 2 groups i.e. 15 subjects in HRT (Group A) and 15 subjects in non-HRT (Group B). The subjects were taken from the hospitals and clinics of Faridabad undergoing HRT in supervision of the consultant gynecologist. The informed consents were signed before including the participants in the study. The body composition and lipid profile were evaluated for all the subjects. Result and Discussion: The BMI, body density, percent body fats and fat mass in both groups showed statistically significant differences i.e. p < 0.05. Our study did not reveal any statistically significant difference between non-HRT and HRT for lipid profile composition of HDL, LDL, VLDL, ratio, triglycerides and total cholesterol although these indicators (LDL, VLDL, ratio, triglycerides and total cholesterol) showed difference clinically with a higher mean values for non-HRT as compared to HRT group. The mean value for HDL was higher for HRT group in contrast to non-HRT group. The result clearly showed that HRT group has a good lipid profile composition. Conclusion: In conclusion, our data show that HRT has statistically significant role in determining BMI, fat percent mass and fat mass. The lipid profile including LDL, HDL, VLDL, ratio, triglycerides and total cholesterol found to be clinically better in HRT group as compared to the non-HRT group. The rationale for non-significant lipid profile probably lie in the fact that hormonal changes need a particular time period and might become significant in post-menopausal period.

Keywords: body composition, hormone replacement therapy, perimenopause, women health

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186 The Influence of Activity Selection and Travel Distance on Forest Recreation Policies

Authors: Mark Morgan, Christine Li, Shuangyu Xu, Jenny McCarty

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The National Wild and Scenic Rivers System was created by the U.S. Congress in 1968 (Public Law 90-542; 16 U.S.C. 1271 et seq.) to preserve outstanding natural, cultural, and recreational values of some U.S. rivers in a free-flowing condition for the enjoyment of present and future generations. This Act is notable for safeguarding the special character of these rivers while supporting management action that encourages public participation for co-creating river protection goals and strategies. This is not an easy task. To meet the challenges of modern ecosystem management, federal resource agencies must address many legal, environmental, economic, political, and social issues. The U.S. Forest Service manages a 44-mile section of the Eleven Point National Scenic River (EPR) in southern Missouri, mainly for outdoor recreation purposes. About half of the acreage is in private lands, while the remainder flows through the Mark Twain National Forest. Private land along the river is managed by scenic easements to ensure protection of scenic values and natural resources, without public access. A portion of the EPR lies adjacent to a 16,500-acre tract known as the Irish Wilderness. The spring-fed river has steep bluffs, deep pools, clear water, and a slow current, making it an ideal setting for outdoor enthusiasts. A 10-month visitor study was conducted at five access points along the EPR during 2019 so the US Forest Service could update their river management plan. A mail-back survey was administered to 560 on-site visitors, yielding a response rate of 53%. Although different types of visitors use the EPR, boating and fishing were the predominant forms of outdoor recreation. Some river use was from locals, but other visitors came from farther away. Formulating unbiased policies for outdoor recreation is difficult because managers must assign relative values to recreational activities and travel distance. Because policymaking is a subjective process, management decisions can affect user groups in different ways (i.e., boaters vs. fishers; proximate vs. distal visitors), as seen through a GIS analysis.

Keywords: activity selection, forest recreation, policy, travel distance

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185 Electromechanical Reliability of ITO/Ag/ITO Multilayer Coated Pet Substrate for Optoelectronic Application

Authors: D. W. Mohammed, J. Bowen, S. N. Kukureka

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Successful design and fabrication of flexible devices for electrode components requires a low sheet resistance, high optical transmittance, high mechanical reliability. Indium tin oxide (ITO) film is currently the predominant transparent conductive oxide (TCO) film in potential applications such as flexible organic light- emitting diodes, flat-panel displays, solar cells, and thin film transistors (TFTs). However ITO films are too brittle and their resistivity is rather high in some cases compared with ITO/Ag/ ITO, and they cannot completely meet flexible optoelectronic device requirements. Therefore, in this work the mechanical properties of ITO /Ag/ITO multilayer film that deposited on Polyethylene terephthalate (PET) compared with the single layered ITO sample were investigated using bending fatigue, twisting fatigue and thermal cycling experiments. The electrical resistance was monitored during the application of mechanical and thermal loads to see the pattern of relationship between the load and the electrical continuity as a consequent of failure. Scanning electron microscopy and atomic force microscopy were used to provide surface characterization of the mechanically-tested samples. The effective embedment of the Ag layer between upper and lower ITO films led to metallic conductivity and superior flexibility to the single ITO electrode, due to the high failure strain of the ductile Ag layer. These results indicate that flexible ITO/Ag/ITO multilayer electrodes are a promising candidate for use as transparent conductor in flexible displays. They provided significantly reduced sheet resistance compared to ITO, and improved bending and twisting properties both as a function of radius, angle and thermal cycling.

Keywords: ITO/Ag/ITO multilayer, failure strain, mechanical properties, PET

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184 Epidemiology and Risk Factors of Injury and Stress Fractures in Male and Female Runners

Authors: Balazs Patczai, Katalin Gocze, Gabriella Kiss, Dorottya Szabo, Tibor Mintal

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Introduction: Running has become increasingly popular on a global scale in the past decades. Amateur athletes are taking their sport to a new level in an attempt to surpass their performance goals. The aim of our study was to assess the musculoskeletal condition of amateur runners and the prevalence of injuries with a special focus on stress fracture risk. Methods: The cross sectional analysis included ankle mobility, hamstring and lower back flexibility, the use of Renne’s test for iliotibial band syndrome, functional tests for trunk and rotary stability, and measurements of bone density. Data was collected at 2 major half-marathon events in Hungary. Results: Participants (n=134) mean age was 41.76±8.57 years (males: 40.67±8.83, females: 42.08±8.56). Measures of hamstring and lower back flexibility fell into the category of good for both genders (males: 7.13±6.83cm, females: 10.17±6.67cm). No side asymmetry nor gender differences were characteristic in the case of ankle mobility. Trunk stability was significantly better for males than in females (p=0.004). Markers of bone health were in the low normal range for females and were significantly better for males (T-score: p=0.003, T-ratio: p=0.014, Z-score: p=0.034, Z-ratio: p=0.011). 5.2% of females had a previous stress fracture and 24.1% experienced irregular menstrual cycles during the past year. As for the knowledge on the possible association of energy deficiency, menstrual disturbances and their effect on bone health, Only 8.6% of females have heard of the female athlete triad either during their studies or from a health professional. Discussion: The overall musculoskeletal state was satisfactory for both genders both physically and functionally. More attention and effort should be placed on primary and secondary prevention of amateur runners. Very few active women are well informed about the effects of low energy availability and menstrual dysfunction and the negative impact these have on bone health.

Keywords: bone health, flexibility, running, stress fracture

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183 Historical Analysis of the Evolution of Swiss Identity and the Successful Integration of Multilingualism into the Swiss Concept of Nationhood

Authors: James Beringer

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Switzerland’s ability to forge a strong national identity across linguistic barriers has long been of interest to nationalism scholars. This begs the question of how this has been achieved, given that traditional explanations of luck or exceptionalism appear highly reductionist. This paper evaluates the theory that successful Swiss management of linguistic diversity stems from the strong integration of multilingualism into Swiss national identity. Using archival analysis of Swiss government records, historical accounts of prominent Swiss citizens, as well as secondary literature concerning the fundamental aspects of Swiss national identity, this paper charts the historical evolution of Swiss national identity. It explains how multilingualism was deliberately and successfully integrated into Swiss national identity as a response to political fragmentation along linguistic lines during the First World War. Its primary conclusions are the following. Firstly, the earliest foundations of Swiss national identity were purposefully removed from any association with a single national language. This produced symbols, myths, and values -such as a strong commitment to communalism, the imagery of the Swiss natural landscape, and the use of Latin expressions, which can be adopted across Swiss linguistic groups. Secondly, the First World War triggered a turning point in the evolution of Swiss national identity. The fundamental building blocks proved insufficient in preventing political fractures amongst linguistic lines, as each Swiss linguistic group gravitated towards its linguistic neighbours within Europe. To avoid a repeat of such fragmentation, a deliberate effort was made to fully integrate multilingualism as a fundamental aspect of Swiss national identity. Existing natural symbols, such as the St Gotthard Mountains, were recontextualized in order to become associated with multilingualism. The education system was similarly reformed to reflect the unique multilingual nature of the Swiss nation. The successful result of this process can be readily observed in polls and surveys, with large segments of the Swiss population highlighting multilingualism as a uniquely Swiss characteristic, indicating the symbiotic connection between multilingualism and the Swiss nation.

Keywords: language's role in identity formation, multilingualism in nationalism, national identity formation, Swiss national identity history

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182 Stepping in Sustainability: Walkability an Upcoming Design Parameter for Transit Based Communities in Lahore, Pakistan

Authors: Sadaf Saeed

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The consideration of walkability as an urban design parameter in conjunction with transit-oriented development is an established trend in the developed countries but an upcoming trend in developing countries. In Pakistan, the first Bus Rapid Transit (locally called as Metro Bus) has been introduced in the city of Lahore in 2013 where around 40 percent of the riders access to transit stations by walking. To what extent the aspect of walkability has been considered in the local scenario? To address this question, this paper presents an account of urban design parameters regarding pedestrian provisions and quality of walking environment between Metro Bus stations and users’ destination in the transit neighbourhoods (areas up to 500-meter radius). The primary and secondary data for objective and subjective walkability measurements has been used for neighbourhoods of five selected transit stations ranked against the predefined critical assessed factors (CAF). The multi-criteria approach including visual and geospatially-based parameters at street level, along with walkability index score at selected sites linked with CAF evaluation were the selected methods for this study. The acceptability of walkability as an urban design parameter for transit planning in terms of connectivity and social implications of the concept has also been analysed in the local context. The paper highlights that the aspect of walkability in Lahore is being derelict owing to the focus of government on other initiatives such as park and ride and feeder bus services for mobility of passengers. However, the pedestrian-friendly design parameters as a part of future transit planning can enhance social, liveable and interactive walking environment within transit neighbourhoods.

Keywords: walkability, sustainability, transit neighborhoods, social communities

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181 Socio-economic Baselining of Selected Icrmp Sites in Southwestern Cebu, Central Philippines

Authors: Rachel Luz P. Vivas-rica, Gloria G. Delan, Christine M. Corrales, Alfonso S. Piquero, Irene A. Monte

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ABSTRACT -Selected Integrated Coastal Resource Management Program (ICRMP) sites in Southwestern Cebu were studied employing a stratified proportional sampling method using semi-structured questionnaires. Four hundred sixteen (416) respondents from five barangays with Marine Protected Areas (MPAs) and four barangays without marine sanctuaries were considered in the study. Results showed similarity of socio-economic characteristics in terms of average age, majority were middle aged, and married. Households were male dominated, obtained low education for both MPA and Non-MPA areas. In terms of occupation, majority in both areas engaged in fulltime fishing however part time jobs as carpenter, construction worker, driver or farmer as another income source. Most of the households were nuclear families with average family size of five for both MPA and Non-MPA. Fishing experience ranged from less than 1 year to more than 50 years. Fishing grounds were within the 15 kilometer radius of each considered site. Even if the respondents were totally dependent on fishing as a major source of income, still their income is way below the poverty threshold both in the MPA and Non-MPA areas. This is further explained by the marginality of their fishing implements wherein majority uses gill nets, hook & line, spear and paddle boat in fishing. Their volume of catch from an average of 6 hours fishing expedition ranges from half a kilo to a maximum of 4 kilos. Majority are not members of fishing groups or organizations.

Keywords: integrated coastal resource management program, marine protected areas, socio-economic, poverty threshold

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180 The Effect of Contrast on Approach Distances of Carcharhinus perezi

Authors: Elizabeth Farquhar, Erich Ritter

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Studying shark's interaction with humans and their behavioral responses will have enormous implications for other fields of marine biology and oceanography. The health of sharks has direct impacts on the stability of human society with a reported 3.5 billion people depending on the ocean for food and/or livelihood. Discovering how sharks behave and interact with people, will have enormous implications for future studies, along with the development of more effective ways to reduce negative shark/human interactions. This specific study investigates the effects of contrasting ponchos worn by divers on the approach distances of Carcharhinus perezi. Data was collected over a two week period at a test site off the shore of Eleuthera Island in the Bahamas, with a depth of approximately 55 feet during mid-August. Sixty-minute dive trials were conducted and videoed from above with 5-meter radius markers on the ocean floor surrounding the two divers, kneeling back-to-back. Five poncho colors were worn by the two divers (black, navy blue, dark green, yellow and orange), rotating the color permutations randomly to test the distance a shark will approach each color. Results indicate significantly closer approach patterns when divers were wearing orange ponchos, and the combination of orange with black and blue ponchos were found to be statistically significant. These results are relevant to understanding how sharks perceive contrast and dive equipment in the marine environment, which could have the potential to prevent negative shark/human interactions.

Keywords: shark behavior, animal behavior, marine biology, conservation

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179 Mesenteric Ischemia Presenting as Acalculous Cholecystitis: A Case Review of a Rare Complication and Aberrant Anatomy

Authors: Joshua Russell, Omar Zubair, Reuben Ndegwa

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Introduction: Mesenteric ischemia is an uncommon condition that can be challenging to diagnose in the acute setting, with the potential for significant morbidity and mortality. Very rarely has acute acalculous cholecystitis been described in the setting of mesenteric ischemia. Case: This was the case in a 78-year-old male, who initially presented with clinical and radiological evidence of small bowel obstruction, thought likely secondary to malignancy. The patient had a 6-week history of anorexia, worsening lower abdominal pain, and ~30kg of unintentional weight loss over a 12-month period and a CT- scan demonstrated a transition point in the distal ileum. The patient became increasingly hemodynamically unstable and peritonitic, and an emergency laparotomy was performed. Intra-operatively, however, no obvious transition point was identified, and instead, the gallbladder was markedly gangrenous and oedematous, consistent with acalculous cholecystitis. An open total cholecystectomy was subsequently performed. The patient was admitted to the Intensive Care Unit post-operatively and continued to deteriorate over the proceeding 48 hours, with two re-look laparotomies demonstrating progressively worsening bowel ischemia, initially in the distribution of the superior mesenteric artery and then the coeliac trunk. On review, the patient was found to have an aberrant right hepatic artery arising from the superior mesenteric artery. The extent of ischemia was considered non-survivable, and the patient was palliated. Discussion: Multiple theories currently exist for the underlying pathophysiology of acalculous cholecystitis, including biliary stasis, sepsis, and ischemia. This case lends further support to ischemia as the underlying etiology of acalculous cholecystitis. This is particularly the case when considered in the context of the patient’s aberrant right hepatic artery arising from the superior mesenteric artery, which occurs in 11-14% of patients. Conclusion: This case report adds further insight to the debate surrounding the pathophysiology of acalculous cholecystitis. It also presents acalculous cholecystitis as a complication of mesenteric ischemia that should always be considered, especially in the elderly patient and in the context of relatively common anatomical variations. Furthermore, the case brings to attention the importance of maintaining dynamic working diagnoses in the setting of evolving pathophysiology and clinical presentations.

Keywords: acalculous cholecystitis, anatomical variation, general surgery, mesenteric ischemia

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178 Dynamics and Advection in a Vortex Parquet on the Plane

Authors: Filimonova Alexanra

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Inviscid incompressible fluid flows are considered. The object of the study is a vortex parquet – a structure consisting of distributed vortex spots of different directions, occupying the entire plane. The main attention is paid to the study of advection processes of passive particles in the corresponding velocity field. The dynamics of the vortex structures is considered in a rectangular region under the assumption that periodic boundary conditions are imposed on the stream function. Numerical algorithms are based on the solution of the initial-boundary value problem for nonstationary Euler equations in terms of vorticity and stream function. For this, the spectral-vortex meshless method is used. It is based on the approximation of the stream function by the Fourier series cut and the approximation of the vorticity field by the least-squares method from its values in marker particles. A vortex configuration, consisting of four vortex patches is investigated. Results of a numerical study of the dynamics and interaction of the structure are presented. The influence of the patch radius and the relative position of positively and negatively directed patches on the processes of interaction and mixing is studied. The obtained results correspond to the following possible scenarios: the initial configuration does not change over time; the initial configuration forms a new structure, which is maintained for longer times; the initial configuration returns to its initial state after a certain period of time. The processes of mass transfer of vorticity by liquid particles on a plane were calculated and analyzed. The results of a numerical analysis of the particles dynamics and trajectories on the entire plane and the field of local Lyapunov exponents are presented.

Keywords: ideal fluid, meshless methods, vortex structures in liquids, vortex parquet.

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177 Perspectives and Challenges a Functional Bread With Yeast Extract to Improve Human Diet

Authors: Cláudia Patrocínio, Beatriz Fernandes, Ana Filipa Pires

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Background: Mirror therapy (MT) is used to improve motor function after stroke. During MT, a mirror is placed between the two upper limbs (UL), thus reflecting movements of the non- affected side as if it were the affected side. Objectives: The aim of this review is to analyze the evidence on the effec.tiveness of MT in the recovery of UL function in population with post chronic stroke. Methods: The literature search was carried out in PubMed, ISI Web of Science, and PEDro database. Inclusion criteria: a) studies that include individuals diagnosed with stroke for at least 6 months; b) intervention with MT in UL or comparing it with other interventions; c) articles published until 2023; d) articles published in English or Portuguese; e) randomized controlled studies. Exclusion criteria: a) animal studies; b) studies that do not provide a detailed description of the intervention; c) Studies using central electrical stimulation. The methodological quality of the included studies was assessed using the Physiotherapy Evidence Database (PEDro) scale. Studies with < 4 on PEDro scale were excluded. Eighteen studies met all the inclusion criteria. Main results and conclusions: The quality of the studies varies between 5 and 8. One article compared muscular strength training (MST) with MT vs without MT and four articles compared the use of MT vs conventional therapy (CT), one study compared extracorporeal shock therapy (EST) with and without MT and another study compared functional electrical stimulation (FES), MT and biofeedback, three studies compared MT with Mesh Glove (MG) or Sham Therapy, five articles compared performing bimanual exercises with and without MT and three studies compared MT with virtual reality (VR) or robot training (RT). The assessment of changes in function and structure (International Classification of Functioning, Disability and Health parameter) was carried out, in each article, mainly using the Fugl Meyer Assessment-Upper Limb scale, activity and participation (International Classification of Functioning, Disability and Health parameter) were evaluated using different scales, in each study. The positive results were seen in these parameters, globally. Results suggest that MT is more effective than other therapies in motor recovery and function of the affected UL, than these techniques alone, although the results have been modest in most of the included studies. There is also a more significant improvement in the distal movements of the affected hand than in the rest of the UL.

Keywords: physical therapy, mirror therapy, chronic stroke, upper limb, hemiplegia

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176 Improving Enhanced Oil Recovery by Using Alkaline-Surfactant-Polymer Injection and Nanotechnology

Authors: Amir Gerayeli, Babak Moradi

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The continuously declining oil reservoirs and reservoirs aging have created a huge demand for utilization of Enhanced Oil Recovery (EOR) methods recently. Primary and secondary oil recovery methods have various limitations and are not practical for all reservoirs. Therefore, it is necessary to use chemical methods to improve oil recovery efficiency by reducing oil and water surface tension, increasing sweeping efficiency, and reducing displacer phase viscosity. One of the well-known methods of oil recovery is Alkaline-Surfactant-Polymer (ASP) flooding that shown to have significant impact on enhancing oil recovery. As some of the biggest oil reservoirs including those of Iran’s are fractional reservoirs with substantial amount of trapped oil in their fractures, the use of Alkaline-Surfactant-Polymer (ASP) flooding method is increasingly growing, the method in which the impact of several parameters including type and concentration of the Alkaline, Surfactant, and polymer are particularly important. This study investigated the use of Nano particles to improve Enhanced Oil Recovery (EOR). The study methodology included performing several laboratory tests on drill cores extracted from Karanj Oil field Asmary Formation in Khuzestan, Iran. In the experiments performed, Sodium dodecyl benzenesulfonate (SDBS) and 1-dodecyl-3-methylimidazolium chloride ([C12mim] [Cl])) were used as surfactant, hydrolyzed polyacrylamide (HPAM) and guar gum were used as polymer, Sodium hydroxide (NaOH) as alkaline, and Silicon dioxide (SiO2) and Magnesium oxide (MgO) were used as Nano particles. The experiment findings suggest that water viscosity increased from 1 centipoise to 5 centipoise when hydrolyzed polyacrylamide (HPAM) and guar gum were used as polymer. The surface tension between oil and water was initially measured as 25.808 (mN/m). The optimum surfactant concentration was found to be 500 p, at which the oil and water tension surface was measured to be 2.90 (mN/m) when [C12mim] [Cl] was used, and 3.28 (mN/m) when SDBS was used. The Nano particles concentration ranged from 100 ppm to 1500 ppm in this study. The optimum Nano particle concentration was found to be 1000 ppm for MgO and 500 ppm for SiO2.

Keywords: alkaline-surfactant-polymer, ionic liquids, relative permeability, reduced surface tension, tertiary enhanced oil recovery, wettability change

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175 Effects of Supplementation of Nano-Particle Zinc Oxide and Mannan-Oligosaccharide (MOS) on Growth, Feed Utilization, Fatty Acid Profile, Intestinal Morphology, and Hematology in Nile tilapia, Oreochromis niloticus (L.) fry

Authors: Tewodros Abate Alemayehu, Abebe Getahun, Akewake Geremew, Dawit Solomon Demeke, John Recha, Dawit Solomon, Gebremedihin Ambaw, Fasil Dawit Moges

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The purpose of this study was to examine the effects of supplementation of zinc oxide (ZnO) nanoparticles and Mannan-oligosaccharide (MOS) on growth performance, feed utilization, fatty acid profiles, hematology, and intestinal morphology of Chamo strain Nile tilapia Oreochromis niloticus (L.) fry reared at optimal temperature (28.62 ± 0.11 ⁰C). Nile tilapia fry (initial weight 1.45 ± 0.01g) were fed basal diet/control diet (Diet-T1), 6 g kg-¹ MOS supplemented diet (Diet-T2), 4 mg ZnO-NPs supplemented diet (Diet-T3), 4 mg ZnO-Bulk supplemented diet (Diet-T4), a combination of 6 g kg-¹ MOS and 4 mg ZnO-Bulk supplemented diet (Diet-T5) and combination of 6 g kg-¹ MOS and 4 mg ZnO-NPs supplemented diet (Diet-T6). Randomly, duplicate aquariums for each diet were assigned and hand-fed to apparent satiation three times daily (08:00, 12:00, and 16:00) for 12 weeks. Fish fed MOS, ZnO-NPs, and a combination of MOS and ZnO-Bulk supplemented diet had higher weight gain, Daily Growth Rate (DGR), and Specific Growth Rate (SGR) than fish fed the basal diet and other feeding groups, although the effect was not significant. According to the GC analysis, Nile tilapia was supplemented with 6 g kg-¹ MOS, 4 mg ZnO-NPs, or a combination of ZnO-NPs, and MOS showed the highest content of EPA, DHA, and higher ratios of PUFA/SFA than other feeding groups. Mean villi length in the proximal and middle portion of the Nile tilapia intestine was affected significantly (p<0.05) by diet. Fish fed Diet-T2 and Diet-T3 had significantly higher villi lengths in the proximal and middle portions of the intestine compared to other feeding groups. The inclusion of additives significantly improved goblet numbers at the proximal, middle, and distal portions of the intestine. Supplementation of additives had also improved some hematological parameters compared with control groups. In conclusion, dietary supplementation of additives MOS and ZnO-NPs could confer benefits on growth performance, fatty acid profiles, hematology, and intestinal morphology of Chamo strain Nile tilapia.

Keywords: chamo strain nile tilapia, fatty acid profile, hematology, intestinal morphology, MOS, ZnO-Bulk, ZnO-NPs

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174 Microwave-Assisted 3D Porous Graphene for Its Multi-Functionalities

Authors: Jung-Hwan Oh, Rajesh Kumar, Il-Kwon Oh

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Porous graphene has extensive potential applications in variety of fields such as hydrogen storage, CO oxidation, gas separation, supercapacitors, fuel cells, nanoelectronics, oil adsorption, and so on. However, the generation of some carbon atoms vacancies for precise small holes have been not extensively studied to prevent the agglomerates of graphene sheets and to obtain porous graphene with high surface area. Recently, many research efforts have been presented to develop physical and chemical synthetic approaches for porous graphene. But physical method has very high cost of manufacture and chemical method consumes so many hours for porous graphene. Herein, we propose a porous graphene contained holes with atomic scale precision by embedding metal nano-particles through microwave irradiation for hydrogen storage and CO oxidation multi- functionalities. This proposed synthetic method is appropriate for fast and convenient production of three dimensional nanostructures, which have nanoholes on the graphene surface in consequence of microwave irradiation. The metal nanoparticles are dispersed quickly on the graphene surface and generated uniform nanoholes on the graphene nanosheets. The morphological and structural characterization of the porous graphene were examined by scanning electron microscopy (SEM), transmission scanning electron microscopy (TEM) and RAMAN spectroscopy, respectively. The metal nanoparticle-embedded porous graphene exhibits a microporous volume of 2.586cm3g-1 with an average pore radius of 0.75 nm. HR-TEM analysis was carried out to further characterize the microstructures. By investigating the RAMAN spectra, we can understand the structural changes of graphene. The results of this work demonstrate a possibility to produce a new class of porous graphene. Furthermore, the newly acquired knowledge for the diffusion into graphene can provide useful guidance for the development of the growth of nanostructure.

Keywords: CO oxidation, hydrogen storage, nanocomposites, porous graphene

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173 Theoretical Analysis and Design Consideration of Screened Heat Pipes for Low-Medium Concentration Solar Receivers

Authors: Davoud Jafari, Paolo Di Marco, Alessandro Franco, Sauro Filippeschi

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This paper summarizes the results of an investigation into the heat pipe heat transfer for solar collector applications. The study aims to show the feasibility of a concentrating solar collector, which is coupled with a heat pipe. Particular emphasis is placed on the capillary and boiling limits in capillary porous structures, with different mesh numbers and wick thicknesses. A mathematical model of a cylindrical heat pipe is applied to study its behaviour when it is exposed to higher heat input at the evaporator. The steady state analytical model includes two-dimensional heat conduction in the HP’s wall, the liquid flow in the wick and vapor hydrodynamics. A sensitivity analysis was conducted by considering different design criteria and working conditions. Different wicks (mesh 50, 100, 150, 200, 250, and, 300), different porosities (0.5, 0.6, 0.7, 0.8, and 0.9) with different wick thicknesses (0.25, 0.5, 1, 1.5, and 2 mm) are analyzed with water as a working fluid. Results show that it is possible to improve heat transfer capability (HTC) of a HP by selecting the appropriate wick thickness, the effective pore radius, and lengths for a given HP configuration, and there exist optimal design criteria (optimal thick, evaporator adiabatic and condenser sections). It is shown that the boiling and wicking limits are connected and occurs in dependence on each other. As different parts of the HP external surface collect different fractions of the total incoming insolation, the analysis of non-uniform heat flux distribution indicates that peak heat flux is not affecting parameter. The parametric investigations are aimed to determine working limits and thermal performance of HP for medium temperature SC application.

Keywords: screened heat pipes, analytical model, boiling and capillary limits, concentrating collector

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172 Secondary Radiation in Laser-Accelerated Proton Beamline (LAP)

Authors: Seyed Ali Mahdipour, Maryam Shafeei Sarvestani

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Radiation pressure acceleration (RPA) and target normal sheath acceleration (TNSA) are the most important methods of Laser-accelerated proton beams (LAP) planning systems.LAP has inspired novel applications that can benefit from proton bunch properties different from conventionally accelerated proton beams. The secondary neutron and photon produced in the collision of protons with beamline components are of the important concern in proton therapy. Various published Monte Carlo researches evaluated the beamline and shielding considerations for TNSA method, but there is no studies directly address secondary neutron and photon production from RPA method in LAP. The purpose of this study is to calculate the flux distribution of neutron and photon secondary radiations on the first area ofLAP and to determine the optimize thickness and radius of the energyselector in a LAP planning system based on RPA method. Also, we present the Monte Carlo calculations to determine the appropriate beam pipe for shielding a LAP planning system. The GEANT4 Monte Carlo toolkit has been used to simulate a secondary radiation production in LAP. A section of new multifunctional LAP beamlinehas been proposed, based on the pulsed power solenoid scheme as a GEANT4 toolkit. The results show that the energy selector is the most important source of neutron and photon secondary particles in LAP beamline. According to the calculations, the pure Tungsten energy selector not be the proper case, and using of Tungsten+Polyethylene or Tungsten+Graphitecomposite selectors will reduce the production of neutron and photon intensities by approximately ~10% and ~25%, respectively. Also the optimal radiuses of energy selectors were found to be ~4 cm and ~6 cm for a 3 degree and 5 degree proton deviation angles, respectively.

Keywords: neutron, photon, flux distribution, energy selector, GEANT4 toolkit

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171 Solid Angle Approach to Quantify the Shape of Daughter Cavity in Drying Nano Colloidal Sessile Droplets

Authors: Rishabh Hans, Saksham Sharma

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Drying of a sessile droplet imbibed with colloidal solution is a complex process in many aspects. Till now, most of the work revolves around; conditions for buckling onset, post-buckling effects, nature of change of droplet shape etc. In this work, we are determining the shape of daughter cavity (DC) formed during post-buckling onset, a less explored stage, and its relationship with experimental parameters. We have introduced solid angle as a special parameter that can quantify the shape of DC at any instant. It facilitates us to compare the shape while experimenting across different substrate types, droplet sizes and particle concentration. Furthermore, the angular location of ‘weak spot’ on the periphery of droplet, which marks the initiation of cavity growth, varies in different conditions. To solve this problem, we have evaluated the deflection angle of weak spots w.r.t. the vertical axis going through the middle of droplet. Subsequently, the solid angle subtended by DC is analyzed about that inclined axis. Finally, results of analysis allude that increasing colloidal concentration has inverse effect on the growth rate of cavity’s shape. Moreover, the cap radius of DC is observed lower for high PLR which makes the capillary pressure higher and thus tougher to expedite cavity formation relatively. This analysis can be helpful in further studies to relate the shape, deflection angle, growth rate of daughter cavity to the type of droplet crust formed in the end. Examining DC stage shall add another layer to nano-colloidal research which aims to influence many industrial applications like patterning, coatings, drug delivery, food processing etc.

Keywords: buckling of sessile droplets, daughter cavity, droplet evaporation, nanoporous shell formation, solid angle

Procedia PDF Downloads 252