2,614 research outputs found
Pengaruh Perlakuan Alkali Terhadap Kekuatan Tarik Serat Tandan Kosong Kelapa Sawit Untuk Digunakan Pada Komposit Serat Tkks
Empty Palm bunches (TKKS) is one of the solid waste generated by industrial palm oil plantations which contain lots of fiber and is one of the natural fiber source that the availability of abundant in Indonesia, especially in the province of Lampung. TKKS fiber can be used as an alternative amplifier to composite materials. This research was conducted to determine the influence of the chemical composition of TKKS fiber and know the tensile strength from TKKS fiber by doing a tensile test. Alkaline treatment NaOH 5% given to fiber to separate lignin and contaminants that contained in fiber so that it can increase the tensile strength fibers. TKKS fiber is obtained processing palm oil factory by the process of boiling oil palm fresh fruit bunches with a pressure of 2.5 until 3atm at temperature 130 C during 50 – 60 minutes. TKKS already parsed and then selected and measured with a length of 6 cm and a diameter of 0.2 mm. And then given an alkaline NaOH 5%. In this research on the treatment of alkaline NaOH 5% provided that treatment during 0 hours (without treatment), 2 hour, 4 hour, 6 hour. Results from the study found that fiber tensile strength affected by the chemical composition on the fiber, the higher the tensile strength of the cellulose content is increasingly high. Tensile strength in fiber with alkali treatment 2 hours of 0,03528 Mpa, 0,3996% strain, 0,088288 MPa elasticity modulus, if compared with fiber without alkali treatment of 0,018946 MPa tensile strength, 0,2056% strain, 0,092149 MPa elasticity modulus. This is due to the levels of cellulose fibers with alkali treatment 2 hours increased by 58,2808%, if compared with fiber without alkali treatment by 13,2848
Ultraviolet Radiation and the Slug Transcription Factor Induce Proinflammatory and Immunomodulatory Mediator Expression in Melanocytes
Despite extensive investigation, the precise contribution of the ultraviolet radiation (UVR) component of sunlight to melanoma etiology remains unclear. UVR induces keratinocytes to secrete proinflammatory and immunomodulatory mediators that promote inflammation and skin tumor development; expression of the slug transcription factor in keratinocytes is required for maximal production of these mediators. In the present studies we examined the possibility that UVR-exposed melanocytes also produce proinflammatory mediators and that Slug is important in this process. Microarray studies revealed that both UVR exposure and Slug overexpression altered transcription of a variety of proinflammatory mediators by normal human melanocytes; some of these mediators are also known to stimulate melanocyte growth and migration. There was little overlap in the spectra of cytokines produced by the two stimuli. However IL-20 was similarly induced by both stimuli and the NFκB pathway appeared to be important in both circumstances. Further exploration of UVR-induced and Slug-dependent pathways of cytokine induction in melanocytes may reveal novel targets for melanoma therapy
Coherent transport in a two-electron quantum dot molecule
We investigate the dynamics of two interacting electrons confined to a pair
of coupled quantum dots driven by an external AC field. By numerically
integrating the two-electron Schroedinger equation in time, we find that for
certain values of the strength and frequency of the AC field we can cause the
electrons to be localised within the same dot, in spite of the Coulomb
repulsion between them. Reducing the system to an effective two-site model of
Hubbard type and applying Floquet theory leads to a detailed understanding of
this effect. This demonstrates the possibility of using appropriate AC fields
to manipulate entangled states in mesoscopic devices on extremely short
timescales, which is an essential component of practical schemes for quantum
information processing.Comment: 4 pages, 3 figures; the section dealing with the perturbative
treatment of the Floquet states has been substantially expanded to make it
easier to follo
Narcotic administration and fall-related injury in the hospital: Implications for patient safety programs and providers
Objective: Identify factors that predict fall-related injury in hospitalized adults. Design: Retrospective cohort study. Setting: 435-bed university hospital. Participants: Inpatients with reported falls in 2010. Results: Medical records were available for 286/293 (98%) of reported falls in 251 patients. 25% (63/286) of falls were associated with injury, 4% (11/286) with serious injury. Compared to all fallers, patients with injury did not differ by gender or age. In univariate analysis, patients who reported hitting their head, had pre-fall confusion, or who received narcotics within 24 hours before falling were more likely to suffer injury (estimated odds ratios 6.04, 2.00 and 5.1, respectfully). In multivariate analysis, receiving a narcotic prior to falling was the strongest predictor of injury (estimated odds ratio 5.59; 95% confidence intervals 2.14 — 14.65, p \u3c0.001). Conclusions: In this single-institution study, 25% of patients who fell suffered injury and 4% serious injury. Neither age nor gender predicted fall-related injury. Recent narcotic administration was the strongest predictor of injury. Strategies to prevent fall-related injury in the hospital should target patients receiving narcotics. When evaluating inpatients who have fallen, providers should be especially vigilant about injury in patients who have pre-fall confusion, hit their head, or have received recent narcotics
Strong Coupling Theory of Two Level Atoms in Periodic Fields
We present a new convergent strong coupling expansion for two-level atoms in
external periodic fields, free of secular terms. As a first application, we
show that the coherent destruction of tunnelling is a third-order effect. We
also present an exact treatment of the high-frequency region, and compare it
with the theory of averaging. The qualitative frequency spectrum of the
transition probability amplitude contains an effective Rabi frequency.Comment: 4 pages with 3 figure
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