1,132 research outputs found
Modelling dependency networks to inform data structures in BIM and smart cities
The pervasive deployment of "smart city" and "smart building" projects in cities world-wide is driving innovation on many fronts including; technology, telematics, engineering and entrepreneurship. This paper focuses on the technical and engineering perspectives of BIM and smart cities, by extending building and urban morphology studies as to respond to the challenges posed by Big Data, and smart infrastructure. The proposed framework incorporates theoretical and modelling descriptions to verify how network-based models can act as the backbone skeletal representation of both building and urban complexity, and yet relate to environmental performance and smart infrastructure. The paper provides some empirical basis to support data information models through building dependency networks as to represent the relationships between different existing and smart infrastructure components. These dependency networks are thought to inform decisions on how to represent building and urban data sets in response to different social and environmental performance requirements, feeding that into void and solid descriptions of data maturity models. It is concluded that network-based models are fundamental to comprehend and represent the complexity of cities and inform urban design and public policy practices, in the design and operation phases of infrastructure projects
Role of hydrogen in volatile behaviour of defects in SiO2-based electronic devices
Charge capture and emission by point defects in gate oxides of metal–oxide–semiconductor field-effect transistors (MOSFETs) strongly affect reliability and performance of electronic devices. Recent advances in experimental techniques used for probing defect properties have led to new insights into their characteristics. In particular, these experimental data show a repeated dis- and reappearance (the so-called volatility) of the defect-related signals. We use multiscale modelling to explain the charge capture and emission as well as defect volatility in amorphous SiO2 gate dielectrics. We first briefly discuss the recent experimental results and use a multiphonon charge capture model to describe the charge-trapping behaviour of defects in silicon-based MOSFETs. We then link this model to ab initio calculations that investigate the three most promising defect candidates. Statistical distributions of defect characteristics obtained from ab initio calculations in amorphous SiO2 are compared with the experimentally measured statistical properties of charge traps. This allows us to suggest an atomistic mechanism to explain the experimentally observed volatile behaviour of defects. We conclude that the hydroxyl-E′ centre is a promising candidate to explain all the observed features, including defect volatility
Effect of electric field on migration of defects in oxides: Vacancies and interstitials in bulk MgO
Dielectric layers composed of metal oxides are routinely subjected to external electric fields during the course
of normal operation of electronic devices. Many phenomenological theories suggest that electric fields strongly
affect the properties and mobilities of defects in oxide films and can even facilitate the creation of new defects.
Although defects in metal oxides have been studied extensively both experimentally and theoretically, the effect
of applied electric fields on their structure and migration barriers is not well understood and still remains subject to
speculations. Here, we investigate how static, homogeneous electric fields affect migration barriers of canonical
defects—oxygen vacancies and interstitial ions—in a prototypical oxide, MgO. Using the modern theory of
polarization within density functional theory (DFT), we apply electric fields to defect migration pathways in
three different charge states. The effect of the field is characterized by the change of the dipole moment of the
system along the migration pathway. The largest changes in the calculated barriers are observed for charged
defects, while those for the neutral defects are barely significant. We show that by multiplying the dipole moment
difference between the initial and the transition states, which we define as the effective dipole moment, by the
field strength, one can obtain an estimate of the barrier change in excellent agreement with the DFT calculated
values. These results will help to assess the applicability of phenomenological models and elucidate linear and
nonlinear effects of field application in degradation of microelectronic devices, electrocatalysis, batteries, and
other applications
The role of self-esteem and self-efficacy in women empowerment in the Kingdom of Saudi Arabia: A cross-sectional study
The study aimed to explore the role of self-esteem and self-efficacy in women empowerment among academic and administrative staff at Saudi universities. A cross-sectional design was carried out at 15 governmental universities. A multistage cluster sampling technique was used to select 5587 participants. Multiple linear regression was used to analyze the predictive relation. Data collection included socio-demographic variables, Rosenberg self-esteem scale, general self-efficacy scale, and women empowerment scale. The results indicated that study participants' self-esteem was equally distributed between moderate (49.8%) and high (50.2%). Also, 66.9% of the participants had high self-efficacy, and 86.8% had high total women's empowerment. Regression coefficient showed that self-esteem (B=0.521, b=0.127, t=13.785 and p<0.001) and self-efficacy (B=2.388, b=0.702, t=76.049 and p<0.001) are important predictors of the total women empowerment. However, self-efficacy was observed to be the most dominant predictor (t=76.049). The total model summary shows that 73.4% of the women empowerment level can be predicted through self-esteem and self-efficacy. The study results can be used as a base to build women empowerment programs in the Kingdom of Saudi Arabia (KSA) and help to achieve the 2030 KSA vision regarding women empowerment.
Keywords: Self-esteem, self-efficacy, women empowerment, 2030 KSA vision
L'étude visait à explorer le rôle de l'estime de soi et de l'efficacité personnelle dans l'autonomisation des femmes parmi le personnelacadémique et administratif des universités saoudiennes. Une conception transversale a été réalisée dans 15 universités gouvernementales. Une technique d'échantillonnage en grappes à plusieurs degrés a été utilisée pour sélectionner 5587 participants.Une régression linéaire multiple a été utilisée pour analyser la relation prédictive. La collecte de données comprenait des variablessociodémographiques, une échelle d'estime de soi de Rosenberg, une échelle d'auto-efficacité générale et une échelle d'autonomisation des femmes. Les résultats ont indiqué que l'estime de soi des participants à l'étude était également répartie entremodérée (49,8%) et élevée (50,2%). En outre, 66,9% des participants avaient une auto-efficacité élevée et 86,8% avaient une forteautonomisation totale des femmes. Le coefficient de régression a montré que l'estime de soi (B = 0,521, b = 0,127, t = 13,785 et p<0,001) et l'auto-efficacité (B = 2,388, b = 0,702, t = 76,049 et p <0,001) sont des prédicteurs importants du l'autonomisation totaledes femmes. Cependant, l'auto-efficacité a été observée comme le prédicteur le plus dominant (t = 76,049). Le résumé total dumodèle montre que 73,4% du niveau d'autonomisation des femmes peut être prédit grâce à l'estime de soi et à l'auto-efficacité. Lesrésultats de l'étude peuvent être utilisés comme base pour élaborer des programmes d'autonomisation des femmes dans le Royaumed'Arabie saoudite (KSA) et aider à réaliser la vision 2030 de la KSA concernant l'autonomisation des femmes.
Mots-clés: Estime de soi, efficacité personnelle, autonomisation des femmes, vision 2030 KS
Hydrogen-induced rupture of strained Si─O bonds in amorphous silicon dioxide
Using ab initio modeling we demonstrate that H atoms can break strained Si─O bonds in continuous amorphous silicon dioxide (a-SiO(2)) networks, resulting in a new defect consisting of a threefold-coordinated Si atom with an unpaired electron facing a hydroxyl group, adding to the density of dangling bond defects, such as E' centers. The energy barriers to form this defect from interstitial H atoms range between 0.5 and 1.3 eV. This discovery of unexpected reactivity of atomic hydrogen may have significant implications for our understanding of processes in silica glass and nanoscaled silica, e.g., in porous low-permittivity insulators, and strained variants of a-SiO(2)
Perceived and real barriers to workplace empowerment among women at Saudi universities: A cross-sectional study
Academic women in the Arab world, especially Saudi women, have numerous barriers inhibiting their leadership power at the workplace. The current study explores the perceived and real barriers to workplace empowerment among women at Saudi universities. A descriptive cross-sectional study was carried out at 15 Saudi governmental universities. A multistage cluster sampling technique was followed to select (5587 participants) The data collection started from the beginning of April to the beginning of September 2020. SPSS 23.0 was used to analyze data using descriptive statistics. Multiple linear regression was used to identify the real barriers to women empowerment at the workplace. The study showed that 52.1% of the study participants had moderate workplace empowerment, and only 10.2% have a low level. Regarding perceived barriers to workplace empowerment, 42.6% of the participants agree that male dominance was a barrier. Moreover, 36.2% of the participants agreed and strongly agree that the customs and traditions are a barrier to women empowerment at the workplace. Multiple linear regression showed that age, followed by years of experience (p<0.000), were the most significant demographic predictors of women empowerment at the workplace. Moreover, positive attitude, high self-esteem, and good knowledge (p<0.000) were considered other variables that positively predict women's empowerment at the workplace. The experience of gender-based violence (p<0.000) was a negative predictor of women empowerment at the workplace. The study concluded that around 62.3% of Saudi female academics and administrative staff have moderate or low workplace empowerment at Saudi Universities. Male dominance is perceived as the highest barrier.
Keywords: Barriers, workplace empowerment, Saudi wome
Molecular identification of adenoviruses associated with respiratory infection in Egypt from 2003 to 2010.
BACKGROUND: Human adenoviruses of species B, C, and E (HAdV-B, -C, -E) are frequent causative agents of acute respiratory infections worldwide. As part of a surveillance program aimed at identifying the etiology of influenza-like illness (ILI) in Egypt, we characterized 105 adenovirus isolates from clinical samples collected between 2003 and 2010. METHODS: Identification of the isolates as HAdV was accomplished by an immunofluorescence assay (IFA) and confirmed by a set of species and type specific polymerase chain reactions (PCR). RESULTS: Of the 105 isolates, 42% were identified as belonging to HAdV-B, 60% as HAdV-C, and 1% as HAdV-E. We identified a total of six co-infections by PCR, of which five were HAdV-B/HAdV-C co-infections, and one was a co-infection of two HAdV-C types: HAdV-5/HAdV-6. Molecular typing by PCR enabled the identification of eight genotypes of human adenoviruses; HAdV-3 (n = 22), HAdV-7 (n = 14), HAdV-11 (n = 8), HAdV-1 (n = 22), HAdV-2 (20), HAdV-5 (n = 15), HAdV-6 (n = 3) and HAdV-4 (n = 1). The most abundant species in the characterized collection of isolates was HAdV-C, which is concordant with existing data for worldwide epidemiology of HAdV respiratory infections. CONCLUSIONS: We identified three species, HAdV-B, -C and -E, among patients with ILI over the course of 7 years in Egypt, with at least eight diverse types circulating
Fish farming in Tanzania: the availability and nutritive value of local feed ingredients
An investigative field survey was performed to gather baseline data on locally available feed ingredients and fish farming practices in different regions of Tanzania. More than 80% of respondents relied on locally available feed ingredients as a major feed supplement for their cultured fish, with maize bran being the most commonly used feed ingredient in all regions. Crude protein content in most analyzed local feed ingredients was medium-high, while crude fat content was high in some animal and agricultural by-products, and medium-low in other ingredients. Most respondents were males and the majority of fish farms were owned by individuals. Earthen pond was the most common fish farming system in all regions except Dar es Salaam. Semi-intensively mixed-sex tilapia monoculture was the dominating fish farming practice. The results of the survey presented provide a good platform for future development of culture systems and feeding strategies for tilapia in Tanzania
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