A STUDY OF THE FLOTATION OF OXIDIZED AHASRA COAL

The flotation of oxidized Amasra Coal which was collected between 1973-1978 and, stored in the atmospheric conditions was examined In this work. Coal samples were fractioned by wet screening to +0.560 mm, -0.500 + 0.140 mm, -0.140 mm particle sizes and first fraction was ground to -0.560 mm before flotation. Motorin and pine oil which had been heated at 125° C for 5 hours were used ns flotation reagents. The influence of impeller speed, aeration rate, solid concent of the pulp, reagent amounts were examined and optimum values were determined. Increase of the pine oil amount added to the pulp, increased the coal. recovery on the flotation of this oxidized coal.     

A combo technology of autotrophic and heterotrophic denitrification processes for groundwater treatment

In this study,a sequential process (heterotrophic up-flow column and completely mixed membrane bioreactors) was proposed combining advantages of the both processes.The system was operated for 249 days with simulated and real groundwater for nitrate removal at concentrations varying from 25 to 145 mg·L-1 NO3-N.The contribution of heterotrophic process to total nitrate removal in the system was controlled by dozing the ethanol considering the nitrate concentration.By this way,sulfur based autotrophic denitrification rate was decreased and the effluent sulfate concentrations were controlled.The alkalinity requirement in the autotrophic process was produced in the heterotrophic reactor,and the system was operated without alkalinity supplementation.Throughout the study,the chemical oxygen demand in the heterotrophic reactor effluent was (23.7 ± 22) mg·L-1 and it was further decreased to(7.5 ± 7.2) mg·L-1 in the system effluent,corresponding to a 70％ reduction.In the last period of the study,the real groundwater containing 145 mg·L-1 NO3-N was completely removed.Membrane was operated without chemical washing in the first 114 days.Between days 115-249 weekly chemical washing was required.     

Online collaboration: Collaborative behavior patterns and factors affecting globally distributed team performance

Studying the collaborative behavior of online learning teams and how this behavior is related to communication mode and task type is a complex process. Research about small group learning suggests that a higher percentage of social interactions occur in synchronous rather than asynchronous mode, and that students spend more time in task-oriented interaction in asynchronous discussions than in synchronous mode. This study analyzed the collaborative interaction patterns of global software development learning teams composed of students from Turkey, US, and Panama. Data collected from students’ chat histories and forum discussions from three global software development projects were collected and compared. Both qualitative and quantitative analysis methods were used to determine the differences between a group’s communication patterns in asynchronous versus synchronous communication mode. K-means clustering with the Ward method was used to investigate the patterns of behaviors in distributed teams. The results show that communication patterns are related to communication mode, the nature of the task, and the experience level of the leader. The paper also includes recommendations for building effective online collaborative teams and describes future research possibilities.     

Determination of Myricetin in Medicinal Plants by High-Performance Liquid Chromatography

The concentrations of myricetin in medicinal plants such as Rosa canina L. (rosa hip), Terebinthina chica L. (terebinth), Urtica dioica L. (nettle), and Portuca oleracea L. (purslane) were determined by high-performance liquid chromatography-mass spectrometry (HPLC-MS). The aglycones of myricetin were extracted using methanol–ascorbic acid– hydrochloric acid, methanol–hydrochloric acid, and methanol, separated within 5 min, and individually quantitated in the positive ionization mode using optimized conditions for HPLC-MS. Methanol–ascorbic acid–hydrochloric acid was the optimum extraction solvent. The myricetin concentration in the plants were between 3 and 58 mg kg^?1, with a limit of quantification equal to 0.1 mg L^?1.     

Penetration Depth in Nanoparticles Incorporated Radiofrequency Hyperthermia into the Tissue: Comprehensive Study with Histology and Pathology Observations

In present study, the effective penetration of radiofrequency (RF) induced gold decorated iron oxide nanoparticles (GS@IONPs) hyperthermia was investigated. The effective penetration depth of RF also the damage potency of hyperthermia was evaluated during histopathology observations which were done on the chicken breast tissue and hepatocellular carcinoma (HCC) models. The thermal damages are well‐ documented in our previous cellular study which was engaged with potency of RF hyperthermia in Epithelial adenocarcinoma (MCF‐7) and fibroblast (L‐929) cells deaths [1]. In recent work, PEGylated iron oxide nanoparticles (IONPs) were used as base platform for gold magnetic nanoparticles (GS@IONPs) formation. The 144.00015 MHz, 180W RF generator was applied for stimulating the nanoparticles. The chicken breast tissue and the hepatocellular tumor model was considered in the experimental section. In histology studies, the structural changes also the effective penetration depth of RF induced nanoparticles was observed through microscopic monitoring of the tissue slices in histology observations (Gazi medical school). The highest damage level was seen in 8.0 µm tissue slices where lower damages were seen in depth of 1.0 cm and more inside tissue. The histology observations clarified the effective penetration depth of RF waves and irreversible damages in the 2.0 cm inside the tissue.Inspec keywords: nanomedicine, tumours, biomedical materials, cellular biophysics, nanoparticles, gold, cancer, hyperthermia, magnetic particles, iron compounds, radiation therapyOther keywords: Au‐Fe₃ O₄ , depth 1.0 cm, depth 8.0 mum, power 180.0 W, size 2.0 cm, frequency 144.00015 MHz, microscopic monitoring, structural changes, hepatocellular tumour model, standing wave ratio, propylene glycol, thermal damages, hepatocellular carcinoma models, radiofrequency hyperthermia, nanoparticle dispersion, tissue alterations, modified tissues, gold shell magnetic nanoparticles, chicken breast tissue, gold‐coated iron oxide nanoparticles, pathology observations, effective penetration depth, histology observations, tissue slices     

Evaluation of the shifting of the line of sight and higher order aberrations of eyes with keratoconus after corneal cross-linking

Aim

To evaluate changes in the coordinates of the line of sight (LoS) and higher order aberrations (HOAs) of eyes with keratoconus, following corneal cross-linking (CXL).

A STUDY OF THE FLOTATION OF OXIDIZED AHASRA COAL

ABSTRACT

The flotation of oxidized Amasra Coal which was collected between 1973–1978 and, stored in the atmospheric conditions was examined In this work. Coal samples were fractioned by wet screening to +0.560 mm, ?0.500 + 0.140 mm, ?0.140 mm particle sizes and first fraction was ground to ?0.560 mm before flotation. Motorin and pine oil which had been heated at 125° C for 5 hours were used ns flotation reagents. The influence of impeller speed, aeration rate, solid concent of the pulp, reagent amounts were examined and optimum values were determined. Increase of the pine oil amount added to the pulp, increased the coal. recovery on the flotation of this oxidized coal.     

Solution thermodynamics of poly(ethylene glycol)/water systems

The unperturbed molecular dimensions of poly(ethylene glycol) (PEG) samples (of different molecular weights) have been evaluated in aqueous solutions from viscosity measurements at 25, 30, 35, and 40°C. The unperturbed dimension, K_θ, has been determined from extrapolation methods, i.e., Kurata–Stockmayer–Fixman (KSF), Inagaki–Suzuki–Kurata (ISK), and Berry equations. The hydrodynamic expansion factor, α_η, as well as the unperturbed root‐mean‐square end‐to‐end distance, 〈r²〉, found for the system indicated that the polymer coils contract as the temperature is raised from 25 to 40°C. The long‐range interaction (excluded volume) parameter, B, was also evaluated and a significant decrease was found for the PEG/water system between 25 and 40°C. The theta temperatures, θ, were obtained from the temperature dependence of (1/2 ? χ) and the second virial coefficient was detected in the temperature interval of 25–40°C for the system and quite a good agreement with the calculated values evaluated via extrapolation and interpolation methods was observed. The thermodynamic interaction parameter χ was evaluated through the sum of the individual values of enthalpy and entropy dilution parameters, χ_H and χ_S, for PEG samples. All the unperturbed molecular dimensions of PEG/water system were calculated and compared according to M _w and M _n values of PEG samples. Calculated values were interpreted mainly on the basis of hydrogen‐bond formation between polymer segments and PEG‐water molecules in solution. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 203–216, 2006     

In-source and post-irradiation polymerization of acenaphthylene in the solid state

Radiation-induced solid state polymerization of acenaphthylene was studied by using ⁶⁰Co γ-rays. The extent of polymerization at room temperature reached 68% when acenaphthylene was irradiated with a dose of 2–5 MGy. Prolonged exposure to the radiation decreased the molecular weight of the polymers. The post-polymerization of acenaphthylene was found to occur at relatively high temperatures close to the melting point of acenaphthylene. Absence of an effective termination step allows the enhancement of post-polymerization at higher temperatures after a limiting conversion is accomplished.