Search results for: physical properties
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 13278

Search results for: physical properties

2628 Wearable Jacket for Game-Based Post-Stroke Arm Rehabilitation

Authors: A. Raj Kumar, A. Okunseinde, P. Raghavan, V. Kapila

Abstract:

Stroke is the leading cause of adult disability worldwide. With recent advances in immediate post-stroke care, there is an increasing number of young stroke survivors, under the age of 65 years. While most stroke survivors will regain the ability to walk, they often experience long-term arm and hand motor impairments. Long term upper limb rehabilitation is needed to restore movement and function, and prevent deterioration from complications such as learned non-use and learned bad-use. We have developed a novel virtual coach, a wearable instrumented rehabilitation jacket, to motivate individuals to participate in long-term skill re-learning, that can be personalized to their impairment profile. The jacket can estimate the movements of an individual’s arms using embedded off-the-shelf sensors (e.g., 9-DOF IMU for inertial measurements, flex-sensors for measuring angular orientation of fingers) and a Bluetooth Low Energy (BLE) powered microcontroller (e.g., RFduino) to non-intrusively extract data. The 9-DOF IMU sensors contain 3-axis accelerometer, 3-axis gyroscope, and 3-axis magnetometer to compute the quaternions, which are transmitted to a computer to compute the Euler angles and estimate the angular orientation of the arms. The data are used in a gaming environment to provide visual, and/or haptic feedback for goal-based, augmented-reality training to facilitate re-learning in a cost-effective, evidence-based manner. The full paper will elaborate the technical aspects of communication, interactive gaming environment, and physical aspects of electronics necessary to achieve our stated goal. Moreover, the paper will suggest methods to utilize the proposed system as a cheaper, portable, and versatile system vis-à-vis existing instrumentation to facilitate post-stroke personalized arm rehabilitation.

Keywords: feedback, gaming, Euler angles, rehabilitation, augmented reality

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2627 Advanced Phosphorus-Containing Polymer Materials towards Eco-Friendly Flame Retardant Epoxy Thermosets

Authors: Ionela-Daniela Carja, Diana Serbezeanu, Tachita Vlad-Bubulac, Corneliu Hamciuc

Abstract:

Nowadays, epoxy materials are extensively used in ever more areas and under ever more demanding environmental conditions due to their remarkable combination of properties, light weight and ease of processing. However, these materials greatly increase the fire risk due to their flammability and possible release of toxic by-products as a result of their chemical composition which consists mainly from carbon and hydrogen atoms. Therefore, improving the fire retardant behaviour to prevent the loss of life and property is of particular concern among government regulatory bodies, consumers and manufacturers alike. Modification of epoxy resins with organophosphorus compounds, as reactive flame retardants or additives, is the key to achieving non-flammable advanced epoxy materials. Herein, a detailed characterization of fire behaviour for a series of phosphorus-containing epoxy thermosets is reported. A carefully designed phosphorus flame retardant additive was simply blended with a bifunctional bisphenol-A based epoxy resin. Further thermal cross-linking in the presence of various aminic hardeners led to eco-friendly flame retardant epoxy resins. The type of hardener, concentration of flame retardant additive, compatibility between the components of the mixture, char formation and morphology, thermal stability, flame retardant mechanisms were investigated. It was found that even a very low content of phosphorus introduced into the epoxy matrix increased the limiting oxygen index value to about 30%. In addition, the peak of the heat release rate value decreased up to 45% as compared to the one of the neat epoxy system. The main flame retardant mechanism was the condensed-phase one as revealed by SEM and XPS measurements.

Keywords: condensed-phase mechanism, eco-friendly phosphorus flame retardant, epoxy resin, thermal stability

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2626 Preparing Undergraduate Nursing and Midwifery Students for Culturally Competent Health Care: A Qualitative Study

Authors: Olayide Ogunsiji, Glenda McDonald

Abstract:

Engendering cultural competence in nursing and midwifery students is germane to reducing disparities in contemporary health care settings, increasingly patronized by people from diverse background. Professional standards for registration in Australia require nurses and midwives to be culturally competent. Nursing and midwifery academics worldwide are responsible for preparing students for clinical practice, yet limited attention is paid to exploring how students are being prepared to care for a culturally diverse population. This paper provides insight into the perceptions of academics about how they are preparing undergraduate nursing and midwifery students for culturally competent health care. Academics were drawn from a tertiary educational institution in metropolitan Australia. They responded to a generic email indicating their interest in participating in the study. A total of nine academics who have taught undergraduate nursing and midwifery students in a unit that focused on health and illness perspectives for culturally diverse communities; and provided written consent to participate were included. These academics were engaged in a qualitative digitally-recorded semi-structured face-to-face or telephone interviews which lasted for about 45-60 minutes. Interview data were transcribed verbatim. Through constant comparison, three themes emerged: experiences of the teachers, strategies used for preparing students and challenges in preparing students. The participants spoke about their experiences of teaching in the unit and with the students. They faced challenges related to physical and relational space. They utilised a number of didactic approaches in teaching the unit and critiqued the adequacy of the content in preparing students for practice. This study demonstrated that didactic classroom approaches need to be supported with clinical practice and cultural immersion for a meaningful preparation of nursing and midwifery students to care for culturally diverse populations.

Keywords: cultural competence, nursing students, preparation, undergraduate

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2625 Psychopathic Disorders and Judges Sentencing: Can Neurosciences Change this Aggravating Factor in a Mitigating Factor?

Authors: Kevin Moustapha

Abstract:

Psychopathy is perceived today as being «the most important concept in the criminal justice system» and as «the most important legal notion of the early 21 th century». The explosion of research related to psychopathy seems to perfectly illustrate this trend. Traditionally, many studies tend to focus on links between insanity defense and psychopathy. That is why our purpose in this article is to analyze psychopathic disorders in the scope of judges sentencing in Canada. Indeed, in every Canadian case related to dangerous offenders, judges must balance between fairness and protection of the individuals rights of the accused and protection of society from dangerous predators who may commit future acts of physical or sexual violence. Increasingly, psychopathic disorders are taking an important part in judge sentencing, especially in Canada. This phenomenon can be illustrated by the high proportion of psychopath offenders incarcerated in North American prisons. Many decisions in Canadians courtrooms seem to point out that psychopathy is often used as a strong argument by the judges to preserve public safety. The fact that psychopathy is often associated with violence, recklessness and recidivism, it could explain why many judges consider psychopathic disorders as an aggravating factor. Generally, the judge reasoning is based on article 753 of Canadian Criminal Code related to dangerous offenders, which is used for individuals who show a pattern of repetitive and persistent aggressive behaviour. However, with cognitive neurosciences, the psychopath’s situation in courtrooms would probably change. Cerebral imaging and news data provided by the neurosciences show that emotional and volitional functions in psychopath’s brains are impaired. Understanding these new issues could enable some judges to recognize psychopathic disorders as a mitigating factor. Two important questions ought to be raised in this article: can exploring psychopaths ‘brains really change the judge sentencing in Canadian courtrooms? If yes, can judges consider psychopathy more as a mitigating factor than an aggravating factor?

Keywords: criminal law, judges sentencing, neurosciences, psychopathy

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2624 Prospectivity Mapping of Orogenic Lode Gold Deposits Using Fuzzy Models: A Case Study of Saqqez Area, Northwestern Iran

Authors: Fanous Mohammadi, Majid H. Tangestani, Mohammad H. Tayebi

Abstract:

This research aims to evaluate and compare Geographical Information Systems (GIS)-based fuzzy models for producing orogenic gold prospectivity maps in the Saqqez area, NW of Iran. Gold occurrences are hosted in sericite schist and mafic to felsic meta-volcanic rocks in this area and are associated with hydrothermal alterations that extend over ductile to brittle shear zones. The predictor maps, which represent the Pre-(Source/Trigger/Pathway), syn-(deposition/physical/chemical traps) and post-mineralization (preservation/distribution of indicator minerals) subsystems for gold mineralization, were generated using empirical understandings of the specifications of known orogenic gold deposits and gold mineral systems and were then pre-processed and integrated to produce mineral prospectivity maps. Five fuzzy logic operators, including AND, OR, Fuzzy Algebraic Product (FAP), Fuzzy Algebraic Sum (FAS), and GAMMA, were applied to the predictor maps in order to find the most efficient prediction model. Prediction-Area (P-A) plots and field observations were used to assess and evaluate the accuracy of prediction models. Mineral prospectivity maps generated by AND, OR, FAP, and FAS operators were inaccurate and, therefore, unable to pinpoint the exact location of discovered gold occurrences. The GAMMA operator, on the other hand, produced acceptable results and identified potentially economic target sites. The P-A plot revealed that 68 percent of known orogenic gold deposits are found in high and very high potential regions. The GAMMA operator was shown to be useful in predicting and defining cost-effective target sites for orogenic gold deposits, as well as optimizing mineral deposit exploitation.

Keywords: mineral prospectivity mapping, fuzzy logic, GIS, orogenic gold deposit, Saqqez, Iran

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2623 Crab Shell Waste Chitosan-Based Thin Film for Acoustic Sensor Applications

Authors: Maydariana Ayuningtyas, Bambang Riyanto, Akhiruddin Maddu

Abstract:

Industrial waste of crustacean shells, such as shrimp and crab, has been considered as one of the major issues contributing to environmental pollution. The waste processing mechanisms to form new, practical substances with added value have been developed. Chitosan, a derived matter from chitin, which is obtained from crab and shrimp shells, performs prodigiously in broad range applications. A chitosan composite-based diaphragm is a new inspiration in fiber optic acoustic sensor advancement. Elastic modulus, dynamic response, and sensitivity to acoustic wave of chitosan-based composite film contribute great potentials of organic-based sound-detecting material. The objective of this research was to develop chitosan diaphragm application in fiber optic microphone system. The formulation was conducted by blending 5% polyvinyl alcohol (PVA) solution with dissolved chitosan at 0%, 1% and 2% in 1:1 ratio, respectively. Composite diaphragms were characterized for the morphological and mechanical properties to predict the desired acoustic sensor sensitivity. The composite with 2% chitosan indicated optimum performance with 242.55 µm thickness, 67.9% relative humidity, and 29-76% light transmittance. The Young’s modulus of 2%-chitosan composite material was 4.89×104 N/m2, which generated the voltage amplitude of 0.013V and performed sensitivity of 3.28 mV/Pa at 1 kHz. Based on the results above, chitosan from crustacean shell waste can be considered as a viable alternative material for fiber optic acoustic sensor sensing pad development. Further, the research in chitosan utilisation is proposed as novel optical microphone development in anthropogenic noise controlling effort for environmental and biodiversity conservation.

Keywords: acoustic sensor, chitosan, composite, crab shell, diaphragm, waste utilisation

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2622 Synthesis of Pyrimidine-Based Polymers Consist of 2-{4-[4,6-Bis-(4-Hexyl-Thiophen-2-yl)-Pyrimidin-2-yl]-Phenyl}-Thiazolo[5,4-B]Pyridine with Deep HOMO Level for Photovoltaics

Authors: Hyehyeon Lee, Jiwon Yu, Juwon Kim, Raquel Kristina Leoni Tumiar, Taewon Kim, Juae Kim, Hongsuk Suh

Abstract:

Photovoltaics, which have many advantages in cost, easy processing, and light-weight, have attracted attention. We synthesized pyrimidine-based conjugated polymers with 2-{4-[4,6-bis-(4-hexyl-thiophen-2-yl)-pyrimidin-2-yl]-phenyl}-thiazolo[5,4-b]pyridine (pPTP) which have an ability of powerful electron withdrawing and introduced into the PSCs. By Stille polymerization, we designed the conjugated polymers, pPTPBDT-12, pPTPBDT-EH, pPTPBDTT-EH and pPTPTTI. The HOMO energy levels of four polymers (pPTPBDT-12, pPTPBDT-EH, pPTPBDTT-EH and pPTPTTI) were at -5.61 ~ -5.89 eV, their LUMO (Lowest Unoccupied Molecular Orbital) energy levels were at -3.95 ~ -4.09 eV. The device including pPTPBDT-12 and PC71BM (1:2) indicated a V_oc of 0.67 V, a J_sc of 1.33 mA/cm², and a fill factor (FF) of 0.25, giving a power conversion efficiency (PCE) of 0.23%. The device including pPTPBDT-EH and PC71BM (1:2) indicated a V_oc of 0.72 V, a J_sc of 2.56 mA/cm², and a fill factor (FF) of 0.30, giving a power conversion efficiency of 0.56%. The device including pPTPBDTT-EH and PC71BM (1:2) indicated a V_oc of 0.72 V, a J_sc of 3.61 mA/cm², and a fill factor (FF) of 0.29, giving a power conversion efficiency of 0.74%. The device including pPTPTTI and PC71BM (1:2) indicated a V_oc of 0.83 V, a J_sc of 4.41 mA/cm², and a fill factor (FF) of 0.31, giving a power conversion efficiency of 1.13%. Therefore, pPTPBDT-12, pPTPBDT-EH, pPTPBDTT-EH, and pPTPTTI were synthesized by Stille polymerization. And We find one of the best efficiency for these polymers, called pPTPTTI. Their optical properties were measured and the results show that pyrimidine-based polymers especially like pPTPTTI have a great promise to act as the donor of the active layer.

Keywords: polymer solar cells, pyrimidine-based polymers, photovoltaics, conjugated polymer

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2621 Exploring the Determinants of Boko Haram Terrorism in Nigerian Security Systems and Economy

Authors: Abara Onu, Augustine Mina Ephraim, Emmanuel Teidi

Abstract:

Terrorism has been a major challenge and is so dare to the Nigerian government in recent times. The actions and activities of the Islamic sect known as Boko Haram had led to enormous loss of lives and properties in the country, mostly the Northern part of Nigeria. Some of these activities entails bombings, suicide attacks, intimidations, sporadic gunfire of the unarmed, blameless and innocent Nigerians, burning of police stations and churches, kidnappings, raping of school girls and women. Nigeria has also been included amongst one of the terrorist countries of the world. This has serious implications for the development of Nigerian economy. Although, Nigeria had made several worried hard work to deal with these challenges masqueraded by terrorism and insecurity in the country but the rate of insurgency and insecurity is still worrisome. The study looks at exploring the determinants of Boko Haram terrorism in Nigerian security systems and economy. Data used for the study work was from questionnaire administered, using Analysis of Variance (ANOVA) method to analyse the data. The result shows that Ideology and funding are significant basic factors that propelled the Boko Haram group in Nigeria. The Boko Haram disaster poses a significant threat to Nigeria’s economy and the military is the best option and solution in tackling the Boko Haram menace in Nigeria. The work x-rayed the following recommendations; government should declare war on terrorism and as well seek support and cooperation from international communities who in time or the other might have faced with this kind ugly experience and challenge and were able to tackle it. Nigerian Military needs to be more empowered with high dangerous weapons to combat the insurgency as well as beef up security across the Country to curb the threats.

Keywords: terrorism, economy, Boko Haram, Nigeria

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2620 The Planning and Development of Green Public Places in Urban South Africa: A Child-Friendly Approach

Authors: E. J. Cilliers, Z. Goosen

Abstract:

The impact that urban green spaces have on sustainability and quality of life is phenomenal. This is also true for the local South African environment. However, in reality green spaces in urban environments are decreasing due to growing populations, increasing urbanization and development pressure. This further impacts on the provision of child-friendly spaces, a concept that is already limited in local context. Child-friendly spaces are described as environments in which people (children) feel intimately connected to, influencing the physical, social, emotional, and ecological health of individuals and communities. The benefits of providing such spaces for the youth are well documented in literature. This research therefore aimed to investigate the concept of child-friendly spaces and its applicability to the South African planning context, in order to guide the planning of such spaces for future communities and use. Child-friendly spaces in the urban environment of the city of Durban, was used as local case study, along with two international case studies namely Mullerpier public playground in Rotterdam, the Netherlands, and Kadidjiny Park in Melville, Australia. The aim was to determine how these spaces were planned and developed and to identify tools that were used to accomplish the goal of providing successful child-friendly green spaces within urban areas. The need and significance of planning for such spaces was portrayed within the international case studies. It is confirmed that minimal provision is made for green space planning within the South African context, when there is reflected on the international examples. As a result international examples and disciples of providing child-friendly green spaces should direct planning guidelines within local context. The research concluded that child-friendly green spaces have a positive impact on the urban environment and assist in a child’s development and interaction with the natural environment. Regrettably, the planning of these child-friendly spaces is not given priority within current spatial plans, despite the proven benefits of such.

Keywords: built environment, child-friendly spaces, green spaces, public places, urban area

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2619 Regression Analysis in Estimating Stream-Flow and the Effect of Hierarchical Clustering Analysis: A Case Study in Euphrates-Tigris Basin

Authors: Goksel Ezgi Guzey, Bihrat Onoz

Abstract:

The scarcity of streamflow gauging stations and the increasing effects of global warming cause designing water management systems to be very difficult. This study is a significant contribution to assessing regional regression models for estimating streamflow. In this study, simulated meteorological data was related to the observed streamflow data from 1971 to 2020 for 33 stream gauging stations of the Euphrates-Tigris Basin. Ordinary least squares regression was used to predict flow for 2020-2100 with the simulated meteorological data. CORDEX- EURO and CORDEX-MENA domains were used with 0.11 and 0.22 grids, respectively, to estimate climate conditions under certain climate scenarios. Twelve meteorological variables simulated by two regional climate models, RCA4 and RegCM4, were used as independent variables in the ordinary least squares regression, where the observed streamflow was the dependent variable. The variability of streamflow was then calculated with 5-6 meteorological variables and watershed characteristics such as area and height prior to the application. Of the regression analysis of 31 stream gauging stations' data, the stations were subjected to a clustering analysis, which grouped the stations in two clusters in terms of their hydrometeorological properties. Two streamflow equations were found for the two clusters of stream gauging stations for every domain and every regional climate model, which increased the efficiency of streamflow estimation by a range of 10-15% for all the models. This study underlines the importance of homogeneity of a region in estimating streamflow not only in terms of the geographical location but also in terms of the meteorological characteristics of that region.

Keywords: hydrology, streamflow estimation, climate change, hydrologic modeling, HBV, hydropower

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2618 Investigating Informal Vending Practices and Social Encounters along Commercial Streets in Cairo, Egypt

Authors: Dalya M. Hassan

Abstract:

Marketplaces and commercial streets represent some of the most used and lively urban public spaces. Not only do they provide an outlet for commercial exchange, but they also facilitate social and recreational encounters. Such encounters can be influenced by both formal as well as informal vending activities. This paper explores and documents forms of informal vending practices and how they relate to social patterns that occur along the sidewalks of Commercial Streets in Cairo. A qualitative single case study approach of ‘Midan El Gami’ marketplace in Heliopolis, Cairo is adopted. The methodology applied includes direct and walk-by observations for two main commercial streets in the marketplace. Four zoomed-in activity maps are also done for three sidewalk segments that displayed varying vending and social features. Main findings include a documentation and classification of types of informal vending practices as well as a documentation of vendors’ distribution patterns in the urban space. Informal vending activities mainly included informal street vendors and shop spillovers, either as product or seating spillovers. Results indicated that staying and lingering activities were more prevalent in sidewalks that had certain physical features, such as diversity of shops, shaded areas, open frontages, and product or seating spillovers. Moreover, differences in social activity patterns were noted between sidewalks with street vendors and sidewalks with spillovers. While the first displayed more buying, selling, and people watching activities, the latter displayed more social relations and bonds amongst traders’ communities and café patrons. Ultimately, this paper provides a documentation, which suggests that informal vending can have a positive influence on creating a lively commercial street and on resulting patterns of use on the sidewalk space. The results can provide a basis for further investigations and analysis concerning this topic. This could aid in better accommodating informal vending activities within the design of future commercial streets.

Keywords: commercial streets, informal vending practices, sidewalks, social encounters

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2617 Service Life Study of Polymers Used in Renovation of Heritage Buildings and Other Structures

Authors: Parastou Kharazmi

Abstract:

Degradation of building materials particularly pipelines causes environmental damage during renovation or replacement and is a time consuming and costly process. Rehabilitation by polymer composites is a solution for renovation of degraded pipeline in heritage buildings and other structures which are less costly, faster and causes less damage to the environment; however, it is still not clear for how long these materials can perform as expected in the field and working condition. To study their service life, two types of composites based on Epoxy and Polyester resins have been evaluated by accelerated exposure and field exposure. The primary degradation agent used in accelerated exposure has been cycling temperature with half of the tests performed in presence of water. Thin films of materials used in accelerated testing were prepared in laboratory by using the same amount of material as well as technique of multi-layers application used in majority of the field installations. Extreme intensity levels of degradation agents have been used only to evaluate materials properties and as also mentioned in ISO 15686, are not directly correlated with degradation mechanisms that would be experienced in service. In the field exposure study, the focus has been to identify possible failure modes, causes, and effects. In field exposure, it has been observed that there are other degradation agents present which can be investigated further such as presence of contaminants and rust before application which prevents formation of a uniform layer of polymer or incompatibility between dissimilar materials. This part of the study also highlighted the importance of application’s quality of the materials in the field for providing the expected performance and service life. Results from extended accelerated exposure and field exposure can help in choosing inspection techniques, establishing the primary degradation agents and can be used for ageing exposure programs with clarifying relationship between different exposure periods and sites.

Keywords: building, renovation, service life, pipelines

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2616 Design, Analysis and Obstacle Avoidance Control of an Electric Wheelchair with Sit-Sleep-Seat Elevation Functions

Authors: Waleed Ahmed, Huang Xiaohua, Wilayat Ali

Abstract:

The wheelchair users are generally exposed to physical and psychological health problems, e.g., pressure sores and pain in the hip joint, associated with seating posture or being inactive in a wheelchair for a long time. Reclining Wheelchair with back, thigh, and leg adjustment helps in daily life activities and health preservation. The seat elevating function of an electric wheelchair allows the user (lower limb amputation) to reach different heights. An electric wheelchair is expected to ease the lives of the elderly and disable people by giving them mobility support and decreasing the percentage of accidents caused by users’ narrow sight or joystick operation errors. Thus, this paper proposed the design, analysis and obstacle avoidance control of an electric wheelchair with sit-sleep-seat elevation functions. A 3D model of a wheelchair is designed in SolidWorks that was later used for multi-body dynamic (MBD) analysis and to verify driving control system. The control system uses the fuzzy algorithm to avoid the obstacle by getting information in the form of distance from the ultrasonic sensor and user-specified direction from the joystick’s operation. The proposed fuzzy driving control system focuses on the direction and velocity of the wheelchair. The wheelchair model has been examined and proven in MSC Adams (Automated Dynamic Analysis of Mechanical Systems). The designed fuzzy control algorithm is implemented on Gazebo robotic 3D simulator using Robotic Operating System (ROS) middleware. The proposed wheelchair design enhanced mobility and quality of life by improving the user’s functional capabilities. Simulation results verify the non-accidental behavior of the electric wheelchair.

Keywords: fuzzy logic control, joystick, multi body dynamics, obstacle avoidance, scissor mechanism, sensor

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2615 Analysis of Sustainability of Groundwater Resources in Rote Island, Indonesia under HADCM3 Global Model Climate Scenarios: Groundwater Flow Simulation and Proposed Adaptive Strategies

Authors: Dua K. S. Y. Klaas, Monzur A. Imteaz, Ika Sudiayem, Elkan M. E. Klaas, Eldav C. M. Klaas

Abstract:

Developing tailored management strategies to ensure the sustainability of groundwater resource under climate and demographic changes is critical for tropical karst island, where relatively small watershed and highly porous soil nature make this natural resource highly susceptible and thus very sensitive to those changes. In this study, long-term impacts of climate variability on groundwater recharge and discharge at the Oemau spring, Rote Island, Indonesia were investigated. Following calibration and validation of groundwater model using MODFLOW code, groundwater flow was simulated for period of 2020-2090 under HadCM3 global model climate (GCM) scenarios, using input data of weather variables downscaled by Statistical Downscaling Model (SDSM). The reported analysis suggests that the sustainability of groundwater resources will be adversely affected by climate change during dry years. The area is projected to variably experience 2.53-22.80% decrease of spring discharge. A subsequent comprehensive set of management strategies as palliative and adaptive efforts was proposed to be implemented by relevant stakeholders to assist the community dealing with water deficit during the dry years. Three main adaptive strategies, namely socio-cultural, technical, and ecological measures, were proposed by incorporating physical and socio-economic characteristics of the area. This study presents a blueprint for assessing groundwater sustainability under climate change scenarios and developing tailored management strategies to cope with adverse impacts of climate change, which may become fundamental necessities across other tropical karst islands in the future.

Keywords: climate change, groundwater, management strategies, tropical karst island, Rote Island, Indonesia

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2614 Plasma Engineered Nanorough Substrates for Stem Cells in vitro Culture

Authors: Melanie Macgregor-Ramiasa, Isabel Hopp, Patricia Murray, Krasimir Vasilev

Abstract:

Stem cells based therapies are one of the greatest promises of new-age medicine due to their potential to help curing most dreaded conditions such as cancer, diabetes and even auto-immune disease. However, establishing suitable in vitro culture materials allowing to control the fate of stem cells remain a challenge. Amongst the factor influencing stem cell behavior, substrate chemistry and nanotopogaphy are particularly critical. In this work, we used plasma assisted surface modification methods to produce model substrates with tailored nanotopography and controlled chemistry. Three different sizes of gold nanoparticles were bound to amine rich plasma polymer layers to produce homogeneous and gradient surface nanotopographies. The outer chemistry of the substrate was kept constant for all substrates by depositing a thin layer of our patented biocompatible polyoxazoline plasma polymer on top of the nanofeatures. For the first time, protein adsorption and stem cell behaviour (mouse kidney stem cells and mesenchymal stem cells) were evaluated on nanorough plasma deposited polyoxazoline thin films. Compared to other nitrogen rich coatings, polyoxazoline plasma polymer supports the covalent binding of proteins. Moderate surface nanoroughness, in both size and density, triggers cell proliferation. In association with polyoxazoline coating, cell proliferation is further enhanced on nanorough substrates. Results are discussed in term of substrates wetting properties. These findings provide valuable insights on the mechanisms governing the interactions between stem cells and their growth support.

Keywords: nanotopography, stem cells, differentiation, plasma polymer, oxazoline, gold nanoparticles

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2613 Kinetics and Thermodynamics Adsorption of Phenolic Compounds on Organic-Inorganic Hybrid Mesoporous Material

Authors: Makhlouf Mourad, Messabih Sidi Mohamed, Bouchher Omar, Houali Farida, Benrachedi Khaled

Abstract:

Mesoporous materials are very commonly used as adsorbent materials for removing phenolic compounds. However, the adsorption mechanism of these compounds is still poorly controlled. However, understanding the interactions mesoporous materials/adsorbed molecules is very important in order to optimize the processes of liquid phase adsorption. The difficulty of synthesis is to keep an orderly and cubic pore structure and achieve a homogeneous surface modification. The grafting of Si(CH3)3 was chosen, to transform hydrophilic surfaces hydrophobic surfaces. The aim of this work is to study the kinetics and thermodynamics of two volatile organic compounds VOC phenol (PhOH) and P hydroxy benzoic acid (4AHB) on a mesoporous material of type MCM-48 grafted with an organosilane of the Trimethylchlorosilane (TMCS) type, the material thus grafted or functionalized (hereinafter referred to as MCM-48-G). In a first step, the kinetic and thermodynamic study of the adsorption isotherms of each of the VOCs in mono-solution was carried out. In a second step, a similar study was carried out on a mixture of these two compounds. Kinetic models (pseudo-first order, pseudo-second order) were used to determine kinetic adsorption parameters. The thermodynamic parameters of the adsorption isotherms were determined by the adsorption models (Langmuir, Freundlich). The comparative study of adsorption of PhOH and 4AHB proved that MCM-48-G had a high adsorption capacity for PhOH and 4AHB; this may be related to the hydrophobicity created by the organic function of TMCS in MCM-48-G. The adsorption results for the two compounds using the Freundlich and Langmuir models show that the adsorption of 4AHB was higher than PhOH. The values ​​obtained by the adsorption thermodynamics show that the adsorption interactions for our sample with the phenol and 4AHB are of a physical nature. The adsorption of our VOCs on the MCM-48 (G) is a spontaneous and exothermic process.

Keywords: adsorption, kinetics, isotherm, mesoporous materials, Phenol, P-hydroxy benzoique acid

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2612 Surface Modification of Pineapple Leaf Fibre Reinforced Polylactic Acid Composites

Authors: Januar Parlaungan Siregar, Davindra Brabu Mathivanan, Dandi Bachtiar, Mohd Ruzaimi Mat Rejab, Tezara Cionita

Abstract:

Natural fibres play a significant role in mass industries such as automotive, construction and sports. Many researchers have found that the natural fibres are the best replacement for the synthetic fibres in terms of cost, safety, and degradability due to the shortage of landfill and ingestion of non biodegradable plastic by animals. This study mainly revolved around pineapple leaf fibre (PALF) which is available abundantly in tropical countries and with excellent mechanical properties. The composite formed in this study is highly biodegradable as both fibre and matrix are both derived from natural based products. The matrix which is polylactic acid (PLA) is made from corn starch which gives the upper hand as both material are renewable resources are easier to degrade by bacteria or enzyme. The PALF is treated with different alkaline solution to remove excessive moisture in the fibre to provide better interfacial bonding with PLA. Thereafter the PALF is washed with distilled water several times before placing in vacuum oven at 80°C for 48 hours. The dried PALF later were mixed with PLA using extrusion method using fibre in percentage of 30 by weight. The temperature for all zone were maintained at 160°C with the screw speed of 50 rpm for better bonding and afterwards the products of the mixture were pelletized using pelletizer. The pellets were placed in the specimen-sized mould for hot compression under the temperature of 170°C at 5 MPa for 5 min and subsequently were cold pressed under room temperature at 5 MPa for 5 min. The specimen were tested for tensile and flexure strength according to American Society for Testing and Materials (ASTM) D638 and D790 respectively. The effect of surface modification on PALF with different alkali solution will be investigated and compared.

Keywords: natural fibre, PALF, PLA, composite

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2611 Phase Changing Dicationic Polymeric Ionic Liquid with CO2 Capture Abilities

Authors: Swati Sundararajan, Asit B. Samui, Prashant S. Kulkarni

Abstract:

Polymeric ionic liquids combine the properties of ionic liquids and polymers into a single material which has gained massive interest in the recent years. These ionic liquids offer several advantages such as high phase change enthalpy, wide temperature range, chemical and thermal stability, non-volatility and the ability to make them task-specific. Separation of CO2 is an area of critical importance due to the concerns over greenhouse gasses leading to global warming. Thermal energy storage materials, also known as phase change materials absorb latent heat during fusion process and release the absorbed energy to the surrounding environment during crystallization. These materials retain this property over a number of cycles and therefore, are useful for bridging the gap between energy requirement and use. In an effort to develop materials, which will help in minimizing the growing energy demand and environmental concerns, a series of dicationic poly(ethylene glycol) based polymeric ionic liquids were synthesized. One part of an acrylate of poly(ethylene glycol) was reacted with imidazolium quarternizing agent and the second part was reacted with triazolium quarternizing agent. These two different monomers were then copolymerized to prepare dicationic polymeric ionic liquid. These materials were characterized for solid-liquid phase transition and the enthalpy by using differential scanning calorimetry. The CO2 capture studies were performed on a fabricated setup with varying pressure range from 1-20 atm. The findings regarding the prepared materials, having potential dual applications in the fields of thermal energy storage and CO2 capture, will be discussed in the presentation.

Keywords: CO2 capture, phase change materials, polyethylene glycol, polymeric ionic liquids, thermal energy storage

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2610 Chrysin-Loaded PLGA-PEG Nanoparticles Designed for Enhanced Inhibitory Effect on the Breast Cancer Cell Line

Authors: Faraz Zarghami, Elham Anari, Nosratollah Zarghami, Yones Pilehvar-Soltanahmadi, Abolfazl Akbarzadeh, Sepideh Jalilzadeh-Tabrizi

Abstract:

The development of nanotherapy has presented a new method of drug delivery targeted directly to the neoplasmic tissues, to maximize the action with fewer dose requirements. In the past two decades, poly(lactic-co-glycolic acid) (PLGA) has frequently been investigated by many researchers and is a popular polymeric candidate, due to its biocompatibility and biodegradability, exhibition of a wide range of erosion times, tunable mechanical properties, and most notably, because it is a FDA-approved polymer. Chrysin is a natural flavonoid which has been reported to have some significant biological effects on the processes of chemical defense, nitrogen fixation, inflammation, and oxidation. However, the low solubility in water decreases its bioavailability and consequently disrupts the biomedical benefits. Being loaded with PLGA-PEG increases chrysin solubility and drug tolerance, and decreases the discordant effects of the drug. The well-structured chrysin efficiently accumulates in the breast cancer cell line (T47D). In the present study, the structure and chrysin loading were delineated using proton nuclear magnetic resonance (HNMR), Fourier-transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM), and the in vitro cytotoxicity of pure and nanochrysin was studied by the MTT assay. Next, the RNA was exploited and the cytotoxic effects of chrysin were studied by real-time PCR. In conclusion, the nanochrysin therapy developed is a novel method that could increase cytotoxicity to cancer cells without damaging the normal cells, and would be promising in breast cancer therapy.

Keywords: MTT assay, chrysin, flavonoids, nanotherapy

Procedia PDF Downloads 230
2609 Improved Performance of Mn Substituted Ceria Nanospheres for Water Gas Shift Reaction: Influence of Preparation Conditions

Authors: Bhairi Lakshminarayana, Surajit Sarker, Ch. Subrahmanyam

Abstract:

The present study reports the development of noble metal free nano catalysts for low-temperature CO oxidation and water gas shift reaction. Mn-substituted CeO2 solid solution catalysts were synthesized by co-precipitation, combustion and hydrothermal methods. The formation of solid solution was confirmed by XRD with Rietveld refinement and the percentage of carbon and nitrogen doping was ensured by CHNS analyzer. Raman spectroscopic confirmed the oxygen vacancies. The surface area, pore volume and pore size distribution confirmed by N2 physisorption analysis, whereas, UV-visible diffuse reflectance spectroscopy and XPS data confirmed the oxidation state of the Mn ion. The particle size and morphology (spherical shape) of the material was confirmed using FESEM and HRTEM analysis. Ce0.8Mn0.2O2-δ was calcined at 400 °C, 600 °C and 800 °C. Raman spectroscopy confirmed that the catalyst calcined at 400 °C has the best redox properties. The activity of the designed catalysts for CO oxidation (0.2 vol%), carried out with GHSV of 21,000 h-1 and it has been observed that co-precipitation favored the best active catalyst towards CO oxidation and water gas shift reaction, due to the high surface area, improved reducibility, oxygen mobility and highest quantity of surface oxygen species. The activation energy of low temperature CO oxidation on Ce0.8Mn0.2O2- δ (combustion) was 5.5 kcal.K-1.mole-1. The designed catalysts were tested for water gas shift reaction. The present study demonstrates that Mn ion substituted ceria at 400 °C calcination temperature prepared by co-precipitation method promise to revive a green sustainable energy production approach.

Keywords: Ce0.8Mn0.2O2-ð, CO oxidation, physicochemical characterization, water gas shift reaction (WGS)

Procedia PDF Downloads 213
2608 Numerical Study of Nonlinear Guided Waves in Composite Laminates with Delaminations

Authors: Reza Soleimanpour, Ching Tai Ng

Abstract:

Fibre-composites are widely used in various structures due to their attractive properties such as higher stiffness to mass ratio and better corrosion resistance compared to metallic materials. However, one serious weakness of this composite material is delamination, which is a subsurface separation of laminae. A low level of this barely visible damage can cause a significant reduction in residual compressive strength. In the last decade, the application of guided waves for damage detection has been a topic of significant interest for many researches. Among all guided wave techniques, nonlinear guided wave has shown outstanding sensitivity and capability for detecting different types of damages, e.g. cracks and delaminations. So far, most of researches on applications of nonlinear guided wave have been dedicated to isotropic material, such as aluminium and steel, while only a few works have been done on applications of nonlinear characteristics of guided waves in anisotropic materials. This study investigates the nonlinear interactions of the fundamental antisymmetric lamb wave (A0) with delamination in composite laminates using three-dimensional (3D) explicit finite element (FE) simulations. The nonlinearity considered in this study arises from interactions of two interfaces of sub-laminates at the delamination region, which generates contact acoustic nonlinearity (CAN). The aim of this research is to investigate the phenomena of CAN in composite laminated beams by a series of numerical case studies. In this study interaction of fundamental antisymmetric lamb wave with delamination of different sizes are studied in detail. The results show that the A0 lamb wave interacts with the delaminations generating CAN in the form of higher harmonics, which is a good indicator for determining the existence of delaminations in composite laminates.

Keywords: contact acoustic nonlinearity, delamination, fibre reinforced composite beam, finite element, nonlinear guided waves

Procedia PDF Downloads 179
2607 Evaluation of Simulated Noise Levels through the Analysis of Temperature and Rainfall: A Case Study of Nairobi Central Business District

Authors: Emmanuel Yussuf, John Muthama, John Ng'ang'A

Abstract:

There has been increasing noise levels all over the world in the last decade. Many factors contribute to this increase, which is causing health related effects to humans. Developing countries are not left out of the whole picture as they are still growing and advancing their development. Motor vehicles are increasing on urban roads; there is an increase in infrastructure due to the rising population, increasing number of industries to provide goods and so many other activities. All this activities lead to the high noise levels in cities. This study was conducted in Nairobi’s Central Business District (CBD) with the main objective of simulating noise levels in order to understand the noise exposed to the people within the urban area, in relation to weather parameters namely temperature, rainfall and wind field. The study was achieved using the Neighbourhood Proximity Model and Time Series Analysis, with data obtained from proxies/remotely-sensed from satellites, in order to establish the levels of noise exposed to which people of Nairobi CBD are exposed to. The findings showed that there is an increase in temperature (0.1°C per year) and a decrease in precipitation (40 mm per year), which in comparison to the noise levels in the area, are increasing. The study also found out that noise levels exposed to people in Nairobi CBD were roughly between 61 and 63 decibels and has been increasing, a level which is high and likely to cause adverse physical and psychological effects on the human body in which air temperature, precipitation and wind contribute so much in the spread of noise. As a noise reduction measure, the use of sound proof materials in buildings close to busy roads, implementation of strict laws to most emitting sources as well as further research on the study was recommended. The data used for this study ranged from the year 2000 to 2015, rainfall being in millimeters (mm), temperature in degrees Celsius (°C) and the urban form characteristics being in meters (m).

Keywords: simulation, noise exposure, weather, proxy

Procedia PDF Downloads 351
2606 Biomechanical Performance of the Synovial Capsule of the Glenohumeral Joint with a BANKART Lesion through Finite Element Analysis

Authors: Duvert A. Puentes T., Javier A. Maldonado E., Ivan Quintero., Diego F. Villegas

Abstract:

Mechanical Computation is a great tool to study the performance of complex models. An example of it is the study of the human body structure. This paper took advantage of different types of software to make a 3D model of the glenohumeral joint and apply a finite element analysis. The main objective was to study the change in the biomechanical properties of the joint when it presents an injury. Specifically, a BANKART lesion, which consists in the detachment of the anteroinferior labrum from the glenoid. Stress and strain distribution of the soft tissues were the focus of this study. First, a 3D model was made of a joint without any pathology, as a control sample, using segmentation software for the bones with the support of medical imagery and a cadaveric model to represent the soft tissue. The joint was built to simulate a compression and external rotation test using CAD to prepare the model in the adequate position. When the healthy model was finished, it was submitted to a finite element analysis and the results were validated with experimental model data. With the validated model, it was sensitized to obtain the best mesh measurement. Finally, the geometry of the 3D model was changed to imitate a BANKART lesion. Then, the contact zone of the glenoid with the labrum was slightly separated simulating a tissue detachment. With this new geometry, the finite element analysis was applied again, and the results were compared with the control sample created initially. With the data gathered, this study can be used to improve understanding of the labrum tears. Nevertheless, it is important to remember that the computational analysis are approximations and the initial data was taken from an in vitro assay.

Keywords: biomechanics, computational model, finite elements, glenohumeral joint, bankart lesion, labrum

Procedia PDF Downloads 131
2605 Comparison of Safety and Efficacy between Thulium Fibre Laser and Holmium YAG Laser for Retrograde Intrarenal Surgery

Authors: Sujeet Poudyal

Abstract:

Introduction: After Holmium:yttrium-aluminum-garnet (Ho: YAG) laser has revolutionized the management of urolithiasis, the introduction of Thulium fibre laser (TFL) has already challenged Ho:YAG laser due to its multiple commendable properties. Nevertheless, there are only few studies comparing TFL and holmium laser in Retrograde Intrarenal Surgery(RIRS). Therefore, this study was carried out to compare the efficacy and safety of thulium fiber laser (TFL) and holmium laser in RIRS. Methods: This prospective comparative study, which included all patients undergoing laser lithotripsy (RIRS) for proximal ureteric calculus and nephrolithiasis from March 2022 to March 2023, consisted of 63 patients in Ho:YAG laser group and 65 patients in TFL group. Stone free rate, operative time, laser utilization time, energy used, and complications were analysed between the two groups. Results: Mean stone size was comparable in TFL (14.23±4.1 mm) and Ho:YAG (13.88±3.28 mm) group, p-0.48. Similarly, mean stone density in TFL (1269±262 HU) was comparable to Ho:YAG (1189±212 HU), p-0.48. There was significant difference in lasing time between TFL (12.69±7.41 mins) and Ho:YAG (20.44±14 mins), p-0.012). TFL group had operative time of 43.47± 16.8 mins which was shorter than Ho:YAG group (58±26.3 mins),p-0.005. Both TFL and Ho:YAG groups had comparable total energy used(11.4±6.2 vs 12±8 respectively, p-0.758). Stone free rate was 87%for TFL, whereas it was 79.5% for Ho:YAG, p-0.25). Two cases of sepsis and one ureteric stricture were encountered in TFL, whereas three cases suffered from sepsis apart from one ureteric stricture in Ho:YAG group, p-0.62). Conclusion: Thulium Fibre Laser has similar efficacy as Holmium: YAG Laser in terms of safety and stone free rate. However, due to better stone ablation rate in TFL, it can become the game changer in management of urolithiasis in the coming days.

Keywords: retrograde intrarenal surgery, thulium fibre laser, holmium:yttrium-aluminum-garnet (ho:yag) laser, nephrolithiasis

Procedia PDF Downloads 49
2604 Deprivation of Adivasi People's Rights to Forest Resources: A Case Study from United Andhra Pradesh India

Authors: Anil Kumar Kursenge

Abstract:

In the State of united Andhra Pradesh, many Adivasi People live in areas rich in living and non-living resources, including forests that contain abundant biodiversity, water and minerals. Of united Andhra Pradesh 76.2m population, over five million are Adivasi population of forest landscape. They depend on forests for a substantial part of their livelihoods and close cultural affinity with forests. However, they are the most impoverished population of the State, and the high levels of poverty in Andhra Pradesh forest landscapes are largely an outcome of historically-rooted institutionalised marginalisation. As the State appropriated forests and forest land for itself, it deprived local people of their customary rights in the forest. The local realities of the forest rights deprivations are extremely complex, reflecting a century and a half of compounded processes. With growing population pressure and ever-increasing demands for natural and mineral resources, Adivasi Peoples' lands, which are often relatively rich in resources, become more and more attractive to 'developers.' The development projects and institutionalised marginalisation have been deprived Adivasi people's rights over natural resources has resulted in serious negative effects on Adivasi people and on their lands. Historically, the desire for development for such resources has resulted in the removal, decimation, or extermination of many tribal communities. These deprivations have led to highly conflictual relations between the State and the Adivasi people and forest areas in Andhra Pradesh. Today, the survival of the Adivasi Peoples requires recognition of their rights to the forest resources found in their lands and territories on which they depend for their economic, cultural, survival, spiritual and physical well-being. In this context, this paper attempts to discuss the issues of deprivation with regard to access to forest resources and development projects where many Adivasis in State uprooted from their homes and lands.

Keywords: tribal people, forest rights, livelihoods, deprivation, marginalisation, Andhra Pradesh

Procedia PDF Downloads 174
2603 An Efficient Approach for Shear Behavior Definition of Plant Stalk

Authors: M. R. Kamandar, J. Massah

Abstract:

The information of the impact cutting behavior of plants stalk plays an important role in the design and fabrication of plants cutting equipment. It is difficult to investigate a theoretical method for defining cutting properties of plants stalks because the cutting process is complex. Thus, it is necessary to set up an experimental approach to determine cutting parameters for a single stalk. To measure the shear force, shear energy and shear strength of plant stalk, a special impact cutting tester was fabricated. It was similar to an Izod impact cutting tester for metals but a cutting blade and data acquisition system were attached to the end of pendulum's arm. The apparatus was included four strain gages and a digital indicator to show the real-time cutting force of plant stalk. To measure the shear force and also testing the apparatus, two plants’ stalks, like buxus and privet, were selected. The samples (buxus and privet stalks) were cut under impact cutting process at four loading rates 1, 2, 3 and 4 m.s-1 and three internodes fifth, tenth and fifteenth by the apparatus. At buxus cutting analysis: the minimum value of cutting energy was obtained at fifth internode and loading rate 4 m.s-1 and the maximum value of shear energy was obtained at fifteenth internode and loading rate 1 m.s-1. At privet cutting analysis: the minimum value of shear consumption energy was obtained at fifth internode and loading rate: 4 m.s-1 and the maximum value of shear energy was obtained at fifteenth internode and loading rate: 1 m.s-1. The statistical analysis at both plants showed that the increase of impact cutting speed would decrease the shear consumption energy and shear strength. In two scenarios, the results showed that with increase the cutting speed, shear force would decrease.

Keywords: Buxus, Privet, impact cutting, shear energy

Procedia PDF Downloads 102
2602 Psychological Distress and Quality of Life in Inflammatory Bowel Disease Patients: The Role of Dispositional Mindfulness

Authors: Kelly E. Tow, Peter Caputi, Claudia Rogge, Thomas Lee, Simon R. Knowles

Abstract:

Inflammatory Bowel Disease (IBD) is a serious chronic health condition, characterised by inflammation of the gastrointestinal tract. Individuals with active IBD experience severe abdominal symptoms, which can adversely impact their physical and mental health, as well as their quality of life (QoL). Given that stress may exacerbate IBD symptoms and is frequently highlighted as a contributing factor for the development of psychological difficulties and poorer QoL, it is vital to investigate stress-management strategies aimed at improving the lives of those with IBD. The present study extends on the limited research in IBD cohorts by exploring the role of dispositional mindfulness and its impact on psychological well-being and QoL. The study examined how disease activity and dispositional mindfulness were related to psychological distress and QoL in a cohort of IBD patients. The potential role of dispositional mindfulness as a moderator between stress and anxiety, depression and QoL in these individuals was also examined. Participants included 47 patients with a clinical diagnosis of IBD. Each patient completed a series of psychological questionnaires and was assessed by a gastroenterologist to determine their disease activity levels. Correlation analyses indicated that disease activity was not significantly related to psychological distress or QoL in the sample of IBD patients. However, dispositional mindfulness was inversely related to psychological distress and positively related to QoL. Furthermore, moderation analyses demonstrated a significant interaction between stress and dispositional mindfulness on anxiety. These findings demonstrate that increased levels of dispositional mindfulness may be beneficial for individuals with IBD. Specifically, the results indicate positive links between dispositional mindfulness, general psychological well-being and QoL, and suggest that dispositional mindfulness may attenuate the negative impacts of stress on levels of anxiety in IBD patients. While further research is required to validate and expand on these findings, the current study highlights the importance of addressing psychological factors in IBD and indicates support for the use of mindfulness-based interventions for patients with the disease.

Keywords: anxiety, depression, dispositional mindfulness, inflammatory bowel disease, quality of life, stress

Procedia PDF Downloads 138
2601 The Effect of Bath Composition for Hot-Dip Aluminizing of AISI 4140 Steel

Authors: Aptullah Karakas, Murat Baydogan

Abstract:

Hot-dip aluminizing (HDA) is one of the several aluminizing methods to form a wear-, corrosion- and oxidation-resistant aluminide layers on the surface. In this method, the substrate is dipped into a molten aluminum bath, hold in the bath for several minutes, and cooled down to the room temperature in air. A subsequent annealing after the HDA process is generally performed. The main advantage of HDA is its very low investment cost in comparison with other aluminizing methods such as chemical vapor deposition (CVD), pack aluminizing and metalizing. In the HDA process, Al or Al-Si molten baths are mostly used. However, in this study, three different Al alloys such as Al4043 (Al-Mg), Al5356 (Al-Si) and Al7020 (Al-Zn) were used as the molten bath in order to see their effects on morphological and mechanical properties of the resulting aluminide layers. AISI 4140 low alloyed steel was used as the substrate. Parameters of the HDA process were bath composition, bath temperature, and dipping time. These parameters were considered within a Taguchi L9 orthogonal array. After the HDA process and subsequent diffusion annealing, coating thickness measurement, microstructural analysis and hardness measurement of the aluminide layers were conducted. The optimum process parameters were evaluated according to coating morphology, such as cracks, Kirkendall porosity and hardness of the coatings. According to the results, smooth and clean aluminide layer with less Kirkendall porosity and cracks were observed on the sample, which was aluminized in the molten Al7020 bath at 700 C for 10 minutes and subsequently diffusion annealed at 750 C. Hardness of the aluminide layer was in between 1100-1300 HV and the coating thickness was approximately 400 µm. The results were promising such that a hard and thick aluminide layer with less Kirkendall porosity and cracks could be formed. It is, therefore, concluded that Al7020 bath may be used in the HDA process of AISI 4140 steel substrate.

Keywords: hot-dip aluminizing, microstructure, hardness measurement, diffusion annealing

Procedia PDF Downloads 50
2600 Consumer Preferences towards Sorbets: A Questionnaire Study

Authors: Kinga Topolska, Agnieszka Filipiak-Florkiewicz, Adam Florkiewicz, Daria Chechelska, Iwona Cieślik, Ewa Cieślik

Abstract:

Food choice is a complex human behaviour, that is influenced by many interrelating factors. It is important to understand what consumers really want to eat. Nowadays, the growing popularity of frozen desserts is observed. Among them, sorbets are of the special interest. They are made primarily of fruit juice or fruit purée, water and sugar. A questionnaire study was done to evaluate the consumer preferences towards sorbets. A hundred respondents were included in the study. The respondents answered the questions concerning, inter alia, on the favourite taste of sorbets, additional ingredients (pieces of fruits, nuts etc.), the reason for choosing the product and also the opinion about potential purchasing or not the new product. Women, more frequently than men, indicated strawberry sorbet or the product on the basis of citrus fruits as a favourite one. In turn, 14% of men chose the apple taste. Pieces of chocolate were chosen by most of respondents. Men, more often than women, regarded raisins, alcohol and nuts as the most desirable additional ingredients of sorbets. The candied fruits and spices were indicated more frequently by women. Most of respondents indicated the taste as the major reason for sorbet buying. In turn, for 20% women the most important determinant was the care for their figure. It was observed that more than a half of women regarded sorbets as healthier than traditional ice creams. Answering the question: 'If you had the opportunity to try a new sorbet, containing the ingredient with proven healthy properties, would you buy it?', significantly more men than women answered 'yes, because I like novelty'. Meanwhile, for 14% respondents (independently of gender) it would be only a publicity stunt. Knowing what the consumers desire in selecting a product, is a very important information to design and offer them a new one. Sorbets could be an interesting alternative to ice creams.

Keywords: consumer, preferences, sorbets, questionnaire study

Procedia PDF Downloads 257
2599 Perceived Stigma, Perception of Burden and Psychological Distress among Parents of Intellectually Disable Children: Role of Perceived Social Support

Authors: Saima Shafiq, Najma Iqbal Malik

Abstract:

This study was aimed to explore the relationship of perceived stigma, perception of burden and psychological distress among parents of intellectually disabled children. The study also aimed to explore the moderating role of perceived social support on all the variables of the study. The sample of the study comprised of (N = 250) parents of intellectually disabled children. The present study utilized the co-relational research design. It consists of two phases. Phase-I consisted of two steps which contained the translation of two scales that were used in the present study and tried out on the sample of parents (N = 70). The Affiliated Stigma Scale and Care Giver Burden Inventory were translated into Urdu for the present study. Phase-1 revealed that translated scaled entailed satisfactory psychometric properties. Phase -II of the study was carried out in order to test the hypothesis. Correlation, linear regression analysis, and t-test were computed for hypothesis testing. Hierarchical regression analysis was applied to study the moderating effect of perceived social support. Findings revealed that there was a positive relationship between perceived stigma and psychological distress, perception of burden and psychological distress. Linear regression analysis showed that perceived stigma and perception of burden were positive predictors of psychological distress. The study did not show the moderating role of perceived social support among variables of the present study. The major limitation of the study is the sample size and the major implication is awareness regarding problems of parents of intellectually disabled children.

Keywords: perceived stigma, perception of burden, psychological distress, perceived social support

Procedia PDF Downloads 193