Dendritic Pattern Formation and Contact Line Forces during Dewetting of Dilute Polymer Solutions on a Hydrophobic Surface

The micro-scale morphology of the receding contact line of dilute polyethylene oxide solution drops (c ∼ 100 ppm) after impact and inertial spreading on a fluorinated hydrophobic surface is investigated. One can observe the formation of transient liquid filaments and dendritic structures that evolve into a bead-on-a-string structure similar to the well-known capillary breakup mechanism of dilute polymer solutions, which confirm the interaction between stetched polymer coils and the receding three-phase contact line. The estimation of the average polymer force per unit contact line lenght provides a quantitative explanation for the reduction of the contact line retraction velocity reduction observed experimentally.

Scale-invariant spins and tumbles in turbulence

A Lagrangian perspective has yielded many new insights in our quest to reveal the intricacies of turbulent flows. Much of this progress has been possible by following the trajectories of idealised, inertialess objects (tracers) traversing through the flow. Their spins and tumbles provide a glimpse into the underlying local velocity gradients of the turbulent field. While it is known that the spinning and tumbling rates of anisotropic particles are modified in turbulence – compared with those in a random flow field – a quantitative explanation for this has remained elusive. Now, Pujara et al. (J. Fluid Mech., vol. 922, 2021, R6) have made an attempt to predict the split between spinning and tumbling rates by accessing the particle's alignment with the local vorticity. Their analysis of filtered turbulent fields reveals a Lagrangian scale invariance, whereby key quantities relating to the particle's rotational statistics are preserved from the dissipative to the integral scale.

Cancer models and statistical analysis of age distribution of cancers

In this paper, mathematical mutational models of the age distribution of cancers are obtained. These are two models -- a simple model and a complex model, which takes into account the growth of the cell population and the transmission of mutations to daughter cells. Using the resulting formulas, we approximated real age-specific cancer incidence datasets in women (colon, lung, mammary, stomach) and men (colon, lung, prostate, stomach). We estimated parameters such as the average number of mutations (per cell per unit of time) and number of mutations required for cancer to occur. The number of mutations averaged (over four types of cancer) required for cancer to occur is 72 (mutations per cell for women) and 221 (mutations per cell for men) for the complex mutational model. The average (for four types of cancer) mutation rate is estimated at 0.05 mutations per year (per cell for women) and at 0.07 mutations per year (per cell for men). The mutational models do not provide a quantitative explanation for the occurrence of cancer due to cellular mutations. As an alternative to mutational models, a model of a single carcinogenic event with an age shift is considered. The model approximates real data better and explains quantitatively the real age distributions of cancers.

Atomic-Scale Imaging

This chapter discusses the imaging mechanism of STM and AFM at the atomic scale. Experimental facts show that at atomic resolution, tip electronic states play a key role. Analytic theoretical treatments provide quantitative explanation of the effect of the tip electronic states. On transition-metal tips, first-principle studies unanimously show that d-type tip electronic states dominate the Fermi-level DOS. First-principle studies of the combined tip-sample systems show that for both STM and AFM, the p- and d-type tip electronic states are the keys to understanding the atomic-scale images. The case of spin-polarized STM and the chemical identification of surface atoms are also discussed in terms of tip electronic structure. The chapter concludes with discussions of experimental verifications of the reciprocity principle: at atomic resolution, the role of tip electronic states and the sample electronic states are interchangeable.

Pengaruh Bukti Fisik, Suasana Ruangan, Dan Harga Terhadap Loyalitas Pelanggan Warunk Upnormal Bogor

The purpose of this research is to find out how much influence of physical evidence, room atmosphere, and price on customer loyalty. Data type of research is quantitative explanation research instruments using questionnaires. Sampel for this research is 100 respondents who were Bogor resident visited and make purchase in Warunk Upnormal Bogor. Analitycal tool used regression analysis and testing hipotesis in this research using formula t count with result physical evidence (5,343>1,66), room atmosphere (-0,610<1,66), price (5,517>1,66) and f count with result (31,909>2,70) with SPSS program version 23 for macintosh. Based on the result of the research noted that physical evidence and price have positive effect and significant on customer loyalty while room atmosphere have no effect on customer loyalty and all three independent variable can determine changes in value from dependent variable as big as 49,9%. While partially, physical evidence variable have positive effect and significant on customer loyalty, room atmosphere variable have no effect on customer loyalty, and price variable have positive effect and significant on customer loyalty. This shows that there is a direct influence between independent variable and dependent variable simultaneously while partially, physical evidence and price have direct influence on customer loyalty while room atmosphere have no direct influence on customer loyalty. Keyword: Physical Evidence, Room Atmosphere, Price, Customer Loyalty

Interplay of Jahn-Teller Ordering and Spin Crossover in Co(II) Compounds

The spin crossover phenomena in Co(II) compounds are in the focus of the present paper. A microscopic theoretical approach for the description of spin transitions in mononuclear Co(II) compounds is suggested. Within the framework of this approach there are taken into account two types of interionic interactions that may be operative in the problem such as the electron-deformational interaction and the cooperative Jahn-Teller interaction arising from the coupling of the low-spin state of the Co(II) ion with the tetragonal vibrations of the nearest surrounding. The different role of these interactions in the spin transformation is demonstrated and discussed. On the basis of developed approach a qualitative and quantitative explanation of the experimental data on the temperature dependence of the magnetic susceptibility for the [Co(pyterpy)2](PF6)2, [Co(pyterpy)2](TCNQ)2⋅DMF⋅MeOH and [Co(pyterpy)2](TCNQ)2⋅MeCN⋅MeOH compounds is given.

Quantitative Explanation of Basic Compound Retention Mechanisms in Reversed-Phase Mode Liquid Chromatography

The quantitative analysis of the chromatographic behavior of basic compounds measured with pentyl-, hexenyl-, and octyl-bonded silica gels were analyzed in silico employing model phases. The main retention force was the van der Waals (VW) interaction, and the main desorption force was an electrostatic (ES) interaction. The contribution of hydrogen bonding (HB) was weak compared to that for acidic compounds. The quantitative explanation was achieved utilizing the calculated VW, HB, and ES energy values obtained from a molecular mechanics program. The electron localization was observed at the molecular interaction-site calculated MOPAC program. This fundamental approach was like that of explaining chemical reactions. The difference was electron localization in chromatography or electron transfer in a chemical reaction.

Quantitative Explanation of Basic Compound Retention Mechanisms in Reversed-Phase Mode Liquid Chromatography

The quantitative analysis of the chromatographic behavior of basic compounds was performed in silico. The liquid chromatography (LC) data measured with pentyl-, hexenyl-, and octyl-bonded silica gels were analyzed in silico employing model phases. The main retention force was the van der Waals (VW) interaction, and the main desorption force was an electrostatic (ES) interaction. The contribution of hydrogen bonding (HB) was weak compared to that for acidic compounds. The quantitative explanation was achieved utilizing the calculated VW, HB, and ES energy values obtained from a molecular mechanics program. The electron localization was observed at the molecular interaction-site calculated MOPAC program. This fundamental approach was like that of explaining chemical reactions. The difference was electron localization in chromatography or electron transfer in a chemical reaction.