Estimation of heat of combustion of triglycerides and fatty acid methyl esters

Equations were developed for the estimation of gross heat of combustion (HG) of triglycerides (TGs) and fatty acid methyl esters (FAMEs) from their saponification number (SN) and iodine value (IV). HG of TG=1,896,000/SN − 0.6 IV — 1600 and HG of FAME=618,000/SN − 0.08 IV — 430. When these equations were tested on cottonseed oil, soybean oil, partially hydrogenated soybean oil, peanut oil, sunflower oil, sunflower oil methyl esters, soybean oil methyl esters and cottonseed oil methyl esters, predicted HG values agreed well with those reported in the literature.     

Control of Aspergillus flavus with essential oil and methanol extract of Satureja hortensis

The essential oil and methanol extract of Satureja hortensis were tested for antifungal activity against Aspergillus flavus in vitro on Petri plates and liquid culture, and under storage conditions. The oil showed strong antifungal activity based on the inhibition zone and minimal inhibitory concentration values against the pathogen on Petri plates assays. The very low concentrations of them also reduced wet and dry mycelium weight of pathogen fungus in liquid culture. When the oils at 25, 12.5 and 6.25 microl/mL concentrations were applied to lemon fruits before seven days of pathogen inoculation on storage conditions, the decay on fruits caused by the pathogen could be prevented completely. The results in this study showed that the essential oil of S. hortensis had strong antifungal activity against pathogen fungi tested. So, the essential oil of S. hortensis could be used for management of this pathogen as a potential source of sustainable eco-friendly botanical fungicides.     

Partial extraction method for the rapid analysis of total lipids and γ-oryzanol contents in rice bran

Total lipids and γ-oryzanol in rice bran were determined by a partial extraction method. The results agreed well with the conventional total extraction methods. The proposed method uses fewer hazardous organic solvents, takes a shorter extraction time and requires no special extraction apparatus. Total lipids and γ-oryzanol in nine rice bran varieties were analysed by the developed technique. Daw Dum 5647 had the highest total lipids and γ-oryzanol while the lowest content was found in KD XBT 313-19-1-1 and SP XBT 43-7, respectively. The adsorption coefficient (K_d) of the lipids and γ-oryzanol, between hexane and bran, at 30 °C are between 1.16 and 2.00 and 2.02 and 2.65, respectively (depending on the moisture content of the bran). From the K_d values, it was estimated that about 92–95% of the lipids and 95–96% of the γ-oryzanol were extracted into hexane at a 10:1 (v/w) ratio of hexane to bran. The effect of solvents on the extraction of γ-oryzanol from rice bran was also studied. It was found that isopropanol was the most suitable solvent for extraction and determination of γ-oryzanol in rice bran. It showed better agreement with the total extraction method.     

Effect of weathering on the geomechanical properties of the Miocene basalts in Malatya,Eastern Turkey

Miocene volcanic rocks are widely exposed in the eastern Taurids, Turkey. The geomechanical properties and weathering degree of the Middle–Upper Miocene basalts were determined at the Boztepe dam site in Malatya, eastern Turkey. An engineering geology map of the Boztepe dam site was made and the joint sets and the degree of weathering determined in the field. The degree of weathering and RQD values were obtained on some 1,195 m of core which was then compared with a series of geomechanical tests including unit weight, porosity, water absorption, uniaxial compressive strength and compressive wave velocity. The geomechanical properties were compared with the weathering classifications of ISRM (Rock characterization, testing and monitoring, p 211, 1981) and Kilic (Environ Eng Geosci 4:475–483, 1999)      

Additive-Free Aqueous MXene Inks for Thermal Inkjet Printing on Textiles

Direct printing of functional inks onto flexible substrates allows for scalable fabrication of wearable electronics. However, existing ink formulations for inkjet printing require toxic solvents and additives, which make device fabrication more complex, limit substrate compatibility, and hinder device performance. Even water-based carbon or metal nanoparticle inks require supplemental surfactants, binders, and cosolvents to produce jettable colloidal suspensions. Here, a general approach is demonstrated for formulating conductive inkjet printable, additive-free aqueous Ti₃C₂T_x MXene inks for direct printing on various substrates. The rheological properties of the MXene inks are tuned by controlling the Ti₃C₂T_x flake size and concentration. Ti₃C₂T_x-based electrical conduits and microsupercapacitors (MSCs) are printed on textile and paper substrates by optimizing the nozzle geometry for high-resolution inkjet printing. The chemical stability and electrical properties of the printed devices are also studied after storing the devices for six months under ambient conditions. Current collector-free, textile-based MSCs show areal capacitance values up to 294 mF cm⁻² (2 mV s⁻¹) in poly(vinyl alcohol)/sulfuric acid gel electrolyte, surpassing reported printed MXene-based MSCs and inkjet-printed MSCs using other 2D nanomaterials. This work is an important step toward increasing the functional capacity of conductive inks and simplifying the fabrication of wearable textile-based electronics.     

The elasto-plastic impact analysis of functionally graded circular plates under low-velocities

In this study, three-dimensional elasto-plastic analysis of functionally graded (FG) circular plates under low-velocity impact loads is presented. The FG circular plate is composed of ceramic (SiC) and metal (Al) phases, varying in a predetermined fashion through the plate thickness. The elasto-plastic behaviour of the FG circular plate is described by the TTO model. In the analyses, the ceramic phase is taken to be an isotropic elastic material whereas the metal phase is taken to be elasto-plastic material in accordance with the TTO model. The locally effective material properties were evaluated using homogenization method which is based on the Mori–Tanaka scheme. The effects of compositional gradient exponent and impactor velocity on the elasto-plastic impact response of the FG circular plates are investigated, and results are presented graphical form. The compositional gradient exponent and impactor velocity have significant effects on the elasto-plastic impact response of the FG circular plates. The elasto-plastic impact response of FG circular plates is similar to those of homogeneous plates. Therefore, the TTO model can be used to describe the mechanical behaviour of FG plates beyond the elastic range, assuming that the material response is essentially governed by the spreading of plasticity in the metal phase.     

Investigation of UV and I–V characteristics of high refractive index polymer thin film for optoelectronic applications

In this study, high refractive index polymer (HRIP) [poly(pentabromobenzyl methacrylate-co-glycidyl methacrylate)] was investigated to obtain its optical and electrical performance for optoelectronic applications. UV characteristics of the polymer in solution of tetrahydrofuran were obtained and optical band gap energy of the polymer was calculated as 3.8 eV. I–V characteristics of the polymer were investigated after HRIP thin film was prepared using spin coating technique. The electrical parameters such as barrier height Φ_Bo, ideality factor n and reverse saturation current I_o were extracted from the forward biasing I–V characteristics. At the same time, series resistance R_s and Φ_Bo were determined by using a modified Norde function combined with conventional forward I–V method.     

Designing of a powder compressing device with vibration and investigation of compressibility of MgO powders with this device

One of metal matrix composite (MMC) production methods is infiltration of liquid metal into preformed reinforcement. In this method, MMCs are produced by infiltration of liquid metal into preformed reinforcement using one of pressure, vacuum or pressureless (free) infiltration methods. For infiltration purposes, reinforcement materials in different figuration are preformed in desired shape and reinforcement volume ratio. In this study a vibration apparatus has been designed to compress the particulate reinforcement in a tube so that pressure or vacuum infiltration can be carried out. The compressibility of MgO powders with different sizes with this apparatus has also been investigated. It has been found that with this apparatus, it is possible to compress desired number of specimens uniformly at the same time and at the same ratio. It has also been determined that MgO powders can be compressed in different ratio due to particle sizes with this device. Compressing time of 3 min is enough to reach maximum compression ratio in MgO powders.     

Geobag Performance as Scour Countermeasure for Bridge Abutments

This paper presents observations and data from a sequence of laboratory experiments conducted to evaluate geobags as a countermeasure to protect bridge-abutment foundations from failure attributable to scour of the alluvial-river channel in which they are placed. Geobags comprise geotextile cloth bags filled with local sediment or concrete. The experiments focused on the performance of geobags placed as an apron around pile-supported wing-wall abutments retaining erodible embankments, and subject to live-bed and clear-water flow conditions. Though an apron of geobags is shown to substantially reduce or eliminate scour immediately at the abutment, the apron must be formed flexibly of linked geobags. Moreover, a performance concern is that the apron may shift scour to a location flanking or downstream of the apron, and in so doing imperil a nearby pier or riverbank. The experiments indicate the importance of protecting the embankment region beneath and immediately behind the abutment’s pile cap. Live-bed conditions proved to be the more critical for abutment protection, owing to the capacity of dunes to destabilize geobags around the edges of the apron. Design guidelines are given and include using current riprap configurations for sizing and placing geobags.     

Poly(methyl methacrylate)/POSS hybrid networks by type II photoinitiated free radical polymerization

A new strategy for organic–inorganic hybrid networks is presented through in‐situ Type II photoinitiated polymerization of methyl methacrylate with diethanolamino‐functionalized polyhedral oligomeric silsesquioxanes (POSS‐DEA). The diethanolamino groups are simply incorporated onto POSS nanoparticles by nucleophilic ring‐opening reaction of commercially available epoxycyclohexyl POSS and diethanol amine. The photoinitiated polymerization of methyl methacrylate in the presence of benzophenone as photosensitizer and POSS‐DEA as hydrogen donor leads to poly(methyl methacrylate) (PMMA)/POSS hybrid networks under UV light irradiation. The morphology and thermal properties of hybrid networks are investigated by using Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and transmission electron microscopy. The morphology results confirm that POSS cages are homogeneously distributed in PMMA matrix at the molecular levels, whereas the thermal analyses shows that the obtained hybrid networks have higher glass transition temperatures and better thermal stabilities compared to parent PMMA homopolymer. POLYM. COMPOS., 35:1614–1620, 2014. © 2013 Society of Plastics Engineers