Computational investigation of structure, dynamics and nucleation kinetics of a family of modified Stillinger-Weber model fluids in bulk and free-standing thin films

In recent decades, computer simulations have found increasingly widespread use as powerful tools of studying phase transitions in wide variety of systems. In the particular and very important case of aqueous systems, the commonly used force-fields tend to offer quite different predictions with respect to a wide range of thermodynamic and kinetic properties, including the ease of ice nucleation, the propensity to freeze at a vapor-liquid interface, and the existence of a liquid-liquid phase transition. It is thus of fundamental and practical interest to understand how different features of a given water model affect its thermodynamic and kinetic properties. In this work, we use the forward-flux sampling technique to study the crystallization kinetics of a family of modified Stillinger-Weber (SW) potentials with energy ($\epsilon$) and length ($\sigma$) scales taken from the monoatomic water (mW) model, but with different tetrahedrality parameters ($\lambda$). By increasing $\lambda$ from 21 to 24, we observe the nucleation rate increases by 48 orders of magnitude at a supercooling of ${\zeta}=T/T_m=0.845$. Using classical nucleation theory, we are able to demonstrate that this change can largely be accounted for by the increase in $|\Delta\mu|$, the thermodynamic driving force. We also perform rate calculations in freestanding thin films of the supercooled liquid, and observe a crossover from a surface-enhanced crystallization at $\lambda = 21$ to a bulk-dominated crystallization for $\lambda\ge22$.Comment: 10 pages, 9 figures, five table

Improvement of Tuberculosis Laboratory Capacity on Pemba Island, Zanzibar: A Health Cooperation Project.

Low-income countries with high Tuberculosis burden have few reference laboratories able to perform TB culture. In 2006, the Zanzibar National TB Control Programme planned to decentralize TB diagnostics. The Italian Cooperation Agency with the scientific support of the "L. Spallanzani" National Institute for Infectious Diseases sustained the project through the implementation of a TB reference laboratory in a low-income country with a high prevalence of TB. The implementation steps were: 1) TB laboratory design according to the WHO standards; 2) laboratory equipment and reagent supplies for microscopy, cultures, and identification; 3) on-the-job training of the local staff; 4) web- and telemedicine-based supervision. From April 2007 to December 2010, 921 sputum samples were received from 40 peripheral laboratories: 120 TB cases were diagnosed. Of all the smear-positive cases, 74.2% were culture-positive. During the year 2010, the smear positive to culture positive rate increased up to 100%. In March 20, 2010 the Ministry of Health and Social Welfare of Zanzibar officially recognized the Public Health Laboratory- Ivo de Carneri as the National TB Reference Laboratory for the Zanzibar Archipelago. An advanced TB laboratory can represent a low cost solution to strengthen the TB diagnosis, to provide capacity building and mid-term sustainability

Women Cry: Men Have Lost their Soul and We Have Lost Our Sex!

It is true that the misery of woman need to be understood in the context of woman itself because her existence in itself is of great significance as it has enabled the man to weave the splendid raiment of human civilization and in the process utilized the sinew of the female folk to its full. Surprisingly, the name of woman continue to miss from epigraph of the cultural tapestry of the world because what has happened to woman in art has happened to her in literature too and not to speak about other aspects that regulate her socio-political life otherwise called the culture. A comparative study of cultures would therefore suggest that no sooner man controlled the horse, he perhaps actively thought of controlling the woman. Woman therefore trusted man and did not, ever resist being stripped off her basic rights and, or being virtually reduced to the level of bearing dependant status that too not less than that of a slave or a vassal. The worst of the whole story being that female has had no choice but to accept whatever man wished to choose for her or even what the former did to her. This paper exposes the influence of men and their lusts leading to the change in humanity of woman and womanhood. It indicates the total submission of women and the leniency of legal teeth in controlling the masculine sensibility. Keywords: Female Genital Mutilation, male sadism and female masochism, Customs and Law

Fabrication of Homogeneous Multi-Walled Carbon Nanotube/ Poly (Vinyl Alcohol) Composite Nanofibers for Microwave Absorption Application

Poly (vinyl alcohol) (PVA) / sodium dodecyl sulfate (SDS) / multi walled carbon nanotubes (MWCNT) camposite nanofibers with various MWCNT contents (up to 10 wt%) were fabricated by electrospinning process and their microwave absorption properties were evaluated by a vector network analyzer in the frequency range of 8 – 12 GHz (X-band) at room temperature. The uniform, stable dispersion and well oriented MWCNT within the PVA matrix were achieved through using SDS as dispersing agent. The SEM analysis of the nanofibers samples revealed that the deformation of the nanofibers increases with increasing MWCNT concentration. Very smooth surface of the composite electrospun nanofibers even for the nanofibers with concentration of 10 wt MWCNT have been successfully prepared because of the high stability dispersion of MWCNT. It was observed that absorption microwave properties improved with increasing in the loading levels of MWCNT. Finally, the PVA/SDS/MWCNT composite nanofibers sample with the 10 wt content of MWCNT has shown the reflection loss of 15 dB at the frequency of 8 GHz. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3558

The Use of Problem Based Learning to Increase Students' Learning Independent and to Investigate Students' Concept Understanding on Rotational Dynamic at Students of SMA Negeri 4 Banda Aceh

The objective of this study is to find out the increase in student's independent learning and concept understanding on the rotational dynamics after getting the PBL learning and handout. This study was conducted by using "pretest - posttest control group" experimental design. The result of analysis data showed the The average value of N-gain understanding concepts for the experimental group was 74,76%, with the higher category, but for the control group obtained N-gain is 26,76% with low category. N-gain self-regulated laerning for the experimental group was 31% with the medium category and for control group of 20% low category. These results were confirmed by t-test with significant value (0.000) under the probability value (0,05). So that it can be said that PBL learning and the handouts could to improve the student independent learning and concept understanding on the rotational dynamic