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Effects of time and diffusion phase-lags in a thick circular plate due to a ring load with axisymmetric heat supply
Get PDFThe purpose of this paper is to depict the effect of time, thermal, and diffusion phase lags due to axisymmetric heat supply in a ring. The problem is discussed within the context of DPLT and DPLD models. The upper and lower surfaces of the ring are traction-free and subjected to an axisymmetric heat supply. The solution is found by using Laplace and Hankel transform techniques. The analytical expressions of displacements, stresses and chemical potential, temperature and mass concentration are computed in transformed domain. Numerical inversion technique has been applied to obtain the results in the physical domain. Numerically simulated results are depicted graphically. The effect of time, diffusion, and thermal phase-lags are shown on the various components. Some particular results are also deduced from the present investigation
Weighted Inequalities for Riemann-Stieltjes Integrals
Get PDFIn this paper first we define a new functional which is a weighted version of the functional defined by Dragomir and Fedotov. Then, some inequalities involving this functional are obtained. Finally, we apply this result to establish new bounds for weighted Chebysev functional
Temperature and probe-to-probe variability effects on the performance of capacitance soil moisture sensors in an oxisol
No full textReliable and accurate monitoring of soil water content (θ) across the landscape is indispensable for many water resources applications. Capacitance-based in situ soil water content measuring devices are extensively used despite their sensitivity to soil properties besides water content, e.g., temperature and organic matter content. The main goals of this study were to: (i) examine the effects of temperature, hysteresis of the temperature response, and probe-to-probe variability on the performance of three (5TE, EC-5, and EC-TM) single capacitance sensors (SCS) in a Hawaiian Oxisol; and (ii) develop empirical calibration equations to correct for temperature and improve measurement accuracy. The SCS raw output and thermocouple temperature measurements were recorded at 1-min intervals during heating and cooling cycles between 1 and 45°C. The three SCS and thermocouples were inserted in uniformly packed soils with θ varying from 0 to 0.55 m3 m−3. We used three probes for each SCS, and the entire experiment was replicated with two heating and cooling cycles. Temperature, hysteresis, and the probe-to-probe variability effects were highly significant (p \u3c 0.05) for all three SCS. Estimated θ using soil-specific calibrations at 25°C significantly increased with increasing temperature for all SCS. The 5TE sensor showed increasing temperature sensitivity with increasing water content. However, the EC-5 and EC-TM sensors exhibited a bidirectional response to temperature, with the highest sensitivity at ~0.10 m3 m−3 water content. An empirically derived temperature-dependent calibration equation substantially reduced the variability (\u3e90% reduction in interquartile range) in measured water content due to changing soil temperature. Applying differing temperature corrections for heating and cooling did not improve the calibration any further
AIDS and discrimination
No full textDiscrimination toward people living with the human immunodeficiency virus (HIV) or the acquired immune deficiency syndrome (AIDS) is a global ethical problem. Such discrimination is not limited to any particular context, but takes place in multiple scenarios, including healthcare settings. For clinicians to remedy HIV- and AIDSrelated discrimination within their clinics, they must understand what discrimination is and how it may be addressed pragmatically. The following chapter provides a pragmatic approach to solving problems of discrimination that occur within clinical contexts toward persons living with HIV/AIDS. This approach includes an overview of stigma and discrimination, as well as suggestions to help clinicians practically address and remedy this type of discrimination. A survey of the problem of discrimination pertaining to people living with HIV or AIDS is followed by a definition and discussion of a pragmatic approach to ethics in the area of discrimination. Considerations are provided for clinicians that promote reducing discrimination and the effects of discrimination within the clinical dynamic of HIV care. In conclusion, a series of reflective questions is provided for use by students and clinicians with the aim of improving service to those impacted by HIV infection
PEDOT:PSS-Containing Nanohydroxyapatite/Chitosan Conductive Bionanocomposite Scaffold: Fabrication and Evaluation
No full textConductive poly(3,4-ethylenedioxythiophene)-poly(4-styrene sulfonate) (PEDOT:PSS) was incorporated into nanohydroxyapatite/chitosan (nHA/CS) composite scaffolds through a freezing and lyophilization technique. The bionanocomposite conductive scaffold was then characterized using several techniques. A scanning electron microscope image showed that the nHA and PEDOT:PSS were dispersed homogeneously in the chitosan matrix, which was also confirmed by energy-dispersive X-ray (EDX) analysis. The conductive properties were measured using a digital multimeter. The weight loss and water-uptake properties of the bionanocomposite scaffolds were studied in vitro. An in vitro cell cytotoxicity test was carried out using mouse fibroblast (L929) cells cultured onto the scaffolds. Using a freezing and lyophilization technique, it was possible to fabricate three-dimensional, highly porous, and interconnected PEDOT:PSS/nHA/CS scaffolds with good handling properties. The porosity was 74% and the scaffold\u27s conductivity was 9.72 ± 0.78 μS. The surface roughness was increased with the incorporation of nHA and PEDOT:PSS into the CS scaffold. The compressive mechanical properties increased significantly with the incorporation of nHA but did not change significantly with the incorporation of PEDOT:PSS. The PEDOT:PSS-containing nHA/CS scaffold exhibited significantly higher cell attachment. The PEDOT:PSS/nHA/CS scaffold could be a potential bionanocomposite conductive scaffold for tissue engineering
Transcriptome profiling of tiller buds provides new insights into phyb regulation of tillering and indeterminate growth in Sorghum
No full textPhytochrome B (phyB) enables plants to modify shoot branching or tillering in response to varying light intensities and ratios of red and far-red light caused by shading and neighbor proximity. Tillering is inhibited in sorghum genotypes that lack phytochrome B (58M, phyB-1) until after floral initiation. The growth of tiller buds in the first leaf axil of wild-type (100M, PHYB) and phyB-1 sorghum genotypes is similar until 6 d after planting when buds of phyB-1 arrest growth, while wild-type buds continue growing and develop into tillers. Transcriptome analysis at this early stage of bud development identified numerous genes that were up to 50-fold differentially expressed in wild-type/phyB-1 buds. Up-regulation of terminal flower1, GA2oxidase, and TPPI could protect axillary meristems in phyB-1 from precocious floral induction and decrease bud sensitivity to sugar signals. After bud growth arrest in phyB-1, expression of dormancy-associated genes such as DRM1, GT1, AF1, and CKX1 increased and ENOD93, ACCoxidase, ARR3/6/9, CGA1, and SHY2 decreased. Continued bud outgrowth in wild-type was correlated with increased expression of genes encoding a SWEET transporter and cell wall invertases. The SWEET transporter may facilitate Suc unloading from the phloem to the apoplast where cell wall invertases generate monosaccharides for uptake and utilization to sustain bud outgrowth. Elevated expression of these genes was correlated with higher levels of cytokinin/sugar signaling in growing buds of wild-type plants
Panther - February 2016 - Vol. XCVI, No. 12
Get PDFhttps://digitalcommons.pvamu.edu/pv-panther-newspapers/1922/thumbnail.jp
Electric field controlled spin interference in a system with Rashba spin-orbit coupling
No full textThere have been intense research efforts over the last years focused on understanding the Rashba spin-orbit coupling effect from the perspective of possible spintronics applications. An important component of this line of research is aimed at control and manipulation of electron\u27s spin degrees of freedom in semiconductor quantum dot devices. A promising way to achieve this goal is to make use of the tunable Rashba effect that relies on the spin-orbit interaction in a two-dimensional electron system embedded in a host semiconducting material that lacks inversion-symmetry. This way, the Rashba spin-orbit coupling effect may potentially lead to fabrication of a new generation of spintronic devices where control of spin, thus magnetic properties, is achieved via an electric field and not a magnetic field. In this work we investigate theoretically the electron\u27s spin interference and accumulation process in a Rashba spin-orbit coupled system consisting of a pair of two-dimensional semiconductor quantum dots connected to each other via two conducting semi-circular channels. The strength of the confinement energy on the quantum dots is tuned by gate potentials that allow leakage of electrons from one dot to another. While going through the conducting channels, the electrons are spin-orbit coupled to a microscopically generated electric field applied perpendicular to the two-dimensional system. We show that interference of spin wave functions of electrons travelling through the two channels gives rise to interference/conductance patterns that lead to the observation of the geometric Berry\u27s phase. Achieving a predictable and measurable observation of Berry\u27s phase allows one to control the spin dynamics of the electrons. It is demonstrated that this system allows use of a microscopically generated electric field to control Berry\u27s phase, thus, enables one to tune the spin-dependent interference pattern and spintronic properties with no need for injection of spin-polarized electrons
Anisotropic Quantum Hall Liquid States with No Translational Invariance in the Lowest Landau Level
No full textStrongly correlated two-dimensional electron systems in a high perpendicular magnetic field have displayed remarkable new physics leading to the discovery of phenomena such as the integer and the fractional quantum Hall effect, to mention a few. Laughlin’s theoretical model and the composite fermion’s (CFs) approach provide a good description of the liquid electronic phases in the lowest Landau level (LLL) at relatively large filling factors. Other electronic phases at smaller filling factors of the LLL likely represent electronic Wigner solid states. It is believed that no other phases with intermediate order stabilize at the liquid–solid transition region. The current study deals with filling factor 1/6 in the LLL, a state which is very close to the critical filling factor where the liquid–solid transition takes place. With the assumption that the underlying signs of crystalline order are starting to appear at this transitional regime, we focus our attention and study the properties of a hybrid electronic phase that lacks translational invariance. To describe such a state, we consider a wave function that lies entirely in the LLL but, unlike a typical quantum Hall liquid phase, does not possess translational invariance. Although inspired by Laughlin’s approach, the wave function we introduce differs from Laughlin’s or CFs wave functions that describe translationally invariant uniform electronic phases. We perform quantum Monte Carlo simulations in a standard disk geometry to gain a better understanding of the properties of this wave function that may be considered as a precursor to the more conventional Wigner crystal phase
Predictors of Growth in the Aftermath of Traumatic Events: The Role of Personal Growth Initiative
No full textThe current study examined the role of personal growth initiative (PGI) in predicting posttraumatic growth and posttraumatic stress, and the extent to which rumination styles explain these relations among 286 college students. As predicted, results showed that the cognitive component of PGI negatively predicted posttraumatic stress. Also, there was a significant positive indirect effect of behavioral PGI on posttraumatic growth through deliberate rumination. However, contrary to our hypothesis, there were also significant positive indirect effects of behavioral PGI on posttraumatic stress through intrusive and deliberate rumination. The current study creates new insights on the application of PGI in trauma research