Search results for: YNi4Si- type DyNi4Si compound
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 7660

Search results for: YNi4Si- type DyNi4Si compound

6850 Condensed Benzo, Pyrido, Pyrimidino-Imidazole Derivatives as Antidiabetic Agents

Authors: Fatima Doganc, Hakan Goker

Abstract:

Benzimidazole moiety is an important pharmacophore and privileged structure for the medicinal chemists, since it exhibits various important biological activities. Some clinically used drugs have benzimidazole moiety, such as omeprazole, astemizole, albendazole and domperidone. 2-(4-tert-Butylphenyl)benzimidazole, is a PGC-1α transcriptional regulator shown to have beneficial effects in diabetic mice. We planned to modify the structure of this compound for developing new antidiabetic drug candidates. Hence, a series of guanidino or amidino, benzo/pyrido/pyrimidino-imidazole derivatives were freshly prepared. Mass, 1H-NMR, 13C-NMR, 2D-NMR spectroscopy techniques were used for the new derivatives to clarify their structures and their purity was controlled through the elemental analysis. Antidiabetic activity studies of the synthesized compounds are under the investigation.

Keywords: antidiabetic agents, benzimidazole, imidazopyridine, imidazopyrimidine

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6849 Research of Interaction between Layers of Compressed Composite Columns

Authors: Daumantas Zidanavicius

Abstract:

In order to investigate the bond between concrete and steel in the circular steel tube column filled with concrete, the 7 series of specimens were tested with the same geometrical parameters but different concrete properties. Two types of specimens were chosen. For the first type, the expansive additives to the concrete mixture were taken to increase internal forces. And for the second type, mechanical components were used. All 7 series of the short columns were modeled by FEM and tested experimentally. In the work, big attention was taken to the bond-slip models between steel and concrete. Results show that additives to concrete let increase the bond strength up to two times and the mechanical anchorage –up to 6 times compared to control specimens without additives and anchorage.

Keywords: concrete filled steel tube, push-out test, bond slip relationship, bond stress distribution

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6848 Analyzing the Potential of Job Creation by Taking the First Step Towards Circular Economy: Case Study of Brazil

Authors: R. Conde

Abstract:

The Brazilian economic projections and social indicators show a future of crisis for the country. Solutions to avoid this crisis scenario are necessary. Several developed countries implement initiatives linked to sustainability, mainly related to the circular economy, to solve their crises quickly - green recovery. This article aims to assess social gains if Brazil followed the same recovery strategy. Furthermore, with the use of data presented and recognized in the international academic society, the number of jobs that can be created, if Brazil took the first steps towards a more circular economy, was found. Moreover, in addition to the gross value in the number of jobs created, this article also detailed the number of these jobs by type of activity (collection, processing, and manufacturing) and by type of material.

Keywords: circular economy, green recovery, job creation, social gains

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6847 p-Type Multilayer MoS₂ Enabled by Plasma Doping for Ultraviolet Photodetectors Application

Authors: Xiao-Mei Zhang, Sian-Hong Tseng, Ming-Yen Lu

Abstract:

Two-dimensional (2D) transition metal dichalcogenides (TMDCs), such as MoS₂, have attracted considerable attention owing to the unique optical and electronic properties related to its 2D ultrathin atomic layer structure. MoS₂ is becoming prevalent in post-silicon digital electronics and in highly efficient optoelectronics due to its extremely low thickness and its tunable band gap (Eg = 1-2 eV). For low-power, high-performance complementary logic applications, both p- and n-type MoS₂ FETs (NFETs and PFETs) must be developed. NFETs with an electron accumulation channel can be obtained using unintentionally doped n-type MoS₂. However, the fabrication of MoS₂ FETs with complementary p-type characteristics is challenging due to the significant difficulty of injecting holes into its inversion channel. Plasma treatments with different species (including CF₄, SF₆, O₂, and CHF₃) have also been found to achieve the desired property modifications of MoS₂. In this work, we demonstrated a p-type multilayer MoS₂ enabled by selective-area doping using CHF₃ plasma treatment. Compared with single layer MoS₂, multilayer MoS₂ can carry a higher drive current due to its lower bandgap and multiple conduction channels. Moreover, it has three times the density of states at its minimum conduction band. Large-area growth of MoS₂ films on 300 nm thick SiO₂/Si substrate is carried out by thermal decomposition of ammonium tetrathiomolybdate, (NH₄)₂MoS₄, in a tube furnace. A two-step annealing process is conducted to synthesize MoS₂ films. For the first step, the temperature is set to 280 °C for 30 min in an N₂ rich environment at 1.8 Torr. This is done to transform (NH₄)₂MoS₄ into MoS₃. To further reduce MoS₃ into MoS₂, the second step of annealing is performed. For the second step, the temperature is set to 750 °C for 30 min in a reducing atmosphere consisting of 90% Ar and 10% H₂ at 1.8 Torr. The grown MoS₂ films are subjected to out-of-plane doping by CHF₃ plasma treatment using a Dry-etching system (ULVAC original NLD-570). The radiofrequency power of this dry-etching system is set to 100 W and the pressure is set to 7.5 mTorr. The final thickness of the treated samples is obtained by etching for 30 s. Back-gated MoS₂ PFETs were presented with an on/off current ratio in the order of 10³ and a field-effect mobility of 65.2 cm²V⁻¹s⁻¹. The MoS₂ PFETs photodetector exhibited ultraviolet (UV) photodetection capability with a rapid response time of 37 ms and exhibited modulation of the generated photocurrent by back-gate voltage. This work suggests the potential application of the mild plasma-doped p-type multilayer MoS₂ in UV photodetectors for environmental monitoring, human health monitoring, and biological analysis.

Keywords: photodetection, p-type doping, multilayers, MoS₂

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6846 An Overbooking Model for Car Rental Service with Different Types of Cars

Authors: Naragain Phumchusri, Kittitach Pongpairoj

Abstract:

Overbooking is a very useful revenue management technique that could help reduce costs caused by either undersales or oversales. In this paper, we propose an overbooking model for two types of cars that can minimize the total cost for car rental service. With two types of cars, there is an upgrade possibility for lower type to upper type. This makes the model more complex than one type of cars scenario. We have found that convexity can be proved in this case. Sensitivity analysis of the parameters is conducted to observe the effects of relevant parameters on the optimal solution. Model simplification is proposed using multiple linear regression analysis, which can help estimate the optimal overbooking level using appropriate independent variables. The results show that the overbooking level from multiple linear regression model is relatively close to the optimal solution (with the adjusted R-squared value of at least 72.8%). To evaluate the performance of the proposed model, the total cost was compared with the case where the decision maker uses a naïve method for the overbooking level. It was found that the total cost from optimal solution is only 0.5 to 1 percent (on average) lower than the cost from regression model, while it is approximately 67% lower than the cost obtained by the naïve method. It indicates that our proposed simplification method using regression analysis can effectively perform in estimating the overbooking level.

Keywords: overbooking, car rental industry, revenue management, stochastic model

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6845 4-DOFs Parallel Mechanism for Minimally Invasive Robotic Surgery

Authors: Khalil Ibrahim, Ahmed Ramadan, Mohamed Fanni, Yo Kobayashi, Ahmed Abo-Ismail, Masakatus G. Fujie

Abstract:

This paper deals with the design process and the dynamic control simulation of a new type of 4-DOFs parallel mechanism that can be used as an endoscopic surgical manipulator. The proposed mechanism, 2-PUU_2-PUS, is designed based on the screw theory and the parallel virtual chain type synthesis method. Based on the structure analysis of the 4-DOF parallel mechanism, the inverse position equation is studied using the inverse analysis theory of kinematics. The design and the stress analysis of the mechanism are investigated using SolidWorks software. The virtual prototype of the parallel mechanism is constructed, and the dynamic simulation is performed using ADAMS TM software. The system model utilizing PID and PI controllers has been built using MATLAB software. A more realistic simulation in accordance with a given bending angle and point to point control is implemented by the use of both ADAMS/MATLAB software. The simulation results showed that this control method has solved the coordinate control for the 4-DOF parallel manipulator so that each output is feedback to the four driving rods. From the results, the tracking performance is achieved. Other control techniques, such as intelligent ones, are recommended to improve the tracking performance and reduce the numerical truncation error.

Keywords: parallel mechanisms, medical robotics, tracjectory control, virtual chain type synthesis method

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6844 Design and Optimization of Spoke Rotor Type Brushless Direct Current Motor for Electric Vehicles Using Different Flux Barriers

Authors: Ismail Kurt, Necibe Fusun Oyman Serteller

Abstract:

Today, with the reduction in semiconductor system costs, Brushless Direct Current (BLDC) motors have become widely preferred. Based on rotor architecture, BLDC structures are divided into internal permanent magnet (IPM) and surface permanent magnet (SPM). However, permanent magnet (PM) motors in electric vehicles (EVs) are still predominantly based on interior permanent magnet (IPM) motors, as the rotors do not require sleeves, the PMs are better protected by the rotor cores, and the air-gap lengths can be much smaller. This study discusses the IPM rotor structure in detail, highlighting its higher torque levels, reluctance torque, wide speed range operation, and production advantages. IPM rotor structures are particularly preferred in EVs due to their high-speed capabilities, torque density and field weakening (FW) features. In FW applications, the motor becomes more suitable for operation at torques lower than the rated torque but at speeds above the rated speed. Although V-type and triangular IPM rotor structures are generally preferred in EV applications, the spoke-type rotor structure offers distinct advantages, making it a competitive option for these systems. The flux barriers in the rotor significantly affect motor performance, providing notable benefits in both motor efficiency and cost. This study utilizes ANSYS/Maxwell simulation software to analyze the spoke-type IPM motor and examine its key design parameters. Through analytical and 2D analysis, preliminary motor design and parameter optimization have been carried out. During the parameter optimization phase, torque ripple a common issue, especially for IPM motors has been investigated, along with the associated changes in motor parameters.

Keywords: electric vehicle, field weakening, flux barrier, spoke rotor.

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6843 Antioxidant Effects of Regular Aerobic Exercise in Postmenopausal Women with Type 2 Diabetes Mellitus

Authors: Parvin Farzanegi

Abstract:

Background: Diabetes is a metabolic disorder associated with increased free radicals and oxidative stress. The evidence indicates that physical inactivity is a modifiable behavioral risk factor for a wide range of chronic disorders such as diabetes mellitus. We investigated the effects of eight-week aerobic exercise on some antioxidant enzyme activities in postmenopausal women with type 2 diabetes mellitus (T2DM). Methods: sixteen sedentary postmenopausal women with T2DM were randomly assigned to the control (n=8; CG) and exercise group (n=8; EG). The exercise consisted of progressive aerobic training at a moderate intensity (50-70% of the maximum heart rate), for 25-60 min/day, and 3 days/week for 8 weeks. Age, sex, and body mass index were similar in the two groups. Antioxidant status was evaluated by measuring the superoxide dismutase (SOD) and catalase (CAT) activity. Also levels of malondialdehyde (MDA) as an index of lipid peroxidation and glucose in the plasma were measured before and after the intervention. Results: Following the 8 weeks of exercise training, the plasma MDA and glucose levels were significantly reduced in EG compared to CG (P=0.001 and P=0.011 respectively). However, SOD (P=0.017) and CAT (P=0.011) activities were increased in EG compared to CG. Conclusion: The present study suggests regular aerobic exercise appears can exert protective effects against oxidative stress due to its ability to increase antioxidant defense and glucose control in postmenopausal women with T2DM.

Keywords: aerobic exercise, antioxidant, diabetes mellitus, type 2

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6842 X-Ray Diffraction and Mӧssbauer Studies of Nanostructured Ni45Al45Fe10 Powders Elaborated by Mechanical Alloying

Authors: N. Ammouchi

Abstract:

We have studied the effect of milling time on the structural and hyperfine properties of Ni45Al45Fe10 compound elaborated by mechanical alloying. The elaboration was performed by using the planetary ball mill at different milling times. The as milled powders were characterized by X-ray diffraction (XRD) and Mӧssbauer spectroscopy. From XRD diffraction spectra, we show that the β NiAl(Fe) was completely formed after 24 h of milling time. When the milling time increases, the lattice parameter increases, whereas the grain size decreases to a few nanometres and the mean level of microstrains increases. The analysis of Mӧssbauer spectra indicates that, in addition to a ferromagnetic phase, α-Fe, a paramagnetic disordered phase Ni Al (Fe) solid solution is observed after 2h and only this phase is present after 12h.

Keywords: NiAlFe, nanostructured powders, X-ray diffraction, Mӧssbauer spectroscopy

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6841 Different Cathode Buffer Layers in Organic Solar Cells

Authors: Radia Kamel

Abstract:

Considerable progress has been made in the development of bulk-heterojunction organic solar cells (OSCs) based on a blend of p-type and n-type organic semiconductors. To optimize the interfacial properties between the active layer and the electrode, a cathode buffer layer (CBL) is introduced. This layer can reduce the leakage current, increasing the open-circuit voltage and the fill factor while improving the OSC stability. In this work, the performance of PM6:Y6 OSC with 1-Chloronaphthalene as an additive is examined. To accomplish this, three CBLs PNDIT-F3N-Br, ZrAcac, and PDINO, are compared using the conventional configuration. The device with PNDIT-F3N-Br as CBL exhibits the highest power conversion efficiency of 16.04%. The results demonstrate that modifying the cathode buffer layer is crucial for achieving high-performance OSCs.

Keywords: bulk heterojunction, cathode buffer layer, efficiency, organic solar cells

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6840 The Influence of Chevron Angle on Plate Heat Exchanger Thermal Performance with Considering Maldistribution

Authors: Hossein Shokouhmand, Majid Hasanpour

Abstract:

A new modification to the Strelow method of chevron-type plate heat exchangers (PHX) modeling is proposed. The effects of maldistribution are accounted in the resulting equation. The results of calculations are validated by reported experiences. The good accuracy of heat transfer performance prediction is shown. The results indicate that considering flow maldistribution improve the accuracy of predicting the flow and thermal behavior of the plate exchanger. Additionally, a wide range of the parametric study has been presented which brings out the effects of chevron angle of PHE on its thermal efficiency with considering maldistribution effect. In addition, the thermally optimal corrugation discussed for the chevron-type PHEs.

Keywords: chevron angle, plate heat exchangers, maldistribution, strelow method

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6839 Review of Suitable Advanced Oxidation Processes for Degradation of Organic Compounds in Produced Water during Enhanced Oil Recovery

Authors: Smita Krishnan, Krittika Chandran, Chandra Mohan Sinnathambi

Abstract:

Produced water and its treatment and management are growing challenges in all producing regions. This water is generally considered as a nonrevenue product, but it can have significant value in enhanced oil recovery techniques if it meets the required quality standards. There is also an interest in the beneficial uses of produced water for agricultural and industrial applications. Advanced Oxidation Process is a chemical technology that has been growing recently in the wastewater treatment industry, and it is highly recommended for non-easily removal of organic compounds. The efficiency of AOPs is compound specific, therefore, the optimization of each process should be done based on different aspects.

Keywords: advanced oxidation process, photochemical processes, degradation, organic contaminants

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6838 The Effect of Visual Access to Greenspace and Urban Space on a False Memory Learning Task

Authors: Bryony Pound

Abstract:

This study investigated how views of green or urban space affect learning performance. It provides evidence of the value of visual access to greenspace in work and learning environments, and builds on the extensive research into the cognitive and learning-related benefits of access to green and natural spaces, particularly in learning environments. It demonstrates that benefits of visual access to natural spaces whilst learning can produce statistically significant faster responses than those facing urban views after only 5 minutes. The primary hypothesis of this research was that a greenspace view would improve short-term learning. Participants were randomly assigned to either a view of parkland or of urban buildings from the same room. They completed a psychological test of two stages. The first stage consisted of a presentation of words from eight different categories (four manmade and four natural). Following this a 2.5 minute break was given; participants were not prompted to look out of the window, but all were observed doing so. The second stage of the test involved a word recognition/false memory test of three types. Type 1 was presented words from each category; Type 2 was non-presented words from those same categories; and Type 3 was non-presented words from different categories. Participants were asked to respond with whether they thought they had seen the words before or not. Accuracy of responses and reaction times were recorded. The key finding was that reaction times for Type 2 words (highest difficulty) were significantly different between urban and green view conditions. Those with an urban view had slower reaction times for these words, so a view of greenspace resulted in better information retrieval for word and false memory recognition. Importantly, this difference was found after only 5 minutes of exposure to either view, during winter, and with a sample size of only 26. Greenspace views improve performance in a learning task. This provides a case for better visual access to greenspace in work and learning environments.

Keywords: benefits, greenspace, learning, restoration

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6837 Social Communication Problems, Social Anxiety, and Mood Problems among Students with Autism Spectrum Disorder from Teachers' Perspective

Authors: Naila Tallas Mahajna, Jamal Al Khateeb

Abstract:

This study examined the level of social communication problems, social anxiety, and mood problems among children with ASD (age 6-13 years) enrolled in special classes (n=46) and regular classes (n=36) from teachers' perspective in the schools of a part of Palestine. Teachers responded to three questionnaires - social communication problems, social anxiety and mood problems- that were used to answer the research questions. Results: social communication problems, social anxiety and mood problems were of medium rates for students with ASD enrolled in reguler and special classes. No significant differences in the level of social communication problems could be attributed to class type (Regular, Special) or the grade level-(1st – 3rd, 4th - 6th). There were significant differences in social anxiety levels that could be attributed to grade level in favor of the 4th - 6th grades but there were no significant differences according to class type (Regular, Special). There were statistically significant differences in mood problems levels that could be attributed to the class type in favor of special classes, but no differences were found according to grade level. There was a direct significant relationship between communication problems, social anxiety, and mood problems. Conclusion: social communication problems may be an important risk factor for the development of social anxiety and mood problems among students with ASD.

Keywords: social communication problems, social anxiety, mood problems, autism spectrum disorders

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6836 Flow Measurement Using Magnetic Meters in Large Underground Cooling Water Pipelines

Authors: Humanyun Zahir, Irtsam Ghazi

Abstract:

This report outlines the basic installation and operation of magnetic inductive flow velocity sensors on large underground cooling water pipelines. Research on the effects of cathodic protection as well as into other factors that might influence the overall performance of the meter are presented in this paper. The experiments were carried out on an immersion type magnetic meter specially used for flow measurement of cooling water pipeline. An attempt has been made in this paper to outline guidelines that can ensure accurate measurement related to immersion type magnetic meters on underground pipelines.

Keywords: magnetic induction, flow meter, Faraday's law, immersion, cathodic protection, anode, cathode, flange, grounding, plant information management system, electrodes

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6835 Study on Seismic Performance of Reinforced Soil Walls in Order to Offer Modified Pseudo Static Method

Authors: Majid Yazdandoust

Abstract:

This study, tries to suggest a design method based on displacement using finite difference numerical modeling in reinforcing soil retaining wall with steel strip. In this case, dynamic loading characteristics such as duration, frequency, peak ground acceleration, geometrical characteristics of reinforced soil structure and type of the site are considered to correct the pseudo static method and finally introduce the pseudo static coefficient as a function of seismic performance level and peak ground acceleration. For this purpose, the influence of dynamic loading characteristics, reinforcement length, height of reinforced system and type of the site are investigated on seismic behavior of reinforcing soil retaining wall with steel strip. Numerical results illustrate that the seismic response of this type of wall is highly dependent to cumulative absolute velocity, maximum acceleration, and height and reinforcement length so that the reinforcement length can be introduced as the main factor in shape of failure. Considering the loading parameters, mechanically stabilized earth wall parameters and type of the site showed that the used method in this study leads to most efficient designs in comparison with other methods which are generally suggested in cods that are usually based on limit-equilibrium concept. The outputs show the over-estimation of equilibrium design methods in comparison with proposed displacement based methods here.

Keywords: pseudo static coefficient, seismic performance design, numerical modeling, steel strip reinforcement, retaining walls, cumulative absolute velocity, failure shape

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6834 Study of Silent Myocardial Ischemia in Type 2 Diabeic Males: Egyptian Experience

Authors: Ali Kassem, Yhea Kishik, Ali Hassan, Mohamed Abdelwahab

Abstract:

Introduction: Accelerated coronary and peripheral vascular atherosclerosis is one of the most common and chronic complications of diabetes mellitus. A recent aspect of coronary artery disease in this condition is its silent nature. The aim of the work: Detection of the prevalence of silent myocardial ischemia (SMI) in Upper Egypt type 2 diabetic males and to select male diabetic population who should be screened for SMI. Patients and methods: 100 type 2 diabetic male patients with a negative history of angina or anginal equivalent symptoms and 30 healthy control were included. Full medical history and thorough clinical examination were done for all participants. Fasting and post prandial blood glucose level, lipid profile, (HbA1c), microalbuminuria, and C-reactive protein were done for all participants Resting ECG, trans-thoracic echocardiography, treadmill exercise ECG, myocardial perfusion imaging were done for all participants and patients positive for one or more NITs were subjected for coronary angiography. Results Twenty nine patients (29%) were positive for one or more NITs in the patients group compared to only one case (3.3%) in the controls. After coronary angiography, 20 patients were positive for significant coronary artery stenosis in the patients group, while it was refused to be done by the patient in the controls. There were statistical significant difference between the two groups regarding, hypertension, dyslipidemia and obesity, family history of DM and IHD with higher levels of microalbuminuria, C-reactive protein, total lipids in patient group versus controls According to coronary angiography, patients were subdivided into two subgroups, 20 positive for SMI (positive for coronary angiography) and 80 negative for SMI (negative for coronary angiography). No statistical difference regarding family history of DM and type of diabetic therapy was found between the two subgroups. Yet, smoking, hypertension, obesity, dyslipidemia and family history of IHD were significantly higher in diabetics positive versus those negative for SMI. 90% of patients in subgroup positive for SMI had two or more cardiac risk factors while only two patients had one cardiac risk factor (10%). Uncontrolled DM was detected more in patients positive for SMI. Diabetic complications were more prevalent in patients positive for SMI versus those negative for SMI. Most of the patients positive for SMI have DM more than 5 years duration. Resting ECG and resting Echo detected only 6 and 11 cases, respectively, of the 20 positive cases in group positive for SMI compared to treadmill exercise ECG and myocardial perfusion imaging that detected 16 and 18 cases respectively, Conclusion: Type 2 diabetic male patients should be screened for detection of SMI when aged above 50 years old, diabetes duration is more than 5 years, presence of two or more cardiac risk factors and/or patients suffering from one or more of the chronic diabetic complications. CRP, is an important parameter for selection of type 2 diabetic male patients who should be screened for SMI. Non invasive cardiac tests are reliable for screening of SMI in these patients in our locality.

Keywords: C-reactive protein, Silent myocardial ischemia, Stress tests, type 2 DM

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6833 Principle Component Analysis on Colon Cancer Detection

Authors: N. K. Caecar Pratiwi, Yunendah Nur Fuadah, Rita Magdalena, R. D. Atmaja, Sofia Saidah, Ocky Tiaramukti

Abstract:

Colon cancer or colorectal cancer is a type of cancer that attacks the last part of the human digestive system. Lymphoma and carcinoma are types of cancer that attack human’s colon. Colon cancer causes deaths about half a million people every year. In Indonesia, colon cancer is the third largest cancer case for women and second in men. Unhealthy lifestyles such as minimum consumption of fiber, rarely exercising and lack of awareness for early detection are factors that cause high cases of colon cancer. The aim of this project is to produce a system that can detect and classify images into type of colon cancer lymphoma, carcinoma, or normal. The designed system used 198 data colon cancer tissue pathology, consist of 66 images for Lymphoma cancer, 66 images for carcinoma cancer and 66 for normal / healthy colon condition. This system will classify colon cancer starting from image preprocessing, feature extraction using Principal Component Analysis (PCA) and classification using K-Nearest Neighbor (K-NN) method. Several stages in preprocessing are resize, convert RGB image to grayscale, edge detection and last, histogram equalization. Tests will be done by trying some K-NN input parameter setting. The result of this project is an image processing system that can detect and classify the type of colon cancer with high accuracy and low computation time.

Keywords: carcinoma, colorectal cancer, k-nearest neighbor, lymphoma, principle component analysis

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6832 Two Dimensional Numerical Analysis for the Seismic Response of the Geosynthetic-Reinforced Soil Integral Abutments

Authors: Dawei Shen, Ming Xu, Pengfei Liu

Abstract:

The joints between simply supported bridge decks and abutments need to be regularly repaired, which would greatly increase the cost during the service life of the bridge. Simply supported girder bridges suffered the most severe damage during earthquakes. Another type of bridge, the integral bridge, of which the superstructure and abutment are rigidly connected, was also used in some European countries. Because no bearings or joints exit in the integral bridge, this type of bridge could significantly reduce maintenance requirements and costs. However, conventional integral bridge usually result in high earth pressure on the abutment and surface settlement in the backfill. To solve these problems, a new type of integral bridge, geosynthetic-reinforced soil (GRS) integral bridge, was come up in recent years. This newly invented bridge has not been used in engineering practices. There was a lack of research on the seismic behavior of the conventional and new type of integral abutments. In addition, no common design code could be found for the calculation of seismic pressure of soil behind the abutment. This paper developed a dynamic constitutive model, which can consider the soil behaviors under cyclic loading. Numerical analyses of the seismic response of a full height integral bridge and GRS integral bridge were carried out using the two-dimensional numerical code, FLAC. A parametric study was also performed to investigate the soil-structure interaction. The results are presented below. The seismic responses of GRS integral bridge together with conventional simply supported bridge, GRS conventional bridge and conventional integral bridge were investigated. The results show that the GRS integral bridge holds the highest seismic stability, followed by conventional integral bridge, GRS simply supported bridge and conventional simply supported bridge. Compared with the integral bridge with 1 m thick abutments, the GRS integral bridge with 0.4 m thick abutments is subjected to a smaller bending moment, and the natural frequency and horizontal displacement remains almost the same. Geosynthetic-reinforcement will be more effective when the abutment becomes thinner or the abutment is higher.

Keywords: geosynthetic-reinforced soil integral bridge, nonlinear hysteretic model, numerical analysis, seismic response

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6831 Investigating the Use of Advanced Manufacturing Technologies in the Assembly Type Manufacturing Companies in Trinidad and Tobago

Authors: Nadine Sangster, Akil James, Rondell Duke, Aaron Ameerali, Terrence Lalla

Abstract:

The market place of the 21st century is evolving into one of merging national markets, fragmented consumer markets, and rapidly changing product technologies. The use of new technologies has become vital to the manufacturing industry for their survival and sustainability. This work focused on the assembly type industry in a small developing country and aimed at identifying the use of advanced manufacturing technologies and their impact on this sector of the manufacturing industry. It was found that some technologies were being used and that they had improved the effectiveness of those companies but there was still quite a bit of room for improvements. Some of the recommendations included benchmarking against international standards, the adoption of a “made in TT” campaign and the effective utilisation of the technologies to improve manufacturing effectiveness and thus improve competitive advantages and strategies.

Keywords: advanced manufacturing technology, Trinidad and Tobago, manufacturing, industrial engineering

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6830 Examining the Effects of National Disaster on the Performance of Hospitality Industry in Korea

Authors: Kim Sang Hyuck, Y. Park Sung

Abstract:

The outbreak of national disasters stimulates the decrease of the both internal and domestic tourism demands, causing bad effects on the hospitality industry. The effective and efficient risk management regarding national disasters are being increasingly required from the hospitality industry practitioners and the tourism policymakers. To establish the effective and efficient risk management strategy on national disasters, the most essential prerequisite condition is the correct estimation of national disasters’ effects in terms of the size and duration of the damages occurred from national disaster on hospitality industry. More specifically, the national disasters are twofold: natural disaster and social disaster. In addition, the hospitality industry has consisted of several types of business, such as hotel, restaurant, travel agency, etc. As reasons of the above, it is important to consider how each type of national disasters differently influences on the performance of each type of hospitality industry. Therefore, the purpose of this study is examining the effects of national disaster on hospitality industry in Korea based on the types of national disasters as well as the types of hospitality business. The monthly data was collected from Jan. 2000 to Dec. 2016. The indexes of industrial production for each hospitality industry in Korea were used with the proxy variable for the performance of each hospitality industry. Two national disaster variables (natural disaster and social disaster) were treated as dummy variables. In addition, the exchange rate, industrial production index, and consumer price index were used as control variables in the research model. The impulse response analysis was used to examine the size and duration of the damages occurred from each type of national disaster on each type of hospitality industries. The results of this study show that the natural disaster and the social disaster differently influenced on each type of hospitality industry. More specifically, the performance of airline industry is negatively influenced by the natural disaster at the time of 3 months later from the incidence. However, the negative impacts of social disaster on airline industry occurred not significantly over the time periods. For the hotel industry, both natural disaster and social disaster negatively influence the performance of hotel industry at the time of 5 months and 6 months later, respectively. Also, the negative impact of natural disaster on the performance of restaurant industry occurred at the time of 5 months later, as well as for both 3 months and 6 months later for the social disaster. Finally, both natural disaster and social disaster negatively influence the performance of travel agency at the time of 3 months and 4 months later, respectively. In conclusion, the types of national disasters differently influence the performance of each type of hospitality industry in Korea. These results would provide an important information to establish the effective and efficient risk management strategy for the national disasters.

Keywords: impulse response analysis, Korea, national disaster, performance of hospitality industry

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6829 Theoretical Study of the Structural and Elastic Properties of Semiconducting Rare Earth Chalcogenide Sm1-XEuXS under Pressure

Authors: R. Dubey, M. Sarwan, S. Singh

Abstract:

We have investigated the phase transition pressure and associated volume collapse in Sm1– X EuX S alloy (0≤x≤1) which shows transition from discontinuous to continuous as x is reduced. The calculated results from present approach are in good agreement with experimental data available for the end point members (x=0 and x=1). The results for the alloy counter parts are also in fair agreement with experimental data generated from the vegard’s law. An improved interaction potential model has been developed which includes coulomb, three body interaction, polarizability effect and overlap repulsive interaction operative up to second neighbor ions. It is found that the inclusion of polarizability effect has improved our results.

Keywords: elastic constants, high pressure, phase transition, rare earth compound

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6828 Predictive Modelling of Curcuminoid Bioaccessibility as a Function of Food Formulation and Associated Properties

Authors: Kevin De Castro Cogle, Mirian Kubo, Maria Anastasiadi, Fady Mohareb, Claire Rossi

Abstract:

Background: The bioaccessibility of bioactive compounds is a critical determinant of the nutritional quality of various food products. Despite its importance, there is a limited number of comprehensive studies aimed at assessing how the composition of a food matrix influences the bioaccessibility of a compound of interest. This knowledge gap has prompted a growing need to investigate the intricate relationship between food matrix formulations and the bioaccessibility of bioactive compounds. One such class of bioactive compounds that has attracted considerable attention is curcuminoids. These naturally occurring phytochemicals, extracted from the roots of Curcuma longa, have gained popularity owing to their purported health benefits and also well known for their poor bioaccessibility Project aim: The primary objective of this research project is to systematically assess the influence of matrix composition on the bioaccessibility of curcuminoids. Additionally, this study aimed to develop a series of predictive models for bioaccessibility, providing valuable insights for optimising the formula for functional foods and provide more descriptive nutritional information to potential consumers. Methods: Food formulations enriched with curcuminoids were subjected to in vitro digestion simulation, and their bioaccessibility was characterized with chromatographic and spectrophotometric techniques. The resulting data served as the foundation for the development of predictive models capable of estimating bioaccessibility based on specific physicochemical properties of the food matrices. Results: One striking finding of this study was the strong correlation observed between the concentration of macronutrients within the food formulations and the bioaccessibility of curcuminoids. In fact, macronutrient content emerged as a very informative explanatory variable of bioaccessibility and was used, alongside other variables, as predictors in a Bayesian hierarchical model that predicted curcuminoid bioaccessibility accurately (optimisation performance of 0.97 R2) for the majority of cross-validated test formulations (LOOCV of 0.92 R2). These preliminary results open the door to further exploration, enabling researchers to investigate a broader spectrum of food matrix types and additional properties that may influence bioaccessibility. Conclusions: This research sheds light on the intricate interplay between food matrix composition and the bioaccessibility of curcuminoids. This study lays a foundation for future investigations, offering a promising avenue for advancing our understanding of bioactive compound bioaccessibility and its implications for the food industry and informed consumer choices.

Keywords: bioactive bioaccessibility, food formulation, food matrix, machine learning, probabilistic modelling

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6827 Toward the Understanding of Shadow Port's Growth: The Level of Shadow Port

Authors: Chayakarn Bamrungbutr, James Sillitoe

Abstract:

The term ‘shadow port’ is used to describe a port whose markets are dominated by an adjacent port that has a more competitive capability. Recently, researchers have put effort into studying the mechanisms of how a regional port, in the shadow of a nearby predominant port which is a capital city port, can compete and grow. However, such mechanism is still unclear. This study thus focuses on understanding the growth of shadow port and the type of shadow port by using the two capital city ports of Thailand; Bangkok port (the former main port) and Laem Chabang port (the current main port), as the case study. By developing an understanding of the mechanisms of shadow, port could ultimately lead to an increase in the competitiveness. In this study, a framework of opportunity capture (introduced by Magala, 2004) will be used to create a framework for the study of the growth of the selected shadow port. In the process of building this framework, five groups of port development experts, consisting of government, council, academia, logistics provider and industry, will be interviewed. To facilitate this work, the Noticing, Collecting and Thinking model which was developed by Seidel (1998) will be used in an analysis of the dataset. The resulting analysis will be used to classify the type of shadow port. The type of these ports will be a significant factor for developing a feasible strategic guideline for the future management planning of ports, particularly, shadow ports, and then to increase the competitiveness of a nation’s maritime transport industry, and eventually lead to a boost in the national economy.

Keywords: shadow port, Bangkok Port, Laem Chabang Port, port growth

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6826 Estimation of Consolidating Settlement Based on a Time-Dependent Skin Friction Model Considering Column Surface Roughness

Authors: Jiang Zhenbo, Ishikura Ryohei, Yasufuku Noriyuki

Abstract:

Improvement of soft clay deposits by the combination of surface stabilization and floating type cement-treated columns is one of the most popular techniques worldwide. On the basis of one dimensional consolidation model, a time-dependent skin friction model for the column-soil interaction is proposed. The nonlinear relationship between column shaft shear stresses and effective vertical pressure of the surrounding soil can be described in this model. The influence of column-soil surface roughness can be represented using a roughness coefficient R, which plays an important role in the design of column length. Based on the homogenization method, a part of floating type improved ground will be treated as an unimproved portion, which with a length of αH1 is defined as a time-dependent equivalent skin friction length. The compression settlement of this unimproved portion can be predicted only using the soft clay parameters. Apart from calculating the settlement of this composited ground, the load transfer mechanism is discussed utilizing model tests. The proposed model is validated by comparing with calculations and laboratory results of model and ring shear tests, which indicate the suitability and accuracy of the solutions in this paper.

Keywords: floating type improved foundation, time-dependent skin friction, roughness, consolidation

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6825 Parametric Dependence of the Advection-Diffusion Equation in Two Dimensions

Authors: Matheus Fernando Pereira, Varese Salvador Timoteo

Abstract:

In this work, we have solved the two-dimensional advection-diffusion equation numerically for a spatially dependent solute dispersion along non-uniform flow with a pulse type source in order to make a systematic study on the influence of medium heterogeneity, initial flow velocity, and initial dispersion coefficient parameters on the solutions of the equation. The behavior of the solutions is then investigated as we change the three parameters independently. Our results show that even though the parameters represent different physical features of the system, the effect on their variation is very similar. We also observe that the effects caused by the parameters on the concentration depend on the distance from the source. Finally, our numerical results are in good agreement with the exact solutions for all values of the parameters we used in our analysis.

Keywords: advection-diffusion equation, dispersion, numerical methods, pulse-type source

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6824 The Relationship between Incidental Emotions, Risk Perceptions and Type of Army Service

Authors: Sharon Garyn-Tal, Shoshana Shahrabani

Abstract:

Military service in general, and in combat units in particular, can be physically and psychologically stressful. Therefore, type of service may have significant implications for soldiers during and after their military service including emotions, judgments and risk perceptions. Previous studies have focused on risk propensity and risky behavior among soldiers, however there is still lack of knowledge on the impact of type of army service on risk perceptions. The current study examines the effect of type of army service (combat versus non-combat service) and negative incidental emotions on risk perceptions. In 2014 a survey was conducted among 153 combat and non-combat Israeli soldiers. The survey was distributed in train stations and central bus stations in various places in Israel among soldiers waiting for the train/bus. Participants answered questions related to the levels of incidental negative emotions they felt, to their risk perceptions (chances to be hurt by terror attack, by violent crime and by car accident), and personal details including type of army service. The data in this research is unique because military service in Israel is compulsory, so that the Israeli population serving in the army is wide and diversified. The results indicate that currently serving combat participants were more pessimistic in their risk perceptions (for all type of risks) compared to the currently serving non-combat participants. Since combat participants probably experienced severe and distressing situations during their service, they became more pessimistic regarding their probabilities of being hurt in different situations in life. This result supports the availability heuristic theory and the findings of previous studies indicating that those who directly experience distressing events tend to overestimate danger. The findings also indicate that soldiers who feel higher levels of incidental fear and anger have pessimistic risk perceptions. In addition, respondents who experienced combat army service also have pessimistic risk perceptions if they feel higher levels of fear. In addition, the findings suggest that higher levels of the incidental emotions of fear and anger are related to more pessimistic risk perceptions. These results can be explained by the compulsory army service in Israel that constitutes a focused threat to soldiers' safety during their period of service. Thus, in this stressful environment, negative incidental emotions even during routine times correlate with higher risk perceptions. In conclusion, the current study results suggest that combat army service shapes risk perceptions and the way young people control their negative incidental emotions in everyday life. Recognizing the factors affecting risk perceptions among soldiers is important for better understanding the impact of army service on young people.

Keywords: army service, combat soldiers, incidental emotions, risk perceptions

Procedia PDF Downloads 234
6823 Investigation of Kinesiophobia in Individuals with Type 2 Diabetes

Authors: Ismail Okur, Betul Taspinar, Turkan Pasali Kilit, Eda O. Okur, Ferruh Taspinar

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Type 2 Diabetes Mellitus (T2DM) is one of the most important global health emergencies and every year more and more people are affected by T2DM. T2DM causes life-changing complications by affecting organ and systems. Although diet and exercise are the best way to treat patients with T2DM, those patients generally have a sedentary life style. This study was planned to determine whether patients with T2DM have kinesiophobia (fear of movement). A controlled trial was conducted on 87 adults. Forty-one individuals with T2DM (study group, 34 female and 7 male) and 46 nondiabetic individuals (control group, 39 female and 7 male) were included in the study. Patients were screened for fear of movement using the Tampa Scale for Kinesiophobia (TSK). The data including age, sex, weight, height, and TSK scores were obtained. Mann Whitney U test were used to analyse the data. The mean ages and BMI of study and control groups were 51.98 ± 6.03 year and 49.52 ± 5.61 year and 31.82 ± 2.88 kg/m2 and 30.22 ± 2.91 kg/m2, respectively. The groups have similar demographic properties. The kinesiophobia scores of study and control groups were 42.78 ± 5.50 and 39.48 ± 5.05, respectively and the difference was statistically significant (p=0.05). This study showed that patients with T2DM had high kinesiophobia scores rather than nondiabetics. Those patients might avoid to do exercise. In other words, patients with T2DM might have lower physical activity level. Therefore the authors suggest that to evaluate and interfere with kinesiophobia before conducting exercise therapy will be useful for diabetes care.

Keywords: diabetes, fear of movement, kinesiophobia, type 2 diabetes mellitus

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6822 Molecular Alterations Shed Light on Alteration of Methionine Metabolism in Gastric Intestinal Metaplesia; Insight for Treatment Approach

Authors: Nigatu Tadesse, Ying Liu, Juan Li, Hong Ming Liu

Abstract:

Gastric carcinogenesis is a lengthy process of histopathological transition from normal to atrophic gastritis (AG) to intestinal metaplasia (GIM), dysplasia toward gastric cancer (GC). The stage of GIM identified as precancerous lesions with resistance to H-pylori eradication and recurrence after endoscopic surgical resection therapies. GIM divided in to two morphologically distinct phenotypes such as complete GIM bearing intestinal type morphology whereas the incomplete type has colonic type morphology. The incomplete type GIM considered to be the greatest risk factor for the development of GC. Studies indicated the expression of the caudal type homeobox 2 (CDX2) gene is responsible for the development of complete GIM but its progressive downregulation from incomplete metaplasia toward advanced GC identified as the risk for IM progression and neoplastic transformation. The downregulation of CDX2 gene have promoted cell growth and proliferation in gastric and colon cancers and ascribed in chemo-treatment inefficacies. CDX2 downregulated through promoter region hypermethylation in which the methylation frequency positively correlated with the dietary history of the patients, suggesting the role of diet as methyl carbon donor sources such as methionine. However, the metabolism of exogenous methionine is yet unclear. Targeting exogenous methionine metabolism has become a promising approach to limits tumor cell growth, proliferation and progression and increase treatment outcome. This review article discusses molecular alterations that could shed light on the potential of exogenous methionine metabolisms, such as gut microbiota alteration as sources of methionine to host cells, metabolic pathway signaling via PI3K/AKt/mTORC1-c-MYC to rewire exogenous methionine and signature of increased gene methylation index, cell growth and proliferation in GIM, with insights to new treatment avenue via targeting methionine metabolism, and the need for future integrated studies on molecular alterations and metabolomics to uncover altered methionine metabolism and characterization of CDX2 methylation in gastric intestinal metaplasia for potential therapeutic exploitation.

Keywords: altered methionine metabolism, Intestinal metaplesia, CDX2 gene, gastric cancer

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6821 Arterial Line Use for Acute Type 2 Respiratory Failure

Authors: C. Scurr, J. Jeans, S. Srivastava

Abstract:

Introduction: Acute type two respiratory failure (T2RF) has become a common presentation over the last two decades primarily due to an increase in the prevalence of chronic lung disease. Acute exacerbations can be managed either medically or in combination with non-invasive ventilation (NIV) which should be monitored with regular arterial blood gas samples (ABG). Arterial lines allow more frequent arterial blood sampling with less patient discomfort. We present the experience from a teaching hospital emergency department (ED) and level 2 medical high-dependency unit (HDU) that together form the pathway for management of acute type 2 respiratory failure. Methods: Patients acutely presenting to Charing Cross Hospital, London, with T2RF requiring non-invasive ventilation (NIV) over 14 months (2011 to 2012) were identified from clinical coding. Retrospective data collection included: demographics, co-morbidities, blood gas numbers and timing, if arterial lines were used and who performed this. Analysis was undertaken using Microsoft Excel. Results: Coding identified 107 possible patients. 69 notes were available, of which 41 required NIV for type 2 respiratory failure. 53.6% of patients had an arterial line inserted. Patients with arterial lines had 22.4 ABG in total on average compared to 8.2 for those without. These patients had a similar average time to normalizing pH of (23.7 with arterial line vs 25.6 hours without), and no statistically significant difference in mortality. Arterial lines were inserted by Foundation year doctors, Core trainees, Medical registrars as well as the ICU registrar. 63% of these were performed by the medical registrar rather than ICU, ED or a junior doctor. This is reflected in that the average time until an arterial line was inserted was 462 minutes. The average number of ABGs taken before an arterial line was 2 with a range of 0 – 6. The average number of gases taken if no arterial line was ever used was 7.79 (range of 2-34) – on average 4 times as many arterial punctures for each patient. Discussion: Arterial line use was associated with more frequent arterial blood sampling during each inpatient admission. Additionally, patients with an arterial line have less individual arterial punctures in total and this is likely more comfortable for the patient. Arterial lines are normally sited by medical registrars, however this is normally after some delay. ED clinicians could improve patient comfort and monitoring thus allowing faster titration of NIV if arteral lines were regularly inserted in the ED. We recommend that ED doctors insert arterial lines when indicated in order improve the patient experience and facilitate medical management.

Keywords: non invasive ventilation, arterial blood gas, acute type, arterial line

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