876 research outputs found
Evolution of optical properties of chromium spinels CdCrO, HgCrS, and ZnCrSe under high pressure
We report pressure-dependent reflection and transmission measurements on
ZnCrSe, HgCrS, and CdCrO single crystals at room
temperature over a broad spectral range 200-24000 cm. The pressure
dependence of the phonon modes and the high-frequency electronic excitations
indicates that all three compounds undergo a pressure-induced structural phase
transition with the critical pressure 15 GPa, 12 GPa, and 10 GPa for
CdCrO, HgCrS, and ZnCrSe, respectively. The
eigenfrequencies of the electronic transitions are very close to the expected
values for chromium crystal-field transitions. In the case of the chalcogenides
pressure induces a red shift of the electronic excitation which indicates a
strong hybridization of the Cr d-bands with the chalcogenide bands.Comment: Accepted for publication in Phys. Rev.
Drivers of Microbial Risk for Direct Potable Reuse and de Facto Reuse Treatment Schemes: The Impacts of Source Water Quality and Blending.
Although reclaimed water for potable applications has many potential benefits, it poses concerns for chemical and microbial risks to consumers. We present a quantitative microbial risk assessment (QMRA) Monte Carlo framework to compare a de facto water reuse scenario (treated wastewater-impacted surface water) with four hypothetical Direct Potable Reuse (DPR) scenarios for Norovirus, Cryptosporidium, and Salmonella. Consumer microbial risks of surface source water quality (impacted by 0-100% treated wastewater effluent) were assessed. Additionally, we assessed risks for different blending ratios (0-100% surface water blended into advanced-treated DPR water) when source surface water consisted of 50% wastewater effluent. De facto reuse risks exceeded the yearly 10-4 infections risk benchmark while all modeled DPR risks were significantly lower. Contamination with 1% or more wastewater effluent in the source water, and blending 1% or more wastewater-impacted surface water into the advanced-treated DPR water drove the risk closer to the 10-4 benchmark. We demonstrate that de facto reuse by itself, or as an input into DPR, drives microbial risks more so than the advanced-treated DPR water. When applied using location-specific inputs, this framework can contribute to project design and public awareness campaigns to build legitimacy for DPR
Diacritics improve comprehension of the Arabic script by providing access to the meanings of heterophonic homographs
The diacritical markers that represent most of the vowels in the Arabic orthography are generally omitted from written texts. Previous research revealed that the absence of diacritics reduces reading comprehension performance even by skilled readers of Arabic. One possible explanation is that many Arabic words become ambiguous when diacritics are missing. Words of this kind are known as heterophonic homographs and are associated with at least two different pronunciations and meanings when written without diacritics. The aim of the two experiments reported in this study was to investigate whether the presence of diacritics improves the comprehension of all written words, or whether the effects are confined to heterophonic homographs. In Experiment 1, adult readers of Arabic were asked to decide whether written words had a living meaning. The materials included heterophonic homographs that had one living and one non-living meaning. Results showed that diacritics significantly increased the accuracy of semantic decisions about ambiguous words but had no effect on the accuracy of decisions about unambiguous words. Consistent results were observed in Experiment 2 where the materials comprised sentences rather than single words. Overall, the findings suggest that diacritics improve the comprehension of heterophonic homographs by facilitating access to semantic representations that would otherwise be difficult to access from print
Teacher Effectiveness and Student Achievement in the Smart School Hyderabad
The study aimed to identify the role of effective teacher on student’s achievement in school, how teachers teaching can be effective and what are the qualities of effective teachers and how it can affect students learning. This study was conducted in Virtual university of Pakistan in Hyderabad campus, total of 266 respondents were selected to collect data from the school “ the smart school” Hyderabad from three different campuses of the school randomly from class 7, 8, 9 and 10 The main research of the study was on the teacher’s effective teaching and its effect of student’s achievements, the researcher used 5 points grading questionnaire paper in which 1: strongly disagree, 2: disagree, 3: neutral, 4: agree and 5: strongly agree was used in order to know the relationship between the variables. This research highlights the main theories and facts of effective teachers teaching, what teachers should adopt, how teachers can influence and keep students motivated towards learning and what are the effect of effective teachers on students' achievement, in their learning and grades
The Role of Technology Entrepreneurship in Higher Education Sector of Developing Countries: A Case Study of Pakistan
In modern theories of growth and development, technological innovation has taken the focus stage and such innovations are commercialized by technology entrepreneurs. Colleges and universities are investing heavily in the development of their student’s entrepreneurial skills and have tremendous impact on innovation and entrepreneurial development. Universities today equally function as an important driving force to enhance economic value by creation of networks with innovators across a region through their incubators and scientific and technology parks. In developed countries many entrepreneurs start up their companies at their universities but in developing countries there are so many challenges yet to be faced by new starts up. Technology entrepreneurship in education basically explores how technology entrepreneurs are applying business practices or technology innovations to transform education to lead to higher performance. As higher education industry is changing radically and that transformation is worth for commercial benefits of businesses and also for innovative startups. Today the presence of colleges and universities are not only meant to be the gatekeeper of knowledge and information instead various innovators are in flowing as entrepreneurs in education industry. This study will explore that in what ways technology entrepreneurship is facilitating the educator sector of the emerging economies specifically in Pakistan. Keywords: Technology entrepreneurship, High Education Sector, Developing economies, Business Incubation Centers
Effect of high pressure on multiferroic BiFeO3
We report experimental evidence for pressure instabilities in the model
multiferroic BiFeO3 and namely reveal two structural phase transitions around 3
GPa and 10 GPa by using diffraction and far-infrared spectroscopy at a
synchrotron source. The intermediate phase from 3 to 9 GPa crystallizes in a
monoclinic space group, with octahedra tilts and small cation displacements.
When the pressure is further increased the cation displacements (and thus the
polar character) of BiFeO3 is suppressed above 10 GPa. The above 10 GPa
observed non-polar orthorhombic Pnma structure is in agreement with recent
theoretical ab-initio prediction, while the intermediate monoclinic phase was
not predicted theoretically.Comment: new version, accepted for publication in Phys. Rev.
Discordant transmission of bacteria and viruses from mothers to babies at birth
BACKGROUND: The earliest microbial colonizers of the human gut can have life-long consequences for their hosts. Precisely how the neonatal gut bacterial microbiome and virome are initially populated is not well understood. To better understand how the maternal gut microbiome influences acquisition of the infant gut microbiome, we studied the early life bacterial microbiomes and viromes of 28 infant twin pairs and their mothers.
RESULTS: Infant bacterial and viral communities more closely resemble those of their related co-twin than unrelated infants. We found that 63% of an infant\u27s bacterial microbiome can be traced to their mother\u27s gut microbiota. In contrast, only 15% of their viral communities are acquired from their mother. Delivery route did not determine how much of the bacterial microbiome or virome was shared from mother to infant. However, bacteria-bacteriophage interactions were altered by delivery route.
CONCLUSIONS: The maternal gut microbiome significantly influences infant gut microbiome acquisition. Vertical transmission of the bacterial microbiome is substantially higher compared to vertical transmission of the virome. However, the degree of similarity between the maternal and infant gut bacterial microbiome and virome did not vary by delivery route. The greater similarity of the bacterial microbiome and virome between twin pairs than unrelated twins may reflect a shared environmental exposure. Thus, differences of the inter-generation transmissibility at birth between the major kingdoms of microbes indicate that the foundation of these microbial communities are shaped by different rules. Video Abstract
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