Techno‐economic optimization model for “sustainable” insulation material developed for energy efficiency

Renewable insulation materials are produced within the scope of this study using clay, fly ash, expanded perlite, epoxidized hemp oil, and hemp fiber. Density, thermal conductivity, and compressive‐tensile strength of the produced materials are analyzed. Economic and environmental analysis of the best sample with the most appropriate characteristics for an insulation material is conducted using a hybrid mathematical model developed for this study. Mathematical formulas of an economic evaluation technique of P₁‐P₂ method is integrated into Simulated Annealing Algorithm as one of the metaheuristic optimization approaches. Applicability of the proposed material for externally insulated walls is tested. For this purpose, optimum insulation thickness, payback period, energy savings for 10 years of lifetime, and CO₂‐SO₂ emissions were calculated for 5 types of energy sources along with a sensitivity analysis. This method is developed and coded in a software platform and used for the first time for the optimization of insulation material thickness. The experimental results obtained from evaluation of the sample H36 indicate that using this material for insulation purposes in the buildings have the potential of making significant contribution for energy efficiency along with various environmental benefits.     

Use of ozone for the preparation of functional silk fibroin-based biomaterial loaded with bioactive compounds for biomedical applications

Silk fibroin (SF) can be used for the preparation of porous functional biomaterials due to its biocompatibility, biodegradability, and minimal in?ammatory reactions. High porosity and homogenous interconnected pore structure is a challenge for the preparation of porous biomaterials. Porous SF foam materials can be formed by bubbling inert gases through aqueous solutions and subsequent freeze drying process. In this study, SF foam structures were prepared by first purging ozone gas and then freeze drying of this ozone-treated aqueous SF solution. Resulting porous materials were efficiently loaded with plant extract for the preparation of functional biomaterials having antimicrobial properties. The interactions of SF with ozone led to chemical modifications that improved both foaming and hydrophobic properties. Intensive ozone treatment caused the crystallinity degree of untreated SF to decrease from 48% to 42%. Ozone treatment also resulted in a significant reduction in surface tyrosine content from 55% to 43%. The use of ozone gas for the preparation of SF foam material enhanced the adsorption capacity of phenolic compounds. The enhancement in the adsorption of phenolic compounds on SF foam structure can be attributed to the oxidation-dependent increase in hydrophobicity.     

Synthesis and characterization of antimicrobial polylactide via ring‐opening polymerization and click chemistry methods

Novel biodegradable polylactide (PLA) copolymers bearing pendant antimicrobial agent groups were successfully fabricated with a combination of ring‐opening copolymerization and copper(I)‐catalysed azide–alkyne cycloaddition click reaction in a two‐step reaction procedure. First, biodegradable PLA copolymers bearing azido groups were synthesized by the ring‐opening copolymerization of l ‐lactide and 2,2‐ bis(azidomethyl)trimethylene carbonate in the presence of 1‐dodecanol as protic co‐initiator and tin(II) 2‐ethylhexanoate (Sn(Oct)₂) as the catalyst. Then, alkyne functionalized quaternary ammonium salts were attached onto the azido groups of the copolymers via a Huisgen 1,3‐dipolar cycloaddition reaction to give PLA imparting antimicrobial activity. The chemical structure and composition of the copolymers were clearly confirmed using ¹H NMR and Fourier transform infrared spectroscopies and gel permeation chromatography. Thermal phase transition temperatures (T_m and T_g) and the thermal stability of the polymers were investigated by DSC and TGA experiments, respectively. The antimicrobial activity tests were carried out against Gram‐negative (Escherichia coli) and Gram‐positive (Staphylococcus aureus) bacteria by the drop plate method. It was observed that antimicrobial agents are more active in the polymeric form than in the monomeric form. Also, the activity depends on the compositional ratio and the length of the alkyl group on the ammonium salts. © 2018 Society of Chemical Industry     

Spray Drying of Yogurt: Optimization of Process Conditions for Improving Viability and Other Quality Attributes

Plain yogurt was subjected to spray drying to determine the optimum processing conditions that yield maximum survival ratio of lactic acid bacteria, maximum overall sensory attributes, minimum color change, and acceptable moisture content. The inlet (150–180°C) and outlet air temperatures (60–90°C) and the feed temperature (4–30°C) were the independent factors. A pilot-scale spray dryer was used to conduct a set of drying experiments where the process conditions were selected according to central composite rotatable design (CCRD). The resulting yogurt powder at each condition was also subjected to the measurement of some physical properties (water activity, titratable acidity [lactic acid, %] and pH) to determine the effects of spray-drying conditions. The morphological structure of the powder was inspected by scanning electron microscopy (SEM) analysis. Optimization by the application of the desirability function method resulted in air inlet temperature of 171°C, air outlet temperature of 60.5°C, and feed temperature of 15°C as the optimum processing condition. The mathematical optimum condition was experimentally verified.     

Microbiological quality of artisanal Sepet cheese

Microbial diversity in milk and in cheese itself affects the biochemical and sensory characteristics of artisanal cheeses. In this study, the microflora of Sepet cheese, which is a traditional artisanal cheese in Turkey, was investigated. Average lactococci, lactobacilli, enterococci, yeast, mould, coliform, psychrotrophic and total aerobic bacteria, presumptive Staphylococcus aureus counts were; 7.31 ± 1.08, 7.19 ± 1.02, 6.84 ± 0.92, 3.19 ± 1.40, 0.84 ± 0.89, 2.18 ± 1.81, 4.92 ± 1.15, 7.53 ± 1.13 and 1.25 ± 1.70 log cfu/g, respectively. Staphylococci, coliform and mould counts were less than 1.00 log cfu/g at the end of ripening, which was at around 6–8 °C for 3 months. According to phenotypic and genotypic identifications, isolates were closely related to Lactobacillus plantarum, Weisella confusa, Weisella paramesenteroides, Pediococcus pentasaceous, Enterococcus casseliflavus, Enterococcus durans and Enterococcus faceium. This study provides baseline data on the microflora of traditional artisanal Sepet cheese, which is a prerequisite for a successful scale up to industrial production.     

Phenolic Characterization and Geographical Classification of Commercial Extra Virgin Olive Oils Produced in Turkey

The aim of this research was to characterize the extra virgin olive oil samples from different locations in the Aegean coastal area of Turkey in terms of their phenolic compositions for two consecutive years to show the classification of oil samples with respect to harvest year and geography. Forty seven commercial olive oil samples were analyzed with HPLC–DAD, and 17 phenolic compounds were quantified. Hydroxytyrosol, tyrosol, vanillic acid, p-coumaric acid, ferulic acid, cinnamic acid, luteolin and apigenin were the characteristic phenols observed in all oil samples for two harvest years. Syringic acid, vanillin and m-coumaric acid were the phenolic compounds appeared in the olive oil depending on the harvest year. Partial least square-discriminant analysis (PLS-DA) of data revealed that oils from the north Aegean and south Aegean areas had different phenolic profiles. The phenolic compounds, which played significant roles in the discrimination of the olive oils, were tyrosol, oleuropein aglycon, cinnamic acid, apigenin and hydroxytyrosol to tyrosol ratio. The Aegean coastal region is the largest olive oil producer and exporter of Turkey. This study shows that the olive oils from different parts of the region have their own defining characteristics that can be used in the authentication studies and geographical labeling of Turkish olive oils.     

Classification of Turkish olive oils with respect to cultivar,geographic origin and harvest year,using fatty acid profile and mid-IR spectroscopy

Fatty acid composition and mid-infrared spectra of olive oils in combination with chemometric techniques were used in the classification of Turkish olive oils with respect to their varieties, growing location and harvest year. In particular, olive oil samples belonging to five different cultivars were obtained from the same orchard in the middle part of Aegean region and two of these varieties were also received from another orchard in northern part of the same region of Turkey in two consecutive harvest years. Evaluation of nine different fatty acid compositions with principal component analysis revealed clear differentiation with respect to variety, geographical origin and harvest year. On the other hand, mid-infrared spectra also achieved varietal and seasonal discrimination to some extent, but differentiation is not as clear as that obtained using fatty acid compositions.     

Objective Quality Assessment of Raw Tilapia (Oreochromis niloticus) Fillets Using Electronic Nose and Machine Vision

ABSTRACT: The ability of an electronic nose and machine vision system to classify tilapia fillets based on their odors and colors was studied. Fresh tilapia ( Oreochromis niloticus ) fillets were treated with 0%, 4%, and 8% sodium lactate and stored at 1.7 and 7.2 °C for 12 d. Trained panelists and an electronic nose with twelve polymer sensors evaluated odors. A machine vision system measured fillet colors. Aerobic plate counts were performed. Correct classification based on experimental variables (percent lactate, microbialload, sensory scores, storage time, and temperature) by discriminant function analysis was poor for color data alone, acceptable for electronic nose data alone, and excellent with these data combined.     

Structural characterization and dehydration kinetics of Kırka inderite mineral: Application of non-isothermal models

Coats-Redfern, Arrhenius, Ozawa, Kissinger, and Doyle non-isothermal kinetic models were used to calculate the dynamic kinetic parameters for dehydration reaction of Mg-borate mineral, inderite (K?rka — Turkey) based on thermogravimetric analysis, derivative thermogravimetric analysis and differential thermal analysis. Dehydration experiments were carried out at different heating rates of 2, 5, 10, 15, and 20 °C/min in a pure nitrogen atmosphere. Structural and morphological properties have been characterized by X-Ray diffraction, Fourier transform-infrared spectroscopy, Scanning electron microscopy-energy dispersive spectroscopy, and Inductively coupled plasma-optical emission spectroscopy techniques.     

Fabrication of Stainless-Steel-Fiber-Reinforced Cordierite-Matrix Composites of Tubular Shape Using Electrophoretic Deposition

Stainless-steel (316L) fiber mats shaped into tubular geometry were used to reinforce cordierite. The cordierite-matrix composites were manufactured using electrophoretic deposition and pressureless sintering. The sintered composites, which had an internal and external deposit thickness of ∼1 mm, were free of surface cracks when a deposition time of 2.5 min was used. Metal-fiber-reinforced cordierite composites such as those developed here may constitute a promising alternative for manufacturing damage-tolerant tubular components for applications at temperatures up to ∼900°C.