Rejection Enhanced Off-Lattice Kinetic Monte Carlo

We introduce a new kinetic Monte Carlo (KMC) algorithm for off-lattice simulation. In off-lattice KMC one needs to calculate the rates for all possible moves from the current state by searching the energy landscape for index-1 saddle points surrounding the current basin of attraction. We introduce a rejection scheme where the true rates are replaced by rate estimates. This is done by first associating each saddle point with a key atom defined to be the atom that moves the most or that corresponds to the largest energy change if the transition were to take a place, then constructing an estimate for the total rate associated with each atom by using a nearest-neighbor bond count. These estimates allow one to select a set of possible transitions, one of which is accepted or rejected based on a localized saddle point search focused on a particular atom. In principle, this allows a performance boost that scales with the number of particles in the system. We test the method on a growing two-species nanocluster with an emerging core-shell structure bound by Lennard-Jones potential. In addition to that, we give a detailed review for the dimer method used in this study to locate index-1 saddle points on the potential energy surface

Inclusive education for students with severe or profound and multiple learning difficulties: Identification of influencing factors and challenges

In the study reported on here we examined the extent of pre-service teachers’ supportiveness for educational inclusion (EI) of students with severe or profound and multiple learning difficulties (SPMLD) in order to identify their attitudinal predictors, as well as the challenges faced in such a process. An attitudinal survey with 33 items was developed to collect data from 542 participants. The results show that the attitudes/beliefs of pre-service teachers (ABpST) regarding inclusion were moderate to positive and strengthened across the teachers’ knowledge and experiences. However, some variations, based on their characteristics and study constructs were revealed. The findings also illustrate the combined effects of practical knowledge and courses, besides teaching and working  experiences in shaping ABpST attitudes towards inclusion of SPMLD students. The implications of these results for educators and national education institutions and other international universities are discussed. Keywords: attitude/beliefs; educational inclusion; pre-service teachers; SPMLD student

Eucalyptus

In Egypt, the River Red Gum (Eucalyptus camaldulensis) is a well-known tree and is highly appreciated by the rural and urban dwellers. The role of Eucalyptus trees in the ecology of Cryptococcus neoformans is documented worldwide. The aim of this survey was to show the prevalence of C. neoformans during the flowering season of E. camaldulensis at the Delta region in Egypt. Three hundred and eleven samples out of two hundred Eucalyptus trees, including leaves, flowers, and woody trunks, were collected from four governorates in the Delta region. Thirteen isolates of C. neoformans were recovered from Eucalyptus tree samples (4.2%). Molecular identification of C. neoformans was done by capsular gene specific primer CAP64 and serotype identification was done depending on LAC1 gene. This study represents an update on the ecology of C. neoformans associated with Eucalyptus tree in Egyptian environment

Effect of zinc supplementation on growth Hormone Insulin growth factor axis in short Egyptian children with zinc deficiency

BACKGROUND: The relationship between zinc (Zn) and growth hormone-insulin growth factor (GH-IGF) system and how Zn therapy stimulates growth in children has not been clearly defined in humans. Thus, we aimed to assess GH-IGF axis in short children with Zn deficiency and to investigate the effect of Zn supplementation on these parameters. METHODS: Fifty pre-pubertal Egyptian children with short stature and Zn deficiency were compared to 50 age-, sex-, and pubertal stage- matched controls. All subjects were subjected to history, auxological assessment and measurement of serum Zn, IGF-1, insulin growth factor binding protein-3 (IGFBP-3); and basal and stimulated GH before and 3 months after Zn supplementation (50 mg/day). RESULTS: After 3 months of Zn supplementation in Zn-deficient patients, there were significant increases in height standard deviation score (SDS, P = 0.033), serum Zn (P < 0.001), IGF-1 (P < 0.01), IGF-1 standard deviation score (SDS,P < 0.01) and IGFBP-3 (P = 0.042). Zn rose in all patients but reached normal ranges in 64 %, IGF-1 levels rose in 60 % but reached normal ranges in 40 % and IGFBP-3 levels rose in 40 % but reached reference ranges in 22 %. Growth velocity (GV) SDS did not differ between cases and controls (p = 0.15) but was higher in GH-deficient patients than non-deficient ones, both having Zn deficiency (p = 0.03). CONCLUSION: Serum IGF-1 and IGFBP-3 levels were low in short children with Zn deficiency, and increased after Zn supplementation for 3 months but their levels were still lower than the normal reference ranges in most children; therefore, Zn supplementation may be necessary for longer periods

Evolution of Durability and Mechanical Behaviour of Mud Mortar Stabilized with Oil Shale Ash, Lime, and Cement

The investigation into earthen construction technologies and materials is now acknowledged as a crucial area requiring further research. Earthen mortars are prevalent in both modern and traditional construction due to the abundance of earth material, their favorable thermal properties, and their low embodied energy. The objective of this study is to support the use of natural materials collected from north Jordan to enhance the mechanical properties and durability of mud mortar. The local soil was stabilized using Oil Shale Ash (OSA), Ordinary Portland Cement (OPC), and lime for producing mud mortar. Particle size analysis, plastic limit, liquid limit, XRD, and XRF were applied to assess the geotechnical characterization and mineral composition of the earthen stabilizers and local soil. In order to examine the mechanical properties (specifically compressive strength) and durability characteristics (such as water absorption and shrinkage) of mud mortar, a total of 8 mixtures were prepared. One of these mixtures served as a control, while the others were created by substituting soil with varying proportions of OSA, cement, and lime. The results show that the mud mortar contained 10% OSA and 10% cement, which exhibited the highest compressive strength. Moreover, an increase in the proportion of OSA in the soil led to a decrease in absorption and linear shrinkage, indicating that OSA is an effective stabilizing agent for mud mortar. Doi: 10.28991/CEJ-2023-09-09-06 Full Text: PD

The relationship between tolerance of ambiguity and creativity in architectural design studio

Creativity is a cognitive ability that enables individuals to come up with both original and functional ideas and products. As architectural design requires producing aesthetic and practically useful solutions, it is a primary concern to enhance creativity in design disciplines. Many theorists argued that design is a non-linear process and many components of design problems are not clear at the beginning. At the start of the process, designers are always working at the periphery of a solution space where there is less coherence and more ambiguity. Thus, they must deal with a lot of ambiguity in every design situation. These states of uncertainty and confusion can be annoying for architecture students. On the other hand, tolerance of ambiguity is a personality trait that has been linked to creative thinking. Therefore, this paper attempts to investigate the correlation between tolerance of ambiguity of architectural students and their creativity via a qualitative study. The researchers implemented a mixed-method approach and recruited 18 architecture students. The results from this study revealed that there is a significant correlation between students’ creative thinking abilities and their tolerance for ambiguity. Our results also indicated that there is no statistically significant correlation between students’ tolerance of ambiguity and their design creativity. Article in English. Santykis tarp tolerancijos dviprasmiškumui ir kūrybiškumo architektūrinio projektavimo studijoje Santrauka Kūrybiškumas kaip kognityvinis gebėjimas sudaro sąlygas asmenims sukurti originalių ir funkcionalių idėjų bei produktų. Kadangi architektūrinis projektavimas reikalauja priimti estetinius ir praktine prasme naudingus sprendimus, todėl pirmiausia reikia rūpintis kūrybiškumo stiprinimu su projektavimu susijusiose disciplinose. Dauguma teoretikų įrodinėja, kad projektavimas yra nelinijinis procesas, o didžioji dalis projektavimo problemų sudedamųjų dalių nuo pat pradžių sudaro neaiškumų. Prasidedant procesui, projektuotojai bet kuriuo atveju darbuojasi sprendimo erdvės paribyje, kuriame yra mažai darnumo, tačiau kur kas daugiau – dviprasmiškumo. Tad jiems tenka spręsti klausimus, susijusius su dideliu dviprasmiškumu bet kurioje projektavimo situacijoje. Šios netikrumo ir painiavos būsenos gali erzinti architektūros studentus. Kita vertus, tolerancija dviprasmiškumui – tai asmenybės bruožas, siejamas su kūrybiniu mąstymu. Todėl šiame straipsnyje siekiama išnagrinėti koreliaciją tarp architektūros studentų tolerancijos dviprasmiškumui ir jų kūrybiškumo, atliekant kokybinį tyrimą. Tyrėjai taikė mišrų metodą, o jų tyrimo objektu tapo 18 architektūros studentų. Šio tyrimo rezultatai atskleidė, kad yra reikšminga koreliacija tarp studentų kūrybinio mąstymo gebėjimų ir jų tolerancijos dviprasmiškumui. Rezultatai, kuriuos gavome, taip pat parodė, kad nėra statistiškai reikšmingos koreliacijos tarp studentų tolerancijos dviprasmiškumui ir to, ar jų atliekamas projektavimas yra kūrybiškas. Reikšminiai žodžiai: architektūros studentai, kūrybiškumas, projektavimo problemos, projektavimo procesas, tolerancija dviprasmiškumui

From binder to mixture: experimental programme on permanent deformation behaviour

Asphalt mixture, the most common road construction material, comprises bitumen, filler, fine and coarse aggregates, and air voids. Traditionally and for simplification, the mixture is treated as a continuous and homogenous material confined in the domain of linear behaviour. The demand for more durable roads, particularly with the progressive growth in traffic volumes and loads, has raised the requirement for improved design methods. Wisely, before the complex adoption of the nonlinear behaviour, understanding the nature of the internal stress-strain relationships at different scales and determining their linearity limits is essentially required taking into consideration the time and temperature dependency. So far, most experimental programs have been concerned with testing either asphalt mixture or bitumen in isolation. This thesis is intended to establish a systematic experimental investigation from binder to the asphalt mixture scale in terms of permanent deformation behaviour. Preliminary conclusions of the components contributions, their interactions, and the effect on the total macroscopic response are drawn from the experimental observations. Investigation of the fillers influence on the viscoelastic property of the mastic (filler +bitumen) binder in the dynamic shear rheometer (DSR), results exhibited that binder behave nonlinearly at high shear stress levels and the linearity range reduces with increasing filler content and/or raising the temperature. Although filler inclusion increased the deformation resistance (stiffness) of the binder, its recoverability decreased. Consequently, a new binder rutting evaluation test was designed to distinguish between the two rutting resistance mechanisms; stiffness and recovery. Results from the new test indicated that the linearity of the modified binders begins after an initial inherent nonlinearity stage and before a secondary nonlinearity stage triggered by the applied state of stresses in the DSR. A new designed mortar type was developed from the mastic and originated from a standard asphalt mixture. The focus of this part in the research emphasised on measuring the stiffening effect of fine aggregates utilising a constitutive stress-strain relationship and determining the influence on the viscoelastic behaviour. Results indicated that the stiffening effect varies depending on the stress condition (uniaxial, triaxial, or shear), temperature, fine aggregate gradation, and binder with filler content. The stress linearity limit was also found to vary at different degrees with the previous parameters. Uniaxial compression constant stress and strain rate tests were conducted on asphalt mixtures of different aggregate gradations at 30 and 500C. X-ray CT was incorporated to characterise the coarse aggregates and air voids through advanced image analysis techniques. The test was shown to be insensitive to the asphalt mixture type in terms of air voids uniformity. Mixtures of coarse aggregates produced larger size and smaller number of air voids, opposite to the fine aggregate ones. Comparing the stiffening effect between fine and coarse aggregates, it was revealed that the air void content is a key factor. Finally, the radial strain as measured along the height followed the pattern of air void distribution in the specimen and exhibited both tensile and compressive forms

From binder to mixture: experimental programme on permanent deformation behaviour

Asphalt mixture, the most common road construction material, comprises bitumen, filler, fine and coarse aggregates, and air voids. Traditionally and for simplification, the mixture is treated as a continuous and homogenous material confined in the domain of linear behaviour. The demand for more durable roads, particularly with the progressive growth in traffic volumes and loads, has raised the requirement for improved design methods. Wisely, before the complex adoption of the nonlinear behaviour, understanding the nature of the internal stress-strain relationships at different scales and determining their linearity limits is essentially required taking into consideration the time and temperature dependency. So far, most experimental programs have been concerned with testing either asphalt mixture or bitumen in isolation. This thesis is intended to establish a systematic experimental investigation from binder to the asphalt mixture scale in terms of permanent deformation behaviour. Preliminary conclusions of the components contributions, their interactions, and the effect on the total macroscopic response are drawn from the experimental observations. Investigation of the fillers influence on the viscoelastic property of the mastic (filler +bitumen) binder in the dynamic shear rheometer (DSR), results exhibited that binder behave nonlinearly at high shear stress levels and the linearity range reduces with increasing filler content and/or raising the temperature. Although filler inclusion increased the deformation resistance (stiffness) of the binder, its recoverability decreased. Consequently, a new binder rutting evaluation test was designed to distinguish between the two rutting resistance mechanisms; stiffness and recovery. Results from the new test indicated that the linearity of the modified binders begins after an initial inherent nonlinearity stage and before a secondary nonlinearity stage triggered by the applied state of stresses in the DSR. A new designed mortar type was developed from the mastic and originated from a standard asphalt mixture. The focus of this part in the research emphasised on measuring the stiffening effect of fine aggregates utilising a constitutive stress-strain relationship and determining the influence on the viscoelastic behaviour. Results indicated that the stiffening effect varies depending on the stress condition (uniaxial, triaxial, or shear), temperature, fine aggregate gradation, and binder with filler content. The stress linearity limit was also found to vary at different degrees with the previous parameters. Uniaxial compression constant stress and strain rate tests were conducted on asphalt mixtures of different aggregate gradations at 30 and 500C. X-ray CT was incorporated to characterise the coarse aggregates and air voids through advanced image analysis techniques. The test was shown to be insensitive to the asphalt mixture type in terms of air voids uniformity. Mixtures of coarse aggregates produced larger size and smaller number of air voids, opposite to the fine aggregate ones. Comparing the stiffening effect between fine and coarse aggregates, it was revealed that the air void content is a key factor. Finally, the radial strain as measured along the height followed the pattern of air void distribution in the specimen and exhibited both tensile and compressive forms