•A numerical study on the conjugate mixed convection of Cu-water nanofluid has been considered.•An enclosure with thick wavy bottom wall is considered.•The computational domain has been transformed ...into an orthogonal co-ordinate system.•The governing equations along with the boundary conditions are solved through a finite volume.•Results showed that heat transfer rate increases remarkably by adding the nanoparticles.
A numerical study on the conjugate heat transfer by mixed convection of a Cu-water nanofluid and conduction in a solid region is conducted in an enclosure with a thick wavy heated wall. The upper lid of the enclosure is made to slide horizontally at a constant speed, along with that the condition of heated outer boundary of the thick bottom wall leads to a mixed convection within the enclosure. The impact of the wavy fluid-solid interface, solid-to-fluid thermal conductivity ratio and nanoparticle volume fraction on the heat transfer characteristics is analyzed for different choice of the Richardson number. The computational domain is transformed into an orthogonal co-ordinate system. The transformed governing equations along with the specified boundary conditions are solved through a finite volume method for a wide range of Richardson number, nanoparticle volume fraction, wave amplitude, wave number and wall-to-fluid conductivity ratio for different Reynolds number. Results show that the heat transfer rate increases substantially due to the inclusion of nanoparticles. Heat transfer rate varies due to the variation of the solid-to-fluid conductivity ratio, amplitude and wave number of the wavy wall. The impact of the wavy surface is stronger when the solid conductivity is in the order of the conductivity of the fluid. The Bejan number and the entropy generation are determined to analyze the thermodynamic optimization of the conjugate mixed convection.
As major historical periods such as Stone Age, Bronze Age, and Iron Age, the development of new materials was the fundamental to all the periods. In the present investigation, a new hybrid composite ...with epoxy as a resin and reinforcing both biowaste (jute) and traditional fiber (glass) as continues layered mat composites and also study experimentally the effect of the stacking sequence on tensile, flexural, and interlaminar shear properties. Composites were prepared by using hand lay-up technique. All the laminates were prepared with a total of four piles, by varying the position of glass and jute. One group of all jute and glass laminate was also fabricated for comparison purpose. Specimen preparation and testing were carried out as per ASTM standards. Tests were conducted on INSTRON H10KS Material Test System at room temperature using automatic data acquisition software. The results indicated that the jute fiber and hybrid composite give encouraging results when compared with the neat epoxy. The morphologies of the composites are also studied by scanning electron microscope.
The aim of this paper is to replace the traditional fiber composites with a natural-fiber composite in perception of tribological and mechanical accepts. A systematic study has been carried out to ...investigate jute fiber properties when incorporated into epoxy matrix. Thermogravimetric analysis has also been carried out for jute and epoxy for thermal property analysis. For a comparison purpose epoxy and glass fiber composites are prepared. The investigation reveals that, due to incorporation of jute into polymer epoxy shows better properties than the resins alone; but the properties are inferior to those of glass reinforced in terms of mechanical. When considering the tribological application, the jute fiber shows superior properties than neat and glass-reinforced epoxy composites. The worn out samples were studied using scanning electron microscope.
Almost all biological macromolecules are inactive in the absence of water. Hydration of a protein/enzyme is particularly important for the stability of the structure and for the function, especially ...the recognition at a specific site.
In this article, we describe an unsupervised feature selection algorithm suitable for data sets, large in both dimension and size. The method is based on measuring similarity between features whereby ...redundancy therein is removed. This does not need any search and, therefore, is fast. A new feature similarity measure, called maximum information compression index, is introduced. The algorithm is generic in nature and has the capability of multiscale representation of data sets. The superiority of the algorithm, in terms of speed and performance, is established extensively over various real-life data sets of different sizes and dimensions. It is also demonstrated how redundancy and information loss in feature selection can be quantified with an entropy measure.
Structural and magnetic phase transformations and magnetocaloric effect of Mn and Co substitutions by Cu in MnCoGe have been investigated using X-ray diffraction, differential scanning calorimetry, ...and magnetization measurements. Increase in Cu concentration reduces the martensitic structural and magnetic phase transition temperatures. However, nearly doubling of the amount of Co substitution is required compared to Mn for an equivalent change in the structural transition temperature. A giant magnetocaloric effect, -ΔSMmax ≈ 50 J kg−1K−1 for Δμ0H = 5 T, resulting from coupling of concomitant structural and magnetic transformations near room temperature has been obtained for a sample with around 11 at% Mn-substitution. Fine tuning of Cu concentration (20 at%) in the case of Co substitution resulted in concurrent structural and magnetic transitions at around 260 K. However, the absence of a magnetostructural coupling resulted in peak entropy change of less than 4 J kg−1K−1. Samples with 15 at% or higher Co-substitution showed complex magnetic behavior and multiple magnetic transitions. The nature of magnetic phase transitions in both Co- and Mn-substituted samples have been investigated and phase diagrams for both sets of samples have been derived based on calorimetry and magnetometry results.
•Effect of Cu substitution for Mn and Co in MnCoGe compound has been investigated.•Optimal Co substitution results in multiple magnetic transition: PM-hex => FM-hex => PM-ortho => FM-ortho.•Mn substitution induces magnetostructural coupling and leads to a giant magnetocaloric effect.•Magnetic phase diagrams of both Mn and Co substituted samples has been presented.
•Enhanced electroosmotic flow in a nano-channel with uncharged hydrophobic patches.•A trigonometric shape of the hydrophobic patches is considered.•A large enhancement occurs when Debye length is in ...the order of the channel height.•Higher bulk ionic concentration creates a hindrance on flow enhancement•Increase in penetration depth of the interface reinforces the average EOF.
We consider the electroosmotic flow (EOF) in a nano-channel in which the channel walls are modulated with a periodic array of curved hydrophobic patches. The objective is to achieve an enhanced flow compared to a slit nano-channel. The shape of the hydrophobic strips are considered to be of sinusoidal form, which resembles the situation in which the channel indentations are filled with immiscible nonconducting fluid over which the electrolyte is considered to be in metastable Cassie state. The homogeneous no-slip portions of the channel walls are considered to posses a constant surface-potential (zeta-potential) or constant surface charge density, while the hydrophobic regions are uncharged. A mathematical model based on the Nernst–Planck–Navier-Stokes equations are considered to analyze the present EOF. A coordinate transformation is adopted to map the irregular physical domain to a regular computational domain. A pressure-correction based control volume approach is adopted to solve the governing equations. We have studied the EOF by varying the amplitude of the hydrophobic region. Our results show that an enhancement in EOF compared to a slit-channel is possible when the Debye length is in the order of the channel height. The EOF in the patterned channel varies with the planform length of the hydrophobic region as well as the relative span of the slip and no-slip regions. A comparison with the pressure-driven flow is also presented to analyze the hindrance created by the electric body force of the unbalanced ions.
Background
Achieving a pathologic complete response (pCR) with neoadjuvant chemotherapy (NAC) in patients with muscle‐invasive bladder cancer (MIBC) has been associated with improved overall survival ...(OS). This study was aimed at evaluating the impact of pathologic downstaging (pDS; ie, a pT stage at least 1 stage lower than the pre‐NAC cT stage) on the OS of patients with MIBC treated with NAC.
Methods
The Retrospective International Study of Cancers of the Urothelial Tract (RISC) and the National Cancer Database (NCDB) were queried for cT2‐4N0M0 patients treated with NAC. A multivariable Cox model including either pDS or pCR was generated. A nested model was built to evaluate the added value of pDS (excluding patients achieving a pCR) to a model including pCR alone. C indices were computed to assess discrimination. NCDB was used for validation. The treatment effect of NAC versus cystectomy alone in achieving pDS was estimated through an inverse probability–weighted regression adjustment.
Results
Overall, 189 and 2010 patients from the RISC and NCDB cohorts, respectively, were included; pDS and pCR were achieved by 33% and 35% and by 20% and 15% in RISC and NCDB, respectively. In both data sets, pDS and pCR were associated with better OS and C indices. Adding pDS excluding pCR to the model with pCR fit the data better (likelihood ratio, P = .019 for RISC and P < .001 for NCDB), and it yielded better discrimination (incremental C index, 4.2 for RISC and 1.6 for NCDB). The treatment effect of NAC in achieving pDS was 2.07‐fold (P < .001) in comparison with cystectomy alone.
Conclusions
A decrease of at least 1 stage from the cT stage to the pT stage is associated with improved OS in patients with MIBC treated with NAC.
Using 2 different cohorts, this study demonstrates that a decrease in tumor size, even without complete disappearance, is associated with better survival than no response in patients with muscle‐invasive bladder cancer treated with neoadjuvant chemotherapy.
PDF
