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Two Temperature Dual-phase-lag Fractional Thermal Investigation of Heat Flow Inside a Uniform Rod
Get PDFA non-classical, coupled, fractionally ordered, dual-phase-lag (DPL) heat conduction model has been presented in the framework of the two-temperature theory in the bounded Cartesian domain. Due to the application of two-temperature theory, the governing heat conduction equation is well-posed and satisfying the required stability criterion prescribed for a DPL model. The mathematical formulation has been applied to a uniform rod of finite length with traction free ends considered in a perfectly thermoelastic homogeneous isotropic medium. The initial end of the rod has been exposed to the convective heat flux and energy dissipated by convection into the surrounding medium through the last end. The State-space approach has been employed to solve the corresponding boundary value problem to obtain the conductive and thermomechanical temperature along with thermal displacement and stresses in the Laplace domain. The role of the time-fractional order and delay time in the heat flux and temperature gradient has been investigated through numerical results representing graphically along the length of the rod. The classical, fractional and generalized thermoelasticity theory have been recovered and the finite speed of thermal wave has been attained
Conversion of levulinic acid and cellulose to γ-valerolactone over Raney-Ni catalyst using formic acid as a hydrogen donor
No full textThe present study aimed to investigate the conversion of levulinic acid (LA) and cellulose (DP∼450) to γ-valerolactone (GVL) over Raney-Ni catalyst. In this process, hydrogenation was fulfilled using formic acid (FA) as the hydrogen donor. The highest LA conversion (100%) and GVL yield (68.5%) were obtained using LA:FA 1:4 ratio, Raney-Ni catalyst (20 mg/mmol of LA) and heating at 200 °C for 48 h. Under similar reaction conditions cellulose (DP∼450) was converted into GVL in 23.3% yield in a single reactor process. The addition of acidic co-catalysts such as Brønsted acids: H2SO4, Amberlyst-15 (H+) or Dowex 50WX8 to the reaction mixture did not improve the GVL yield. The SEM analysis of the Raney Ni-catalyst used in transformation of cellulose to GVL showed that catalyst surface gets contaminated with carbon deposits in the single reactor process
Photothermal effect and cytotoxicity of CuS nanoflowers deposited over folic acid conjugated nanographene oxide
No full textHerein, we present the rational synthesis of a multimode photothermal agent, NGO-FA-CuS, for the advancement of photothermal therapy of cancer. The hierarchical architecture created in NGO-FA-CuS was attained by the covalent conjugation of folic acid (FA) to nanographene oxide (NGO) through amide bonding, followed by the hydrothermal deposition of CuS nanoflowers. In this approach, instead of mere mixing or deposition, FA was covalently bonded to NGO, which helped in retaining their intrinsic properties after binding and allowed to access them in the resulting hybrid nanostructure. In this specifically designed photothermal agent, NGO-FA-CuS, each component has an explicit task,i.e., NGO, FA and CuS act as the quencher, cancer cell-targeting moiety and photothermal transduction agent, respectively. Prior to the grafting of FA molecules and the deposition of CuS nanoflowers, sulfonic acid groups were introduced into NGO to provide stability under physiological conditions. Under irradiation using a 980 nm laser, NGO-FA-CuS was able to attain a temperature of 63.1 °C within 5 min, which is far beyond the survival temperature for cancer cells. Therefore, the resulting temperature recorded for NGO-FA-CuS was sufficient to induce hyperthermia in cancer cells to cause their death. When coming into contact with cancer cells, NGO-FA-CuS can cause a rapid increase in the temperature of their nucleus, destroy the genetic substances, and ultimately lead to exhaustive apoptosis under illumination using a near-infrared (NIR) laser. An excellent photothermal efficiency of 46.2% under illumination using a 980 nm laser and outstanding cytotoxicity against HeLa, SKOV3 and KB cells were attained with NGO-FA-CuS. Moreover, NGO-FA-CuS displays exceptional persistent photo-stability without photo-corrosiveness. The photothermal effect of NGO-FA-CuS was found to be dependent on its concentration and the power density of the laser source. It was found that its cytotoxicity toward cancer cells was enhanced with an increase in the concentration of NGO-FA-CuS and the incubation period
Purple variety of sweet potato
Get PDFPurple sweet potatoes are versatile enough to be used in cupcakes as well as ice cream. However, when cooked in their natural state, they are dry and starchy, prompting most to use the purple sweet potatoes as flour for baked goods, or in some cases, for ice cream. Dr. Gao wants his variety of purple sweet potato to be more palatable. Gao earned the coveted USDA-National Institute of Food and Agriculture 1890 Institution Capacity Building Grant to support his research. The project will focus on developing a variety that is enjoyable in its natural state and is moist and tastefully sweet. Gao states, “This funding will enable us to conduct field testing of a new purple-sweet potato hybrid for public release, and studies to better understand the anthocyanin synthesis or the formation of purple flesh color.”https://digitalcommons.pvamu.edu/datasets-collection/1001/thumbnail.jp
Proteomic fertility markers in ram sperm
No full textPrecise estimation of ram fertility is important for sheep farming to sustain reproduction efficiency and profitability of production. There, however, is no conventional method to accurately predict ram fertility. The objective of this study, therefore, was to ascertain proteomic profiles of ram sperm having contrasting fertility phenotypes. Mature rams (n = 66) having greater pregnancy rates than average (89.4 ± 7.2%) were assigned into relatively-greater fertility (GF; n = 31; 94.5 ± 2.8%) whereas those with less-than-average pregnancy rates were assigned into a lesser-fertility (LF; n = 25; 83.1 ± 5.73%; P = 0.028) group. Sperm samples from the outlier greatest- and least-fertility rams (n = 6, pregnancy rate; 98.4 ± 1.8% and 76.1 ± 3.9%) were used for proteomics assessments utilizing Label-free LC-MS/MS. A total of 997 proteins were identified, and among these, 840 were shared by both groups, and 57 and 93 were unique to GF and LF, respectively. Furthermore, 190 differentially abundant proteins were identified; the abundance of 124 was larger in GF while 66 was larger in LF rams. The GF ram sperm had 79 GO/pathway terms in ten major biological networks while there were 47 GO/pathway terms in six biological networks in sperm of LF rams. Accordingly, differential abundances of sperm proteins between sperm of GF and LF rams were indicative of functional implications of sperm proteome on male fertility. The results of this study emphasize there are potential protein markers for evaluation of semen quality and estimation of ram sperm fertilizing capacity
Existence of measure-valued solutions in optimal control of age-structured populations
No full textWe consider a nonlinear profit maximization problem in the Lotka–McKendrick model of age-structured harvested population describing farmed populations in agriculture and aquaculture. The control functions are time- and age-dependent harvesting rate and time dependent supply of newborns. We establish the existence of optimal controls with measure-valued harvesting rate by using distributional partial derivatives of functions of bounded variation through the equivalent integrated form to the original problem
A possible conceptualization of the information systems (IS) artifact: A general systems theory perspective\u3csup\u3e1\u3c/sup\u3e
No full textThis opinion paper addresses and contributes to the discourse on whether there is a central artifact that captures the essence of the information systems (IS) discipline. It argues that the IS discipline can, and should be, faithfully captured by an IS artifact. We offer a theoretical conception of the IS artifact by drawing upon General Systems Theory (GST). Key concepts of GST are distilled as meta-principles which inform our formulation of the IS artifact. We use the meta-principles of the IS artifact to develop salient assertions that theorize what an ‘IS’ is. To demonstrate the appropriateness of our conception, we illustrate how the assertions we developed are consistent with patterns related to emerging topics in IS research, notably, healthcare and IT, and Fintech. We formulate a research agenda on these emerging topics—based upon the conceptions developed in the paper—to guide future research. We conclude with the contributions and implications of our study, including the relevance for IT-enabled work in the era of the COVID-19 pandemic
Construction of Hexagonal Structures Using a 3D Bioprinter Based on Customized G-Code
No full textThree-dimensional (3D) bioprinting is adopted from the existing technology of 3D printing that is able to recreate the microenvironment of tissue structures or organs. However, the existing printing mechanism is normally based on slices of a 3D structure in computer-aided slicer software and prints in horizontal and diagonal manners. Such printing mechanism involving soft bioink which does not polymerise in short period of time produces distorted constructs due to the thixotropic properties of the bioink. To circumvent this problem, G-codes for simple 3D bioprinting mechanism were derived. A 3D bioprinter has been developed to implement unidirectional printing for different concentration of bioink. The modified coding was successfully customized for printing single layer to multilayer hexagonal structures. Additionally, the dimension accuracy of the 3D printing in producing similar dimensions of a design in CAD software is highly dependent on the concentration of the bioink applied. The results show that up to 97 % of printing accuracy can be achieved by applying 10: 50 % v/v of alginate/gelatin bioink
(R1887) Inferring Trends of Point Processes from Non-iid Samples
Get PDFWe discuss unprecedented, albeit rudimentary, tools to infer the evolution of a point process where the available samples are both truncated and non independently drawn. To achieve this goal, we lay in an intermediate domain between probability models and fuzzy sets, still maintaining probabilistic features of the employed statistics as the reference KPI of the tools. The overall strategy is to frame the problem within the Algorithmic Inference framework and use a sort of kernel trick to distort the seeds of the observed variable so as to render them an iid sample of a random variable in a proper feature space. Numerical results highlight the suitability of the proposed tools
(R1458) A New Finite Difference Scheme for High-Dimensional Heat Equation
Get PDFIn this research, a new second-order finite difference scheme is proposed to solve two and three- dimensional heat equation. Finite difference equations are determined via a discretization approach in which spatial second order partial derivatives in x and y directions are approximated simultaneously while in the classic method, each spatial partial derivative is replaced by a central finite difference approximation, separately. By this new discretization scheme and also using the forward difference to the first-order time derivative, a finite difference equation is obtained for the parabolic equation. This approach is explicit and similar to other explicit approaches, an interval for the Courant number, r is determined. This region for r is obtained through Fourier stability analysis. The advantage of this approach is that its stability interval is larger than the interval for traditional methods. Numerical experiments are presented to confirm the theoretical results. It is shown that more accurate approximations can be obtained by the new scheme