Search results for: bar model method

Authors: Pei-Chen Wu

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Both preexisting cross-sectional and longitudinal studies of personality-depression relationship have suffered from one main limitation: they ignored the stability of the construct of interest (e.g., personality and depression) can be expected to influence the estimate of the association between personality and depression. To address this limitation, the Trait-State-Occasion (TSO) modeling was adopted to analyze the sources of variance of the focused constructs. A TSO modeling was operated by partitioning a state variance into time-invariant (trait) and time-variant (occasion) components. Within a TSO framework, it is possible to predict change on the part of construct that really changes (i.e., time-variant variance), when controlling the trait variances. 750 high school students were followed for 4 waves over six-month intervals. The baseline data (T1) were collected from the senior high schools (aged 14 to 15 years). Participants were given Beck Depression Inventory and Big Five Inventory at each assessment. TSO modeling revealed that 70~78% of the variance in personality (five constructs) was stable over follow-up period; however, 57~61% of the variance in depression was stable. For personality construct, there were 7.6% to 8.4% of the total variance from the autoregressive occasion factors; for depression construct there were 15.2% to 18.1% of the total variance from the autoregressive occasion factors. Additionally, results showed that when controlling initial symptom severity, the time-invariant components of all five dimensions of personality were predictive of change in depression (Extraversion: B= .32, Openness: B = -.21, Agreeableness: B = -.27, Conscientious: B = -.36, Neuroticism: B = .39). Because five dimensions of personality shared some variance, the models in which all five dimensions of personality were simultaneous to predict change in depression were investigated. The time-invariant components of five dimensions were still significant predictors for change in depression (Extraversion: B = .30, Openness: B = -.24, Agreeableness: B = -.28, Conscientious: B = -.35, Neuroticism: B = .42). In sum, the majority of the variability of personality was stable over 2 years. Individuals with the greater tendency of Extraversion and Neuroticism have higher degrees of depression; individuals with the greater tendency of Openness, Agreeableness and Conscientious have lower degrees of depression.

Keywords: assessment, depression, personality, trait-state-occasion model

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Authors: Masoumeh Khailghi Sikaroudi, Mohsen Masoodi, Fazad Shidfar, Meghdad Sedaghat

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Background: The hypertonicity of internal anal sphincter resting pressure is one of the main reasons for chronic anal fissures. The aim of this study is to assess the effect of oral administration of L-arginine on anal fissure symptom improvement by relaxation of the internal anal sphincter. Method: Seventy-six chronic anal fissure patients (age: 18-65 years) took part in this randomized, double-blind, placebo-controlled trial study from February 2019 to October 2020 at Rasoul-e-Akram Hospital, Tehran, Iran. Participants were allocated into treatment (L-arginine) or placebo groups. They took a 1000 mg capsule three times a day for one month and were followed up at the end of the first and third months after receiving the intervention. Clinical symptoms, anal sphincter resting pressure, and quality of life (QoL) were completed at baseline and the end of the study. Result: The analysis of data was shown significant improvement in bleeding, fissure size, and pain within each group; however, this effect was more seen in the arginine group compared to the control group at the end of the study (P-values<0.001). Following that, a significant increase in QoL was seen just in patients who were treated with arginine (P-value=0.006). Also, the comparison of anal pressures to baseline and between groups at the end of the study showed a significant reduction in sphincter pressure in treated patients (P-value<0.001, =0.049; respectively). Conclusion: Oral administration of 3000 mg L-arginine can heal chronic anal fissures by reducing anal internal sphincter pressure with fewer side effects. However, a long-term study with more follow-up is recommended.

Keywords: L-arginine, anal fissure, sphincter pressure, clinical symptoms, quality of life

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Authors: Rahmat Ali, Inamullah Khan, Amjad Naseer, Abid A. Shah

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Hydronic Heating and Cooling systems in concrete slab based buildings are increasingly becoming a popular substitute to conventional heating and cooling systems. In exploring the materials, techniques employed, and their relative performance measures, a fair bit of uncertainty exists. This research has identified the simplest method of determining the thermal field of a single hydronic pipe when acting as a part of a concrete slab, based on which the spacing and positioning of pipes for a best thermal performance and surface temperature control are determined. The pipe material chosen is the commonly used PEX pipe, which has an all-around performance and thermal characteristics with a thermal conductivity of 0.5W/mK. Concrete Test samples were constructed and their thermal fields tested under varying input conditions. Temperature sensing devices were embedded into the wet concrete at fixed distances from the pipe and other touch sensing temperature devices were employed for determining the extent of the thermal field and validation studies. In the first stage, it was found that the temperature along a specific distance was the same and that heat dissipation occurred in well-defined layers. The temperature obtained in concrete was then related to the different control parameters including water supply temperature. From the results, the temperature of water required for a specific temperature rise in concrete is determined. The thermally effective area is also determined which is then used to calculate the pipe spacing and positioning for the desired level of thermal comfort.

Keywords: thermally activated building systems, concrete slab temperature, thermal field, energy efficiency, thermal comfort, pipe spacing

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Authors: Yao Jiajia, Wu Guanlin, LIU Fang, Xue Junshuai, Zhang Jincheng, Hao Yue

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Resonant tunneling diodes (RTDs) based on GaN have been extensively studied. However, no results of multiple logic states achieved by RTDs were reported by the methods of epitaxy in the GaN materials. In this paper, the multiple negative-differential resistance regions by combining two discrete double-barrier RTDs in series have been first demonstrated. Plasma-assisted molecular beam epitaxy (PA-MBE) was used to grow structures consisting of two vertical RTDs. The substrate was a GaN-on-sapphire template. Each resonant tunneling structure was composed of a double barrier of AlN and a single well of GaN with undoped 4-nm space layers of GaN on each side. The AlN barriers were 1.5 nm thick, and the GaN well was 2 nm thick. The resonant tunneling structures were separated from each other by 30-nm thick n+ GaN layers. The bottom and top layers of the structures, grown neighboring to the spacer layers that consist of 200-nm-thick n+ GaN. These devices with two tunneling structures exhibited uniform peaks and valleys current and also had two negative differential resistance NDR regions equally spaced in bias voltage. The current-voltage (I-V) characteristics of resonant tunneling structures with diameters of 1 and 2 μm were analyzed in this study. These structures exhibit three stable operating points, which are investigated in detail. This research demonstrates that using molecular beam epitaxy MBE to vertically grow multiple resonant tunneling structures is a promising method for achieving multiple negative differential resistance regions and stable logic states. These findings have significant implications for the development of digital circuits capable of multi-value logic, which can be achieved with a small number of devices.

Keywords: GaN, AlN, RTDs, MBE, logic state

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Authors: Ali Akbar Jabbari

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The present study assessed the acquisition of L3 French direct objects by Persian speakers who had already learned English as their L2. The ultimate goal of this paper is to extend the current knowledge about the CLI phenomenon in the realm of third language acquisition by examining the role of Persian and English as background languages and learners’ English level of proficiency in their performance on French direct object. To fulfill this, the assumptions of three L3 hypotheses, namely L1 Transfer, L2 Status Factor, and Cumulative Enhancement Model, were examined. The research sample was comprised of 40 undergraduate students in the fields of English language and literature and translation studies at Birjand University in Iran. According to the English proficiency level of learners revealed by the Quick Oxford English Placement test, the participants were grouped as upper intermediate and lower intermediate. A grammaticality judgment and a translation test were administered to gather the required data on learners' comprehension and production of the desired structure in French. It was demonstrated that the rate of positive transfer from previously learned languages was more potent than the rate of negative transfer. A Comparison of groups' performances revealed a significant difference between upper and lower intermediate groups in positing French direct objects correctly. However, the upper intermediate group did not significantly differ from the lower intermediate group in negative transfer. It can be said that by increasing the L2 proficiency of the learners, they could use their previous linguistic knowledge more efficiently. Although further examinations are needed, the current study contributed to a better characterization of cross-linguistic influence in third language acquisition. The findings help French teachers and learners to positively exploit the prior knowledge of Persian and English and apply it in in the multilingual context of French direct object's teaching and learning process.

Keywords: Cross-Linguistic Influence, Persian, French & English Direct Object, Third Language Acquisition, Language Transfer

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Authors: Adel M. Al-Shutairi, Ahmed H. Al-Zahrani

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Tea is a popular beverage drunk by millions of people throughout the globe. Tea has considerable health advantages, in-cluding antioxidant, antibacterial, antiviral, chemopreventive, and anticarcinogenic properties. As a result of environmental pollution (atmospheric deposition) and the production process, tealeaves may also include a variety of dangerous substances, such as polycyclic aromatic hydrocarbons (PAHs). In this study, graphene oxide reinforced chitosan/poly-nitroaniline polymer was prepared to develop a sensitive and reliable solid phase extraction method (SPE) for extraction of PAH7 in tea samples, followed by high-performance liquid chromatography- fluorescence detection. The prepared adsorbent was validated in terms of linearity, the limit of detection, the limit of quantification, recovery (%), accuracy (%), and precision (%) for the determination of the PAH7 (benzo[a]pyrene, benzo[a]anthracene, benzo[b]fluoranthene, chrysene, benzo[b]fluoranthene, Dibenzo[a,h]anthracene and Benzo[g,h,i]perylene) in tea samples. The concentration was determined in two types of tea commercially available in Saudi Arabia, including black tea and green tea. The maximum mean of Σ7PAHs in black tea samples was 68.23 ± 0.02 ug kg-1 and 26.68 ± 0.01 ug kg-1 in green tea samples. The minimum mean of Σ7PAHs in black tea samples was 37.93 ± 0.01 ug kg-1 and 15.26 ± 0.01 ug kg-1 in green tea samples. The mean value of benzo[a]pyrene in black tea samples ranged from 6.85 to 12.17 ug kg-1, where two samples exceeded the standard level (10 ug kg-1) established by the European Union (UE), while in green tea ranged from 1.78 to 2.81 ug kg-1. Low levels of Σ7PAHs in green tea samples were detected in comparison with black tea samples.

Keywords: polycyclic aromatic hydrocarbons, CS, PNA and GO, black/green tea, solid phase extraction, Saudi Arabia

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Authors: Ghadeer Jalloul, Nour Hijazi, Cassia Boyadjian, Hussein Awala, Mohammad N. Ahmad, ‎Ahmad Albadarin

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In this study, we applied Fe-sensitized TiO₂ supported over embryonic Beta zeolite (BEA) zeolite ‎for the photocatalytic degradation of Tetracycline (TC) antibiotic under visible light. Four different ‎samples having 20, 40, 60, and 100% w/w as a ratio of TiO₂/BEA were prepared. The ‎immobilization of solgel TiO₂ (33 m²/g) over BEA (390 m²/g) increased its surface area to (227 ‎m²/g) and enhanced its adsorption capacity from 8% to 19%. To expand the activity of TiO₂ ‎photocatalyst towards the visible light region (λ>380 nm), we explored two different metal ‎sensitization techniques with Iron ions (Fe³⁺). In the ion-exchange method, the substitutional cations ‎in the zeolite in TiO₂/BEA were exchanged with (Fe³⁺) in an aqueous solution of FeCl₃. In the ‎doping technique, solgel TiO₂ was doped with (Fe³⁺) from FeCl₃ precursor during its synthesis and ‎before its immobilization over BEA. (Fe-TiO₂/BEA) catalysts were characterized using SEM, XRD, ‎BET, UV-VIS DRS, and FTIR. After testing the performance of the various ion-exchanged catalysts ‎under blue and white lights, only (Fe-TiO₂/BEA 60%) showed better activity as compared to pure ‎TiO₂ under white light with 100 ppm initial catalyst concentration and 20 ppm TC concentration. As ‎compared to ion-exchanged (Fe-TiO₂/BEA), doped (Fe-TiO₂/BEA) resulted in higher photocatalytic ‎efficiencies under blue and white lights. The 3%-Fe-doped TiO₂/BEA removed 92% of TC ‎compared to 54% by TiO₂ under white light. The catalysts were also tested under real solar ‎irradiations. This improvement in the photocatalytic performance of TiO₂ was due to its higher ‎adsorption capacity due to BEA support combined with the presence of Iron ions that enhance the ‎visible light absorption and minimize the recombination effect by the charge carriers. ‎

Keywords: Tetracycline, photocatalytic degradation, immobilized TiO₂, zeolite, iron-doped TiO₂, ion-exchange

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Authors: Tri Nopiyanto, Rahardhyani Dwiannisa, Arief Ismaryanto

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One main issue for a certain region in order to achieve development is if the government that consists of the executive, legislative and judicial board are able to work together. However, there are certain conditions that these boards are the sources of conflict, especially between the executive and legislative board. One of the example of the conflict is between the Local Government and Legislative Board (DPRD) in the Province of Jakarta in 2015. The cause of this conflict is because of the occurrence of pokir (pokok pikiran or ideas of budgeting). Pokir is driven by a budgeting plan that is arranged by DPRD that is supposed to be sourced from the aspiration of the people and delivered 5 months before the legalization of Local Government Budget (APBD), but the current condition in Jakarta is that pokir is a project by DPRD members itself and delivered just 3 days before the legalization in order to facilitate the interests of the members of the legislative. This paper discusses how pokir happens and what factors caused it. This paper uses political budgeting theory by Andy Norton and Diane Elson to analyze the issue. The method used in this paper is qualitative to collect the data and solve the problem of this research. The methods involved are in depth interview, experimental questionnaire, and literature studies. Results of this research are that Pokir occurs because of the distribution of power among DPRD members, between parties, executive, and legislative board. Beside that, Pokir also occurs because of the lack of the people’s participation in budgeting process and monitoring. Other than that, this paper also found that pokir also happens because of the budgeting system that is not able to provide a clean budgeting process, so it enables the creation of certain slots to add pokir into the budgets. Pokir also affects the development of Jakarta that goes through stagnation. This research recommends the implementation of e-budgeting to prevent the occurrence of pokir itself in the Province of Jakarta.

Keywords: legislative and executive board, Jakarta, political budgeting, Pokir

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Authors: Nuo Xu, Sijing Chen

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Background: Childbirth is considered a critical traumatic event throughout our lives, positively or negatively impacting the mother's physiology, psychology, and even the whole family. Adverse birth experiences, such as labor pain, anxiety, and fear can negatively impact the mother. Studies had shown that the immersive nature of VR can distract attention from pain and increase focus on interventions for pain relief. However, the existing studies that applied VR to maternal delivery were still in their infancy and showed disparate results, and the small sample size is not representative, so this review analyzed the effects of VR in labor, such as on maternal pain and anxiety, with a view to providing a basis for future applications. Search strategy: We searched Pubmed, Embase, Web of Science, the Cochrane Library, CINAHL, China National Knowledge Infrastructure, Wan-Fang database from the building to November 17, 2021. Selection Criteria: Randomized controlled trials (RCTs) that intervened the pregnant women aged 18-35 years with gestational >34 weeks and without complications with VR technology were contained within this review. Data Collection and Analysis: Two researchers completed the study selection, data extraction, and assessment of study quality. For quantitative data we used MD or SMD, and RR (risk ratio) for qualitative data. Random-effects model and 95% confidence interval (95% CI) were used. Main Results: 12 studies were included. Using VR could relieve pain during labor (MD=-1.81, 95% CI (-2.04, -1.57), P< 0.00001) and active period (SMD=-0.41, 95% CI (-0.68, -0.14), P= 0.003), reduce anxiety (SMD=-1.39, 95% CI (-1.99, -0.78), P< 0.00001) and improve satisfaction (RR = 1.32; 95% CI (1.10, 1.59); P = 0.003), but the effect on the duration of first (SMD=-1.12, 95% CI (-2.38, 0.13), P=0.08) and second (SMD=-0.22, 95% CI (-0.67, 0.24), P=0.35) stage of labor was not statistically significant. Conclusions: Compared with conventional care, VR technology can relieve labor pain and anxiety and improve satisfaction. However, extensive experimental validation is still needed.

Keywords: virtual reality, delivery, labor pain, anxiety, meta-analysis, systematic review

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Authors: S. Pushkar, O. Verbitsky

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Currently, green rating systems are mainly utilized for correctly sizing mechanical and electrical systems, which have short lifetime expectancies. In these systems, passive solar and bio-climatic architecture, which have long lifetime expectancies, are neglected. Urban rating systems consider buildings and services in addition to neighborhoods and public transportation as integral parts of the built environment. The main goal of this study was to develop a more consistent point allocation system for urban building standards by using six different lifetime shearing layers: Site, Structure, Skin, Services, Space, and Stuff, each reflecting distinct environmental damages. This shearing-layer concept was applied to internationally well-known rating systems: Leadership in Energy and Environmental Design (LEED) for Neighborhood Development, BRE Environmental Assessment Method (BREEAM) for Communities, and Comprehensive Assessment System for Building Environmental Efficiency (CASBEE) for Urban Development. The results showed that LEED for Neighborhood Development and BREEAM for Communities focused on long-lifetime-expectancy building designs, whereas CASBEE for Urban Development gave equal importance to the Building and Service Layers. Moreover, although this rating system was applied using a building-scale assessment, “Urban Area + Buildings” focuses on a short-lifetime-expectancy system design, neglecting to improve the architectural design by considering bio-climatic and passive solar aspects.

Keywords: green rating system, urban community, sustainable design, standardization, shearing-layer concept, passive solar architecture

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Authors: Aikaterini Tavoulari

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This research aims to address the types of repetitive behaviours (RBs) observed by adults in children with vision impairment (VI) or autism spectrum disorder (ASD), the explanations the adults employ to interpret these behaviours, and the impact RBs have on the child, the caregiver, the professional and society. The underlying reason for this is an attempt to discover any potential differences between two different disabilities in a comparative fashion. The study is based on the interpretivism paradigm and follows a qualitative approach. A comparative case study design based on the ecological systems theory (EST) is adopted. Thirty-five caregivers and accredited professionals were recruited (17 for the VI group, out of whom 8 were caregivers and 9 were professionals, and 18 for the ASD group, out of whom 9 were caregivers and 9 were professionals). Following the completion of a pilot study, all participants were interviewed regarding one specific child – their own child/student – via semi-structured interviews. During the interviews, the researcher used a research diary as a methodological tool and video elicitation as a facilitation tool. A cross-case analysis was conducted, and data were analysed according to the method of thematic analysis. A link has been indicated between VI and ASD, which concerns perceptions about the socially constructed manner in which an RB is perceived. ASD is perceived by the participants as a disability with challenging characteristics, such as an RB. The ASD group perceived RB as linked to ableism, social stigmatisation, and taboo, in contrast to VI, where the existence of RB seems to be a consequence of sensory loss. Bi-directionality of EST seems to have been lost completely, and the macrosystem seems to drive the interactions between the ecological systems.

Keywords: ableism, social stigma, disability, repetitive behaviour, vision impairment, autism spectrum disorder, perceptions

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Authors: Yajun Qiao, Yaner Yan, Ning Li, Shuqing An

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In order to relieve the pressure on a land resource from a huge population, reclamation has occurred in many coastal wetlands. Plants can maintain their elemental composition within normal limits despite the variations of external conditions. Reclamation may affect carbon (C), nitrogen (N) and phosphorus (P) stoichiometry in the plant to some extent by altering physical and chemical properties of soil in a coastal wetland. We reported the seasonal dynamic of C, N and P stoichiometry in root, stem and leaf of Suaeda salsa (L.) Pall. and in soil between reclamation plots and natural plots. Our results of three-way ANOVA indicated that sampling season always had significant effect on C, N, P concentrations and their ratios; organ had no significant effect on N, P concentration and N:P; plot type had no significant effect on N concentration and C:N. Sampling season explained the most variability of tissue N and P contents, C:N, C:P and N:P, while it’s organ for C using the restricted maximum likelihood (REML) method. By independent sample T-test, we found that reclamation affect more on C, N and P stoichiometry of stem than that of root or leaf on the whole. While there was no difference between reclamation plots and natural plots for soil in four seasons. For three organs, C concentration had peak values in autumn and minimum values in spring while N concentration had peak values in spring and minimum values in autumn. For P concentration, three organs all had peak values in spring; however, the root had minimum value in winter, the stem had that in autumn, and leaf had that in summer. The seasonal dynamic of C, N and P stoichiometry in a leaf of Suaeda salsa were much steadier than that in root or stem under the drive of reclamation.

Keywords: nitrogen, phosphorus, reclamation, seasonal dynamic, Suaeda salsa

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Authors: Zahra khaksari, Mahboobeh Mehrabi

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One of the biggest health problems in communities, suicide is now one of the top ten causes of death in the world. This study aimed to investigate the risk factors of suicide attempt in Minab city over two years. This was a descriptive and cross-sectional study. Subjects of this study were cases who admitted in Hazrat Abolfazl hospital of minab city over two years Since the beginning of 1389 to end of 1390. During this period,their cases were reviewed. To analyze data, descriptive statistics was applied. During this two-year period, 275 patients who had attempted suicide, of which 65 percent are female and most of them were 15-24 years. 60% of them were single and 70 % of rural areas. 51% of suicides in 1390 and most of the suicide attempts occurred at a rate of 37 percent in summer. and the most common way of attempting suicide was medication poisoning (74%). The suicide rate leading to death was 1.5% The chi-square test showes that there were significant relationship between suicide by gender and residence status. This means that more women are committing suicide of rural areas.based on The chi-square test there were significant relation between the gender and method, gender and the result of suicide and means that more women than men commit suicide with the use of drugs. Males were more successful suicide. who had attempted with organophosphates and hanging were more successful in suicide. The finding of the current study showed that most of the suicide victims were female ,rural deweller,14-24 years old,single, serious attention must be paid to the problems of this group. It also extends the field of education professionals and health centers, and psychological therapy that focuses specifically on this topic.

Keywords: attempt to suicide, minab, risk factors, suicide

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Authors: Mahani Razali, Nordin Mamat

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The purpose of the study is to explore how computer technology is integrated into pre-school activities and its relationship with children’s social interaction behaviour in pre-school classroom. The major question of interest in the present study is to investigate the social interaction behaviour of children when using computers in the Malaysian pre-school classroom. This research is based on three main objectives which are to identify children`s social interaction during computer play activities, teacher’s role and parent’s participation to develop children`s social interaction. This qualitative study was carried out among 25 pre-school children, three teachers and three parents as the research sample. On the other hand, parent’s support was obtained from their discussions, supervisions and communication at home. The data collection procedures involved structured observation which was to identify social interaction behaviour among pre-school children through computer play activities; as for semi-structured interviews, it was done to study the perception of the teachers and parents on the acquired social interaction behaviour among the children. Besides, documentation analysis method was used as to triangulate acquired information with observations and interviews. In this study, the qualitative data analysis was tabulated in descriptive manner with frequency and percentage format. This study primarily focused on social interaction behaviour elements among the pre-school children. Findings revealed that the children showed positive outcomes on the social interaction behaviour during their computer play. This research summarizes that teacher’s role and parent’s support can improve children`s social interaction behaviour through computer play activities. As a whole, this research highlighted the significance of computer play activities as to stimulate social interaction behavior among the pre-school children.

Keywords: early childhood, emotional development, parent support, play

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Authors: Jelena Vucicevic

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Reliability analysis represents a very important task in different areas of work. In any industry, this is crucial for maintenance, efficiency, safety and monetary costs. There are ways to calculate reliability, unreliability, failure density and failure rate. In this paper, the results for the reliability of diesel generator fans were calculated through Extreme Value Theory. The Extreme Value Theory is not widely used in the engineering field. Its usage is well known in other areas such as hydrology, meteorology, finance. The significance of this theory is in the fact that unlike the other statistical methods it is focused on rare and extreme values, and not on average. It should be noted that this theory is not designed exclusively for extreme events, but for extreme values in any event. Therefore, this is a great opportunity to apply the theory and test if it could be applied in this situation. The significance of the work is the calculation of time to failure or reliability in a new way, using statistic. Another advantage of this calculation is that there is no need for technical details and it can be implemented in any part for which we need to know the time to fail in order to have appropriate maintenance, but also to maximize usage and minimize costs. In this case, calculations have been made on diesel generator fans but the same principle can be applied to any other part. The data for this paper came from a field engineering study of the time to failure of diesel generator fans. The ultimate goal was to decide whether or not to replace the working fans with a higher quality fan to prevent future failures. The results achieved in this method will show the approximation of time for which the fans will work as they should, and the percentage of probability of fans working more than certain estimated time. Extreme Value Theory can be applied not only for rare and extreme events, but for any event that has values which we can consider as extreme.

Keywords: extreme value theory, lifetime, reliability analysis, statistic, time to failure

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Authors: Samantha Meyr, Eman Mirdamadi, Martha Wang, Tao Lowe, Ryan Smith, Quinn Burke

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Critical-sized bone defects (CSD) treatment options remain a major clinical orthopedic challenge. They are uniquely contoured diseased or damaged bones and can be defined as those that will not heal spontaneously and require surgical intervention. Autografts are the current gold standard CSD treatment, which are histocompatible and provoke a minimal immunogenic response; however, they can cause donor site morbidity and will not suffice for the size required for replacement. As an alternative to traditional surgical methods, bone tissue engineering will be implemented via 3D printing methods. A freeze-dried bone matrix (FDBM) is a type of graft material available but will only function as desired when in the presence of bone growth factors. Polycaprolactone (PCL) is a known biodegradable material with good biocompatibility that has been proven manageable in 3D printing as a medical device. A 3D-extrusion printing strategy is introduced to print these materials into scaffolds for bone grafting purposes, which could be more accessible and rapid than the current standard. Mechanical, thermal, cytotoxic, and physical properties were investigated throughout a degradation period of 6 months using fibroblasts and dental pulp stem cells. PCL-FDBM scaffolds were successfully printed with high print fidelity in their respective pore sizes and allograft content. Additionally, we have created a method for evaluating PCL using differential scanning calorimetry (DSC) and have evaluated PCL degradation over roughly 6 months.

Keywords: 3D printing, bone tissue engineering, cytotoxicity, degradation, scaffolds

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Authors: Gorazd Karer

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When performing a diagnostic procedure or surgery in general anesthesia (GA), a proper introduction and dosing of anesthetic agents are one of the main tasks of the anesthesiologist. However, depth of anesthesia (DoA) also seems to be a suitable process for closed-loop control implementation. To implement such a system, one must be able to acquire the relevant signals online and in real-time, as well as stream the calculated control signal to the infusion pump. However, during a procedure, patient monitors and infusion pumps are purposely unable to connect to an external (possibly medically unapproved) device for safety reasons, thus preventing closed-loop control. The paper proposes a conceptual solution to the aforementioned problem. First, it presents some important aspects of contemporary clinical practice. Next, it introduces the closed-loop-control-system structure and the relevant information flow. Focusing on transferring the data from the patient to the computer, it presents a non-invasive image-based system for signal acquisition from a patient monitor for online depth-of-anesthesia assessment. Furthermore, it introduces a UDP-based communication method that can be used for transmitting the calculated anesthetic inflow to the infusion pump. The proposed system is independent of a medical device manufacturer and is implemented in Matlab-Simulink, which can be conveniently used for DoA control implementation. The proposed scheme has been tested in a simulated GA setting and is ready to be evaluated in an operating theatre. However, the proposed system is only a step towards a proper closed-loop control system for DoA, which could routinely be used in clinical practice.

Keywords: closed-loop control, depth of anesthesia (DoA), modeling, optical signal acquisition, patient state index (PSi), UDP communication protocol

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Authors: Wei-Ting Hung

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Inbound tourist expenditure might not only have influenced by individual tourist characteristics but may also be affected by nationality characteristics. The cross national distance effects on tourist consumption behavior should be incorporated in the analytical framework. Additionally, the often used factor analysis, cluster analysis and regression analysis overlook the hierarchical tourist consumption data structure and may lead to misleading results. The objectives of the present study were twofold. First, we propose a multilevel model that takes individual and cross-national differences into account under a hierarchical framework. Second, we further sought to determine the types of cross-national differences affecting tourist expenditure. Thus, this study incorporates the individual tourist effects and cross national distance effects simultaneously, uses the data of 2010 Annual Survey Report on Visitors’ Expenditure and Trends in Taiwan to investigate the determinants of inbound tourist expenditure. Multilevel analysis was used to investigate the influence of individual tourist effects and cross national distance effects on inbound tourist expenditure. The empirical results show that cross national distance plays a crucial role in tourist consumption behavior. Our findings also indicate age and income have positive influence on tourism expenditure., whereas education and gender do not have significant impact. Regarding macro-level factors, geographic and cultural differences exhibited significant positive relationships on tourism expenditure, while economic differences did not. Based on the above empirical results, it is suggested that tour operators should take tourists’ individual attributes, particularly their income and age, into consideration when arranging tours. In addition, nationality holds sway over tourists’ consumption behavior, of which geographic and cultural differences are the two major factors at play. The empirical results of this study serve as practical suggestions for tourism marketing strategies and policy implications for government policies.

Keywords: cross national distance, inbound tourist, multilevel analysis, tourist expenditure

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Authors: Haibin Zhou, Pingping Yao, Kunyang Fan

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Copper-based sintered friction materials are widely used in the brake system of different applications such as engineering machinery or high-speed train, due to the excellent mechanical, thermal and tribological performance. Considering the diversity of the working conditions of brake system, it is necessary to identify well and understand the tribological performance and wear mechanisms of friction materials for different conditions. Fe has been a preferred reinforcement for copper-based friction materials, due to its ability to improve the wear resistance and mechanical properties of material. Wear map is well accepted as a useful research method for evaluation of wear performances and wear mechanisms over a wider range of working conditions. Therefore, it is significantly important to construct a wear map which can give out the effects of work condition and Fe reinforcement on tribological performance of Cu-based friction materials. In this study, the copper-based sintered friction materials with the different addition of Fe reinforcement (0-20 vol. %) were studied. The tribological tests were performed against stainless steel in a ring-on-ring braking tester with varying braking energy density (0-5000 J/cm2). The linear wear and friction coefficient were measured. The worn surface, cross section and debris were analyzed to determine the dominant wear mechanisms for different testing conditions. On the basis of experimental results, the wear map and wear mechanism map were established, in terms of braking energy density and the addition of Fe. It was found that with low contents of Fe and low braking energy density, adhesive wear was the dominant wear mechanism of friction materials. Oxidative wear and abrasive wear mainly occurred under moderate braking energy density. In the condition of high braking energy density, with both high and low addition of Fe, delamination appeared as the main wear mechanism.

Keywords: Cu-based friction materials, Fe reinforcement, wear map, wear mechanism

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Authors: Friba Haidari

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The aim of the study is to identify Russia's role in managing the Nagorno-Karabakh conflict betweenArmenia and Azerbaijan during the years 1990 to 2020. The Nagorno-Karabakh crisis can not be considered a mere territorial conflict but also a crossroads of interests of foreign actors. Geopolitical rivalries and the access to energy by regional and trans-regional actors have complicated the crisis and created a security challenge in the region, which is likely to escalate into a full-blown war between the parties involved. The geopolitical situation of Nagorno-Karabakh and its current situation have affected all peripheral states in some way. Russia, as one of the main actors in this scene, has been actively involved since the beginning of the crisis. The Russians have always sought to strengthen their influence and presence in the Nagorno-Karabakh crisis. Russia's efforts to weaken the role of the Minsk Group, The presence of Western actors, and the deployment of Russian forces in the disputed area can be assessed in this context. However, this study seeks to answer the question of what role did Russia play in managing the Nagorno-Karabakh conflict between Armenia and Azerbaijan between 1990 and 2020? The study hypothesizes that Russia has prevented the escalation of the Nagorno-Karabakh conflict through mediation and some coercion. This study is divided into four parts, including conflict management as a theoretical framework; Examining the competition and the role of actors in the Caucasus region, especially the role of the Minsk Group, and what approach or tools and methods Russia has used in its foreign policy in managing the conflict, and finally what are the relations between the countries involved and what will be Russia's role in the future? Was discussed. This study examines the analysis and transfer of ideas and information using authoritative international sources with an explanatory method and shares its results with everyone.

Keywords: Russia, conflict, nagorno-karabakh, management

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Authors: Vibha Kriti

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Background: Polycystic ovary syndrome (PCOS) is a common endocrine disorder generally found in reproductive women. It is associated with significant reproductive, metabolic, cosmetic, and psychological consequences. Objective: There is a high prevalence of PCOS found among reproductive-age women, therefore, the major objective of the present study is to identify the illness perception of PCOS women and to explore the relationship between illness perception and health-related quality of life (HRQoL). Material and Method: A cross-sectional study was conducted in a university tertiary-care center, Sir Sunder Lal Hospital, Banaras Hindu University (B.H.U). Tools used for data collection were self-structured, which included socio-demographic status, illness perception questionnaire (revised version), and short-form 36 for assessing illness perception and health-related quality of life, respectively. Statistical analysis was done by SPSS version ‘24’. Results: The results of correlation analyses indicated that there is a strong relationship between strong illness perception and HRQoL. Stepwise regression indicated that illness identity, long illness duration, and severe consequences were associated with the worse outcome on emotional functioning and on social functioning. A high score on the controllability of the disease and seeking social support was significantly related to better functioning. Conclusion: Illness perception is an important factor in self-care behaviors in PCOS females and has a strong association with health-related quality of life and has a profound effect on it.

Keywords: polycystic ovary syndrome, illness perception, quality of life, young females, mental health

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Authors: Manon Giraud, Francois-Damien Delapierre, Guenaelle Jasmin-Lebras, Cecile Feraudet-Tarisse, Stephanie Simon, Claude Fermon

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Early diagnosis or detection of harmful substances at low level is a growing field of high interest. The ideal test should be cheap, easy to use, quick, reliable, specific, and with very low detection limit. Combining the high specificity of antibodies-functionalized magnetic beads used to immune-capture biologic objects and the high sensitivity of a GMR-based sensors, it is possible to even detect these biologic objects one by one, such as a cancerous cell, a bacteria or a disease biomarker. The simplicity of the detection process makes its use possible even for untrained staff. Giant Magneto Resistance (GMR) is a recently discovered effect consisting in the electrical resistance modification of some conductive layers when exposed to a magnetic field. This effect allows the detection of very low variations of magnetic field (typically a few tens of nanoTesla). Magnetic nanobeads coated with antibodies targeting the analytes are mixed with a biological sample (blood, saliva) and incubated for 45 min. Then the mixture is injected in a very simple microfluidic chip and circulates above a GMR sensor that detects changes in the surrounding magnetic field. Magnetic particles do not create a field sufficient to be detected. Therefore, only the biological objects surrounded by several antibodies-functionalized magnetic beads (that have been captured by the complementary antigens) are detected when they move above the sensor. Proof of concept has been carried out on NS1 mouse cancerous cells diluted in PBS which have been bonded to magnetic 200nm particles. Signals were detected in cells-containing samples while none were recorded for negative controls. Binary response was hence assessed for this first biological model. The precise quantification of the analytes and its detection in highly diluted solution is the step now in progress.

Keywords: early diagnosis, giant magnetoresistance, lab-on-a-chip, submicron particle

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Authors: Nnedum Obiajuru Anthony Ugochukwu, Emmanuel Ezechukwu

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This study was designed to investigate into Nigerian consumers’ preference for foreign products. Studies have discovered that Nigerian consumers like their counterparts in most developing countries have an insatiable preference for foreign products especially those from more technologically advanced countries (Okechukwu & Onyema, 1999; Agbonifoh & Elimimian, 1999). This attitude of the Nigerian consumers has resulted in many problems which challenge the industrial sector in Nigeria – lack of patronage resulting to, non-performing firms, endemic unemployment, underdeveloped industries and general lack of industrial growth. The major objective of this study is to investigate the reasons behind such attitude, and the factors that drive consumer preference for foreign products among Nigerian consumers. The study investigated specifically the psychological dimensions (personal values, self-concept, lifestyle and prestige), and demographic factors (age, gender, level of education, income and occupation) that impact consumers’ preference for imported products in Nigeria. The study was cross-sectional and used survey method to collect data from one hundred and eighty-six respondents among postgraduate and part-time students of Nnamdi Azikiwe University, Awka and consumers from Awka metropolis. The results of the study indicated that all the psychological variables used to measure consumer preference for foreign products were largely positive and significant determinants of consumer preference for foreign products. Demographic variables of age, gender, and income were not significant determinants of preference for foreign products. The results of the study, however, showed that level of education and occupation has the significant effect on consumer preference for foreign products.

Keywords: country of origin, xenocentrism, Nigeria, ethnocentrism, foreign products, consumer preference

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Authors: Osama Ahmed Ibrahim Masoud, Mohamed Ibrahim Mohamed Abdelhadi, Ahmed Mohamed Seddik Hassan

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The problem of study focuses on thermal comfort realization in a residential building during hot and dry climate periods consumes a major electrical energy for air conditioning operation. Thermal comfort realization in a residential building during such climate becomes more difficult regarding the phenomena of climate change, and the use of building and construction materials which have the feature of heat conduction as (bricks-reinforced concrete) and the global energy crises. For that, this study aims to how to realize internal thermal comfort through how to make the best use of building services (temporarily used service spaces) for reducing the electrical energy transfer and saving self-shading. In addition, the possibility of reduction traditional energy (fossil fuel) consumed in cooling through the use of building services for reducing the internal thermal comfort and the relationship between them. This study is based on measuring the consumed electrical energy rate in cooling (by using Design-Builder program) for a residential building (the place of study is: Egypt- Suez Canal- Suez City), this design model has lots of alternatives designs for the place of building services (center of building- the eastern front- southeastern front- the southern front- the south-west front, the western front). The building services are placed on the fronts with different rates for determining the best rate on fronts which realizes thermal comfort with the lowest of energy consumption used in cooling. Findings of the study indicate to that the best position for building services is on the west front then the south-west front, and the more the building services increase, the more energy consumption used in cooling of residential building decreases. Recommendations indicate to the need to study the building services positions in the new projects progress to select the best alternatives to realize ‘Energy conservation’ used in cooling or heating into the buildings in general, residential buildings particularly.

Keywords: residential buildings, energy conservation, thermal comfort, building services, temporary used service spaces, DesignBuilder

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Authors: Kayondoamunmose Kamafrika

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Experimental based Engineering education approach plays a vital role in the development of student’s deep understanding of both social and physical sciences. Experimental based education approach through laboratory class activities prepare students to meet national demand for high-tech skilled individuals in the government and private sector. However, students across the country are faced with difficulties in classes that involve laboratory activities: poor experimental based exposure in their early development of student’s education-life-cycle, lack of student engagement in scientific method practical thinking approach, lack of communication between students and the instructor during class, a large number of students in one classroom, lack of instruments and improper equipment calibration. The purpose of this paper is to help students develop their own scientific knowledge and understanding, develop their methodologies in the design of experiments, collect and analyze data, write laboratory reports, present and explain their findings. Experimental based laboratory activities allow students to learn with high-level understanding as well as engage in the design processes of constructing knowledge through practical means of doing science. Experimental based education systems approach will act as a catalyst in the development of practical-based-educational methodologies in social and physical science and engineering domain of learning; thereby, converting laboratory classes into pilot industries and students into professional experts in finding a solution for complex problems, research, and development of super high- tech systems.

Keywords: experimental, engineering, innovation, practicability

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Authors: Di Yao, Gunther Prokop, Kay Buttner

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Dynamic parameters, including the center of gravity, mass and inertia moments of vehicle, play an essential role in vehicle simulation, collision test and real-time control of vehicle active systems. To identify the important vehicle dynamic parameters, a systematic parameter identification procedure is studied in this work. In the first step of the procedure, a conceptual parallel manipulator (virtual test rig), which possesses three rotational degrees-of-freedom, is firstly proposed. To realize kinematic characteristics of the conceptual parallel manipulator, the kinematic analysis consists of inverse kinematic and singularity architecture is carried out. Based on the Euler's rotation equations for rigid body dynamics, the dynamic model of parallel manipulator and derivation of measurement matrix for parameter identification are presented subsequently. In order to reduce the sensitivity of parameter identification to measurement noise and other unexpected disturbances, a parameter optimization process of searching for optimal exciting trajectory of parallel manipulator is conducted in the following section. For this purpose, the 321-Euler-angles defined by parameterized finite-Fourier-series are primarily used to describe the general exciting trajectory of parallel manipulator. To minimize the condition number of measurement matrix for achieving better parameter identification accuracy, the unknown coefficients of parameterized finite-Fourier-series are estimated by employing an iterative algorithm based on MATLAB®. Meanwhile, the iterative algorithm will ensure the parallel manipulator still keeps in an achievable working status during the execution of optimal exciting trajectory. It is showed that the proposed procedure and methods in this work can effectively identify the vehicle dynamic parameters and could be an important application of parallel manipulator in the fields of parameter identification and test rig development.

Keywords: parameter identification, parallel manipulator, singularity architecture, dynamic modelling, exciting trajectory

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Authors: Fahd I. Alghunaimi, Hind S. Dossary, Norah W. Aljuryyed, Tawfik A. Saleh

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Produced water (PW) is one of the largest by-volume waste streams and one of the most challenging effluents in the oil and gas industry. This is due to the variation of contaminants that make up PW. Severalmaterialshavebeen developed, studied, and implemented to remove hydrocarbonsfrom PW. Adsorption is one of the most effective ways ofremoving oil fromPW. In this work, three new and cost-effective hydrophobic adsorbentmaterials based on 9-octadecenoic acid grafted graphene (POG) were synthesized for oil/water separation. Graphene derived from graphite was modified with 9-octadecenoic acid to yield 9-octadecenoic acid grafted graphene (OG). The newsynthesized materials which called POG25, POG50, and POG75 were characterized by using N₂-physisorption (BET) and Fourier transform infrared (FTIR). The BET surface area of POG75 was the highest with 288 m²/g, whereas POG50 was 225 m²/g and POG25 was lowest 79 m²/g. These three materials were also evaluated for their oil-water separation efficiency using a model mixture, whichdemonstrated that POG-75 has the highest oil removal efficiency and the faster rate of the adsorption (Figure-1). POG75 was regenerated, and its performance was verified again with a little reduced adsorption rate compared to the fresh material. The mixtures that used in the performance test were prepared by mixing nonpolar organic liquids such as heptane, dodecane, or hexadecane into the colored water. In general, the new materials showed fast uptake of the certain quantity of the oildue to the high hydrophobicity nature of the materials, which repel water as confirmed by the contact angle of approximately 150˚. Besides that, novel superhydrophobic material was also synthesized by introducing hydrophobic branches of laurate on the surface of the stainless steel mesh (SSM). This novel mesh could help to hold the novel adsorbent materials in a column to remove oil from PW. Both BOG-75 and the novel mesh have the potential to remove oil contaminants from produced water, which will help to provide an opportunity to recover useful components, in addition, to reduce the environmental impact and reuse produced water in several applications such as fracturing.

Keywords: graphite to graphene, oleophilic, produced water, separation

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Authors: P. Mirahmadpour, M. H. Banitaba, D. Nematollahi

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The chemistry of coordination polymers in recent years has grown exponentially not only because of their interesting architectures but also due to their various technical applications in many fields including ion exchange, chemical catalysis, small molecule separations, and drug release. The use of bridging ligands for the controlled self-assembly of one, two or three dimensional metallo-supramolecular species is the subject of serious study in last decade. Numerous different synthetic methods have been offered for the preparation of coordination polymers such as (a) diffusion from the gas phase, (b) slow diffusion of the reactants into a polymeric matrix, (c) evaporation of the solvent at ambient or reduced temperatures, (d) temperature controlled cooling, (e) precipitation or recrystallisation from a mixture of solvents and (f) hydrothermal synthesis. The electrosynthetic process suggested several advantages over conventional approaches. A general advantage of electrochemical synthesis is that it allows synthesis under milder conditions than typical solvothermal or microwave synthesis. In this work we have introduced a simple electrochemical method for growing metal coordination polymers based on copper with a flexible 2,2’-thiodiacetic acid (TDA) and rigid 1,2,4,5-benzenetetracarboxylate (BTC) ligands. The structure of coordination polymers were characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), elemental analysis, thermal gravimetric (TG) and differential thermal analyses (DTA). The single-crystal X-ray diffraction analysis revealed that different conformations of the ligands and different coordination modes of the carboxylate group as well as different coordination geometries of the copper atoms. Electrochemical synthesis of coordination polymers has different advantages such as faster synthesis at lower temperature in compare with conventional chemical methods and crystallization of desired materials in a single synthetic step.

Keywords: 1, 2, 4, 5-benzenetetracarboxylate, coordination polymer, copper, 2, 2’-thiodiacetic acid

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Authors: Simeon Adebayo Oladipo

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Institutional administrators are currently facing pressure and challenges in their daily operations. Reasons for this may include the increasing multiplicity, uncertainty and tension that permeate institutional leadership. Authentic engagement for institutional leadership is premised on the ethical foundation that the leaders in the schools are engaged. The institutional effectiveness is dependent on the relationship that exists between the leaders and employees in the workplace. Leader’s self-awareness, relational transparency, emotional control, strong moral code and accountability have a positive influence on authentic engagement which variably determines leadership effectiveness. This study therefore examined the role of authentic engagement in effective school leadership; explored the interrelationship of authentic engagement indices in school leadership. The study adopted the descriptive research of the survey type using a quantitative method to gather data through a questionnaire among school leaders in Lagos State Tertiary Institutions. The population for the study consisted of all Heads of Departments, Deans and Principal Officers in Lagos State Tertiary Institutions. A sample size of 255 Heads of Departments, Deans and Principal Officers participated in the study. The data gathered were analyzed using descriptive and inferential statistical tools. The findings indicated that authentic engagement plays a crucial role in increasing leadership effectiveness amongst Heads of Departments, Deans and Principal Officers. The study recommended among others that there is a need for effective measures to enhance authentic engagement of institutional leadership practices through relevant educational support systems and effective quality control.

Keywords: authentic engagement, self-awareness, relational transparency, emotional control

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Authors: Shabnam Monadizadeh, Charles Kibert, Jiaxuan Li, Janghoon Woo, Ashish Asutosh, Samira Roostaei, Maryam Kouhirostami

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A significant share of the technology that has emerged over the past several decades produces electromagnetic field (EMF) radiation. Communications devices, household appliances, industrial equipment, and medical devices all produce EMF radiation with a variety of frequencies, strengths, and ranges. Some EMF radiation, such as Extremely Low Frequency (ELF), Radio Frequency (RF), and the ionizing range have been shown to have harmful effects on human health. Depending on the frequency and strength of the radiation, EMF radiation can have health effects at the cellular level as well as at brain, nervous, and cardiovascular levels. Health authorities have enacted regulations locally and globally to set critical values to limit the adverse effects of EMF radiation. By introducing a more comprehensive field of EMF radiation study and practice, architects and designers can design for a safer electromagnetic (EM) indoor environment, and, as building and construction specialists, will be able to monitor and reduce EM radiation. This paper identifies the nature of EMF radiation in the built environment, the various EMF radiation sources, and its human health effects. It addresses European and US regulations for EMF radiation in buildings and provides a preliminary action plan. The challenges of developing measurement protocols for the various EMF radiation frequency ranges and determining the effects of EMF radiation on building occupants are discussed. This paper argues that a mature method for measuring EMF radiation in building environments and linking these measurements to human health impacts occupant health should be developed to provide adequate safeguards for human occupants of buildings for future research.

Keywords: biological affection, electromagnetic field, building regulation, human health, healthy building, clean construction

Procedia PDF Downloads 185