1,852 research outputs found

    Finite Element Analysis of Slab and a Comparative Study with Others Analytical Solution

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    Slabs are one of the most widely used structural elements. The function of slabs is to resist loads normal to their plane. In many structures, in addition to support transverse load, the slab also forms an integral portion of the structural frame to resist lateral load. Inspite of their widespread use, there has never been a universally accepted method of designing all slabs systems. The paper presents finite element analysis of slabs. The finite element method is chosen as this is more powerful and versatile compared to other numerical methods. A slab element is developed on the basis of conventional slab theory expressed in terms of rectangular co-ordinates and displacement. The element incorporates 20 degree of freedom, namely, normal displacement with its first derivatives along longitudinal and transverse direction respectively and two tangential displacements. A computer program is developed for solution of finite element equations as well as to check rigid body modes and to obtain the results. The results are compared with analytical solution and previously developed finite element solution with the help of a table

    CP violation in the decay mode BπγγB\to \pi \gamma \gamma

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    Within the framework of Standard Model, the exclusive decay mode BπγγB\to \pi \gamma \gamma is studied. Although the usual short distance contribution is small compared to the similar BKγγB\to K\gamma\gamma mode, the process offers the possibility of studying the CP violation, a feature absent in the BKB \to K counterpart.Comment: 11 page latex file including 2 ps figures. Typos corrected, minor changes. To appear in PR

    Improvement of third-order intermodulation product of RF and microwave amplifiers by injection

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    This paper discusses the improvement in the third-order intermodulation product (IM3) performance obtainable from RF and microwave amplifiers by two alternative injection techniques. The first is the addition to the amplifier input of the second harmonics of the input spectrum and the second is the addition to the amplifier input of the difference frequencies between the spectral components of the input signal. Both techniques are considered in theory, by simulation and in practice. Both techniques give useful improvements in two-tone IM3 performance. The second harmonic technique reduced the IM3 level by 43 dB in an amplifier at 835 MHz. The difference-frequency technique gave a reduction of 48 dB in an amplifier at 880 MHz. The difference-frequency technique also gives a greater improvement for complex spectra signal

    Association between disability measures and healthcare costs after initial treatment for acute stroke

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    <p><b>Background and Purpose:</b> The distribution of 3-month modified Rankin scale (mRS) scores has been used as an outcome measure in acute stroke trials. We hypothesized that hospitalization and institutional care home stays within the first 90 days after stroke should be closely related to 90-day mRS, that each higher mRS category will reflect incremental cost, and that resource use may be less clearly linked to the National Institutes of Health Stroke Scale (NIHSS) or Barthel index.</p> <p><b>Methods:</b> We examined resource use data from the GAIN International trial comparing 90-day mRS with total length of stay in hospital or other institutions during the first 90 days. We repeated analyses using NIHSS and Barthel index scores. Relationships were examined by analysis of variance (ANOVA) with Bonferroni contrasts of adjacent score categories. Estimated costs were based on published Scottish figures.</p> <p><b>Results:</b> We had full data from 1717 patients. Length of stay was strongly associated with final mRS (P<0.0001). Each mRS increment from 0 to 1–2 to 3–4 was significant (mean length of stay: 17, 25, 44, 58, 79 days; P<0.0005). Ninety-five percent confidence limits for estimated costs (£) rose incrementally: 2493 to 3412, 3369 to 4479, 5784 to 7008, 7300 to 8512, 10 095 to 11 141, 11 772 to 13 560, and 2623 to 3321 for mRS 0 to 5 and dead, respectively. Weaker relationships existed with Barthel and NIHSS.</p> <p><b>Conclusions:</b> Each mRS category reflects different average length of hospital and institutional stay. Associated costs are meaningfully different across the full range of mRS outcomes. Analysis of the full distribution of mRS scores is appropriate for interpretation of treatment effects after acute stroke and more informative than Barthel or NIHSS end points.</p&gt

    Effect of ethanolic extract of beet roots and leaves on motor coordination in male Wistar rats

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    زمینه و هدف: عدم تعادل حرکتی در اثر عوامل مختلفی از جمله ضایعات مغزی عصبی، مشکلات عضلانی، کم خونی و مصرف داروها رخ می دهد. گیاه چغندر با نام علمی Beta vulgaris L. دارای اثرات متنوع از جمله اثرات ضد التهابی، آنتی اکسیدانی، ضد استیل کولین استرازی و کاهش قند خون می باشد که در این مطالعه اثر عصاره اتانولی برگ و ریشه این گیاه بر تعادل حرکتی بررسی شده است. روش بررسی: در این مطالعه تجربی عصاره اتانولی ریشه و برگ گیاه چغندر به روش ماسراسیون تهیه شد. موش های صحرایی نر بالغ به طور تصادفی در 7 گروه 8 تایی تقسیم شدند و به مدت 25 روز آب مقطر، دوزهای مختلف عصاره ریشه (250،500 و mg/kg1000) و برگ چغندر (50 و mg/kg100) را به صورت داخل صفاقی دریافت کردند. روز 26، نیم ساعت بعد از آخرین تزریق قدرت حفظ تعادل حرکتی موش ها به وسیله روتارود اندازه گیری شد. یافته ها: عصاره ریشه چغندر در دوزهای 500 و mg/kg1000 سبب افزایش معنی دار در تعادل حرکتی شد (p0.05). نتیجه گیری: عصاره های ریشه و برگ گیاه چغندر باعث بهبود فعالیت حرکتی در موش های صحرایی نر بالغ می شود

    Тенденції розвитку світового ринку логістики

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    Розвиток світового ринку логістики в 21-му столітті визначається достатньо суперечливими тенденціями. Будучи, по своїй природі, складовою інфраструктурного сектору міжнародної економіки, світовий транспортно-логістичний комплекс знаходиться в залежному положенні від галузей матеріально-речового виробництва. Тому кризові явища у виробничій сфері не можуть не позначатися на світовому ринку логістичних послуг. Водночас, логістичний ринок сам виступає чинником інтенсифікації та оптимізації виробництва. Тому виробничий сектор та сектор транспорно – логістичних послуг є взаємопов’язані складним чином, але мають дещо відмінну один від одного динаміку та тенденції розвитку. При цитуванні документа, використовуйте посилання http://essuir.sumdu.edu.ua/handle/123456789/2639

    Seroprevalence and risk factors of Toxoplasma gondii infection among healthy blood donors in south‐east of Iran

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    This prospective cross-sectional study was aimed to evaluate the prevalence of IgM and IgG anti-T. gondii antibodies and the associated risk factors among healthy blood donors in Kerman province, south-eastern Iran. Structured questionnaires (before the donors gave blood) were used to obtain information on risk factors for infection. Totally, 500 serum samples from healthy blood donors of Kerman Blood Transfusion Organization (KBTO) at Kerman, Iran, were screened for IgG and IgM anti-T. gondii antibodies by enzyme-linked immunosorbent assay (ELISA) and Roche Elecsys Toxo IgM assay. Real-time PCR was used to detect DNA of T. gondii in the IgM-positive samples. Seroprevalence of IgG and IgM anti-T. gondii antibodies was 28�8% and 3�2%, respectively. In the multiple logistic regression, it could be observed that living in rural regions, having B blood type, being in contact with cats, consuming raw vegetables and raw milk/egg and doing agricultural activities were independent risk factors for Toxoplasma seropositivity. T. gondii DNA was also found in one (9�0%) of IgM-positive samples. In this study, it was found that T. gondii infection was present among healthy blood donors in south-east of Iran. Therefore, it is suggested to design screening programmes for preventing transfusion-transmitted toxoplasmosi

    Impurity induced resonant state in a pseudogap state of a high temperature superconductor

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    We predict a resonance impurity state generated by the substitution of one Cu atom with a nonmagnetic atom, such as Zn, in the pseudogap state of a high-T_c superconductor. The precise microscopic origin of the pseudogap is not important for this state to be formed, in particular this resonance will be present even in the absence of superconducting fluctuations in the normal state. In the presence of superconducting fluctuations, we predict the existence of a counterpart impurity peak on a symmetric bias. The nature of impurity resonance is similar to the previously studied resonance in the d-wave superconducting state.Comment: 4 pages, 2 figure
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