Thermodynamic quantities at high pressures in the i and θ phases of solid nitrogen deduced by raman frequency shifts for the internal modes in literature

The pressure dependence of the Raman frequencies of the internal modes is analyzed (T = 300 K) for the phases i and θ of solid nitrogen using the experimental data from the literature. Through the mode Grüneisen parameter, the isothermal compressibility κT, thermal expansion p and the specific heat Cp-Cv are calculated as a function of pressure using the Raman data in these phases. We obtain that the p varies linearly with the (1/υ)(∂υ/∂P) T and also that the Cp-Cv varies linearly with the p for N2. Our results show that by means of the analysis given here, the p, κT and C p-Cv can be predicted from the Raman frequency shifts for the i and θ phases of solid nitrogen. © 2013 World Scientific Publishing Company

Biotechnologies and bioinspired materials for the construction industry : an overview

Published online: 16 Oct 2013Looking back to less than three centuries of industrialization, responsible for alarming levels of pollution and consumption of non-renewable resources that has led to the exhaustion of the earth’s capacity, the humankind only now begins to grasp the overwhelming potential of natural systems. During almost 40 million centuries, Nature has developed materials and processes with optimal performance which are totally biodegradable. Analysis of bioinspired materials requires the knowledge of both biological and engineering principles which are being a part of a large research area termed biotechnology. This hot area is one of the six strategic Key Enabling Technologies that will be funded under the EU Framework Programme Horizon 2020. This paper reviews the current knowledge on the potential of this emerging field, particularly in the development of materials and technologies for the construction industry. It covers the use of bacteria for enhancing concrete durability and for soil stabilization. It also covers bioinspired tough composite materials, bioinspired adhesives and coatings, and self-cleaning materials. Incorporation of biology basics in the civil engineering curriculum would ease the communication between biologists and civil engineers, helping to foster research on biotechnologies and bioinspired materials for the construction industry

A novel Fontan Y-graft for interrupted inferior vena cava and azygos continuation

OBJECTIVES To evaluate the hemodynamicdynamic advantage of a new Fontan surgical template that is intended for complex single-ventricle patients with interrupted inferior vena cava-azygos and hemi-azygos continuation. The new technique has emerged from a comprehensive pre-surgical simulation campaign conducted to facilitate a balanced hepatic flow and somatic Fontan pathway growth after Kawashima procedure. METHODS For 9 patients, aged 2 to18 years, majority having poor preoperative oxygen saturation, a pre-surgical computational fluid dynamics customization is conducted. Both the traditional Fontan pathways and the proposed novel Y-graft templates are considered. Numerical model was validated against in vivo phase-contrast magnetic resonance imaging data and in vitro experiments. RESULTS The proposed template is selected and executed for 6 out of the 9 patients based on its predicted superior hemodynamic performance. Pre-surgical simulations performed for this cohort indicated that flow from the hepatic veins (HEP) do not reach to the desired lung. The novel Y-graft template, customized via a right- or left-sided displacement of the total cavopulmonary connection anastomosis location resulted a drastic increase in HEP flow to the desired lung. Orientation of HEP to azygos direct shunt is found to be important as it can alter the flow pattern from 38% in the caudally located direct shunt to 3% in the cranial configuration with significantly reversed flow. The postoperative measurements prove that oxygen saturation increased significantly (P-value = 0.00009) to normal levels in 1 year follow-up. CONCLUSIONS The new Y-graft template, if customized for the individual patient, is a viable alternative to the traditional surgical pathways. This template addresses the competing hemodynamic design factors of low physiological venous pressure, high postoperative oxygen saturation, low energy loss and balanced hepatic growth factor distribution possibly assuring adequate lung development. Date and number of IRB approval 25 October 2019, 280011928-604.01.01

THE RAMAN FREQUENCY SHIFTS RELATED TO THE THERMODYNAMIC QUANTITIES CLOSE TO THE PHASE I - PHASE II TRANSITION IN NH4_4Br

Author Institution: Department of Physics, Middle East Technical University,; Ankara, 06531 - TurkeyWe establish here the modified Pippard relations by relating the specific heat $C_p$ to the frequency shifts $\frac{1}{\nu }\left( {\frac{{\partial \nu }}{{\partial T}}} \right)_P$ and also the thermal expansivity $\alpha_p$ to the $\frac{1}{\nu }\left( {\frac{{\partial \nu }}{{\partial P}}} \right)_T$ for the $\nu$ (140 cm$^{-1}$) Raman mode of NH$_4$Br close to its phase I- phase II transition. From our linear plots of $C_p$ vs. $\frac{1}{\nu }\left( {\frac{{\partial \nu }}{{\partial T}}} \right)_P$ and $\alpha_p$ vs. $\alpha_p$ to the $\frac{1}{\nu }\left( {\frac{{\partial \nu }}{{\partial P}}} \right)_T$, we extract the values of the slope DP/dT, which are close to the experimental value of 28.2 bar/$^irc$C near the phase I-phase II transition in NH$_4$Br

FREQUENCY SHIFTS NEAR THE FIRST ORDER PHASE TRANSITION IN NH4ClNH_{4}Cl

Author Institution: Department of Physics, Istanbul Technical UniversityWe study here our correlations between the volume changes and the frequency shifts for the q[110] mode of $NH_{4}Cl$ for the pressures of $0, 0.5$ and $0.95$ kbars (first order phase region). By determing the mode Gr\""{u}neisen parameter for the q[110] mode, we have predicted the ultrasonic frequencies for this mode using the length-change measurements for the $NH_{4}Cl$ crystals from the literature. Our calculated frequencies are in good agreement with the observed frequencies for the q[110] mode in the first order phase region of $NH_{4}Cl$. This shows that our method of calculating the frequencies from the observed length-change data is reasonable and that we can then predict the observed behaviour of $NH_{4}Cl$