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

Carboxyhemoglobin levels should be considered important on carbonmonoxide poisoning [Karbonmonoksit zehirlenmelerinde karboksihemoglobin düzeyleri önemsenmelidir]

Introduction: Carbonmonoxide (CO) one of the leading causes of poisoning death in developing countries. This study sought to determine whether symptoms correlate with carboxyhemoglobine (COHb) levels in CO poisoned children. It also aimed to investigate the relationship of the concentration of COHb with end organ damage such as acute myocardial injury and delayed neurologic sequelae. Methods: All children who presented to the emergency department due to CO poisoning, between November 2011-May 2012 were included. Age, gender, month of presentation, time to presentation, presenting symptoms, source of CO, COHb levels, biochemical markers of end organ damage, treatment and outcome were recorded. Groups are classified based on blood COHb levels as (>%20, 20%. Hyperbaric oxygen treatment (HBO) administered for patients with COHb levels >20%, cardiac and/or neurologic involvement. Delayed neuropsychiatric complications were occurred in only one patient. Discussion and Conclusion: COHb levels >20% can be used as a predictor marker of end organ damage in pediatric CO poisoning. Therefore, COHb level should be obtained for all children with CO poisoning. © 2017, Galenos Yayincilik. All rights reserved

Damping Constant Calculated as a Function of Temperature for the Tetragonal Raman Mode Close to the Paraelectric-Ferroelectric Transition in BaTiO3

The damping constant for the tetragonal Raman peak at 308cm(-1) is calculated as a function of temperature close to the paraelectric-ferroelectric (T-C approximate to 400K) transition in BaTiO3. Expressions derived for the damping constant from the pseudospin-phonon coupled model and the energy fluctuation model are fitted to the experimental data for the bandwidths and integrated intensities of this Raman mode at various temperatures close to the paraelectric-ferroelectric transition in BaTiO3. The damping constant calculated from the pseudospin-phonon coupled model agrees well with the observed bandwidths of the tetragonal Raman mode studied in BaTiO3. The energy fluctuation model is not satisfactory to explain the observed behavior of the paraelectric-ferroelectric transition in BaTiO3. The experimental data from other sources also show similar critical behavior as our calculated values for the Raman bandwidths in BaTiO3. Our method of calculating the damping constant can be applied to some other ferroelectric crystals

Analysis of the Critical Magnetic Field and the Dielectric Susceptibility for the Smectic A-Smectic C* Transition in DOBAMBC

The temperature dependences of the critical magnetic field H-c and the dielectric susceptibility x(at constant magnetic fields) are analyzed close to the smectic Asmectic C* transition in DOBAMBC using the experimental data according to a power-law formula. These analyses are performed below T-c in the smectic C* phase. Values of the critical exponent delta for the critical magnetic field are determined in a given temperature interval (Tc-T) with increasing and decreasing H-c. Also, values of the critical exponent gamma for the dielectric susceptibility x (dielectric constant) are determined in the two different temperature intervals (T-c-T) for constant magnetic fields ranging from 0 to 6 T. From our analysis of the temperature dependences of Hc and x, we extract the values of the critical exponent Phi to describe the magnetic field dependence of the dielectric susceptibility close to the AC* transition in DOBAMBC

Calculation of the Infrared Frequencies as a Function of Temperature Using the Volume Data in the Ferroelectric Phase of NaNO2

We calculate the temperature dependence of the infrared frequencies of the TO and LO modes with the symmetries of A(1), B-1 and B-2 mainly in the ferroelectric phase of NaNO2. This calculation is carried out using the volume dependence of the infrared frequencies through the mode Gruneisen parameter in this crystal. The volume dependences of the infrared frequencies are fitted to the observed frequencies by using constant mode Gruneisen parameter in the ferroelectric phase of NaNO2. Our results show that this method of calculating the infrared frequencies describes the observed behaviour of NaNO2 adequately

Brillouin frequency shifts in the ferroelectric phase of NaNO2

In this study we calculate the Brillouin frequencies for the L-mode [010], [001] and [100] in the ferroelectric phase of NaNO2 (T-C = 163 C) by means of gamma -Gruneisen relations using the thermal expansivity data from the literature. The predicted frequencies are in good agreement with the observed Brillouin frequencies for the modes studied in the ferroelectric phase of NaNO2. This indicates that our method presented here predicts the observed behavior of NaNO2 in the ferroelectric phase

Specific heat of NH4Br and NH4BrxCl1-x crystals close to the antiferroelectric transition

We calculate the specific heat C-VI of NH4Br and mixed crystals of NH4BrxCl1-x using the Ising model for the transition between the disordered (D) and antiferro- (AF) electric phases in these crystalline systems. Our C-VI values, which we calculated for x(Br)=1, 0.26, and 0.51 are in good agreement, both below and above T-C, with the observed C-P data from the literature. Our value of congruent to 0.1 (T T-C) for the critical exponent of the specific heat agrees with the value of 0.125 predicted by a three-dimensional Ising model