Atomic White-Out: Enabling Atomic Circuitry Through Mechanically Induced Bonding of Single Hydrogen Atoms to a Silicon Surface

We report the mechanically induced formation of a silicon-hydrogen covalent bond and its application in engineering nanoelectronic devices. We show that using the tip of a non-contact atomic force microscope (NC-AFM), a single hydrogen atom could be vertically manipulated. When applying a localized electronic excitation, a single hydrogen atom is desorbed from the hydrogen passivated surface and can be transferred to the tip apex as evidenced from a unique signature in frequency shift curves. In the absence of tunnel electrons and electric field in the scanning probe microscope junction at 0 V, the hydrogen atom at the tip apex is brought very close to a silicon dangling bond, inducing the mechanical formation of a silicon-hydrogen covalent bond and the passivation of the dangling bond. The functionalized tip was used to characterize silicon dangling bonds on the hydrogen-silicon surface, was shown to enhance the scanning tunneling microscope (STM) contrast, and allowed NC-AFM imaging with atomic and chemical bond contrasts. Through examples, we show the importance of this atomic scale mechanical manipulation technique in the engineering of the emerging technology of on-surface dangling bond based nanoelectronic devices.Comment: 9 pages (including references and Supplementary Section), 8 figures (5 in the main text, 3 in Supplementary

New fabrication technique for highly sensitive qPlus sensor with well-defined spring constant

A new technique for the fabrication of highly sensitive qPlus sensor for atomic force microscopy (AFM) is described. Focused ion beam was used to cut then weld onto a bare quartz tuning fork a sharp micro-tip from an electrochemically etched tungsten wire. The resulting qPlus sensor exhibits high resonance frequency and quality factor allowing increased force gradient sensitivity. Its spring constant can be determined precisely which allows accurate quantitative AFM measurements. The sensor is shown to be very stable and could undergo usual UHV tip cleaning including e-beam and field evaporation as well as in-situ STM tip treatment. Preliminary results with STM and AFM atomic resolution imaging at $4.5\,K$ of the silicon $Si(111)-7\times 7$ surface are presented.Comment: 5 pages, 3 figure

Binary Atomic Silicon Logic

It has long been anticipated that the ultimate in miniature circuitry will be crafted of single atoms. Despite many advances made in scanned probe microscopy studies of molecules and atoms on surfaces, challenges with patterning and limited thermal stability have remained. Here we make progress toward those challenges and demonstrate rudimentary circuit elements through the patterning of dangling bonds on a hydrogen terminated silicon surface. Dangling bonds sequester electrons both spatially and energetically in the bulk band gap, circumventing short circuiting by the substrate. We deploy paired dangling bonds occupied by one movable electron to form a binary electronic building block. Inspired by earlier quantum dot-based approaches, binary information is encoded in the electron position allowing demonstration of a binary wire and an OR gate

Arabic cultural/educational and linguistic background as factors affecting EFL writing performance

Effective communication in a foreign language depends on more thanknowing the rules of its lexicon, grammar, and phonology. It involvesthe processing of cultural as well as linguistic knowledge. Any formof communication (and language is one form of communication) has itsown strategies. The strategies of language communication varysystematically across languages and cultures. The differences in thegeneral ethos of one community as compared to another lead todifferences in the strategies of communication, as certain aspects ofthe communicative properties of languages might be culture- andlanguage-specific.As a result, foreign language learners might fail to communicateeffectively in the foreign language. This failure seems to be greatlydue to a transferance of the native-language communicative strategiesto the foreign language. The most appropriate way to solve thisproblem as suggested in this thesis, alongside many other foreignlanguage teachers and applied linguists, is contrastive language workthrough translation. Such approach makes possible the juxtaposition ofthe native language and the foreign language, thus allowing thestudents to see practically and for themselves the culturo-linguisticdifferences and similarities between the two languages. Otherwise,native language interference will persist and successful performancein the foreign language will not be achieved.The present study sets to investigate two major factors that seemto considerably affect Arab students' learning of English as a foreign language. First, the culturo- educational background which is almosttotally ignored as being the second major factor affecting foreignlanguage learning. Second, the linguistic (or mother tongue) factorwhich, though more researched, no appropriate solutions are yetprovided.Due to culturo-educational influence --dealt with in the firstpart of this thesis-- Arab students tend to approach the foreignlanguage in the same way they approach their native language. Theyseem to rely on memorization in the study of the foreign language andin their essay-writing. For this reason, they are often accused ofplagiarism, a practice for which the blame should not be laid uponthem alone. The Arab educational system should undergo- the biggestportion of the blame.Arab students, from a very young age and from the earliesteducational stage, the kuttaab, are instructed basically orally andtrained to rely heavily on their memories. Though such training suitsyoung children and the major subject they are taught (Qurlan), it doesnot stop at this stage, nor does it confine itself to that particularsubject. Rather, it escorts them up till university level and extendsto most subjects. A solution to get over such a problem as to EFLteaching is suggested in the concluding chapter to this thesis.The second major factor affecting foreign language learning--dealt with in the second part of this thesis-- is the influence fromthe native language, which is seen to manifest itself on the two majorlevels of language: the micro and the macro levels. The micro level oflanguage is that of the word and sentence. Influence at such a level appears from the early stages of foreign language learning. However,it is not as serious and as persistent as that at the macro level, ie.the discourse or text level. Here, Arab students often make gravedeviations from the norms of the foreign language. Such deviations,their nature, and their cultural and linguistic background arediscussed through the examination of the major rhetorical and textualcharacteristics pertaining to Arabic and English.Translation is proposed as an effective approach of teachingcomposition to advanced EFL students. Such approach, if appliedmethodically, will help students develop a much needed awareness ofthe textual pecularities of the, foreign language; an awareness whichwill sensitize them to the general linguistic differences and, inparticular, those of composing that exist between their mother tongueand the foreign language. Besides, it will certainly help them enlargemore quickly and more practically their EFL lexical and idiomaticrepertoire

Annealing effect on physical properties of evaporated molybdenum oxide thin films for ethanol sensing

This paper deals with some physical investigations on molybdenum oxide thin films growing on glass substrates by the thermal evaporation method. These films have been subjected to an annealing process under vacuum, air and oxygen at various temperatures 673, 723 and 773 K. First, the physical properties of these layers were analyzed by means of X-ray diffraction, Raman spectroscopy, scanning electron microscopy (SEM) and optical measurements. These techniques have been used to investigate the oxygen index in MoOx properties during the heat treatment. Second, from the reflectance and transmittance optical measurements, it was found that the direct band gap energy value increased from 3.16 to 3.90 eV. Finally, the heat treatments reveal that the oxygen index varies in such molybdenum oxides showing noticeably sensitivity toward ethanol gas

Faculty Members Perspectives on the Impact of Educational Technology on the Teaching and Learning Process at the University of Sharjah

Educational technology is increasingly being employed in universities to boost students learning and performance. It became a key component of communication, information storage and transmission, audio-visual media usage and creation, and knowledge sharing. The purpose of the study is to determine the impact of modern educational technologies on education quality and development at the College of Arts and Humanities at Sharjah University from the perspective of faculty members by developing a questionnaire with (20) items and distributing it to a random sample of (91) faculty members. According to the studys findings, the usage of educational technology has a significant impact on education, not just in terms of boosting instructors communication skills, instructional techniques, and advising students on how to utilize this technology. We actively support the employment of as much information technology as possible in the classroom in order to increase instructors abilities and students knowledge

Clinical effectiveness and safety of olaparib in BRCA-mutated, HER2-negative metastatic breast cancer in a real-world setting: final analysis of LUCY

Breast cancer; Olaparib; Progression-free survivalCàncer de mama; Olaparib; Supervivència lliure de progressióCáncer de mama; Olaparib; Supervivencia libre de progresiónPurpose The interim analysis of the phase IIIb LUCY trial demonstrated the clinical effectiveness of olaparib in patients with germline BRCA-mutated (gBRCAm), human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer (mBC), with median progression-free survival (PFS) of 8.11 months, which was similar to that in the olaparib arm of the phase III OlympiAD trial (7.03 months). This prespecified analysis provides final overall survival (OS) and safety data. Methods The open-label, single-arm LUCY trial of olaparib (300 mg, twice daily) enrolled adults with gBRCAm or somatic BRCA-mutated (sBRCAm), HER2-negative mBC. Patients had previously received a taxane or anthracycline for neoadjuvant/adjuvant or metastatic disease and up to two lines of chemotherapy for mBC. Results Of 563 patients screened, 256 (gBRCAm, n = 253; sBRCAm, n = 3) were enrolled. In the gBRCAm cohort, median investigator-assessed PFS (primary endpoint) was 8.18 months and median OS was 24.94 months. Olaparib was clinically effective in all prespecified subgroups: hormone receptor status, previous chemotherapy for mBC, previous platinum-based chemotherapy (including by line of therapy), and previous cyclin-dependent kinase 4/6 inhibitor use. The most frequent treatment-emergent adverse events (TEAEs) were nausea (55.3%) and anemia (39.2%). Few patients (6.3%) discontinued olaparib owing to a TEAE. No deaths associated with AEs occurred during the study treatment or 30-day follow-up. Conclusion The LUCY patient population reflects a real-world population in line with the licensed indication of olaparib in mBC. These findings support the clinical effectiveness and safety of olaparib in patients with gBRCAm, HER2-negative mBC. Clinical trial registration Clinical trials registration number: NCT03286842This study was funded by AstraZeneca and is part of an alliance between AstraZeneca and Merck Sharp & Dohme LLC, a subsidiary of Merck & Co., Inc., Rahway, NJ, USA. The funding source was involved in the study design, analysis, data interpretation, writing of the manuscript, and the decision to submit the article for publication