Search results for: spatial frequency measurement

Authors: Fereshteh Pourmohammad, Mehdi Zare

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The city of Karaj, having a population of 2.2 millions (est. 2022) is located in the South West of Alborz Mountain Belt in Northern Iran. The region is known to be a highly active seismic zone. This study is focused on the geological and seismological analyses within a radius of 200 km from the center of Karaj. There are identified five seismic zones and seven linear seismic sources. The maximum magnitude was calculated for the seismic zones. Scine tghe seismicity catalog is incomplete, we have used a parametric-historic algorithm and the Kijko and Sellevoll (1992) method was used to calculate seismicity parameters, and the return periods and the probability frequency of recurrence of the earthquake magnitude in each zone obtained for 475-years return period. According to the calculations, the highest and lowest earthquake magnitudes of 7.6 and 6.2 were respectively obtained in Zones 1 and 4. This result is a new and extremely important in view point of earthquake risk in a densely population city. The maximum strong horizontal ground motion for the 475-years return period 0.42g and for 2475-year return period 0.70g also the maximum strong vertical ground motion for 475-years return period 0.25g and 2475-years return period 0.44g was calculated using attenuation relationships. These acceleration levels are new, and are obtained to be about 25% higher than presented values in the Iranian building code.

Keywords: seismic zones, ground motion, return period, hazard analysis

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Authors: Kiatnarong Supapanmanee, Ekkarin Phongphinittana, Pongsak Nimdum

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Natural fibers are readily available raw materials that are widely used as composite materials. The most common problem facing many researchers with composites made from this fiber is the adhesion between the natural fiber contact surface and the matrix material. Part of the problem is due to the hydrophilic properties of natural fibers and the hydrophobic properties of the matrix material. Based on the aforementioned problems, this research selected bamboo fiber, which is a strong natural fiber in the research study. The first step was to study the effect of the mechanical properties of the pure bamboo strip by testing the tensile strength of different measurement lengths. The bamboo strip was modified surface with sodium hydroxide (NaOH) at 6wt% concentrations for different soaking periods. After surface modification, the physical and mechanical properties of the pure bamboo strip fibers were studied. The modified and unmodified bamboo strips were molded into a composite material using epoxy as a matrix to compare the mechanical properties and adhesion between the fiber surface and the material with tensile and bending tests. In addition, the results of these tests were compared with the finite element method (FEM). The results showed that the length of the bamboo strip affects the strength of the fibers, with shorter fibers causing higher tensile stress. Effects of surface modification of bamboo strip with NaOH, this chemical eliminates lignin and hemicellulose, resulting in the smaller dimension of the bamboo strip and increased density. From the pretreatment results above, it was found that the treated bamboo strip and composite material had better Ultimate tensile stress and Young's modulus. Moreover, that results in better adhesion between bamboo fiber and matrix material.

Keywords: bamboo fiber, bamboo strip, composite material, bamboo composite, pure bamboo, surface modification, mechanical properties of bamboo, bamboo finite element method

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Authors: Adefarati Oloruntoba, Yongmin Zhang, Hongliang Xiao

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An annular fluidized bed (AFB) is gaining extensive application in the process industry due to its efficient gas-solids contacting. But a direct evaluation of its reaction performance is still lacking. In this paper, comparative 3D Euler–Lagrange multiphase-particle-in-cell (MP-PIC) computations are performed to assess the reaction performance of AFB relative to a bubbling fluidized bed (BFB) in an FCC regeneration process. By using the energy-minimization multi-scale (EMMS) drag model with a suitable heterogeneity index, the MP-PIC simulation predicts the typical fountain region in AFB and solids holdup of BFB, which is consistent with an experiment. Coke combustion rate, flue gas and temperature profile are utilized as the performance indicators, while related bed hydrodynamics are explored to account for the different performance under varying superficial gas velocities (0.5 m/s, 0.6 m/s, and 0.7 m/s). Simulation results indicate that the burning rates of coke and its species are relatively the same in both beds, albeit marginal increase in BFB. Similarly, the shape and evolution time of flue gas (CO, CO₂, H₂O and O₂) curves are indistinguishable but match the coke combustion rates. However, AFB has high proclivity to high temperature-gradient as higher gas and solids temperatures are predicted in the freeboard. Moreover, for both beds, the effect of superficial gas velocity is only conspicuous on the temperature but negligible on combustion efficiency and effluent gas emissions due to constant gas volumetric flow rate and bed loading criteria. Cross-flow of solids from the annulus to the spout region as well as the high primary gas in the AFB directly assume the underlying mechanisms for its unique gas-solids hydrodynamics (pressure, solids holdup, velocity, mass flux) and local spatial homogeneity, which in turn influence the reactor performance. Overall, the study portrays AFB as a cheap alternative reactor to BFB for catalyst regeneration.

Keywords: annular fluidized bed, bubbling fluidized bed, coke combustion, flue gas, fountaining, CFD, MP-PIC, hydrodynamics, FCC regeneration

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Authors: G. Wagner, R. Herrmann

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Cytotoxic platinum compounds play a major role in the chemotherapy of a large number of human cancers. However, due to the severe side effects for the patient and other problems associated with their use, there is a need for the development of more efficient drugs and new methods for their selective delivery to the tumours. One way to achieve the latter could be in the use of nanoparticular substrates that can adsorb or chemically bind the drug. In the cell, the drug is supposed to be slowly released, either by physical desorption or by dissolution of the particle framework. Ideally, the cytotoxic properties of the platinum drug unfold only then, in the cancer cell and over a longer period of time due to the gradual release. In this paper, we report on our first steps in this direction. The binding properties of a series of cytotoxic Pt(II) oxadiazoline compounds to mesoporous silica particles has been studied by NMR and UV/vis spectroscopy. High loadings were achieved when the Pt(II) compound was relatively polar, and has been dissolved in a relatively nonpolar solvent before the silica was added. Typically, 6-10 hours were required for complete equilibration, suggesting the adsorption did not only occur to the outer surface but also to the interior of the pores. The untreated and Pt(II) loaded particles were characterised by C, H, N combustion analysis, BET/BJH nitrogen sorption, electron microscopy (REM and TEM) and EDX. With the latter methods we were able to demonstrate the homogenous distribution of the Pt(II) compound on and in the silica particles, and no Pt(II) bulk precipitate had formed. The in vitro cytotoxicity in a human cancer cell line (HeLa) has been determined for one of the new platinum compounds adsorbed to mesoporous silica particles of different size, and compared with the corresponding compound in solution. The IC50 data are similar in all cases, suggesting that the release of the Pt(II) compound was relatively fast and possibly occurred before the particles reached the cells. Overall, the platinum drug is chemically stable on silica and retained its activity upon prolonged storage.

Keywords: cytotoxicity, mesoporous silica, nanoparticles, platinum compounds

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Authors: Rishabh Nagpal, Riya Uchagaonkar, Venkata Naga Narasimha Ashish Mernedi, Ahmed Hambaba

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The rapid evolution of technology in the communication sector continually seeks to bridge the gap between different communities, notably between the deaf community and the hearing world. This project develops a comprehensive American Sign Language (ASL) recognition system, leveraging the advanced capabilities of convolutional neural networks (CNNs) and vision transformers (ViTs) to interpret and translate ASL in real-time. The primary objective of this system is to provide an effective communication tool that enables seamless interaction through accurate sign language interpretation. The architecture of the proposed system integrates dual networks -VGG16 for precise spatial feature extraction and vision transformers for contextual understanding of the sign language gestures. The system processes live input, extracting critical features through these sophisticated neural network models, and combines them to enhance gesture recognition accuracy. This integration facilitates a robust understanding of ASL by capturing detailed nuances and broader gesture dynamics. The system is evaluated through a series of tests that measure its efficiency and accuracy in real-world scenarios. Results indicate a high level of precision in recognizing diverse ASL signs, substantiating the potential of this technology in practical applications. Challenges such as enhancing the system’s ability to operate in varied environmental conditions and further expanding the dataset for training were identified and discussed. Future work will refine the model’s adaptability and incorporate haptic feedback to enhance the interactivity and richness of the user experience. This project demonstrates the feasibility of an advanced ASL recognition system and lays the groundwork for future innovations in assistive communication technologies.

Keywords: sign language, computer vision, vision transformer, VGG16, CNN

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Authors: A. Benatiallah, D. Benatiallah, F. Abaidi, B. Nasri, A. Harrouz, S. Mansouri

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The region of Adrar is located in the south-western Algeria and covers a total area of 443.782 km², occupied by a population of 432,193 inhabitants. The main activity of population is agriculture, mainly based on the date palm cultivation occupies a total area of 23,532 ha. Adrar region climate is a continental desert characterized by a high variation in temperature between months (July, August) it exceeds 48°C and coldest months (December, January) with 16°C. Rainfall is very limited in frequency and volume with an aridity index of 4.6 to 5 which corresponds to a type of arid climate. Geologically Adrar region is located on the edge North West and is characterized by a Precambrian basement cover stolen sedimentary deposit of Phanerozoic age transgressive. The depression is filled by Touat site Paleozoic deposits (Cambrian to Namurian) of a vast sedimentary basin extending secondary age of the Saharan Atlas to the north hamada Tinhirt Tademaït and the plateau of south and Touat Gourara west to Gulf of Gabes in the Northeast. In this work we have study geothermal potential of Adrar region from the borehole data eatable in various sites across the area of 400,000 square kilometres; from these data we developed a GIS (Adrar_GIS) that plots data on the various points and boreholes in the region specifying information on available geothermal potential has variable depths.

Keywords: sig, geothermal, potenteil, temperature

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Authors: Yasser Almazrua

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Terrorism is a multidimensional phenomenon that has increased recently. Many countries started combating terrorism through security forces; however, there has been relatively little attention given to rehabilitation programs for people involved in such terrorism acts. In Saudi Arabia, after facing so many terrorist attacks, they started understanding and countering terrorism differently by establishing Mohammad bin Naif Counselling and Care Center in 2006. The center now is considered one of the top experience centers in the world for terrorist rehabilitation and ideology correction. The center offers different programs such as training, educational, social, art and psychological programs. One of the approaches that have been used by psychological experts at the center is Narrative Therapy. It is a therapeutic approach that focuses on the ability of the client to identify their personal life story. The client during therapy works as a storyteller where he or she gets insight, meaning and better understanding of their own lives. Because each client at the center had a story, it can be better fit method for rehabilitation towards healing and personal development. The case describes a 34-years-old man who was involved in some terrorism activities locally by technically and financially supporting a terrorist group related to Al-Qaida. The beneficiary joined Mohammad bin Naif Counseling and Care Center after serving his sentence. Informed of consent has been given to the beneficiary before starting the therapeutic program. Both qualitative and quantitative data on the beneficiary are collected by self-reporting during the initial session, and by using a psychological measurement. The result found that the beneficiary was not insightful about himself, and he had a high level of repression which relatedly moved him to be targeted for recruitment in the terrorist group. With rehabilitation and by using the therapeutic approach, the beneficiary improved on the level of insight, specifically about himself and also about the experience. This case illustrates the importance of considering the effect of Narrative Therapy in terrorist rehabilitation programs.

Keywords: narrative therapy, rehabilitation, Saudi Arabia, terrorism

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Authors: Chuan Yang, Jing Bie, Yueh-Lung Lin, Zhong Wang

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Transportation planning is an academic integration discipline combining research and practice with the aim of mobility and accessibility improvements at both strategic-level policy-making and operational dimensions of practical planning. Transportation planning could build the linkage between traffic and social development goals, for instance, economic benefits and environmental sustainability. The transportation planning analysis and evaluation tend to apply empirical quantitative approaches with the guidance of the fundamental principles, such as efficiency, equity, safety, and sustainability. Space syntax theory has been applied in the spatial distribution of pedestrian movement or vehicle flow analysis, however rare has been written about its application in transportation planning. The correlated relationship between the variables of space syntax analysis and authentic observations have declared that the urban configurations have a significant effect on urban dynamics, for instance, land value, building density, traffic, crime. This research aims to explore the potentials of applying Space Syntax methodology to evaluate urban transportation planning through studying the effects of urban configuration on cities transportation performance. By literature review, this paper aims to discuss the effects that urban configuration with different degrees of integration and accessibility have on three elementary components of transportation planning - transportation efficiency, transportation safety, and economic agglomeration development - via intensifying and stabilising the nature movements generated by the street network. And then the potential and limits of Space Syntax theory to study the performance of urban transportation and transportation planning would be discussed in the paper. In practical terms, this research will help future research explore the effects of urban design on transportation performance, and identify which patterns of urban street networks would allow for most efficient and safe transportation performance with higher economic benefits.

Keywords: transportation planning, space syntax, economic agglomeration, transportation efficiency, transportation safety

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Authors: Vladimir Littva, Peter Kutis

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Based on common practice, we know that an empathic approach to a patient is one of the characteristics of a physiotherapist. Although empathy is regarded as an essential condition of the psychotherapeutic relationship, it has taken quite a while for attention to be paid to it in clinical practice. Patients who are experiencing a sense of understanding from health care providers are more willing to cooperate, and treatment within the optimistic attunes a more comfortable framework of care. Age, experience, family, education and the working environment may have an impact on the degree of empathy for paramedics. Within the KEGA project no. 003KU-4-2021, we decided to investigate the level of empathy in the work of physiotherapists in Slovakia. Research sample and Methods: The sample comprised 194 respondents – physiotherapists working on the territory of Slovakia. 112 were men and 82 women. The age of respondents was between 21 and 64 years of age. 133 were married, 51 were single and ten were divorced. 98 were living in the countryside and 96 in towns. Twenty-two grew up without siblings, 95 with one sibling and 77 with two and more siblings. In the survey, we used the Empathy Assessment Questionnaire (EAQ) with 18 questions with four possible answers: strongly disagree, disagree, agree; and strongly agree, which we validated linguistically and psychometrically. All data were statistically processed by SPSS 25. Results: We evaluated the intrinsic reliability of the questionnaire EAQ using Cronbach's Alpha and the coefficient is 0.756 in the whole set. This means that the questionnaire is a quite strong and reliable measurement tool. The mean for individual questions ranged from 2.39 to 3.74 (maximum was 4). In Pearson's correlations, we confirmed the significant differences between the groups regarding sex in 8 questions out of 18, regarding age in 5 questions, regarding family status in 4 questions and regarding siblings in 4 questions out of 18 at the level 5% (p <0.05). Conclusion: The results obtained during the research show the importance of adequate communication with the patient due to his health and well-being. Empathy in the physiotherapists’ profession is very important. It would be worthwhile if the students of physiotherapy would receive a course during their study that would deal exclusively with empathy, empathic approach, burnout, or psycho-emotional hygiene.

Keywords: empathy, approach, clinical practice, physiotherapists

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Authors: Emil Danehorn, Ulla Peterson, Marie Oscarsson, Goldina Smirthwaite, Katarina Swahnberg

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Swedish students who choose to study abroad are common, but there has been limited research on exchange students. There are indications that some Swedish exchange students have been exposed to violence, but it is not known if they, already before their semester abroad, are more exposed to violence than students who remain on campus. Our aim was to investigate potential differences in exposure to physical, sexual, and emotional violence between prospective exchange students and campus students and between male and female students in general, as well as to determine any associations between mental health and exposure to violence among students in the total sample. Method: Comparative cross-sectional design using an online survey containing the NorVold Abuse Questionnaire and the General Health Questionnaire 12. A total of 565 participants took part in the study. Results: Prospective exchange students were less exposed to emotional violence compared to campus students. About one-half of all the participating female students had been exposed to sexual violence and about one-third of all the male students had been exposed to physical violence. The results also indicated that exposure to more than one form of violence was associated with poor mental health for students as a group. Conclusion: Prospective exchange students as a group do not report more exposure to physical and sexual violence than campus students but do report less exposure to emotional violence. However, the overall frequency of exposure to violence among the students was high. This highlights the need for proactive efforts for everyone, not least for exchange students who will be staying in a new environment unknown to them.

Keywords: sexual violence, physical violence, emotional violence, exchange students, mental health

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Authors: Hare Krishna Doley

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Drawing upon empirical data, this paper tries to examine how ethnic groups like Ahom, Moran, Motok, and Chutia creates and recreates ethnic boundaries while making claims for recognition as Scheduled Tribes (STs) under the Sixth Schedule of the Constitution of India, in the state of Assam. Underlying such claim is the distinct identity consciousness amongst these groups as they assert themselves originally as tribe drawing upon primordial elements. For them, tribal identity promises social justice and give credence to their claims of indigeneity while preserving their exclusivity within the multifarious society of Assam. Having complex inter-group relationships, these groups under study displays distinct as well as overlapping identities, which demonstrate fluidity of identities across groups while making claims for recognition. In this process, the binary of ‘us’ and ‘them’ are often constructed amongst these groups, which are in turn difficult to grasp as they share common historical linkages. This paper attempts to grapple with such complex relationships the studied groups and their assertion as distinct cultural entities while making ethnic boundaries on the basis of socio-cultural identities. Such claims also involve frequent negotiation with the Sate as well as with other ethnic groups, which further creates strife among indigenous groups for tribal identity. The paper argues that identity consciousnesses amongst groups have persisted since the introduction of resource distribution on ethnic lines; therefore, issues of exclusive ethnic identity in the state of Assam can be contextualised within the colonial and post-colonial politics of redrawing ethnic and spatial boundaries. Narrative of the ethnic leaders who are in the forefront of struggle for ST status revealed that it is not merely to secure preferential treatment, but it also encompasses entitlement to land and their socio-cultural identity as aboriginal. While noting the genesis of struggle by the ethnic associations for ST status, this paper will also delineate the interactions among ethnic groups and how the identity of tribe is being performed by them to be included in the official categories of ST.

Keywords: ethnic, identity, sixth schedule, tribe

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Authors: Zhuanfang Fred Zhang, Tim C. Johnson, Yilin Fang, Chris E. Strickland

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A variety of geophysical techniques are available to image the opaque subsurface with little or no contact with the soil. It is common to conduct time-lapse surveys of different types for a given site for improved results of subsurface imaging. Regardless of the chosen survey methods, it is often a challenge to process the massive amount of survey data. The currently available software applications are generally based on the one-dimensional assumption for a desktop personal computer. Hence, they are usually incapable of imaging the three-dimensional (3D) processes/variables in the subsurface of reasonable spatial scales; the maximum amount of data that can be inverted simultaneously is often very small due to the capability limitation of personal computers. Presently, high-performance or integrating software that enables real-time integration of multi-process geophysical methods is needed. E4D-MP enables the integration and inversion of time-lapsed large-scale data surveys from geophysical methods. Using the supercomputing capability and parallel computation algorithm, E4D-MP is capable of processing data across vast spatiotemporal scales and in near real time. The main code and the modules of E4D-MP for inverting individual or combined data sets of time-lapse 3D electrical resistivity, spectral induced polarization, and gravity surveys have been developed and demonstrated for sub-surface imaging. E4D-MP provides capability of imaging the processes (e.g., liquid or gas flow, solute transport, cavity development) and subsurface properties (e.g., rock/soil density, conductivity) critical for successful control of environmental engineering related efforts such as environmental remediation, carbon sequestration, geothermal exploration, and mine land reclamation, among others.

Keywords: gravity survey, high-performance computing, sub-surface monitoring, electrical resistivity tomography

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Authors: Ebru Ergi̇n, Funda Kutlu

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Emerging adulthood is a developmental period and the formation of identity is crucial task of emerging adults in this period. In this frame, the main aim of the study was to compare college students and full-time workers on emerging adulthood dimensions and identity statuses in relation to some demographic variables in Turkey. The participants of the study were university students studying in Ankara and the employees working full-time in Ankara and Bursa. The mean age of the sample was 20.84 (sd=1.84), ranging from 18 to 25. The measurement instruments of the study were Inventory of Dimensions of Emerging Adulthood and Extended Objective Measure of Ego Identity Status (EOMEIS-II). The participants’ data (N=313) were analyzed to test the research questions and hypotheses of the study. A series of MANOVA were performed to test the group differences for some demographic characteristics (such as: employee/student, male/female, living with family/living apart from family) on scores of emerging adulthood dimensions and identity status. The results of the MANOVAs indicated that students, females and participants who live apart from their families had higher scores on emerging adulthood dimensions. The results of the identity status scores differences depending on the demographic characteristic pointed out that there were a significant group differences for identity foreclosure identity scores between employees and students. Employees’ foreclosure identity scores were higher than students. Furthermore, the identity scores were differed significantly according to gender of the participants. Male participants had higher scores in moratorium and foreclosure identity and female participants have higher achievement identity scores than males. Also, the participants who live with their family scored higher in foreclosure identity and the participants who live apart from their family scored higher in identity achievement status.

Keywords: college students, emerging adulthood, full-time employees, identity statuses

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Authors: Manal Ahmed, Amal Shehata, Shereen Deeb

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The study's purpose was to determine the effect of the perioperative protocol of care on clinical outcomes among patients undergoing coronary artery bypass graft. Subjects: A sample of 100 adult patients who were planned for coronary artery bypass graft, were selected and divided alternatively and randomly into two equal groups (50 study -50 control).The study was carried out at National heart Institute in Cairo and open heart surgical intensive care unit in Shebin El-Kom Teaching Hospital. Instruments: Four instruments were used for data collection: Interviewing questionnaire, dyspnea analogue scale, Biophysiological measurement instrument, and Compliance assessment sheet. Results: There were statistically significant differences between both groups regarding most respiratory system assessment findings at discharge. More than two-thirds of the study group of the current study had a continuous and regular commitment to diet regimen, which ranked first followed by the compliance of daily living activities then quitting smoking. Conclusions: The perioperative protocol of care has a significant improving effect on respiratory findings, dyspnea degree, duration of mechanical ventilation, length of hospital stay, compliance to diet, therapeutic regimen, daily living activities, and quit smoking among study group undergoing CABG. Recommendations: Perioperative protocol of care should be carried out for CABG patients at open-heart surgical units as well as an illustrative colored booklet about CAD, CABG and perioperative care should be available and distributed to all CABG patients.

Keywords: perioperative, effect, clinical outcomes, coronary artery, bypass graft, protocol of care

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Authors: Reza Fardid, Aliyeh Alipour

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Introduction: Coronary heart disease (CHD) is the most common and deadliest diseases. A coronary angiography is an important tool for the diagnosis and treatment of this disease. Because angiography is performed by exposure to ionizing radiation, it can lead to harmful effects. Ionizing radiation induces double-stranded breaks in DNA, which is a potentially life-threatening injury. The purpose of the present study is an investigation of the phosphorylation of histone H2AX in the location of the double-stranded break in Peripheral blood lymphocytes as an indication of Biological effects of radiation on angiography patients. Materials and Methods: This method is based on measurement of the phosphorylation of histone (gamma-H2AX, gH2AX) level on serine 139 after formation of DNA double-strand break. 5 cc of blood from 24 patients with angiography were sampled before and after irradiation. Blood lymphocytes were removed, fixed and were stained with specific ϒH2AX antibodies. Finally, ϒH2AX signal as an indicator of the double-strand break was measured with Flow Cytometry Technique. Results and discussion: In all patients, an increase was observed in the number of breaks in double-stranded DNA after irradiation (20.15 ± 14.18) compared to before exposure (1.52 ± 0.34). Also, the mean of DNA double-strand break was showed a linear correlation with DAP. However, although induction of DNA double-strand breaks associated with radiation dose in patients, the effect of individual factors such as radiosensitivity and regenerative capacity should not be ignored. If in future we can measure DNA damage response in every patient angiography and it will be used as a biomarker patient dose, will look very impressive on the public health level. Conclusion: Using flow cytometry readings which are done automatically, it is possible to detect ϒH2AX in the number of blood cells. Therefore, the use of this technique could play a significant role in monitoring patients.

Keywords: coronary angiography, DSB of DNA, ϒH2AX, ionizing radiation

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Authors: Kittipong Tripetch, Nobuhiko Nakano

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This paper proposes one stage and two stage CMOS Complementary Regulated Cascode Distributed Amplifier (CRCDA) design based on Inductive and Transformer coupling techniques. Usually, Distributed amplifier is based on inductor coupling between gate and gate of MOSFET and between drain and drain of MOSFET. But this paper propose some new idea, by coupling with differential primary windings of transformer between gate and gate of MOSFET first stage and second stage of regulated cascade amplifier and by coupling with differential secondary windings transformer of MOSFET between drain and drain of MOSFET first stage and second stage of regulated cascade amplifier. This paper also proposes polynomial modeling of Silicon Transformer passive equivalent circuit from Nanyang Technological University which is used to extract frequency response of transformer. Cadence simulation results are used to verify validity of transformer polynomial modeling which can be used to design distributed amplifier without Cadence. 4 parameters of scattering matrix of 2 port of the propose circuit is derived as a function of 4 parameters of impedance matrix.

Keywords: CMOS regulated cascode distributed amplifier, silicon transformer modeling with polynomial, low power consumption, distribute amplification technique

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Authors: W. Swiderski

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In the paper introduced the diagnostic technique making possible the research of internal structures in composite materials reinforced fibres using in different applications. The main reason of damages in structures of these materials is the changing distribution of load in constructions in the lifetime. Appearing defect is largely complicated because of the appearance of disturbing of continuity of reinforced fibres, binder cracks and loss of fibres adhesiveness from binders. Defect in composite materials is usually more complicated than in metals. At present, infrared thermography is the most effective method in non-destructive testing composite. One of IR thermography methods used in non-destructive evaluation is vibrothermography. The vibrothermography is not a new non-destructive method, but the new solution in this test is use ultrasonic waves to thermal stimulation of materials. In this paper, both modelling and experimental results which illustrate the advantages and limitations of ultrasonic IR thermography in inspecting composite materials will be presented. The ThermoSon computer program for computing 3D dynamic temperature distribuions in anisotropic layered solids with subsurface defects subject to ulrasonic stimulation was used to optimise heating parameters in the detection of subsurface defects in composite materials. The program allows for the analysis of transient heat conduction and ultrasonic wave propagation phenomena in solids. The experiments at MIAT were fulfilled by means of FLIR SC 7600 IR camera. Ultrasonic stimulation was performed with the frequency from 15 kHz to 30 kHz with maximum power up to 2 kW.

Keywords: composite material, ultrasonic, infrared thermography, non-destructive testing

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Authors: Bi Zhao

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Neural network technology has greatly improved the output of machine translation in terms of both fluency and accuracy, which greatly increases its appeal for young users. The present exploratory study aims to find out how the Chinese undergraduates perceive and use machine translation in their daily life. A survey is conducted to collect data from 100 undergraduate students from multiple Chinese universities and with varied academic backgrounds, including arts, business, science, engineering, and medicine. The survey questions inquire about their use (including frequency, scenarios, purposes, and preferences) of and attitudes (including trust, quality assessment, justifications, and ethics) toward machine translation. Interviews and tasks of evaluating machine translation output are also employed in combination with the survey on a sample of selected respondents. The results indicate that Chinese undergraduate students use machine translation on a daily basis for a wide range of purposes in academic, communicative, and entertainment scenarios. Most of them have preferred machine translation tools, but the availability of machine translation tools within a certain scenario, such as the embedded machine translation tool on the webpage, is also the determining factor in their choice. The results also reveal that despite the reportedly limited trust in the accuracy of machine translation output, most students lack the ability to critically analyze and evaluate such output. Furthermore, the evidence is revealed of the inadequate awareness of ethical responsibility as machine translation users among Chinese undergraduate students.

Keywords: Chinese undergraduates, machine translation, trust, usage

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Authors: Kotchamon Yodkhum, Thawatchai Phaechamud

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Hydrophobic chitosan-based materials have been developed as controlled drug delivery system. This study was aimed to prepare and evaluate chitosan-aluminum monostearate composite dispersion (CLA) as fabricating liquid for construct a hydrophobic, controlled-release solid drug delivery matrix. This work was attempted to blend hydrophobic substance, aluminum monostearate (AMS), with chitosan in acidic aqueous medium without using any surfactants or grafting reaction, and high temperature during mixing that are normally performed when preparing hydrophobic chitosan system. Lactic acid solution (2%w/v) was employed as chitosan solvent. CLA dispersion was prepared by dispersing different amounts of AMS (1-20% w/w) in chitosan solution (4% w/w) with continuous agitation using magnetic stirrer for 24 h. Effect of AMS amount on physicochemical properties of the dispersion such as viscosity, rheology and particle size was evaluated. Morphology of chitosan-AMS complex (dispersant) was observed under inverted microscope and atomic force microscope. Stability of CLA dispersions was evaluated after preparation within 48 h. CLA dispersions containing AMS less than 5 % w/w exhibited rheological behavior as Newtonian while that containing higher AMS amount exhibited as pseudoplastic. Particle size of the dispersant was significantly smaller when AMS amount was increased up to 5% w/w and was not different between the higher AMS amount system. Morphology of the dispersant under inverted microscope displayed irregular shape and their size exhibited the same trend with particle size measurement. Observation of the dispersion stability revealed that phase separation occurred faster in the system containing higher AMS amount which indicated lower stability of the system. However, the dispersions were homogeneous and stable more than 12 hours after preparation that enough for fabrication process. The prepared dispersions had ability to be fabricated as a porous matrix via lyophilization technique.

Keywords: chitosan, aluminum monostearate, dispersion, controlled-release

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Authors: Ali Kassem

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Background: In the last few years, factors such as insulin resistance (IR) and hepatic steatosis have been linked to progression of hepatic fibrosis.Patients with chronic liver disease, and cirrhosis in particular, are known to be prone to IR. However, chronic HCV (hepatitis C) infection may induce IR, regardless of the presence of liver cirrhosis. Our aims are to study insulin resistance (IR) assessed by HOMA-IR (Homeostatic Model Assessment Insulin Resistance) as a possible risk factor in disease progression in cirrhotic patients and to evaluate the role of IR in hepatic fibrosis progression. The correlations of HOMA-IR values to laboratory, virological and histopathological parameters of chronic HCV are also examined. Methods: The study included 50 people divided into 30 adult chronic hepatitis C patients diagnosed by PCR (polymerase chain reaction) within previous 6 months and 20 healthy controls. The functional and morphological status of the liver were evaluated by ultrasonography and laboratory investigations including liver function tests and by liver biopsy. Fasting blood glucose and fasting insulin levels were measured and body mass index and insulin resistance were calculated. Patients having HOMA-IR >2.5 were labeled as insulin resistant. Results: Chronic hepatitis C patients with IR showed significantly higher mean values of BMI (body mass index) and fasting insulin than those without IR (P < 0.000). Patients with IR were more likely to have steatosis (p = 0.006), higher necroinflammatory activity (p = 0.05). No significant differences were found between the two groups regarding hepatic fibrosis. Conclusion: HOMA-IR measurement could represent a novel marker to identify the cirrhotic patients at greater risk for the progression of liver disease. As IR is a potentially modifiable risk factor, these findings may have important prognostic and therapeutic implications. Assessment of IR by HOMA-IR and improving insulin sensitivity are recommended in patients with HCV and related chronic liver disease.

Keywords: hepatic fibrosis, hepatitis C virus infection, hepatic steatosis, insulin resistance

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Authors: Jiajia Yao, Guanlin Wu, Fang Liu, Junshuai Xue, Yue Hao

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As the production process of self-standing GaN substrates evolves, the commercialization of low dislocation density, large-scale, semi-insulating self-standing GaN substrates is gradually becoming a reality. This advancement has given rise to increased interest in GaN materials' homoepitaxial technology. However, at the homoepitaxial interface, there are considerable concentrations of impurity elements, including C, Si, and O, which generate parasitic leakage channels at the re-growth junction. This phenomenon results in leaked HEMTs that prove difficult to switch off, rendering them effectively non-functional. The emergence of leakage channels can also degrade the high-frequency properties and lower the power devices' breakdown voltage. In this study, the uniform epitaxy of AlGaN/GaN heterojunction with high electron mobility was accomplished through the surface treatment of the GaN substrates prior to growth and the design of the AlN isolation layer structure. By employing a procedure combining gallium atom in-situ cleaning and plasma nitridation, the C and O impurity concentrations at the homoepitaxial interface were diminished to the scale of 10¹⁷ cm-³. Additionally, the 1.5 nm nitrogen-rich AlN isolation layer successfully prevented the diffusion of Si impurities into the GaN channel layer. The result was an AlGaN/GaN heterojunction with an electron mobility of 1552 cm²/Vs and an electron density of 1.1 × 10¹³ cm-² at room temperature, obtained on a Fe-doped semi-insulating GaN substrate.

Keywords: MBE, AlGaN/GaN, homogenerous epitaxy, HEMT

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Authors: Hassan M. Al-Ahmadi

Abstract:

The fatality index (deaths/100 K population) due to road traffic accidents in the Kingdom of Saudi Arabia (KSA) is over 25, according to the World Health Organization Statistics (WHO) statistics, which is much higher than in the neighboring Arab regions. The KSA has implemented measures to mitigate traffic accidents by enforcing road safety regulations. As a result, there has been a slight decline in the frequency of road traffic accidents within the Kingdom. This study was based on the variations in the accidents for three provinces of KSA, i.e., Riyadh, Eastern Province (EP), & Qaseem, for 2016 and 2017 using ANOVA method. Data appropriateness for the ANOVA method was confirmed by the normality and the randomness of residuals. Additionally, the half-normal plot was used to identify the significant terms for the ANOVA analysis. The analysis revealed that the accidents in the EP were significantly higher than in the other two provinces during the analysis period. The monthly variation showed a spike in the accidents from month 7th to 9th month in the EP region and a slight drop in the accidents in the Qaseem and the Riyadh region during the same period, which was attributed to the increased leisure travels from the other regions to the EP. Furthermore, most of the accidents were found to occur in the age group of 18+ and 30+, and also the major reduction of accidents in 2017 as compared to 2016 was found to have occurred in the same group. These findings can be beneficial for developing strategies to further reduce the number of accidents.

Keywords: fatality index, emergency, road traffic accident, safety, leisure travels

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Authors: Khalifa Abdunaser, Salem Eljawashi

Abstract:

Study area is threatened by numerous petroleum activities. The most important risk is associated with dramatic dangers of misuse and oil and gas pollutions, such as significant volumes of produced water, which refers to waste water generated during the production of oil and natural gas and disposed on the surface surrounded oil and gas fields. This work concerns the impact of oil exploration and production activities on the physical and environment fate of the area, focusing on the investigation and observation of crude oil migration as toxic fluid. Its penetration in groundwater resulted from the produced water impacted by oilfield operations disposed to the earth surface in Al Wahat area. Describing the areal distribution of the dominant groundwater quality constituents has been conducted to identify the major hydro-geochemical processes that affect the quality of water and to evaluate the relations between rock types and groundwater flow to the quality and geochemistry of water in Post-Eocene aquifer. The chemical and physical characteristics of produced water, where it is produced, and its potential impacts on the environment and on oil and gas operations have been discussed. Field work survey was conducted to identify and locate a large number of monitoring wells previously drilled throughout the study area. Groundwater samples were systematically collected in order to detect the fate of spills resulting from the various activities at the oil fields in the study area. Spatial distribution maps of the water quality parameters were built using Kriging methods of interpolation in ArcMap software. Thematic maps were generated using GIS and remote sensing techniques, which were applied to include all these data layers as an active database for the area for the purpose of identifying hot spots and prioritizing locations based on their environmental conditions as well as for monitoring plans.

Keywords: Sirt Basin, produced water, Al Wahat area, Ground water

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Authors: Robert P. Dufresne, Hamid Arabzadeh

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The current study investigates the effectiveness of a new form of permanent baseboard insulators with an umbrella action, hereinafter referred to as Coronary Insulator, in supporting and protecting the assembly of electrodes immersed in an electrolytic cell and in increasing the lifespan of the lateral sides of the electrolytic cell, in both electro-winning and electro-refinery method. The advantages of using a coronary insulator in addition to the top capping board (equipotential insulator) were studied compared to the conventional assembly of an electrolytic cell. Then, a thermal imaging technique was utilized during high-temperature thermal (heat transfer) tests for sample cell walls with and without coronary insulators in their assembly to show the effectiveness of coronary insulators in protecting the cell wall under extreme conditions. It was shown that, unlike the conventional assembly, which is highly prone to damages to the cell wall under thermal shocks, the presence of coronary insulator can significantly increase the level of protection of the cell due to their ultra-high thermal and chemical resistance, as well as decreasing the replacement frequency of insulators to almost zero. Besides, the results of the study showed that the test assembly with the coronary insulator provides better consistency in positioning and, subsequently, better contact, compared to the conventional method, which reduces the chance of electric short-circuit in the system.

Keywords: capping board, coronary insulator, electrolytic cell, thermal shock.

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Authors: Rasheed F. G., Hassan H. A., Shehu F. A., Mukhtar M. M., Muhammad Y. Y., Ibrahim S. S., Shehu D., Abdulsalam K., N. Abdullahi

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A cross sectional randomized, descriptive cross sectional study was conducted on the frequency of GSTT1 null alleles in patients diagnosed with type-2-diabetes mellitus (T2DM). A total of 40 patients with T2DM and 10 non-diabetic controls were included in the study. GSTT1 null-alleles genotyping was carried out using multiplex PCR amplification to amplify GSTT1 gene (460bp) while using β-globulin (250bp) as an internal control. The results showed that 55% of T2DM patients had BMI within reference limits, 13% are overweight. Additionally, patients with T2DM were found to have significantly higher (p<0.05) serum levels of glucose, total cholesterol, triglyceride and low density lipoprotein. Furthermore, the presence of null genotype of GSTT1 (deletion in GSTT1) was observed in 28% of diabetic patients. Subjects with GSTT1 deletion have significantly higher (p<0.05) levels of serum glucose, low-density lipoprotein and total cholesterol when compared with individuals without deletion (diabetic and non-diabetic). This results suggests that the deletion of GSTT1 gene might serve as a predisposing factor in the development of T2DM and dyslipideamia

Keywords: diabetes, glutathione-S-transferase, lipid profile, PCR, polymorphism.

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Authors: O. Hakim, K. Hart, P. McCabe, J. Berry, L. E. Rhodes, N. Spyrou, A. Alfuraih, S. Lanham-New

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It is known that skin pigmentation reduces the penetration of ultraviolet radiation (UVR) and thus photosynthesis of 25(OH)D. However, the ethnic differences in 25(OH)D production remain to be fully elucidated. This study aimed to investigate the differences in vitamin D production between Asian and Caucasian postmenopausal women, in response to a defined, controlled UVB exposure. Seventeen women; nine white Caucasian (skin phototype II and III), eight South Asian women (skin phototype IV and V) participated in the study, acting as their controls. Three blood samples were taken for measurement of 25(OH)D during the run-in period (nine days, no sunbed exposure) after which all subjects underwent an identical UVR exposure protocol irrespective of skin colour (nine days, three sunbed sessions: 6, 8 and 8 minutes respectively with approximately 80% of body surface exposed). Skin tone was measured four times during the study. Both groups showed a gradual increase in 25(OH)D with final levels significantly higher than baseline (p<0.01). 25(OH)D concentration mean from a baseline of 43.58±19.65 to 57.80±17.11 nmol/l among Caucasian and from 27.03±23.92 to 44.73±17.74 nmol/l among Asian women. The baseline status of vitamin D was classified as deficient among the Asian women and insufficient among the Caucasian women. The percentage increase in vitamin D3 among Caucasians was 39.86% (21.02) and 207.78% (286.02) in Asian subjects respectively. This greater response to UVR exposure reflects the lower baseline levels of the Asian subjects. The mixed linear model analysis identified a significant effect of duration of UVR exposure on the production of 25(OH)D. However, the model shows no significant effect of ethnicity and skin tone on the production of 25(OH)D. These novel findings indicate that people of Asian ethnicity have the full capability to produce a similar amount of vitamin D compared to the Caucasian group; initial vitamin D concentration influences the amount of UVB needed to reach equal serum concentrations.

Keywords: ethnicity, Caucasian, South Asian, vitamin D, ultraviolet radiation, UVR

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Authors: Nasir Ashraf, Sajid Rahid Ahmad, Adeel Ahmad

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Pakistan is a major tea consumer country and ranked as the third largest importer of tea worldwide. Out of all beverage consumed in Pakistan, tea is the one with most demand for which tea import is inevitable. Being an agrarian country, Pakistan should cultivate its own tea and save the millions of dollars cost from tea import. So the need is to identify the most suitable areas with favorable weather condition and suitable soils where tea can be planted. This research is conducted over District Mansehra and District Abbottabad in Khyber Pakhtoonkhwah Province of Pakistan where the most favorable conditions for tea cultivation already exist and National Tea Research Institute has done successful experiments to cultivate high quality tea. High tech approach is adopted to meet the objectives of this research by using the remotely sensed data i.e. Aster DEM, Landsat8 Imagery. The Remote Sensing data was processed in Erdas Imagine, Envi and further analyzed in ESRI ArcGIS spatial analyst for final results and representation of result data in map layouts. Integration of remote sensing data with GIS provided the perfect suitability analysis. The results showed that out of all study area, 13.4% area is highly suitable while 33.44% area is suitable for tea plantation. The result of this research is an impressive GIS based outcome and structured format of data for the agriculture planners and Tea growers. Identification of suitable tea growing areas by using remotely sensed data and GIS techniques is a pressing need for the country. Analysis of this research lets the planners to address variety of action plans in an economical and scientific manner which can lead tea production in Pakistan to meet demand. This geomatics based model and approach may be used to identify more areas for tea cultivation to meet our demand which we can reduce by planting our own tea, and our country can be independent in tea production.

Keywords: agrarian country, GIS, geoinformatics, suitability analysis, remote sensing

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Authors: Siddiq Mohammed

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This study sought to identify the perceived difficult concepts in the new mathematics curriculum by senior secondary school students and mathematics teachers in Kwara State. The study involved a survey research type. Random sampling technique was used to select the 32 sampled schools, 469 students, and 103 teachers. The instrument used in data collection was a research-designed questionnaire tagged 'Perceived Difficult Concepts in Mathematics' (PDCM) was validated by two experts in mathematics education. The test-retest reliability index of 0.69 was obtained. Data analysis was carried out using frequency count percentages and chi-square. The result of the study showed that eight topics were identified as difficult to teach by the teachers, while 14 topics were also identified as difficult to learn by the students. This study also revealed that there was no significant difference in the topics perceived as difficult between the teachers teaching in the school located in urban and rural area. However, there was a significant difference in the perceived difficult topics between student schooling in the schools located in urban and rural area. It was therefore recommended among others that mathematics teachers should undergo training on how to concretize the abstractness of some of the topics especially the new ones as well as use appropriate teaching aid to facilitate teaching/learning of the difficult concepts. It was also recommended that there is a need for evenly development of human and materials among the schools in urban and rural areas.

Keywords: curriculum, difficult concepts, mathematics, perceived

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Authors: Evan Hajani, Ataur Rahman, Khaled Haddad

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Climate change will affect the hydrological cycle in many different ways such as increase in evaporation and rainfalls. There have been growing interests among researchers to identify the nature of trends in historical rainfall data in many different parts of the world. This paper examines the trends in annual maximum rainfall data from 30 stations in New South Wales, Australia by using two non-parametric tests, Mann-Kendall (MK) and Spearman’s Rho (SR). Rainfall data were analyzed for fifteen different durations ranging from 6 min to 3 days. It is found that the sub-hourly durations (6, 12, 18, 24, 30, and 48 minutes) show statistically significant positive (upward) trends whereas longer duration (sub-daily and daily) events generally show a statistically significant negative (downward) trend. It is also found that the MK test and SR test provide notably different results for some rainfall event durations considered in this study. Since shorter duration sub-hourly rainfall events show positive trends at many stations, the design rainfall data based on stationary frequency analysis for these durations need to be adjusted to account for the impact of climate change. These shorter durations are more relevant to many urban development projects based on smaller catchments having a much shorter response time.

Keywords: climate change, Mann-Kendall test, Spearman’s Rho test, trends, design rainfall

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Authors: Arowosafe Folusade Catherine, Arowosafe Olubunmi, Aina Samson

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In many countries, tourism has been portrayed as a contributor to small-scale enterprises, contributing to improved standards of living, a catalyst for community development, and poverty alleviation. This study assessed the willingness of the host communities to provide homestay accommodation and also identified the homestay facilities available to host visitors to the community. A random sampling method was used to administer 150 copies of the questionnaire to the residents in Idanre. Data collected were subjected to descriptive and inferential statistical analysis, and results were presented using frequency and percentage tables. Results: Findings revealed that the majority of the residents were above 60 years (47.3%), with 33% of them aware of the concept of homestay accommodation, and 32% had primary education. The majority were self-employed (43.3%), earning less than ₦30,000 per month; it also revealed that 80.7% of the residents owned at least one house and had adequate water supply facility (100%) and electricity (99.3%). Some constraints observed revealed that safety for the host family (mean 4.81) was ranked high as a possible deterrent to providing homestay accommodation to strangers. Results revealed a correlation between the resident’s awareness and willingness to provide homestay accommodation services (r.0.05, p<0.05). This study recommends that sensitization programs to create awareness of the potential benefits of homestay accommodation in the host communities of Idanre Hills should be carried out by the relevant stakeholders.

Keywords: accommodation, benefits, homestay, Idanre Hills

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