278 research outputs found
Nature inspired materials: Emerging trends and prospects
The term ‘Nature-inspired’ is associated with a sequence of efforts to understand, synthesise and imitate any natural object or phenomenon either in the tangible or intangible form which allows us to obtain improved insights into nature. Such inspirations can come through materials, processes, or designs that we see around. Materials as opposed to processes and designs found in nature due to being tangible can readily be used without engineering efforts. One such example is that of an aquaporin which is used to filter water. The scope of this work in Nature-inspired materials is to define, clarify and consolidate the current understanding by probing new insights in the recent developments by reviewing examples from the laboratory to industrial scale while highlighting newer opportunities in this area. A careful analysis of the “nature-inspired materials” shows that they possess specific functionality that relies on our ability to harness peculiar electrical, mechanical, biological, chemical, sustainability or combined gains
Pelaksanaan Pendidikan Karakter di Madrasah Aliyah Negeri 2 Palembang
Moral degeneration has become a common phenomenon that plagues mankind in various parts of the world today, including in Indonesia. Various moral cases have occurred and adorned mass media almost all the time, ranging from cases of corruption, acts of violence, sexual harassment, pornography, prostitution, drug abuse, even murder. Since 2010 the Center for Curriculum and Bookkeeping has initiated a pioneering program of character education implementation in several districts / cities in all provinces in Indonesia.This study uses a combination of quantitative and qualitative approaches. The data were collected using interviews and questionnaires. Data analysis is done descriptively in order to explain / describe the implementation of character education and the factors that become obstacles of its implementation.In this research can be concluded that character education in MAN 2 Palembang has not been implemented maximally. Some things that have not been implemented related to the implementation of character education are: not all contextual learning strategies used, not all teachers use contextual learning strategies, there has been no specific effort to revitalize the activities of co-curricular and extra curricular, related to the integration of teachers in learning, there are still 33.33 % of teachers are doing poorly (20.8% are poor in learning planning, 25% on learning implementation aspects, and 4.2% on learning assessment aspects). Many factors constraints and support the implementation of character education in MAN 2 Palembang. The obstacles faced by the madrasah include: difficulty in carrying out routine activities, difficulties in performing spontaneous activities, and difficulties in conducting conditioning activities. While the constraints factor from the teacher side is the difficulty of integrating character education in the learning process, which include: difficulties linking character education with materials, methods, strategies, and learning media, difficulty determining the value of character to be achieved, difficulty measuring the attainment of character education in participants students, too many students per class, not all teachers and employees can be role models, the number of things that affect the character, as well as the many aspects of character that must be developed. While the factors supporting the implementation of character education in MAN 2 Palembang include: support of all madrasah residents, family environment, madrasah infrastructure facilities, budget, student association, and student motivation
Antimicrobial resistance and pathogenicity of Escherichia coli isolated from common dairy products in the Lebanon
In a recent study, bacteria have been isolated from popular Lebanese dairy products, which had been collected in the Beqaa Valley, in north-eastern Lebanon. The foods investigated were two cheeses (shankleesh and baladi) and a dried fermented mixture of yogurt and wheat grains (kishk). Bacterial colonies on McConkey and sorbitol-McConkey agar that showed the morphology of Escherichia coli were biochemically tested and then classified, using PCR-based assays, into the various strains of pathogenic and non-pathogenic E. coli. Some of the confirmed E. coli isolates were proven to be pathogenic, including two identified as E. coli O157:H7. When the pathogenic isolates were tested for their susceptibility to 10 different antibiotics (all commonly used, by clinicians and veterinarians, for the treatment of infections with Gram-negative bacteria), each tested isolate was found to be highly resistant to at least one antibiotic. It therefore appears that, in Lebanon, some popular dairy products pose a public-health hazard, acting as vehicles for the transmission of drug-resistant pathogens. © The Liverpool School of Tropical Medicine 2009
Polymorphisms of the Steroid Sulfatase [STS] Gene are Associated With Attention Deficit Hyperactivity Disorder and Influence Brain Tissue mRNA Expression
Previous studies in animals and humans have implicated the X-chromosome STS gene in the etiology of attentional difficulties and attention deficit hyperactivity disorder (ADHD). This family based association study has fine mapped a region of the STS gene across intron 1 and 2 previously associated with ADHD, in an extended sample of 450 ADHD probands and their parents. Significant association across this region is demonstrated individually with 7 of the 12 genotyped SNPs, as well as an allele specific haplotype of the 12 SNPs. The over transmitted risk allele of rs12861247 was also associated with reduced STS mRNA expression in normal human post-mortem frontal cortex brain tissue compared to the non-risk allele (P = 0.01). These results are consistent with the hypothesis arising from previous literature demonstrating that boys with deletions of the STS gene, and hence no STS protein are at a significantly increased risk of developing ADHD. Furthermore, this study has established the brain tissue transcript of STS, which except from adipose tissue, differs from that seen in all other tissues investigated. © 2010 Wiley-Liss, Inc
Approach of the NGC 1977 star cluster to the TOI-2796 host star
We study of possible encounters in past epochs of the open star cluster NGC
1977 with host stars. For this purpose, the age of the cluster was determined
based on our catalog data. Stars with planetary systems were selected from the
NASA Archive. The age of the cluster was determined using the color - absolute
magnitude diagram and the isochron system. By extending the track of the
movement of the cluster and stars in past epochs, 10 Myr. The time of the
maximum approach 32 pc of the host star with planetary system TOI-2796 with the
NGC 1977 are found. The place of approach in the sky is shown, this point can
be considered as the place of appearance of interstellar comets. Thus, the
result of our work is that the we found approach of the host star to the
cluster entailed effects associated with the gravitational influence of the
cluster on the nuclei of comets located in the outer parts of the Oort cloud of
the planetary system. The effect of approach on comets is estimated
Fabrication of functionalised surfaces on Gum metal (Ti-30Nb) using micromachining
Structured surfaces are attracting deep interest, as they allow tailoring the functionality via changes in the surface topography. Applications for these surfaces range greatly, including, optical surfaces for antireflective surfaces, thermal structures to assist in heat dispersion and anti-fouling surfaces to reduce micro-organisms from adhering to components. Gum metal is a relatively newer kind of beta titanium alloy that has earmarked its place as the next generation Ortheopedic implant material. In a timely effort, this work investigated the generation of micron level structured surfaces on Gum metal (Ti-30Nb – a beta titanium alloy) to explore micromilling as the robust scalable process to achieve low dimensional surfaces in titanium alloy. During micromilling, the feedrate, spindle speed, axial depth of cut and tool step over were varied to optimise these parameters for achieving superior quality of machining
Porohyperelastic anatomical models for hydrocephalus and idiopathic intracranial hypertension
This is the accepted manuscript of a paper published in the Journal of Neurosurgery, Published online February 6, 2015; DOI: 10.3171/2014.12.JNS14516.OBJECT Brain deformation can be seen in hydrocephalus and idiopathic intracranial hypertension (IIH) via medical images. The phenomenology of local effects, brain shift, and raised intracranial pressure and herniation are textbook concepts. However, there are still uncertainties regarding the specific processes that occur when brain tissue is subject to the mechanical stress of different temporal and spatial profiles of the 2 neurological disorders. Moreover, recent studies suggest that IIH and hydrocephalus may be diseases with opposite pathogenesis. Nevertheless, the similarities and differences between the 2 subjects have not been thoroughly investigated. METHODS An anatomical porohyperelastic finite element model was used to assess the brain tissue responses associated with hydrocephalus and IIH. The same set of boundary conditions, with the exception of brain loading for development of the transmantle pressure gradient, was applied for the 2 models. The distribution of stress and strain during tissue distortion is described by the mechanical parameters. RESULTS The results of both the hydrocephalus and IIH models correlated with pathological characteristics. For the hydrocephalus model, periventricular edema was associated with the presence of positive volumetric strain and void ratio in the lateral ventricle horns. By contrast, the IIH model revealed edema across the cerebral mantle, including the centrum semiovale, with a positive void ratio and volumetric strain. CONCLUSIONS The model simulates all the clinical features in correlation with the MR images obtained in patients with hydrocephalus and IIH, thus providing support for the role of the transmantle pressure gradient and capillary CSF absorption in CSF-related brain deformation. The finite element methods can be used for a better understanding of the pathophysiological mechanisms of neurological disorders associated with parenchymal volumetric fluctuation.Dr. M. Czosnyka is a consultant for J&J (Codman), and has received payment for lectures from Integra Lifescience. This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRFK) funded by the Ministry of Science, ICT, & Future Planning (2013R1A1A1004827); and the International Research & Development Program of the NRFK funded by the Ministry of Education, Science, and Technology of Korea (Grant No. 2014K1A3A1A21001366)
Development of carbonaceous tin-based solder composite achieving unprecedented joint performance
Weight reduction and improved strength are two common engineering goals in the joining sector to benefit transport, aerospace, and nuclear industries amongst others. Here, in this paper, we show that the suitable addition of carbon nanomaterials to a tin-based solder material matrix (C-Solder® supplied by Cametics Ltd.) results in two-fold strength of soldered composite joints. Single-lap shear joint experiments were conducted on soldered aluminium alloy (6082 T6) substrates. The soldering material was reinforced in different mix ratios by carbon black, graphene, and single-walled carbon nanotubes (SWCNT) and benchmarked against the pristine C-solder®. The material characterisation was performed using Vickers micro-indentation, differential scanning calorimetry and nano-indentation, whereas functional testing involved mechanical shear tests using single-lap aluminium soldered joints and creep tests. The hardness was observed to improve in all cases except for the 0.01 wt.% graphene reinforced solders, with 5% and 4% improvements in 0.05 carbon black and SWCNT reinforced solders, respectively. The maximum creep indentation was noted to improve for all solder categories with maximum 11% and 8% improvements in 0.05 wt.% carbon black and SWCNT reinforced ones. In general, the 0.05 wt.% nanomaterial reinforced solders promoted progressive cohesion failure in the joints as opposed to instantaneous fully de-bonded failure observed in pristine soldered joints, which suggests potential application in high-performance structures where no service load induced adhesion failure is permissible (e.g. aerospace assemblies). The novel innovation developed here will pave the way to achieving high-performance solder joining without carrying out extensive surface preparations
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Magnetic field assisted 3D printing of short carbon fibre-reinforced polymer composites
This paper investigates and discusses the outcomes from an ongoing feasibility research being conducted at Advanced Composites Research Focused Group on 3D printing polymers and carbon composites subjected to localised magnetic field force lines. Magnetic equipped composite processes are starting to become an important new development for structural applications. Specific to this paper, in-situ alignment of short carbon fibres (∼1 mm length) in thermoplastic polymer filaments (Onyx FR, a Nylon base with micro carbon-fibres with a flame retardant additive supplied by Markforged) during a fused deposition modelling (FDM) based 3D printing (MakerBot Replicator 2). An experiment took place in which samples of PLA and onyx were printed, both with and without a magnetic field present. This was done to see what effects, if any, the magnetic field had on the flow orientation of these materials when printed. The results from using a high-resolution optical microscopy and scanning electron microscopy showed that while carbon fibres within the Onyx had aligned in response to the magnetic field, the PLA samples were visibly unchanged by the magnetic field. The observations have been partially supported by theoretical calculations utilizing Multiphysics constitutive equations
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