1,721,368 research outputs found
A Study on monitoring and optimisation of chromium uptake in tanning process
No full textBu tezin, veri tabanı üzerinden yayınlanma izni bulunmamaktadır. Yayınlanma izni olmayan tezlerin basılı kopyalarına Üniversite kütüphaneniz aracılığıyla (TÜBESS üzerinden) erişebilirsiniz.ÖZET TABAKLAMADA KROM TÜKETİMİNİN BİLGİSAYAR YARDIMI İLE İZLENMESİ VE OPTİMİZASYONU ÜZERİNE BİR ARAŞTIRMA MUTLU, Mehmet Mete Yüksek Lisans Tezi, Deri Teknolojisi Bölümü Tez Yöneticisi : Prof. Dr. Özcan SARI Ocak 1999, 114 sayfa Bu araştırmada; krom tüketiminin bilgisayar yardımıyla izlenmesi için deri örnekleri farklı sıcaklık ve bazifıkasyon zamanlan ile tabaklanmış ve tabaklama süresince flottede krom konsantrasyonu kısa zaman aralıkları ile spektrofotometrede ölçülerek banyodaki krom tüketimi bilgisayar grafikleri ile izlenmiştir. Grafiklerden elde edilen bilgiler ve mamul deri örneklerine uygulanan fiziksel test ve kimyasal analiz sonuçlan karşılaştınlarak krom tüketiminin optimal koşullan tesbit edilmeye çalışılmıştır. Anahtar sözcükler : Proses kontrol, krom tabaklama, krom tüketimiVII ABSTRACT A STUDY ON MONITORING AND OPTIMISATION OF CHROMIUM UPTAKE IN TANNING PROCESS MUTLU, Mehmet Mete MSc in Leather Technology Supervisor : Prof. Dr. Özcan SARI January 1999, 114 pages In this research, for computer aided monitoring of chromium exhaustion, leather samples have been tanned with various application times of temperature and basification and chromium exhaustion of the float has been monitored by computer graphics by measuring the chromium concentration of the float with a spectrophotometer in short time intervals. Optimal conditions of chromium tannage have been tried to be determined by comparing the datas obtained from graphics and results of the physical tests and chemical analysis applied to the leather samples.. Keywords : Process control, chrome tanning, chrome exhaustio
Sterilization of food contacting surfaces via non-thermal plasma treatment: A model study with Escherichia coli-contaminated stainless steel and polyethylene surfaces
No full textWOS: 000325869900001This study focuses on the utilization of glow discharge technique for the reduction of microorganisms on food contacting surfaces to determine whether non-thermal, low-pressure plasma could provide an effective alternative to current sterilization methods. Radio frequency (13.6 MHz) plasma environment was developed and tested for the inactivation of E. coli K12. Different plasma parameters (discharge power 0-100 W, exposure time 0-30 min) and selected gases (nitrogen, oxygen, air, water vapor) were tested. Following plasma treatment, survival curves and D values were determined. Contact angle measurements were performed to state the change of surface hydrophilicity. Determinations of structural changes on microorganisms were accomplished by atomic force microscopy (AFM) and transmission electron microscopy (TEM). Improved bacterial inactivation efficiency was achieved when air was used instead of pure oxygen or nitrogen gases. Water vapor was found to be the most effective (approximately 7 log(10) reduction) agent in destruction of the microorganisms. The results showed that surface topography and hydrophilicity also have an effect on the efficiency of plasma treatment. In this study, the E. coli inoculated on polyethylene surfaces showed more resistance to plasma treatment. Fragmentation of bacterial cell wall and leakage of cytoplasmic matter were observed following plasma experiments. This study demonstrates that plasma is a promising technology for sterilization of food contacting surfaces, because of its safety, easy handling, capability of processing at low-temperature ( < 44 A degrees C), relatively rapid sterilization
Preparation of superhydrophobic membranes by HMDSO plasma modified electrospun nanofibers
No full textEurobiotech Agriculture Symposium -- APR 12-14, 2012 -- Erciyes Univ, Kayseri, TURKEYWOS: 000318064700159European Biotechnol Themat Network Asso
Modification of quartz crystal microbalance surfaces via electrospun nanofibers intended for biosensor applications
No full textWOS: 000317537500004The major aim of this study is to increase the performance of mass sensitive biosensor surfaces by making modifications on quartz crystal microbalance (QCM) surfaces via electrospinning and plasma polymerization techniques. Polyvinyl alcohol (PVA) nanofibers with a diameter of approximately 150 nm were collected on the QCM surfaces by electrospinning technique. Allylamine monomer was used to create specific groups on these nanofiber coated surfaces by plasma polymerization technique. Modified surfaces were characterized by contact angle measurements, scanning electron microscopy, atomic force microscopy, fourier transform infrared spectroscopy and QCM frequency measurements in order to determine the physical and chemical characteristics of the surfaces after each experimental stage. N-H, C-N, C-H and C=O group bands were determined in the IR spectra of the materials. Decrease in the contact angle values of the modified materials indicated the increase in hydrophilicity. Those results showed that amine containing films on the surfaces were successfully deposited using plasma. The performance of modified QCM surfaces was tested via resonance frequency shifts measurements after bovine serum albumin immobilization. In this group of tests, "dip and dry" method and "flow-cell method" were performed and 548 +/- 4 Hz and 50 +/- 5 Hz frequency shifts were obtained respectively. Results of this study revealed that plasma treated electrospun PVA nanofiber modified surfaces can be used for further biosensor applications
Plasma processing of materials for biotechnological applications
No full textEuropean Biotechnology Congress -- SEP 28-OCT 01, 2011 -- Istanbul, TURKEYWOS: 000295310800173European Biotechnol Themat Network Asso
Nanofabrication and plasma polymerization assisted surface modification of a transducer based on localized surface plasmon resonance of gold nanostructure arrays for biosensor applications
Full text linkThe nanofabrication and surface modification of a transducer based on localized surface plasmon resonance (LSPR) of gold nanostructure arrays for biosensing was studied. We used electron beam lithography for the nanopatterning technique, which let us choose LSPR sensor properties by providing immense control over nanostructural geometry. A critical step in the utilization of this transducer is to form a selective biolayer over the gold nanostructures. We applied plasma polymerization and wet chemistry techniques for ethylenediamine (EDA) modification and glutaraldehyde immobilization as intermediate layers, respectively. The gold nanostructure arrays were primarily modified using EDA in order to activate the surface with amine groups that are cross-linked with later added avidin molecules by the help of glutaraldhyde layer residing in between. The success of plasma polymerization was validated with x-ray photoelectron spectroscopy measurements. As a last step, we introduced biotin to the surface (biotin has a high affinity for avidin). We were able to detect the LSPR resonance wavelength shift in the transmission spectra at each step of modification, including the avidin-biotin interaction, which acts as a model for specific molecule detection using LSPR. (C) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE)
Surface modification of polyethersulfone membrane to improve its hydrophobic characteristics for waste frying oil filtration: Radio frequency plasma treatment
No full textWOS: 000298086500025In this study, polyethersulfone (PES) membrane was subjected to surface modification using hexamethyldisiloxane (HMDSO) and 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) in radio frequency (RF) plasma system to improve its hydrophobic property for recovery of waste frying oil. Structural and morphological changes on the membrane surfaces were characterized by contact angle measurements, Fourier transform infrared spectroscopy-attenuated total reflection (FTIR-ATR) and atomic force microscopy (AFM). Permeate fluxes, physical and chemical properties of waste frying oil and waste frying oil-methanol micella (oil/methanol 1/3, 1/1, 1/3, v/v) after filtration through unmodified and modified PES membranes were investigated. The results showed that PES membranes modified with HMDSO at 75 W for 5 min (discharge power-exposure time) selectively rejected total polar compounds (TPC) and free fatty acids (FFAs) of waste frying oil to the extent of 46.9-48% and 35.3-40%, respectively. Furthermore, the viscosity of waste frying oil was reduced to the extent of 9.4-12.8%. RF-plasma-treated PES membranes appeared to improve the regeneration of waste frying oils and allow these oils to be used for either repeated frying operations or biodiesel production. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 123: 3402-3411, 2012Ministry of Trade and Industry, Republic of Turkey; Deltamed Life Sciences and Plasma Technologies Research and Development Corp. [00032.STZ.2006-1]This work has been supported by the Ministry of Trade and Industry, Republic of Turkey, and Deltamed Life Sciences and Plasma Technologies Research and Development Corp. as SAN-TEZ project (Project No: 00032.STZ.2006-1). The authors thank Prof. Dr. Arzu Topacli and Prof. Dr. Cafer Topacli from Physics Department of Hacettepe University, Ankara, Turkey for FTIR-ATR analysis
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
- …
