Search results for: core level shift
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 15030

Search results for: core level shift

14790 Influence of UV Aging on the Mechanical Properties of Polycarbonate

Authors: S. Redjala, N. Ait Hocine, M. Gratton, N. Poirot, R. Ferhoum, S. Azem

Abstract:

Polycarbonate (PC) is a promising polymer with high transparency in the range of the visible spectrum and is used in various fields, for example medical, electronic, automotive. Its low weight, chemical inertia, high impact resistance and relatively low cost are of major importance. In recent decades, some materials such as metals and ceramics have been replaced by polymers because of their superior advantages. However, some characteristics of the polymers are highly modified under the effect of ultraviolet (UV) radiation and temperature. The changes induced in the material by such aging depend on the exposure time, the wavelength of the UV radiation and the temperature level. The UV energy is sufficient to break the chemical bonds leading to a cleavage of the molecular chains. This causes changes in the mechanical, thermal, optical and morphological properties of the material. The present work is focused on the study of the effects of aging under ultraviolet (UV) radiation and under different temperature values on the physical-chemical and mechanical properties of a PC. Thus, various investigations, such as FTIR and XRD analyses, SEM and optical microscopy observations, micro-hardness measurements and monotonic and cyclic tensile tests, were carried out on the PC in the initial state and after aging. Results have shown the impact of aging on the properties of the PC studied. In fact, the MEB highlighted changes in the superficial morphology of the material by the presence of cracks and material de-bonding in the form of debris. The FTIR spectra reveal an attenuation of the peaks like the hydroxyl (OH) groups located at 3520 cm-1. The XRD lines shift towards a larger angle, reaching a maximum of 3°. In addition, Vickers micro-hardness measurements show that aging affects the surface and the core of the material, which results in different mechanical behaviours under monotonic and cyclic tensile tests. This study pointed out effects of aging on the macroscopic properties of the PC studied, in relationship with its microstructural changes.

Keywords: mechanical properties, physical-chemical properties, polycarbonate, UV aging, temperature aging

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14789 Enhancement of coupler-based delay line filters modulation techniques using optical wireless channel and amplifiers at 100 Gbit/s

Authors: Divya Sisodiya, Deepika Sipal

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Optical wireless communication (OWC) is a relatively new technology in optical communication systems that allows for high-speed wireless optical communication. This research focuses on developing a cost-effective OWC system using a hybrid configuration of optical amplifiers. In addition to using EDFA amplifiers, a comparison study was conducted to determine which modulation technique is more effective for communication. This research examines the performance of an OWC system based on ASK and PSK modulation techniques by varying OWC parameters under various atmospheric conditions such as rain, mist, haze, and snow. Finally, the simulation results are discussed and analyzed.

Keywords: OWC, bit error rate, amplitude shift keying, phase shift keying, attenuation, amplifiers

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14788 An Experimental Investigation of Microscopic and Macroscopic Displacement Behaviors of Branched-Preformed Particle Gel in High Temperature Reservoirs

Authors: Weiyao Zhu, Bingbing Li, Yajing Liu, Zhiyong Song

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Branched-preformed particle gel (B-PPG) is a newly developed profile control and oil displacement agent for enhanced oil recovery in major oilfields. To provide a better understanding of the performance of B-PPG in high temperature reservoirs, a comprehensive experimental investigation was conducted by utilizing glass micromodel and synthetic core. The microscopic experimental results show that the B-PPG can selectively flow and plug in large pores. In terms of enhanced oil recovery, the decrease of residual oil in the margin regions (24.6%) was higher than that in the main stream (13.7%), which indicates it enlarged the sweep area. In addition, the effects of B-PPG injection concentration and injection rate on enhanced oil recovery were implemented by core flooding. The macroscopic experimental results indicate that the enhanced oil recovery increased with the increasing of injection concentration. However, the injection rate had a peak value. It is significant to get insight into the behaviors of B-PPG in reservoirs.

Keywords: branched-preformed particle gel, enhanced oil recovery, micromodel, core flooding

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14787 A Near Ambient Pressure X-Ray Photoelectron Spectroscopy Study on Platinum Nanoparticles Supported on Zr-Based Metal Organic Frameworks

Authors: Reza Vakili, Xiaolei Fan, Alex Walton

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The first near ambient pressure (NAP)-XPS study of CO oxidation over Pt nanoparticles (NPs) incorporated into Zr-based UiO (UiO for Universitetet i Oslo) MOFs was carried out. For this purpose, the MOF-based Catalysts were prepared by wetness impregnation (WI-PtNPs@UiO-67) and linker design (LD-PtNPs@UiO-67) methods along with PtNPs@ZrO₂ as the control catalyst. Firstly, the as-synthesized catalysts were reduced in situ prior to the operando XPS analysis. The existence of Pt(II) species was proved in UiO-67 by observing Pt 4f core level peaks at a high binding energy of 72.6 ± 0.1 eV. However, by heating the WI-PtNPs@UiO-67 catalyst in situ to 200 °C under vacuum, the higher BE components disappear, leaving only the metallic Pt 4f doublet, confirming the formation of Pt NPs. The complete reduction of LD-PtNPs@UiO-67 is achieved at 250 °C and 1 mbar H₂. To understand the chemical state of Pt NPs in UiO-67 during catalytic turnover, we analyzed the Pt 4f region using operando NAP-XPS in the temperature-programmed measurements (100-260 °C) with reference to PtNPs@ZrO₂ catalyst. CO conversion during NAP-XPS experiments with the stoichiometric mixture shows that LD-PtNPs@UiO-67 has a better CO turnover frequency (TOF, 0.066 s⁻¹ at 260 °C) than the other two (ca. 0.055 s⁻¹). Pt 4f peaks only show one chemical species present at all temperatures, but the core level BE shifts change as a function of reaction temperature, i.e., Pt 4f peak from 71.8 eV at T < 200 °C to 71.2 eV at T > 200 °C. As this higher BE state of 71.8 eV was not observed after in situ reductions of the catalysts and only once the CO/O₂ mixture was introduced, we attribute it to the surface saturation of Pt NPs with adsorbed CO. In general, the quantitative analysis of Pt 4f data from the operando NAP-XPS experiments shows that the surface chemistry of the Pt active phase in the two PtNPs@UiO-67 catalysts is the same, comparable to that of PtNPs@ZrO₂. The observed difference in the catalytic activity can be attributed to the particle sizes of Pt NPs, as well as the dispersion of active phase in the support, which are different in the three catalysts.

Keywords: CO oxidation, heterogeneous catalysis, MOFs, Metal Organic Frameworks, NAP-XPS, Near Ambient Pressure X-ray Photoelectron Spectroscopy

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14786 Investigation of Minor Actinide-Contained Thorium Fuel Impacts on CANDU-Type Reactor Neutronics Using Computational Method

Authors: S. A. H. Feghhi, Z. Gholamzadeh, Z. Alipoor, C. Tenreiro

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Currently, thorium fuel has been especially noticed because of its proliferation resistance than long half-life alpha emitter minor actinides, breeding capability in fast and thermal neutron flux and mono-isotopic naturally abundant. In recent years, efficiency of minor actinide burning up in PWRs has been investigated. Hence, a minor actinide-contained thorium based fuel matrix can confront both proliferation resistance and nuclear waste depletion aims. In the present work, minor actinide depletion rate in a CANDU-type nuclear core modeled using MCNP code has been investigated. The obtained effects of minor actinide load as mixture of thorium fuel matrix on the core neutronics has been studiedwith comparingpresence and non-presence of minor actinide component in the fuel matrix.Depletion rate of minor actinides in the MA-contained fuel has been calculated using different power loads.According to the obtained computational data, minor actinide loading in the modeled core results in more negative reactivity coefficients. The MA-contained fuel achieves less radial peaking factor in the modeled core. The obtained computational results showed 140 kg of 464 kg initial load of minor actinide has been depleted in during a 6-year burn up in 10 MW power.

Keywords: minor actinide burning, CANDU-type reactor, MCNPX code, neutronic parameters

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14785 Foregrounding Events in Modern Sundanese: The Pragmatics of Particle-to-Active Voice Marking Shift

Authors: Rama Munajat

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Discourse information levels may be viewed from either a background-foreground distinction or a multi-level perspective, and cross-linguistic studies on this area suggest that each information level is marked by a specific linguistic device. In this sense, Sundanese, spoken in Indonesia’s West Javanese Province, further differentiates the background and foreground information into ordinary and significant types. This paper will report an ongoing shift from particle-to-active voice marking in the way Sundanese signals foregrounding events. The shift relates to decades of contact with Bahasa Indonesia (Indonesia’s official language) and linguistic compatibility between the two surface marking strategies. Representative data analyzed include three groups of short stories in both Sundanese and Bahasa Indonesia (Indonesian) published in three periods: before 1945, 1965-2006, and 2016-2019. In the first group of Sundanese data, forward-moving events dominantly appear in particle KA (Kecap Anteuran, word-accompanying) constructions, where the KA represents different particles that co-occur with a special group of verbs. The second group, however, shows that the foregrounded events are more frequently described in active-voice forms with a subject-predicate (SP) order. Subsequently, the third offers stronger evidence for the use of the SP structure. As for the Indonesian data, the foregrounding events in the first group occur in verb-initial and passive-voice constructions, while in the second and third, the events more frequently appear in active-voice structures (subject-predicate sequence). The marking shift above suggests a structural influence from Indonesian, stemmed from generational differences among authors of the Sundanese short stories, particularly related to their education and language backgrounds. The first group of short stories – published before 1945 or before Indonesia's independence from Dutch – were written by native speakers of Sundanese who spoke Indonesian as a foreign language and went through the Dutch education system. The second group of authors, on the other hand, represents a generation of Sundanese native speakers who spoke Indonesian as a second language. Finally, the third group consists of authors who are bilingual speakers of both Sundanese and Indonesian. The data suggest that the last two groups of authors completed the Indonesian education system. With these, the use of subject-predicate sequences to denote foregrounding events began to appear more frequently in the second group and then became more dominant in those of the third. The coded data also signify that cohesion, coherence, and pragmatic purposes in Particle KA constructions are intact in their respective active-voice structure counterparts. For instance, the foregrounding events in Particle KA constructions occur in Sentence-initial KA and Pre-verbal KA forms, whereas those in the active-voice are described in Subject-Predicate (SP) and Zero-Subject active-voice patterns. Cross-language data further demonstrate that the Sentence-initial KA and the SP active-voice structures each contain an overt noun phrase (NP) co-referential with one of the entities introduced in a preceding context. Similarly, the pre-verbal KA and Zero-Subject active-voice patterns have a deleted noun phrase unambiguously referable to the only one entity previously mentioned. The presence and absence of an NP inform a pragmatic strategy to place prominence on topic/given and comment/new information, respectively.

Keywords: discourse analysis, foregrounding marking, pragmatics, language contact

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14784 The Outcome of Early Balance Exercises and Agility Training in Sports Rehabilitation for Patients Post Anterior Cruciate Ligament (ACL) Reconstruction

Authors: S. M. A. Ismail, M. I. Ibrahim, H. Masdar, F. M. Effendi, M. F. Suhaimi, A. Suun

Abstract:

Introduction: It is generally known that the rehabilitation process is as important as the reconstruction surgery. Several literature has focused on how early the rehabilitation modalities can be initiated after the surgery to ensure a safe return of patients to sports or at least regaining the pre-injury level of function following an ACL reconstruction. Objectives: The main objective is to study and evaluate the outcome of early balance exercises and agility training in sports rehabilitation for patients post ACL reconstruction. To compare between early balance exercises and agility training as intervention and control. (material or non-material). All of them were recruited for material exercise (balance exercises and agility training with strengthening) and strengthening only rehabilitation protocol (non-material). Followed the prospective intervention trial. Materials and Methods: Post-operative ACL reconstruction patients performed in Selayang and Sg Buloh Hospitals from 2012 to 2014 were selected for this study. They were taken from Malaysian Knee Ligament Registry (MKLR) and all patients had single bundle reconstruction with autograft hamstring tendon (semitendinosus and gracilis). ACL injury from any type of sports were included. Subjects performed various type of physical activity for rehabilitation in every 18 week for a different type of rehab activity. All subject attended all 18 sessions of rehabilitation exercises and evaluation was done during the first, 9th and 18th session. Evaluation format were based on clinical assessment (anterior drawer, Lachmann, pivot shift, laxity with rolimeter, the end point and thigh circumference) and scoring (Lysholm Knee scoring and Tegner Activity Level scale). Rehabilitation protocol initiated from 24 week after the surgery. Evaluation format were based on clinical assessment (anterior drawer, Lachmann, pivot shift, laxity with rolimeter, the end point and thigh circumference) and scoring (Lysholm Knee scoring and Tegner Activity Level scale). Results and Discussion: 100 patients were selected of which 94 patients are male and 6 female. Age range is 18 to 54 year with the average of 28 years old for included 100 patients. All patients are evaluated after 24 week after the surgery. 50 of them were recruited for material exercise (balance exercises and agility training with strengthening) and 50 for strengthening only rehabilitation protocol (non-material). Demographically showed 85% suffering sports injury mainly from futsal and football. 39 % of them have abnormal BMI (26 – 38) and involving of the left knee. 100% of patient had the basic radiographic x-ray of knee and 98% had MRI. All patients had negative anterior drawer’s, Lachman test and Pivot shift test during the post ACL reconstruction after the complete rehabilitation. There was 95 subject sustained grade I injury, 5 of grade II and 0 of grade III with 90% of them had soft end-point. Overall they scored badly on presentation with 53% of Lysholm score (poor) and Tegner activity score level 3/10. After completing 9 weeks of exercises, of material group 90% had grade I laxity, 75% with firm end-point, Lysholm score 71% (fair) and Tegner activity level 5/10 comparing non-material group who had 62% of grade I laxity , 54% of firm end-point, Lyhslom score 62 % (poor) and Tegner activity level 4/10. After completed 18 weeks of exercises, of material group maintained 90% grade I laxity with 100 % with firm end-point, Lysholm score increase 91% (excellent) and Tegner activity level 7/10 comparing non-material group who had 69% of grade I laxity but maintained 54% of firm end-point, Lysholm score 76% (fair) and Tegner activity level 5/10. These showed the improvement were achieved fast on material group who have achieved satisfactory level after 9th cycle of exercises 75% (15/20) comparing non-material group who only achieved 54% (7/13) after completed 18th session. Most of them were grade I. These concepts are consolidated into our approach to prepare patients for return to play including field testing and maintenance training. Conclusions: The basic approach in ACL rehabilitation is to ensure return to sports at post-operative 6 month. Grade I and II laxity has favourable and early satisfactory outcome base on clinical assessment and Lysholm and Tegner scoring point. Reduction of laxity grading indicates satisfactory outcome. Firm end-point showed the adequacy of rehabilitation before starting previous sports game. Material exercise (balance exercises and agility training with strengthening) were beneficial and reliable in order to achieve favourable and early satisfactory outcome comparing strengthening only (non-material).We have identified that rehabilitation protocol varies between different patients. Therefore future post ACL reconstruction rehabilitation guidelines should look into focusing on rehabilitation techniques instead of time.

Keywords: post anterior cruciate ligament (ACL) reconstruction, single bundle, hamstring tendon, sports rehabilitation, balance exercises, agility balance

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14783 Human’s Sensitive Reactions during Different Geomagnetic Activity: An Experimental Study in Natural and Simulated Conditions

Authors: Ketevan Janashia, Tamar Tsibadze, Levan Tvildiani, Nikoloz Invia, Elguja Kubaneishvili, Vasili Kukhianidze, George Ramishvili

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This study considers the possible effects of geomagnetic activity (GMA) on humans situated on Earth by performing experiments concerning specific sensitive reactions in humans in both: natural conditions during different GMA and by the simulation of different GMA in the lab. The measurements of autonomic nervous system (ANS) responses to different GMA via measuring the heart rate variability (HRV) indices and stress index (SI) and their comparison with the K-index of GMA have been presented and discussed. The results of experiments indicate an intensification of the sympathetic part of the ANS as a stress reaction of the human organism when it is exposed to high level of GMA as natural as well as in simulated conditions. Aim: We tested the hypothesis whether the GMF when disturbed can have effects on human ANS causing specific sensitive stress-reactions depending on the initial type of ANS. Methods: The study focuses on the effects of different GMA on ANS by comparing of HRV indices and stress index (SI) of n= 78, 18-24 years old healthy male volunteers. Experiments were performed as natural conditions on days of low (K= 1-3) and high (K= 5-7) GMA as well as in the lab by the simulation of different GMA using the device of geomagnetic storm (GMS) compensation and simulation. Results: In comparison with days of low GMA (K=1-3) the initial values of HRV shifted towards the intensification of the sympathetic part (SP) of the ANS during days of GMSs (K=5-7) with statistical significance p-values: HR (heart rate, p= 0.001), SDNN (Standard deviation of all Normal to Normal intervals, p= 0.0001), RMSSD (The square root of the arithmetical mean of the sum of the squares of differences between adjacent NN intervals, p= 0.0001). In comparison with conditions during GMSs compensation mode (K= 0, B= 0-5nT), the ANS balance was observed to shift during exposure to simulated GMSs with intensities in the range of natural GMSs (K= 7, B= 200nT). However, the initial values of the ANS resulted in different dynamics in its variation depending of GMA level. In the case of initial balanced regulation type (HR > 80) significant intensification of SP was observed with p-values: HR (p= 0.0001), SDNN (p= 0.047), RMSSD (p= 0.28), LF/HF (p=0.03), SI (p= 0.02); while in the case of initial parasympathetic regulation type (HR < 80), an insignificant shift to the intensification of the parasympathetic part (PP) was observed. Conclusions: The results indicate an intensification of SP as a stress reaction of the human organism when it is exposed to high level of GMA in both natural and simulated conditions.

Keywords: autonomic nervous system, device of magneto compensation/simulation, geomagnetic storms, heart rate variability

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14782 From Mobility to Complexity: French Language Use among Algerian Doctoral Postgraduates in Scotland

Authors: Hadjer Chellia

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The study explores the phenomenon of second language use in a migratory setting and uses the case of Algerian international students in Scotland, United Kingdom. The linguistic history of Algeria reveals that French language has a high status among the Algerians’ verbal repertoires and Algerian English students consider it as a language of prestige. With mobility of some of these students towards Scotland -in the guise of internationalization of higher education, mobility and exchange programs, the transition was deemed to bring more complexity to their pre-migratory linguistic repertoires and resulted into their French language- being endangered and threatened by a potential shift to English. The study employed semi-structured interviews among six Ph.D. ethnically related students, and the main aim behind that is to explore their current experiences with regards to French language use and to provide an account of the factors which assist in shifting to English as a second language instead. The six participants identified in interviews were further invited to focus group sessions based on an in-group interaction fashion to discuss different topics using heritage languages. This latter was opted for as part of the methodology as a means to observe their real linguistic practice and to investigate the link between behaviors and previous perceptions. The findings detect a variety of social, individual and socio-psychological factors that would contribute in refining the concept of language shift among newly established émigré communities with short stay vis a vis the linguistic outcomes of immigrants with long stay, across generational basis that was –to some extent-the focus of previous research on language shift. The results further reveal a mismatch between students' perceptions and observed behaviors. The research is then largely relevant to international students’ sociolinguistic experience of study abroad.

Keywords: complexity, mobility, potential shift, sociolinguistic experience

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14781 Shear Behavior of Steel-Fiber-Reinforced Precast/Prestressed Concrete Hollow Core Slabs

Authors: Thi Nguyet Hang Nguyen, Kang Hai Tan

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Precast/prestressed concrete hollow core (PCHC) slabs, especially ones with depth more than 300 mm, are susceptible to web-shear failure. The reasons lie on the fact that the production process of PCHC slabs, i.e., the extrusion method (the most common method to cast PCHC slabs nowadays), does not allow them to contain any shear reinforcement. Moreover, due to the presence of the longitudinal voids, cross sections of PCHC slabs are reduced. Therefore, the shear capacity of the slabs depends solely on the tensile strength of concrete which is relatively low. Given that shear is a major concern in using hollow-core slabs, this paper investigates the possibility of adopting steel fibers in PCHC slabs produced by the extrusion method to enhance the shear capacity of the slabs. Three full-scale PCHC slabs with and without hooked-steel fibers were cast and tested until failure. Three different volumetric fiber contents of 0, 0.51 and 0.89% were investigated. The test results showed that there were substantial increases in shear capacity and ductility with the use of hooked-steel fibers. Ultimate shear strength increased with fiber content. In addition, while the specimen without steel fibers and the one with the steel-fiber volume fraction of 0.51% failed in web-shear mode, the specimen with the higher fiber content (0.89%) collapsed in flexural-shear mode. However, as the hooked-steel fibers with the fiber content of 0.89% were used, difficulties in concrete consolidation were observed while concrete was being cast. This could lead to a lower ultimate shear capacity due to a poorer bond between the concrete and the steel fibers.

Keywords: hollow-core slabs, shear strength, steel fibers, web-shear failure

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14780 Run-Time Customisation of Soft-Core CPUs on Field Programmable Gate Array

Authors: Rehab Abdullah Shendi

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The use of customised soft-core processors in which instructions can be integrated into a system in application hardware is increasing in the Field Programmable Gate Array (FPGA) field. Specifically, the partial run-time reconfiguration of FPGAs in specialised processors for a particular domain can be very beneficial. In this report, the design and implementation for the customisation of a soft-core MIPS processor using an FPGA and partial reconfiguration (PR) of FPGA technology will be addressed to achieve efficient resource use. This can be achieved using a PR design flow that helps the design fit into a smaller device. Moreover, the impact of static power consumption could be reduced due to runtime reconfiguration. This will be done by configurable custom instructions implemented in the hardware as an extension on the MIPS CPU. The aim of this project is to investigate the PR of FPGAs for run-time adaptations of the instruction set of a soft-core CPU, including the integration of custom instructions and the exploration of the potential to use the MultiBoot feature available in Xilinx FPGAs to carry out the PR process. The system will be evaluated and tested on a Nexus 3 development board featuring a Xilinx Spartran-6 FPGA. The system will be able to load reconfigurable custom instructions dynamically into user programs with the help of the trap handler when the custom instruction is called by the MIPS CPU. The results of this experiment demonstrate that custom instructions in hardware can speed up a certain function and many instructions can be saved when compared to a software implementation of the same function. Implementing custom instructions in hardware is perfectly possible and worth exploring.

Keywords: customisation, FPGA, MIPS, partial reconfiguration, PR

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14779 Dental Students' Acquired Knowledge of the Pre-Contemplation Stage of Change

Authors: S. Curtin, A. Trace

Abstract:

Introduction: As patients can often be ambivalent about or resistant to any change in their smoking behavior the traditional ‘5 A’ model may be limited as it assumes that patients are ready and motivated to change. However, there is a stage model that is helpful to give guidance for dental students: the Transtheoretical Model (TTM). This model allows students to understand the tasks and goals for the pre-contemplation stage. The TTM was introduced in early stages as a core component of a smoking cessation programme that was integrated into a Behavioral Science programme as applied to dentistry. The aim of the present study is to evaluate and illustrate the students’ current level of knowledge from the questions the students generated in order to engage patients in the tasks and goals of the pre-contemplation stage. Method: N=47 responses of fifth-year undergraduate dental students. These responses were the data set for this study and related to their knowledge base of appropriate questions for a dentist to ask at the pre-contemplation stage of change. A deductive -descriptive analysis was conducted on the data. The goals and tasks of the pre-contemplation stage of the TTM provided a template for this deductive analysis. Results: 51% of students generated relevant, open, exploratory questions for the pre-contemplation stage, whilst 100% of students generated closed questions. With regard to those questions appropriate for the pre-contemplation stage, 19% were open and exploratory, while 66% were closed questions. A deductive analysis of the open exploratory questions revealed that 53% of the questions addressed increased concern about the current pattern of behavior, 38% of the questions concerned increased awareness of a need for change and only 8% of the questions dealt with the envisioning of the possibility of change. Conclusion: All students formulated relevant questions for the pre-contemplation stage, and half of the students generated the open, exploratory questions that increased patients’ awareness of the need to change. More training is required to facilitate a shift in the formulation from closed to open questioning, especially given that, traditionally, smoking cessation was modeled on the ‘5 As’, and that the general training for dentists supports an advisory and directive approach.

Keywords: behaviour change, pre-contemplation stage, trans-theoretical model, undergraduate dentistry students

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14778 Pre-Service Teacher Education Reforms in India and Pakistan: Challenges and Possibilities

Authors: Jyoti Sharma

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India and Pakistan are two strategically important neighboring countries in Asia-Pacific region. Since independence of more than six decades, both, India and Pakistan have transverse different paths, India as a Sovereign, Democratic, Republic Country and Pakistan as Islamic Republic of Pakistan. The advent of democracy in India and Islamic republic in Pakistan resulted in new hopes, aspirations and demands on education. During the six decades after Independence, teacher education in both countries has come a long way from its initial bleak stature to gain an identity as a complex network of institutions and programs. The present paper takes a close look into the paradigm shift in teacher education programs in India and Pakistan and how much the shift is influenced by constitutional frameworks of each country.

Keywords: pre-service teachers, teacher education reforms, India, Pakistan

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14777 Annual and Seasonal Variations in Air Quality Index of the National Capital Region, India

Authors: Surinder Deswal, Vineet Verma

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Air Quality Index (AQI) is used as a tool to indicate the level of severity and disseminate the information on air pollution to enable the public to understand the health and environmental impacts of air pollutant concentration levels. The annual and seasonal variation of criteria air pollutants concentration based on the National Ambient Air Quality Monitoring Programme has been conducted for a period of nine years (2006-2014) using the AQI system. AQI was calculated using IND-AQI methodology and Maximum Operator Concept is applied. An attempt has been made to quantify the variations in AQI on an annual and seasonal basis over a period of nine years. Further, year-wise frequency of occurrence of AQI in each category for all the five stations is analysed, which presents in depth analysis of trends over the period of study. The best air quality was observed in the Noida residential area, followed by Noida industrial area during the study period; whereas, Bulandshahar industrial area and Faridabad residential area were observed to have the worst air quality. A shift in the worst air quality from winter to summer season has also been observed during the study period. Further, the level of Respirable Suspended Particulate Matter was found to be above permissible limit at all the stations. The present study helps in enhancing public awareness and calls for the need of immediate measures to be taken to counter-effect the cause of the increasing level of air pollution.

Keywords: air quality index, annual trends, criteria pollutants, seasonal variation

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14776 Optimizing Multimodal Teaching Strategies for Enhanced Engagement and Performance

Authors: Victor Milanes, Martha Hubertz

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In the wake of COVID-19, all aspects of life have been estranged, and humanity has been forced to shift toward a more technologically integrated mode of operation. Essential work such as Healthcare, business, and public policy are a few notable industries that were initially dependent upon face-to-face modality but have completely reimagined their operation style. Unique to these fields, education was particularly strained because academics, teachers, and professors alike were obligated to shift their curriculums online over the course of a few weeks while also maintaining the expectation that they were educating their students to a similar level accomplished pre-pandemic. This was notable as research indicates two key concepts: Students prefer face-to-face modality, and due to the disruption in academic continuity/style, there was a negative impact on student's overall education and performance. With these two principles in mind, this study aims to inquire what online strategies could be best employed by teachers to educate their students, as well as what strategies could be adopted in a multimodal setting if deemed necessary by the instructor or outside convoluting factors (Such as the case of COVID-19, or a personal matter that demands the teacher's attention away from the classroom). Strategies and methods will be cross-analyzed via a ranking system derived from various recognized teaching assessments, in which engagement, retention, flexibility, interest, and performance are specifically accounted for. We expect to see an emphasis on positive social pressure as a dominant factor in the improved propensity for education, as well as a preference for visual aids across platforms, as research indicates most individuals are visual learners.

Keywords: technological integration, multimodal teaching, education, student engagement

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14775 Study of Chemical State Analysis of Rubidium Compounds in Lα, Lβ₁, Lβ₃,₄ and Lγ₂,₃ X-Ray Emission Lines with Wavelength Dispersive X-Ray Fluorescence Spectrometer

Authors: Harpreet Singh Kainth

Abstract:

Rubidium salts have been commonly used as an electrolyte to improve the efficiency cycle of Li-ion batteries. In recent years, it has been implemented into the large scale for further technological advances to improve the performance rate and better cyclability in the batteries. X-ray absorption spectroscopy (XAS) is a powerful tool for obtaining the information in the electronic structure which involves the chemical state analysis in the active materials used in the batteries. However, this technique is not well suited for the industrial applications because it needs a synchrotron X-ray source and special sample file for in-situ measurements. In contrast to this, conventional wavelength dispersive X-ray fluorescence (WDXRF) spectrometer is nondestructive technique used to study the chemical shift in all transitions (K, L, M, …) and does not require any special pre-preparation planning. In the present work, the fluorescent Lα, Lβ₁ , Lβ₃,₄ and Lγ₂,₃ X-ray spectra of rubidium in different chemical forms (Rb₂CO₃ , RbCl, RbBr, and RbI) have been measured first time with high resolution wavelength dispersive X-ray fluorescence (WDXRF) spectrometer (Model: S8 TIGER, Bruker, Germany), equipped with an Rh anode X-ray tube (4-kW, 60 kV and 170 mA). In ₃₇Rb compounds, the measured energy shifts are in the range (-0.45 to - 1.71) eV for Lα X-ray peak, (0.02 to 0.21) eV for Lβ₁ , (0.04 to 0.21) eV for Lβ₃ , (0.15 to 0.43) eV for Lβ₄ and (0.22 to 0.75) eV for Lγ₂,₃ X-ray emission lines. The chemical shifts in rubidium compounds have been measured by considering Rb₂CO₃ compounds taking as a standard reference. A Voigt function is used to determine the central peak position of all compounds. Both positive and negative shifts have been observed in L shell emission lines. In Lα X-ray emission lines, all compounds show negative shift while in Lβ₁, Lβ₃,₄, and Lγ₂,₃ X-ray emission lines, all compounds show a positive shift. These positive and negative shifts result increase or decrease in X-ray energy shifts. It looks like that ligands attached with central metal atom attract or repel the electrons towards or away from the parent nucleus. This pulling and pushing character of rubidium affects the central peak position of the compounds which causes a chemical shift. To understand the chemical effect more briefly, factors like electro-negativity, line intensity ratio, effective charge and bond length are responsible for the chemical state analysis in rubidium compounds. The effective charge has been calculated from Suchet and Pauling method while the line intensity ratio has been calculated by calculating the area under the relevant emission peak. In the present work, it has been observed that electro-negativity, effective charge and intensity ratio (Lβ₁/Lα, Lβ₃,₄/Lα and Lγ₂,₃/Lα) are inversely proportional to the chemical shift (RbCl > RbBr > RbI), while bond length has been found directly proportional to the chemical shift (RbI > RbBr > RbCl).

Keywords: chemical shift in L emission lines, bond length, electro-negativity, effective charge, intensity ratio, Rubidium compounds, WDXRF spectrometer

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14774 Disaggregate Travel Behavior and Transit Shift Analysis for a Transit Deficient Metropolitan City

Authors: Sultan Ahmad Azizi, Gaurang J. Joshi

Abstract:

Urban transportation has come to lime light in recent times due to deteriorating travel quality. The economic growth of India has boosted significant rise in private vehicle ownership in cities, whereas public transport systems have largely been ignored in metropolitan cities. Even though there is latent demand for public transport systems like organized bus services, most of the metropolitan cities have unsustainably low share of public transport. Unfortunately, Indian metropolitan cities have failed to maintain balance in mode share of various travel modes in absence of timely introduction of mass transit system of required capacity and quality. As a result, personalized travel modes like two wheelers have become principal modes of travel, which cause significant environmental, safety and health hazard to the citizens. Of late, the policy makers have realized the need to improve public transport system in metro cities for sustaining the development. However, the challenge to the transit planning authorities is to design a transit system for cities that may attract people to switch over from their existing and rather convenient mode of travel to the transit system under the influence of household socio-economic characteristics and the given travel pattern. In this context, the fast-growing industrial city of Surat is taken up as a case for the study of likely shift to bus transit. Deterioration of public transport system of bus after 1998, has led to tremendous growth in two-wheeler traffic on city roads. The inadequate and poor service quality of present bus transit has failed to attract the riders and correct the mode use balance in the city. The disaggregate travel behavior for trip generations and the travel mode choice has been studied for the West Adajan residential sector of city. Mode specific utility functions are calibrated under multi-nominal logit environment for two-wheeler, cars and auto rickshaws with respect to bus transit using SPSS. Estimation of shift to bus transit is carried indicate an average 30% of auto rickshaw users and nearly 5% of 2W users are likely to shift to bus transit if service quality is improved. However, car users are not expected to shift to bus transit system.

Keywords: bus transit, disaggregate travel nehavior, mode choice Behavior, public transport

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14773 Rethinking Literary Language: A Philsophicus-Logico Approach. The Novel ‘’ Sympathizer ‘’ as a Case Study

Authors: Oublal Ali

Abstract:

Due scholarly attention given to Ludwig Wittgenstein since the appearance of Tractatus is resulted from revolutionary shift he has made in the conception of language. True, his first and foremost concern was to solve the issue of language philosophers failed to recognize. Not only Tracturain’s approach to language that argues for philosophers failure of understanding the logic of language, but also his later conception which is developed in philosophical investigations and the reminder of all his remarks. On such a basis, it is claimed that Wittgenstein’s theory of language should not be confined to the language within philosophical streams with this premise we therefore propose to analytically read one of the literary propositions in the sympathizer as linguistic corpus. Our investigation of the literary proposition weaves us into claiming that Wittgenstein’s language games -later philosophy- is apposite to the analysis of literary works thanks to the shift Wittgenstein has made from demarcated use of language to the multiplicity and non-uniformity of its use.

Keywords: language, context, use, language games, literary propositions

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14772 English as a Foreign Language Teachers' Perspectives on the Workable Approaches and Challenges that Encountered them when Teaching Reading Using E-Learning

Authors: Sarah Alshehri, Messedah Alqahtani

Abstract:

Reading instruction in EFL classes is still challenging for teachers, and many students are still behind their expected level. Due to the Covid-19 pandemic, there was a shift in teaching English from face-to face to online classes. This paper will discover how the digital shift during and post pandemic has influenced English literacy instruction and what methods seem to be effective or challenging. Specifically, this paper will examine English language teachers' perspectives on the workable approaches and challenges that encountered them when teaching reading using E-Learning platform in Saudi Arabian Secondary and intermediate schools. The study explores public secondary school EFL teachers’ instructional practices and the challenges encountered when teaching reading online. Quantitative data will be collected through a 28 -item Likert type survey that will be administered to Saudi English teachers who work in public secondary and intermediate schools. The quantitative data will be analyzed using SPSS by conducting frequency distributions, descriptive statistics, reliability tests, and one-way ANOVA tests. The potential outcomes of this study will contribute to better understanding of digital literacy and technology integration in language teaching. Findings of this study can provide directions for professionals and policy makers to improve the quality of English teaching and learning. Limitations and results will be discussed, and suggestions for future directions will be offered.

Keywords: EFL reading, E-learning- EFL literacy, EFL workable approaches, EFL reading instruction

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14771 Travel Delay and Modal Split Analysis: A Case Study

Authors: H. S. Sathish, H. S. Jagadeesh, Skanda Kumar

Abstract:

Journey time and delay study is used to evaluate the quality of service, the travel time and study can also be used to evaluate the quality of traffic movement along the route and to determine the location types and extent of traffic delays. Components of delay are boarding and alighting, issue of tickets, other causes and distance between each stops. This study investigates the total journey time required to travel along the stretch and the influence the delays. The route starts from Kempegowda Bus Station to Yelahanka Satellite Station of Bangalore City. The length of the stretch is 16.5 km. Modal split analysis has been done for this stretch. This stretch has elevated highway connecting to Bangalore International Airport and the extension of metro transit stretch. From the regression analysis of total journey time it is affected by delay due to boarding and alighting moderately, Delay due to issue of tickets affects the journey time to a higher extent. Some of the delay factors affecting significantly the journey time are evident from F-test at 10 percent level of confidence. Along this stretch work trips are more prevalent as indicated by O-D study. Modal shift analysis indicates about 70 percent of commuters are ready to shift from current system to Metro Rail System. Metro Rail System carries maximum number of trips compared to private mode. Hence Metro is a highly viable choice of mode for Bangalore Metropolitan City.

Keywords: delay, journey time, modal choice, regression analysis

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14770 Nanoscale Metal-Organic Framework Coated Carbon Nitride Nanosheet for Combination Cancer Therapy

Authors: Rui Chen, Jinfeng Zhang, Chun-Sing Lee

Abstract:

In the past couple of decades, nanoscale metal-organic frameworks (NMOFs) have been highlighted as promising delivery platforms for biomedical applications, which combine many potent features such as high loading capacity, progressive biodegradability and low cytotoxicity. While NMOF has been extensively used as carriers for drugs of different modalities, so far there is no report on exploiting the advantages of NMOF for combination therapy. Herein, we prepared core-shell nanoparticles, where each nanoparticle contains a single graphitic-phase carbon nitride (g-C3N4) nanosheet encapsulated by a zeolitic-imidazolate frameworks-8 (ZIF-8) shell. The g-C3N4 nanosheets are effective visible-light photosensitizer for photodynamic therapy (PDT). When hosting DOX (doxorubicin), the as-synthesized core-shell nanoparticles could realize combinational photo-chemo therapy and provide dual-color fluorescence imaging. Therefore, we expect NMOFs-based core-shell nanoparticles could provide a new way to achieve much-enhanced cancer therapy.

Keywords: carbon nitride, combination therapy, drug delivery, nanoscale metal-organic frameworks

Procedia PDF Downloads 398
14769 Resilience among Children with and without Hearing Loss: A Comparative Study in Pakistan

Authors: Bushra Akram, Amina Tariq

Abstract:

Objective: This cross-sectional descriptive study aimed to compare the level of resilience among children with and without hearing loss. Methodology: In this descriptive cross sectional study total 500 children (with hearing loss = 250 and without hearing loss = 250) were recruited conveniently. Children with hearing loss were recruited from the special schools whereas children without hearing loss were selected from regular schools located in cities of Gujrat and Jhelum of Pakistan. Respondents’ age ranged from 9-14 years. Resiliency scale named RSCA (Resiliency Scales for children and adolescents) developed by Sandra Prince Embury (2006) was used. RSCA consist of three core theoretical areas: MAS (Sense of Mastery Scale), REL (Sense of Relatedness Scale) and REA (Emotional Reactivity Scale). Results: Findings indicated that there was a significant difference in the resilience level of participants with and without hearing loss. The mean comparison showed that the children with hearing loss showed lower scores on MAS (X̅ = 43.32, SD = 7.55) as well as on REL (X̅ = 49.96, SD = 7.65) as compared to their counterparts on MAS (X̅ = 53.96, SD = 9.90, t= -7.31***) and on REL (X̅ = 68.43, SD = 14.57,t= -10.18***). However children with hearing loss showed higher scores on REA (X̅ = 42.12, SD = 5.84) as compared to hearing participants (X̅ = 28.84, SD = 13.97, t = -8.20***). The findings revealed no significance difference in the resilience level of hearing and deaf children on the basis of their gender and age. Research Outcomes and Future Scope: Children with hearing loss showed a lower level of resilience, therefore, needs a program to develop resilience for better social-emotional adjustment and enhancement of their psychological well-being. In the end, the researcher gave recommendations for future research.

Keywords: children with hearing loss, psychological Wellbeing, resiliency scales for children and adolescents, resilience

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14768 Long-Term Trends of Sea Level and Sea Surface Temperature in the Mediterranean Sea

Authors: Bayoumy Mohamed, Khaled Alam El-Din

Abstract:

In the present study, 24 years of gridded sea level anomalies (SLA) from satellite altimetry and sea surface temperature (SST) from advanced very-high-resolution radiometer (AVHRR) daily data (1993-2016) are used. These data have been used to investigate the sea level rising and warming rates of SST, and their spatial distribution in the Mediterranean Sea. The results revealed that there is a significant sea level rise in the Mediterranean Sea of 2.86 ± 0.45 mm/year together with a significant warming of 0.037 ± 0.007 °C/year. The high spatial correlation between sea level and SST variations suggests that at least part of the sea level change reported during the period of study was due to heating of surface layers. This indicated that the steric effect had a significant influence on sea level change in the Mediterranean Sea.

Keywords: altimetry, AVHRR, Mediterranean Sea, sea level and SST changes, trend analysis

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14767 Effectiveness of Blended Learning in Public School During Covid-19: A Way Forward

Authors: Sumaira Taj

Abstract:

Blended learning is emerged as a prerequisite approach for teaching in all schools after the outbreak of the COVID-19 pandemic. However, how much public elementary and secondary schools in Pakistan are ready for adapting this approach and what should be done to prepare schools and students for blended learning are the questions that this paper attempts to answer. Mixed-method research methodology was used to collect data from 40 teachers, 500 students, and 10 mothers. Descriptive statistics was used to analyze quantitative data. As for as readiness is concerned, schools lack resources for blended/ virtual/ online classes from infra-structure to skills, parents’ literacy level hindered students’ learning process and teachers’ skills presented challenges in a smooth and swift shift of the schools from face-to-face learning to blended learning. It is recommended to establish a conducive environment in schools by providing all required resources and skills. Special trainings should be organized for low literacy level parents. Multiple ways should be adopted to benefit all students.

Keywords: blended learning, challenges in online classes, education in covid-19, public schools in pakistan

Procedia PDF Downloads 143
14766 The Role of Questioning Techniques in a Literature Classroom

Authors: Barbara Magallona

Abstract:

Given the observations between students who were active participants in a dialogue with their teacher and students who simply answered the teacher’s questions, the researcher will investigate the relationship between student-teacher dialogue in the classroom and the development of higher level thinking skills with an emphasis on the questioning techniques used by the teacher. The study posits the main question: What is the relationship between teachers’ questioning techniques and the development of students’ higher level thinking skills in a literature class (or in literature classes) in Xavier? The following are the study’s sub-questions: a) What types of questions do literature teachers at Xavier School ask? b) What types of responses do literature students at Xavier School give to teachers' questions? c) To what extent is the development of students' higher level thinking skills shown in teacher-student classroom dialogues in Xavier School's literature classroom? Since questioning techniques and student responses in the literature classroom form the core of this paper and in order to evaluate them, the study uses Andersen and Krathwohl’s revision of Harold Bloom’s Taxonomy of Educational Objectives. Teun van Dijk’s discourse-cognition-society triangle will be used as a theoretical framework to design and to guide the classroom interaction.

Keywords: discourse analysis, literature classroom, questioning techniques, secondary education

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14765 Antibacterial Activity of Noble Metal Functionalized Magnetic Core-Zeolitic Shell Nanostructures

Authors: Mohsen Padervand

Abstract:

Functionalized magnetic core-zeolitic shell nanostructures were prepared by the hydrothermal and coprecipitation methods. The products were characterized by Vibrating Sample Magnetometer (VSM), X-ray powder diffraction (XRD), Fourier Transform Infrared spectra (FTIR), nitrogen adsorption-desorption isotherms (BET) and Transmission Electron Microscopy (TEM). The growth of mordenite nanoparticles on the surface of silica coated nickel ferrite nanoparticles at the presence of organic templates was well approved. The antibacterial activity of prepared samples was investigated by the inactivation of E.coli as a gram negative bacterium. A new mechanism was proposed to inactivate the bacterium over the prepared samples. Minimum Inhibitory Concentration (MIC) and reuse ability were studied too. TEM images of the destroyed microorganism after the treatment time were applied to illustrate the inactivation mechanism. The interaction of the noble metals with organic components on the surface of nanostructures studied theoretically and the results were used to interpret the experimental results.

Keywords: nickel ferrite nanoparticles, magnetic core-zeolitic shell, antibacterial activity, E. coli

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14764 Re-Thinking Community Relationship for Resolving Conflict and Building Peace in Ethiopia: The Need to Shift from Com-Animation to Communication

Authors: Sisaye Tamrat Ayalew

Abstract:

In Ethiopia, the relationships between different communities have been characterized by mistrust, prejudice, and conflict, resulting in mass killings, displacement, and human rights violations. These relationships are mainly based on ethnic, religious, and linguistic lines, leading to a polarized society. The aim of this study is to appraise the nature of two major community relationships, namely the I-Thou relationship, characterized by genuine dialogue and mutual understanding, and the I-It relationship, characterized by a monologue and mutual suspicion. The study also aims to analyze how these two types of relationships contribute to either resolving or aggravating conflicts and building or deteriorating peace in Ethiopia. The study adopts a qualitative approach, specifically hermeneutics, to explore the nature of the I-Thou and I-It relationships in the Ethiopian context. It also examines how political elites shape these relationships within the community. The study finds that the dominant relationship in Ethiopian society is the I-It relationship, which is manifested as "com-animation." This relationship is characterized by mutual mistrust, prejudice, hostility, and misunderstanding. As a result, conflicts have arisen, leading to violence, displacement, and human rights violations. The study concludes that there is a need to shift from the I-It (com-animation) relationship to the I-Thou (communication) relationship in Ethiopian society. This shift would involve rethinking and readjusting societal relationships, especially among political elites, to foster genuine dialogue, mutual understanding, and lasting peace. It is imperative to overcome mutual mistrust, prejudice, and misunderstanding in order to resolve conflicts and build a harmonious society in Ethiopia. The study's findings and recommendations contribute to raising awareness among both Ethiopians and the international community on the potential for conflict resolution and peacebuilding through a shift in community relationships.

Keywords: dialogue, I-Thou relationship, I-It relationship, conflict resolution, building peace

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14763 Internalising Islamic Principles of Theocracy as a Pedestal for Good Governance in Nigeria

Authors: Busari Moshood Olanyi

Abstract:

Good governance remains the expectation of every political party in power, especially in this democratic dispensation of the Nigerian Nation. The need to ensure that the citizenry enjoys the dividends of democracy as often promised during various electioneering campaigns is envisioned to be the motif for different agendas and political slogans by different administrations. Unfortunately, different political agendas towards the security of lives and properties, halting the pillage of the economy by corrupt public officials and creation of employment opportunities for the youths, have a record of setback in the history of political leadership and governance in Nigeria. Therefore, the paper examined the principles of Islamic theocracy in its advocacy for a paradigm shift in the Nigerian political system, with a view to engendering good governance. Islamic political terms such as Shūrā (mutual consultation), ‘Adālah (equality and justice), Khilāfah (succession and stewardship) Majlis ash-Shūrā (consultative forum) and Muḥāsabah (accountability) were espoused as sacrosanct to implementing Islamic theocracy as an alternative system of government in Nigeria. The paper concluded by being flexible on the nomenclature of the suggested political system, considering the multi-religious nature of the country as a political entity. Among other recommendations, infusion of politics into our moral/religious system and not the other way round was considered a good step in the direction of a political paradigm shift for ensuring good governance and guaranteeing its sustainability in Nigeria.

Keywords: Nigerian nation, democracy, good governance, Islamic theocracy, paradigm shift

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14762 Appropriate Legal System for Protection of Plant Innovations in Afghanistan

Authors: Mohammad Reza Fooladi

Abstract:

Because of the importance and effect of plant innovations on economy, industry, and especially agriculture, they have been on the core attention of legislators at the national level, and have been a topic of international documents related to intellectual innovations in the recent decades. For protection of plant innovations, two legal systems (i.e. particular system based on International Convention for protection of new variety of plants, and the patent system) have been considered. Ease of access to the support and the level of support in each of these systems are different. Our attempt in this paper, in addition to describing and analyzing the characteristics of each system, is to suggest the compatible system to the industry and agriculture of Afghanistan. Due to the lack of sufficient industrial infrastructure and academic research, the particular system based on the International Convention on the protection of new variety of plants is suggested. At the same time, appropriate industrial and legal infrastructures, as well as laboratories and research centers should be provided in order that plant innovations under the patent system could also be supported.

Keywords: new varieties of plant, patent, agriculture, Afghanistan

Procedia PDF Downloads 299
14761 Predictive Value of Hepatitis B Core-Related Antigen (HBcrAg) during Natural History of Hepatitis B Virus Infection

Authors: Yanhua Zhao, Yu Gou, Shu Feng, Dongdong Li, Chuanmin Tao

Abstract:

The natural history of HBV infection could experience immune tolerant (IT), immune clearance (IC), HBeAg-negative inactive/quienscent carrier (ENQ), and HBeAg-negative hepatitis (ENH). As current biomarkers for discriminating these four phases have some weaknesses, additional serological indicators are needed. Hepatits B core-related antigen (HBcrAg) encoded with precore/core gene contains denatured HBeAg, HBV core antigen (HBcAg) and a 22KDa precore protein (p22cr), which was demonstrated to have a close association with natural history of hepatitis B infection, but no specific cutoff values and diagnostic parameters to evaluate the diagnostic efficacy. This study aimed to clarify the distribution of HBcrAg levels and evaluate its diagnostic performance during the natural history of infection from a Western Chinese perspective. 294 samples collected from treatment-naïve chronic hepatitis B (CHB) patients in different phases (IT=64; IC=72; ENQ=100, and ENH=58). We detected the HBcrAg values and analyzed the relationship between HBcrAg and HBV DNA. HBsAg and other clinical parameters were quantitatively tested. HBcrAg levels of four phases were 9.30 log U/mL, 8.80 log U/mL, 3.00 log U/mL, and 5.10 logU/mL, respectively (p < 0.0001). Receiver operating characteristic curve analysis demonstrated that the area under curves (AUCs) of HBcrAg and quantitative HBsAg at cutoff values of 9.25 log U/mL and 4.355 log IU/mL for distinguishing IT from IC phases were 0.704 and 0.694, with sensitivity 76.39% and 59.72%, specificity 53.13% and 79.69%, respectively. AUCs of HBcrAg and quantitative HBsAg at cutoff values of 4.15 log U/mlmL and 2.395 log IU/mlmL for discriminating between ENQ and ENH phases were 0.931 and 0.653, with sensitivity 87.93% and 84%, specificity 91.38% and 39%, respectively. Therefore, HBcrAg levels varied significantly among four natural phases of HBV infection. It had higher predictive performance than quantitative HBsAg for distinguishing between ENQ-patients and ENH-patients and similar performance with HBsAg for the discrimination between IT and IC phases, which indicated that HBcrAg could be a potential serological marker for CHB.

Keywords: chronic hepatitis B, hepatitis B core-related antigen, hepatitis B surface antigens, hepatitis B virus

Procedia PDF Downloads 385