81,521 research outputs found
2D simulation of transient enhanced boron out-diffusion from the base of a SiGe HBT due to an extrinsic base implant
No full textTransient enhanced diffusion of boron in SiGe HBTs is studied by comparing measurements of the temperature dependence of the collector current with the predictions of 2D process and device simulations. The collector current is chosen for modelling because it is extremely sensitive to very small amounts of out-diffusion from the SiGe base, and hence provides a rigorous test for the accuracy of the transient enhanced diffusion models. The SiGe HBT studied incorporates an ion implanted extrinsic base adjacent to the SiGe base, which allows the influence of the implantation damage on the boron diffusion to be studied. The process simulations show that point defects generated by the extrinsic base implant lead to a broadening of the basewidth around the perimeter of the emitter due to transient enhanced diffusion of boron from the SiGe base. This causes parasitic energy barriers to form, which in the worst case, extend laterally several microns from the edge of the extrinsic base. The electrical effect of the transient enhanced diffusion is a decrease in collector current as the emitter geometry is reduced. Transistors with different emitter geometries and undoped SiGe spacer thicknesses are studied and the collector/base reverse bias is varied to modulate the parasitic energy barrier at the collector/base junction. The trends in the measured collector current are in all cases well predicted by a simplified "plus one" transient enhanced diffusion model
Nanomaterials as alternative control means against postharvest diseases in fruit crops
No full textPost-harvest diseases of fruit and vegetables have to be controlled because of the high added value of commodities and the great economic loss related to spoilage. Synthetic fungicides are the first choice worldwide to control post-harvest diseases of fruit and vegetables. However, several problems and constraints related to their use have forced scientists to develop alternatives control means to prevent post-harvest diseases. Physical and biological means, resistance inducers, and GRAS (generally recognized as safe) compounds are the most important alternatives used during the last 20 years. Recently, nanomaterial treatments have demonstrated promising results and they are being investigated to reduce the utilization of synthetic fungicides to control post-harvest rot in fruit and vegetables. The collective information in this review article covers a wide range of nanomaterials used to control post-harvest decays related to each selected fruit crop including grape, citrus, banana, apple, mango, peach, and nectarine. Other examples also used are apricot, guava, avocado, papaya, dragon, pear, longan, loquat, jujubes, and pomegranate fruits
Fig. 3. – Telipogon peruvianus T. Hashim. A in Notes and emended description of Telipogon peruvianus T. Hashim. (Orchidaceae)
No full textFig. 3. – Telipogon peruvianus T. Hashim. A. Habit; B. Sepals in dorsal view; C. Anther in frontal view; D. Anther in dorsal view; E. Pollinarium in frontal view; F. Pollinarium in dorsal view; G. Column in frontal view; H. Column in lateral view; I. Sepals, petals and lip. [Nauray & Farfán 3765, MOL] [Drawn by W. Nauray]Published as part of Martel, Carlos & Huari, William Nauray, 2013, Notes and emended description of Telipogon peruvianus T. Hashim. (Orchidaceae), pp. 245-250 in Candollea 68 (2) on page 249, DOI: 10.15553/c2012v682a8, http://zenodo.org/record/574725
Video interview with author and manuscript owner Professor Sa’adiya Omar
No full textFieldwork Team: Dr. Mustapha Hashim Kurfi (Principal Investigator), Hauwa Usman (Local Project Manager), Alhaji Abubakar Maikudi Aishat (General Field Facilitator). Technical Team: Prof. Fallou Ngom (Project Director and former Director of the African Studies Center), and Eleni Castrol (Technical Lead, BU Libraries). These collections on Gender in Nigerian Ajami Manuscripts are copied as part of the African Studies Center’s African Ajami Library. Access Condition and Copyright: These materials are subject to copyright. All rights reserved to the author. For use, distribution or reproduction contact Professor Fallou Ngom ([email protected]). Required Citation: Kurfi, M. H., Hauwa U., Ngom, F., and Castro, E. (2020). African Ajami Library: Gender in Nigerian Ajami Manuscripts. Boston: Boston University Libraries: http://hdl.handle.net/2144/41953. For Inquiries: Please Contact Professor Fallou Ngom ([email protected]).Video interview with author and manuscript owner Professor Sa’adiya Omar. Professor Sa’adiya Omar, the most celebrated author of women in the Sokoto Caliphate of Northern Nigeria. Professor Sa’adiya currently occupies the position of Nana Asma’u and Modibbo Kilo, the leaders of the Yantaru movement, i.e. Uwartaru (the Mother of the Yantaru). Equally, she had served as the National Amirah (President) of the largest Muslim umbrella organization in Nigeria – Federation of Muslim Women’s Associations in Nigeria (FOMWAN). As at the present, she serves in many capacities and is a member of various Islamic committees in Sokoto state and in Nigeria in general
Results of the Heart Protection Study: Can we still assume a class effect?
No full textStatins share several common features including the mechanism of action, i.e. inhibition of HMG-CoA reductase, as well as LDL-cholesterol (LDL-C) and triglyceride lowering properties. However, statins show minor differences in chemical structure, lipophilicity that could translate into a different pharmacological properties. For example, simvastatin exerted a more favorable effect on HDL-C levels than did atorvastatin when higher doses of the two drugs were compared. Finally, the major considerations to chose between statins for CVD patient therapy include clinical benefits and safety (i.e. evidence-based medicine). Primary prevention trials with pravastatins and lovastatin and secondary prevention trials with pravastatin, fluvastatin and simvastatin have established the clinical benefits of statins. In addition, HPS study was designed to investigate the benefits of simvastatin 40 mg in a broad range of patients at high risk for heart disease including women, the elderly and those with a history of hearth attacks, diabetes, hypertension or vascular disease. The results show the ability of simvastatin to reduce all causes of mortality, vascular death and cardiovascular morbidity. The trial also confirms the safety of simvastatin 40 mg although 60% of patients were receiving additional pharmacological treatment. In summary, it appears that statins are not the same and the choice of the more appropriate statin in high-risk patients should be driven by the evidence-based medicine both in terms of safety and efficacy
Current mode group delay equalisation using pole-zero mirroring techniques
No full textThis paper describes a new efficient method for designing current mode group delay equaliers. The method is based on introducing zeros into the right-hand s-plane by mirroring the poles of an LC ladder network. This is achieved by developing a current mode model capable of implementing the pole-zero mirroring technique. Using MO-OTA and grounded capacitors, the model is used to derive an nth-order active group-delay equaliser structure which is simpler, has better correction accuracy and is less sensitive when compared to cascaded based equaliers. The equaliser design involves two optimisation algorithms. Simulated and measured results demonstrate that the equaliser can effectively compensate the delay characteristics of a 7th-order 5.75MHz lowpass elliptic video filter to < 5ns ripple over 90% of the filter passband
Investigation on Optimized Flavonoid Extraction from Leucas zeylanica and Its Anthelmintic Activity
No full textExtraction has been the primary method of concentrating and obtaining a crude essence of plants, and to an extend fruits and nuts. In modern times, there are many methods of extraction developed from simple maceration to using Soxhlet extractor to microwave assisted extraction and ultrasound assisted extraction. However, the more time saving and energy efficient method for the extraction of plants needs to be investigated. This research explored optimization of ultrasound assisted extraction of flavonoids from Leucas zeylanica and the optimization was done on parameters of sonication time (minutes), water bath temperature (°C), volume of solvent to solid ratio (ml/g) and solvent concentration (%) using response surface methodology (RSM). By measuring the total flavonoid content using aluminium colorimetric method and UV visible spectrophotometry, highest flavonoid yield is achieved with 30.38% increase compared to unoptimized method. This occurred with sonication time of 42 minutes, temperature of 55°C, solvent to solid ratio of 40 ml/g and solvent concentration of 100%. The resulting extract was then tested for its anthelmintic (anti-worm) ability, obtaining 40% efficacy of that of Albendazole
A Relational Unsupervised Approach to Author Identification
No full textIn the last decades speaking and writing habits have changed.
Many works faced the author identification task by exploiting frequencybased
approaches, numeric techniques or writing style analysis. Following
the last approach we propose a technique for author identification
based on First-Order Logic. Specifically, we translate the complex data
represented by natural language text to complex (relational) patterns
that represent the writing style of an author. Then, we model an author
as the result of clustering the relational descriptions associated to the
sentences. The underlying idea is that such a model can express the typical
way in which an author composes the sentences in his writings. So,
if we can map such writing habits from the unknown-author model to
the known-author model, we can conclude that the author is the same.
Preliminary results are promising and the approach seems viable in real
contexts since it does not need a training phase and performs well also
with short texts
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Also By The Same Author: AKTiveAuthor, a Citation Graph Approach to Name Disambiguation
No full textThe desire for definitive data and the semantic web drive for inference over heterogeneous data sources requires co-reference resolution to be performed on those data. In particular, name disambiguation is required to allow accurate publication lists, citation counts and impact measures to be determined. This paper describes a graph-based approach to author disambiguation on large-scale citation networks. Using self-citation, co-authorship and document source analyses, AKTiveAuthor clusters papers, achieving precision of 0.997 and recall of 0.818 over a test group of eight surname clusters
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