Prevalence of arcobacter species in drinking water, spring water, and raw milk as determined by multiplex PCR

The aim of this study was to investigate the incidence of Arcobacter species in water sources and raw milk from healthy animals in Kayseri, Turkey. A total of 175 samples of drinking water (n = 100), spring water (n = 25), and raw milk (n = 50) were examined. Arcobacter species were isolated using the membrane filtration technique. Overall, 7 (4%) of the 175 samples yielded Arcobacter spp.: 3 (3%) drinking water samples, 1 (4%) spring water sample, and 3 (6%) raw milk samples. Two species of Arcobacter were recovered from the seven positive samples: Arcobacter butzleri, Arcobacter skirrowii, and A. butzleri plus A. skirrowii found in 3 (1.7%), 2 (1.1%), and 2 (1.1%) samples, respectively. Our study is the first to report the isolation of both A. butzleri and A. skirrowii together from drinking water and is the first report of Arcobacter in milk from healthy cows in Turkey. Based on these findings, the presence of Arcobacter species in environmental waters and raw milk may pose a potential hazard for human health.     

A new application for the valorisation of pomegranate seed oil: nanoencapsulation of pomegranate seed oil into electrospun nanomats for food preservation

Pomegranate seed oil (PSO) contains many bioactive materials including antimicrobials, antioxidants, tocopherol and unsaturated fatty acids such as punicic acids. Utilising PSO with nanotechnological ways is a novel approach. Therefore, in this study, PSO-loaded nanomats having an average diameter of 327 nm with 97.6% encapsulation efficiency were produced. Then, the protection potential of nanomats was determined in terms of the microbial and oxidative deterioration of food samples. On the 1st day of storage, the TMAB load of the control kashar cheese was 4.35 log CFU g⁻¹, while it was 3.05 log CFU g⁻¹ in the coated cheese (change: 1.3 logs). On the 20th day of storage, the TMAB load of the CK sample and PSc sample was 5.52 and 4.22 log CFU g⁻¹, respectively (change: 1.3 logs). For fish fillets, nanoencapsulated PSO enabled a bacterial reduction of 1.22 log cycles after 9 days of storage. The total mould and yeast number of cheese samples increased during storage, but the increase was lower in the coated group. Nanomats also increased the oxidative stability of food samples. Thiobarbituric acid values of coated samples were lower than uncoated samples.     

Conventional and enhanced exergy analysis of a hydrogen liquefaction system

In the present work, conventional and enhanced exergy analyses were applied to the cryogenic liquefaction process of hydrogen gas. The hydrogen liquefaction unit consists of a multi-stage compressor, booster compressor-turbine pair, and heat exchanger block. Convectional exergy analysis cannot identify parts of exergy inefficiencies. In addition, by convectional exergy analysis, it cannot determine inevitable exergy losses that occur due to technological limits. For this reason, enhanced exergy analysis should be applied to the system. The exergy destruction affecting the exergy efficiency of the hydrogen liquefaction unit was investigated in detail. This study suggests an enhanced exergy analysis of a cryogenic liquefaction system. According to the results of the convectional exergy analysis, exergy efficiency of the whole liquefaction process are 32.22%. Also, the highest and lowest endogenous exergy destruction among whole components is calculated as 9563 kW and 92.83 kW in the turbine and CM-1, respectively. With these calculated results, the potential for improvement in the turbine in the liquefaction system was found to be high.     

Exergetic analysis and evaluation of a new application of gas engine heat pumps (GEHPs) for food drying processes

In this study, three medicinal and aromatic plants (Foeniculum vulgare, Malva sylvestris L. and Thymus vulgaris) were dried in a pilot scale gas engine driven heat pump drier, which was designed, constructed and installed in Ege University, Izmir, Turkey. Drying experiments were performed at an air temperature of 45 °C with an air velocity of 1 m/s. In this work, the performance of the drier along with its main components is evaluated using exergy analysis method. The most important component for improving the system efficiency is found to be the gas engine, followed by the exhaust air heat exchanger for the drying system. An exergy loss and flow diagram (the so-called Grassmann diagram) of the whole drying system is also presented to give quantitative information regarding the proportion of the exergy input dissipated in the various system components, while the sustainability index values for the system components are calculated to indicate how sustainability is affected by changing the exergy efficiency of a process. Gas engine, expansion valve and drying ducts account for more than 60% amount of exergy in the system. The exergetic efficiency values are in the range of 77.68–79.21% for the heat pump unit, 39.26–43.24% for the gas engine driven heat pump unit, 81.29–81.56% for the drying chamber and 48.24–51.28% for the overall drying system.     

Nitrate Ion Sensing Properties of Peripheral 3,4,5-Trimethoxyphenoxy and Chlorine Substituted Metallo and Metal-free Phthalocyanines

Journal of Inorganic and Organometallic Polymers and Materials - The purpose of this study is to investigate the capability of novel peripheral metal-free and metallo (2H, Fe, Co, Zn) mono nuclear...     

Ta/Si Schottky diodes fabricated by magnetron sputtering technique

Electrical properties of Ta/n-Si and Ta/p-Si Schottky barrier diodes obtained by sputtering of tantalum (Ta) metal on semiconductors have been investigated. The characteristic parameters of these contacts like barrier height, ideality factor and series resistance have been calculated using current voltage (I-V) measurements. It has seen that the diodes have ideality factors more than unity and the sum of their barrier heights is 1.21 eV which is higher than the band gap of the silicon (1.12 eV). The results have been attributed the effects of inhomogeneities at the interface of the devices and native oxide layer. In addition, the barrier height values determined using capacitance-voltage (C-V) measurements have been compared the ones obtained from I-V measurements. It has seen that the interface states have strong effects on electrical properties of the diodes such as C-V and R_s-V measurements.     

The effect of biodiesel fuel obtained from waste frying oil on direct injection diesel engine performance and exhaust emissions

In this study, usage of methyl ester obtained from waste frying oil (WFO) is examined as an experimental material. A reactor was designed and installed for production of methyl ester from this kind of oil. Physical and chemical properties of methyl ester were determined in the laboratory. The methyl ester was tested in a diesel engine with turbocharged, four cylinders and direct injection. Gathered results were compared with No. 2 diesel fuel. Engine tests results obtained with the aim of comparison from the measures of torque, power; specific fuel consumptions are nearly the same. In addition, amount of emission such as CO, CO₂, NO_x, and smoke darkness of waste frying oils are less than No. 2 diesel fuel.     

Surface Characterization and Biocompatibility of Selenium‐Doped Hydroxyapatite Coating on Titanium Alloy

Selenium‐doped hydroxyapatite (HA) was biomimetically coated on Ti6Al4V plates with the aim of combining the anticancer and antibacterial properties of selenium with the biocompatibility and bioactivity of HA. For the coating process, the composition of 1.5 × SBF (solution with ion concentrations at 1.5 times that of simulated body fluid, SBF) was modified to include 0.15 mM selenate (SeO₄^2?) ion. The selenium‐doped HA coating was characterized by several methods, such as scanning electron microscopy, X‐ray diffraction, and Fourier transform infrared spectroscopy. The cytotoxicity of selenium on osteoblast and osteosarcoma cells was determined. The coating was shown to inhibit the growth of Staphylococcus epidermidis.     

Understanding the advisor–advisee relationship via scholarly data analysis

Advisor–advisee relationship is important in academic networks due to its universality and necessity. Despite the increasing desire to analyze the career of newcomers, however, the outcomes of different collaboration patterns between advisors and advisees remain unknown. The purpose of this paper is to find out the correlation between advisors’ academic characteristics and advisees’ academic performance in Computer Science. Employing both quantitative and qualitative analysis, we find that with the increase of advisors’ academic age, advisees’ performance experiences an initial growth, follows a sustaining stage, and finally ends up with a declining trend. We also discover the phenomenon that accomplished advisors can bring up skilled advisees. We explore the conclusion from two aspects: (1) Advisees mentored by advisors with high academic level have better academic performance than the rest; (2) Advisors with high academic level can raise their advisees’ h-index ranking. This work provides new insights on promoting our understanding of the relationship between advisors’ academic characteristics and advisees’ performance, as well as on advisor choosing.