318 research outputs found

    Simulation of ion behavior in an open three-dimensional Paul trap using a power series method

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    Simulations of the dynamics of ions trapped in a Paul trap with terms in the potential up to the order 10 have been carried out. The power series method is used to solve numerically the equations of motion of the ions. The stability diagram has been studied and the buffer gas cooling has been implemented by a Monte Carlo method. The dipole excitation was also included. The method has been applied to an existing trap and it has shown good agreement with the experimental results and previous simulations using other methods

    Doubling the Number of Connected Devices in Narrow-band Internet of Things while Maintaining System Performance: An STC-based Approach

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    Narrow-band Internet of Things (NB-IoT) is a low-power wide-area network (LPWAN) method that was first launched by the 3rd generation partnership project (3GPP) Rel- 13 with the purpose of enabling low-cost, low-power and wide-area cellular connection for the Internet of Things (IoT). As the demand for over-the-air services grows and with the number of linked wireless devices reaching 100 billion, wireless spectrum is becoming scarce, necessitating creative techniques that can increase the number of connected devices within a restricted spectral resource in order to satisfy service needs. Consequently, it is vital that academics develop efficient solutions to fulfill the quality of service (QoS) criteria of the NB-IoT in the context of 5th generation (5G) and beyond. This study paves the way for 5G networks and beyond to have increased capacity and data rate for NB-IoT. Whereas, this article suggests a method for increasing the number of connected devices by using a technique known as symbol time compression (STC). The suggested method compresses the occupied bandwidth of each device without increasing complexity, losing data throughput or bit error rate (BER) performance. The STC approach is proposed in the literature to work with the conventional orthogonal frequency division multiplexing (OFDM) to reduce bandwidth usage by 50% and improve the peak-to-average power ratio (PAPR). Specifically, An STC-based method is proposed that exploits the unused bandwidth to double the number of connected devices while keeping system performance and complexity. Furthermore, the {\mu}-law companding technique is leveraged to reduce the PAPR of the transmitted signals. The obtained simulation results reveal that the proposed approach using the {\mu}-law companding technique increases the transmitted data by twice and reduces the PAPR by 3.22 dB while maintaining the same complexity and BER

    Plasma Β-Endorphin and Cortisol Profiles around Periparturient Period at Stressful Conditions in Egyptian Buffalo

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    The study determined the level of plasma β-endorphin and cortisol concentrations in peripheral blood circulation of buffalo cows suffering from reproductive disorders (dystocia and retained placenta) and weakness body condition score during periparturient period. Twenty multi-parous Egyptian buffalo cows at late pregnancy period were used for two months before parturition. β-endorphin concentrations were higher in buffalo suffering from reproductive disorders groups. Whereas, β-endorphin concentrations were 134.9±4.8 for retained placenta, 121.3±4.9 for dystocia, 114.2±8.4 for weakness and 113.5±6.5 pg/ml for control. In the closer period around parturition both of plasma β-endorphin and cortisol followed the same trend toward a gradually increased values during -2,-1days and zero time in all groups. A concomitant trend was noticed in β-endorphin and cortisol concentrations in postpartum period with reduce values were observed in all groups after parturition continued for month or more. Buffalo suffering from reproductive disorders were showed a high relative values in β-endorphin and cortisol concentrations. A significant differences (P<0.01) were observed between the experimental groups. Generally, buffaloes suffering reproductive disorders had a clear impact on blood plasma β-endorphin concentration around parturition process.The aim of this study was to determine the relationship between various reproductive disorders as a stress factors with plasma β–endorphin and cortisol in buffalo cows around parturition and changes in these parameters could be used as an objective measure of the stress associated labour. Stress has been hypothesized to be a cause of impaired reproductive efficiency. Stress may cause an overproduction of beta-endorphins and free radical

    Effect of vitamin B17 on experimentally induced colon cancer in adult male albino rat

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    Background: Colon cancer is considered to be the third most common cancer worldwide. At diagnosis of colon cancer, 3.7–11% developed bone metastasis. Diet based strategies are important for prevention and treatment of colon cancer. This study investigated the effect of vitamin B17 on a DMH induced rat model of colon cancer. Materials and methods: Eighty young adult male albino rats were divided into five groups: group I (control group), group II (vitamin B17), group III (colon cancer), group IV (protected) and group V (treated). Distal colon sections were prepared for light and scanning electron microscopic examination. Lumbar vertebrae specimens were prepared for light microscopic study. Morphometric and statistical analysis were done. Results: In comparison with the control, both colon cancer and treated groups showed invasion of the colonic tissue by pleomorphic branching colonic glands of variable shapes and sizes lined with dysplastic elongated hyperchromatic nuclei with frequent mitotic figures or stratified multi-layered crowded nuclei with an extremely significant (p < 0.0001) reduction of goblet cell number when compared to the control together with major pathological bone changes were observed in colon cancer and the treated groups. Conclusions: While the protected group showed impressive improvement of all previously mentioned diameters

    Građa i optička svojstva tankih polikristaliničnih slojeva CuGaxIn1−xSe2

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    Structural and optical properties of CuGaxIn1−xSe2 (0 ≤ x ≤ 0.75) polycrystalline thin films deposited by vacuum evaporation were studied as a function of composition. The optical absorption spectra of CuGaxIn1−xSe2 thin films (x /=0) show four energy gaps (Eg1 , Eg2 , Eg3 and Eg4 ) which are attributed to the fundamental edge, band splitting by crystal-field and spin-orbit splitting, and to transitions originating from copper 3d levels, respectively. The primary transition energies exhibit bowing behaviour expressed by the relationship Eg1 (x) = 1.011 + 0.448x + 0.186x 2 . The second and third transition energies are higher than the primary transition energies by 0.10–0.11 eV and 0.18–0.185 eV, respectively. The effect of thermal treatment on the values of energy gaps is discussed in terms of the structure of the films. The primary transition energies of annealed CuGaxIn1−xSe2 can be fitted by the parabolic form Eg1 (x) = 1.04 + 0.46x + 0.22x 2 .Proučavali smo strukturna i optička svojstva tankih polikristaliničnih slojeva CuGaxIn1−xSe2, isparenih u vakuumu, u ovisnosti o sastavu (0 ≤ x ≤ 0.75). Optički apsorpcijski spektri tankih slojeva CuGaxIn1−xSe2, (x /=0), pokazuju četiri energijska procijepa (Eg1 , Eg2 , Eg3 i Eg4 ) koji se pridjeljuju osnovnom rubu, cijepanju vrpci kristalnim poljem i cijepanju spin-staza, odnosno prijelazima iz 3d stanja bakra. Prvotni prijelazi pokazuju kvadratnu ovisnost koju izražavamo relacijom Eg1 (x) = 1.011 + 0.448x + 0.186x 2 . Druga i treća prijelazna energija su (0.10 − 0.11 eV) odnosno (0.18 − 0.185 eV) više od primarne prijelazne energije. Pomoću građe slojeva objašnjavamo učinak toplinske obrade na vrijednosti energijskih procijepa. Prvotne prijelazne energije opuštenog CuGaxIn1−xSe2 mogu se predstaviti kvadratnim izrazom Eg1 (x) = 1.04 + 0.46x + 0.22x 2

    Građa i optička svojstva tankih polikristaliničnih slojeva CuGaxIn1−xSe2

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    Structural and optical properties of CuGaxIn1−xSe2 (0 ≤ x ≤ 0.75) polycrystalline thin films deposited by vacuum evaporation were studied as a function of composition. The optical absorption spectra of CuGaxIn1−xSe2 thin films (x /=0) show four energy gaps (Eg1 , Eg2 , Eg3 and Eg4 ) which are attributed to the fundamental edge, band splitting by crystal-field and spin-orbit splitting, and to transitions originating from copper 3d levels, respectively. The primary transition energies exhibit bowing behaviour expressed by the relationship Eg1 (x) = 1.011 + 0.448x + 0.186x 2 . The second and third transition energies are higher than the primary transition energies by 0.10–0.11 eV and 0.18–0.185 eV, respectively. The effect of thermal treatment on the values of energy gaps is discussed in terms of the structure of the films. The primary transition energies of annealed CuGaxIn1−xSe2 can be fitted by the parabolic form Eg1 (x) = 1.04 + 0.46x + 0.22x 2 .Proučavali smo strukturna i optička svojstva tankih polikristaliničnih slojeva CuGaxIn1−xSe2, isparenih u vakuumu, u ovisnosti o sastavu (0 ≤ x ≤ 0.75). Optički apsorpcijski spektri tankih slojeva CuGaxIn1−xSe2, (x /=0), pokazuju četiri energijska procijepa (Eg1 , Eg2 , Eg3 i Eg4 ) koji se pridjeljuju osnovnom rubu, cijepanju vrpci kristalnim poljem i cijepanju spin-staza, odnosno prijelazima iz 3d stanja bakra. Prvotni prijelazi pokazuju kvadratnu ovisnost koju izražavamo relacijom Eg1 (x) = 1.011 + 0.448x + 0.186x 2 . Druga i treća prijelazna energija su (0.10 − 0.11 eV) odnosno (0.18 − 0.185 eV) više od primarne prijelazne energije. Pomoću građe slojeva objašnjavamo učinak toplinske obrade na vrijednosti energijskih procijepa. Prvotne prijelazne energije opuštenog CuGaxIn1−xSe2 mogu se predstaviti kvadratnim izrazom Eg1 (x) = 1.04 + 0.46x + 0.22x 2

    Deterministic seismic hazard assessment for Sultanate of Oman

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    The Sultanate of Oman forms the southeastern part of the Arabian plate, which is surrounded by relatively high active tectonic zones. Studies of seismic risk assessment in Oman have been an important on-going socioeconomic concern. Using the results of the seismic hazard assessment to improve building design and construction is an effective way to reduce the seismic risk. In the current study, seismic hazard assessment for the Sultanate of Oman is performed through the deterministic approach with particular attention on the uncertainty analysis applying a recently developed method. The input data set contains a defined seismotectonic model consisting of 26 seismic zones, maximum magnitudes, and 6 alternative ground motion prediction equations that were used in four different tectonic environments: obduction zone earthquake (Zagros fold thrust belt), subduction zone earthquakes (Makran subduction zones), normal and strike-slip transform earthquakes (Owen and Gulf of Aden zones), and stable craton seismicity (Arabian stable craton). This input data set yielded a total of 76 scenarios at each point of interest. A 10 % probability that any of the 76 scenarios may exceed the largest median ground acceleration is selected. The deterministic seismic hazards in terms of PGA, 5 % damped spectral acceleration at 0.1, 0.2, 1.0 and 2.0 s are performed at 254 selected points. The ground motion was calculated at the 50th and 84th percentile levels for selected probability of exceeding the median value. The largest ground motion in the Sultanate of Oman is observed in the northeastern part of the country.Oman Ministerial Cabinet (Project 22409017

    Probabilistic seismic hazard maps for the sultanate of Oman

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    This study presents the results of the first probabilistic seismic hazard assessment (PSHA) in the framework of logic tree for Oman. The earthquake catalogue was homogenized, declustered, and used to define seismotectonic source model that characterizes the seismicity of Oman. Two seismic source models were used in the current study; the first consists of 26 seismic source zones, while the second is expressing the alternative view that seismicity is uniform along the entire Makran and Zagros zones. The recurrence parameters for all the seismogenic zones were determined using the doubly bounded exponential distribution except the zones of Makran, which were modelled using the characteristic distribution. Maximum earthquakes were determined and the horizontal ground accelerations in terms of geometric mean were calculated using ground-motion prediction relationships developed based upon seismic data obtained from active tectonic environments similar to those surrounding Oman. The alternative seismotectonic source models, maximum magnitude, and ground-motion prediction relationships were weighted and used to account for the epistemic uncertainty. Hazard maps at rock sites were produced for 5 % damped spectral acceleration (SA) values at 0.1, 0.2, 0.3, 1.0 and 2.0 s spectral periods as well as peak ground acceleration (PGA) for return periods of 475 and 2,475 years. The highest hazard is found in Khasab City with maximum SA at 0.2 s spectral period reaching 243 and 397 cm/s[superscript 2] for return periods 475 and 2,475 years, respectively. The sensitivity analysis reveals that the choice of seismic source model and the ground-motion prediction equation influences the results most.Oman Ministerial Cabinet (project number 22409017

    Decay constants, semi-leptonic and non-leptonic decays in a Bethe-Salpeter Model

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    We evaluate the decay constants for the B and DD mesons and the form factors for the semileptonic decays of the B meson to DD and DD^* mesons in a Bethe-Salpeter model. From data we extract Vcb=0.039±0.002V_{cb}=0.039 \pm 0.002 from BˉDlνˉ{\bar B} \to D^* l {\bar{\nu}} and Vcb=0.037±0.004V_{cb}=0.037 \pm 0.004 from BˉDlνˉ{\bar B} \to D l {\bar{\nu}} decays. The form factors are then used to obtain non-leptonic decay partial widths for BDπ(K) B\to D \pi (K) and BDD(Ds)B \to D D (D_s) in the factorization approximation.Comment: 15 Pages, 3 Postscript figures (available also from [email protected]

    Some Functional, Chemical, and Sensory Characteristics of Cactus Pear Rice-Based Extrudates

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    ABSTRACT Both orange-yellow and red cactus pear pulps were concentrated (to 40ºBrix), and then added to rice grits to produce a delectable product of rice-based extrudates. Both concentrated pulps were added to rice grits in five levels 0, 5, 10, 15 and 20%. The effects of added concentrated pulps on some physical (expansion ratio (ER), bulk density (BD), water absorption index (WAI), water solubility index (WSI), breaking strength (BS), and color attributes (L*, a* and b*); chemical (moisture, total carbohydrate, crude protein, crude fat and ash); and sensory (taste, crispness, chewiness, odor, color, pore distribution, surface characteristics, and overall acceptability) characteristics of extruded products were evaluated. The expansion ratio (ER), water absorption index (WAI), and water soluble index (WSI) of all products decreased by increasing the added concentrated-pulp ratio, while breaking strength (BS) decreased up to 10% of the added ratio, then increased. Bulk density, ash content and color attributes (a* and b*) increased for all extruded products. Adding both concentrated cactus pear pulps to rice flour extremely enhanced the sensory characteristics of final extruded products, and the obtained results showed the possibility of producing a new value-added snack-type extrudate based on cactus pear pulp concentrates
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