Bleaching of Hemp (Cannabis Sativa L.) Fibers with Peracetic Acid for Textiles Industry Purposes

Görkem Gedik,Ozan Avinc 한국섬유공학회 2018 Fibers and polymers Vol.19 No.1

Hemp plant exhibits various eco-friendly properties and hemp fiber processing does not cause environmental damage, however, it is known that most chemical operations have a risk to interrupt a sustainable production. As stated in several studies, peracetic acid is an important environmental friendly bleaching agent when compared to its conventional competitors. In this study, hemp fabric was bleached with peracetic acid with exhaustion and padding methods. The effects of temperature, pH, process time, concentration on whiteness values were determined. The influences of bleaching processes were investigated via instrumental and imaging methods. Physical properties of the treated fibers were also tested. Besides peracetic acid, hydrogen peroxide bleaching was carried out for comparison. COD values of bleaching effluents wereanalyzed for selected samples. Higher whiteness values were obtained with exhaustion bleachings than pad-batch bleachings.Quite high whiteness values (up to 68.13 Stensby whiteness index) attained in peracetic acid without significant fiber damage.

Production of Metal Oxide Containing Antibacterial Coated Textile Material and Investigation of the Mechanism of Action

Gorkem Gedik,Aysun Aksit,Birol Engin,Ufuk Paksu 한국섬유공학회 2018 Fibers and polymers Vol.19 No.12

The main aim of this study was to produce PVC coated textile based antibacterial textile material and to investigate the antibacterial mechanism with detailed analyzes. Metal oxide (calcium oxide, zinc oxide, magnesium oxide) powders were used to provide antibacterial functionality to coated materials. Metal oxide concentrations were varied between 5-35 %. Antibacterial tests were performed according to ISO 22196-2011 standard. Antibacterial efficiency of the samples was tested for each metal oxide type and concentration with L. innocua species. The antibacterial mechanism was investigated with ESR technique, fluorescent microscobe and microplate reader using DCFH-DA probe, UV-vis spectrometer using fluorescein probe. The results indicated that the antibacterial effect of used metal oxides was strongly arisen from radical oxygen species. The morphology of coatings was investigated with SEM and the distribution of metal oxide particles on the surface was examined with EDX analysis and EDX mapping. The changes on the molecular basis of the coating due to the metal oxide addition was analyzed with FT-IR spectroscopy. High antibacterial efficiencies (up to 100 %) were detected. It is suggested that the non-toxic metal oxides can be used as an effective and economically feasible alternative to conventional antibacterial additives for industrial applications such as conveyor belts.

Simultaneous Eco-friendly Bleaching and Retting Wastewater Treatment of Hemp Fiber with Ozone Application

Görkem Gedik,Yağmur Meltem Aydın Kızılkaya,Vedat Uyak,Ahmet Koluman 한국섬유공학회 2023 Fibers and polymers Vol.24 No.1

The main aim of this study was to reduce the biological load in the retting effluents by eliminating the microorganism and at the same time, to bleach hemp fibers in the retting liquor, with ozone treatment. In addition to prevention of the environmentalpollution, time, energy, water and chemical consumption decrease were targeted by the ozone bleaching of hemp fiber in the retting liquor. For this purpose, retting liquor was treated with ozone gas in different concentrations (5–25 g/h) anddurations (5–90 min) while hemp stems were still in it. The environmental impact was investigated by TOC (Total Organic Carbon), BOD (Biochemical Oxygen Demand) and COD (Chemical Oxygen Demand) measurements. Ozone applicationresulted in dramatic reductions on BOD and TOC values. Total bacteria count in the untreated retting liquor and ozonetreated samples was determined, up to 100% sanitation effect was achieved by ozone application. Whiteness degrees of the hemp fibers increased up to 72% with ozone application compared with the retted sample. The chemical compositions of the fibers were stated by chemical tests and oxidative damage related to ozone treatment was investigated. The lignin ratio was significantly reduced after ozone application. The results of the chemical tests were supported by FTIR measurements. The mechanical properties such as tenacity and elongation were analyzed with tensile tests. The crystallographic characteristics were investigated with XRD, the crystallinity index was increased with ozone treatment.

Acute Necrotizing Pancreatitis and Coronavirus Disease-2019 (COVID-19)

( Ulaş Aday ),( Ercan Gedik ),( Mehmet Tolga Kafadar ),( Erdal Özbek ) 대한소화기학회 2021 대한소화기학회지 Vol.78 No.6

Coronavirus disease-19 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV- 2) and has resulted in increased mortality worldwide. Several studies have identified the involvement of the gastrointestinal tract, respiratory tract, and other tissues. Although it has been reported that the angiotensin-converting enzyme-2 receptor affected by SARS-CoV is expressed more in the pancreas than in the lungs, the issue regarding the occurrence of pancreatitis is controversial. SARS Cov-2 rarely causes acute necrotizing pancreatitis without significantly affecting the respiratory and other systems. This paper presents a patient who underwent laparotomy due to acute necrotizing pancreatitis and hemodynamic instability caused by COVID-19 without any known risk factors. (Korean J Gastroenterol 2021;78:353-358)

Evaluation of Left Atrial Electromechanical Delay and Left Atrial Phasic Functions in Surgical Early Menopause Patients

Murat Akcay,Metin Coksevim,Hasan Ulubaşoğlu,Omer Gedikli,Ozcan Yılmaz 한국심초음파학회 2019 Journal of Cardiovascular Imaging (J Cardiovasc Im Vol.27 No.2

BACKGROUND: This study evaluated the atrial electromechanical delay (AEMD) and the left atrial (LA) mechanical functions in patients with surgical early menopause. METHODS: A total of 62 patients were included in the study: 33 patients with surgical early menopause and 29 age- and sex-matched healthy controls. The duration distance from the start of the P wave to the beginning of the A wave for the lateral mitral annulus, septal mitral annulus, and lateral tricuspid annulus was assessed by tissue Doppler echocardiography. The differences in these durations were used to calculate the inter- and intra-atrial mechanical delays. LA volumes were evaluated using the biplane area-length technique, and LA mechanical function values were measured. RESULTS: The baseline laboratory and clinical characteristics were similar between the two groups. Surgical early menopause patients displayed increased static atrial electromechanical connection (PA′) times for the septal mitral annulus and lateral tricuspid annulus compared to the controls. However, the lateral mitral annulus, the inter-atrial, the intra-LA, and the right atrial EMD PA′ times were not significantly altered in surgical early menopause patients compared to controls. Importantly, the LA volume index (28.1 ± 8.17 vs. 24.89 ± 7.96 mL/m2, p = 0.019), the maximal LA volume (49.6 ± 14.1 vs. 42.9 ± 16.1 mL, p = 0.004), the minimal LA volume (18.4 ± 7.0 vs. 15.2 ± 9.0 mL, p = 0.022), and the atrial precontraction LA volume (31.0 ± 10.9 vs. 24.9 ± 10.1 mL, p = 0.006) were higher in the patients with surgical early menopause compared to the controls. The LA reservoir, conduit and pumping functions and the total, passive, and active emptying volumes were all comparable between the two groups (p = 0.09; 0.06; 0.68; 0.06; 0.48; 0.07, respectively). CONCLUSIONS: Patients with surgical early menopause demonstrated impaired atrial electrical delay and electromechanical functions.

Nuclear energy consumption, nuclear fusion reactors and environmental quality: The case of G7 countries

Nigar Demircan Çakar,Seyfettin Erdogan,Ayfer Gedikli,Mehmet Akif Oncü 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.4

Global climate change brings environmental quality sensitivity, especially in developed countries. Developed countries use non-renewable energy sources intensively both in their own countries and inother countries, they make productions that cause an enormous rate of increase in CO2 emissions andunsustainable environmental costs. This has increased the interest in environmentally friendly alternative energy sources. The aim of this study is to investigate the impact of nuclear energy consumptionand technological innovation on environmental quality in G7 countries using annual data over the period1970e2015. The Panel Threshold Regression Model was used for the analysis. Empirical findings haveindicated that the relationship between nuclear energy consumption and carbon emissions differs according to innovation for nuclear power plants. It was also concluded that nuclear energy consumptionreduces carbon emissions more after a certain level of innovation. This result shows that the increase ininnovative technologies for nuclear power plants not only increases energy efficiency but also contributes positively to environmental quality

Efficiency calibration of a coaxial HPGe detector-Marinelli beaker geometry using an 152Eu source prepared in epoxy matrix and its validation by efficiency transfer method

Haluk Yücel,Senem Zümrüt,Recep Bora Narttürk,Gizem Gedik 한국원자력학회 2019 Nuclear Engineering and Technology Vol.51 No.2

In this study, an in-house 152Eu calibration source was produced from a custom epoxy matrix with adensity of r ¼ 1.14 g cm 3, which is chemically stable and durable form after its solidification. The homogeneityof 152Eu in matrix was obtained better than 98%. For a Marinelli beaker geometry, an efficiencycalibration procedure was applied to a n-type, coaxial, 78.5% relative efficient HPGe detector in theenergy range of 121.7e1408.0 keV by using in-house 152Eu calibration source. Then the measured efficienciesfor Marinelli geometry were compared with the results calculated by MEFFTRAN and ANGLEsoftwares for the validation. Although MEFFTRAN and ANGLE have two different efficiency transfer algorithmsto calculate the efficiencies, they usually need to use a reliable and accurate reference efficiencyvalues as input data. Hence, reference efficiency values were obtained experimentally from a multinuclide standard sourcefor the same detector- Marinelli geometry. In the present source characterization, the correctionsrequired for self-absorption and true coincidence summing effects for 152Eu gamma-rays were alsoobtained for a such close counting geometry condition. The experimental results confirmed the validityof efficiency calculations obtained by MEFFTRAN and ANGLE softwares that are calculation tools.

Swallowing and Aspiration: How Much Is Affected by the Number of Arytenoid Cartilages Remaining After Supracricoid Partial Laryngectomy?

Caner Kılıç,Ümit Tunçel,Metin Kaya,Ela Cömert,Samet Özlügedik 대한이비인후과학회 2017 Clinical and Experimental Otorhinolaryngology Vol.10 No.4

Objectives. The aim of this study was to compare the effect of the presence of one or two arytenoids on early/late period swallowing-aspiration functions. Methods. Supracricoid partial laryngectomy (SCPL) with the diagnosis of laryngeal cancer between 2012 and 2014 were retrospectively evaluated. The patients were categorized into two groups as follows: group I, patients who underwent SCPL with one arytenoid cartilage and group II, patients who underwent SCPL with two arytenoid cartilages. The time of decannulation and oral feeding onset, and swallowing-aspiration functions were evaluated and compared in the early nutritional period, first, and third months. Results. There was no significant correlation between decannulation time and swallowing-aspiration. The aspiration rates in group I and group II were similar and there was no significant difference in oral feeding onset and aspiration grades in the first and third months between both groups. Conclusion. We found similar oncological and functional outcomes in SCPL which protected one or two arytenoid cartilages. Therefore we suggest to be performed one arytenoid cartilage SCPL in selected patients who was advance stage and tumor volume over with larynx cancer.

Dietary Habits Contributing to the Cancer Prevention Among Health College Students in Turkey

Nogay, Nalan Hakime,Akinci, Ayse Cil,Sert, Havva,Kurtulus, Zeynep,Gedik, Selda Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.3

This descriptive study was made to evaluate the dietary habits contributing to cancer prevention of 319 health college students. Data collection form included questions about demographic characteristics and 33 statements which evaluate dietary habits contributing to cancer prevention. Among the students, 56.1% consumed fast food outside the home/dormitory twice a week or more and 47% never exercised. Moreover, 63.9% of the students reported that their dietary habits changed negatively and 69% stated that their fruit and vegetable consumption decreased after starting the health college. The students mostly paid attention to preserving food and water consumption while they paid least attention to maintaining healthy weight and whole grain consumption. Female students, those who paid attention to the amount and calorie of the food they consumed, students who did not consume fast food, and students who exercised twice a week or three times a week had better dietary habits contributing to cancer prevention (p<0.05). According to these results we recommend that interventions which will reduce fast food consumption and increase fruit and vegetable consumption and exercising in university students should be implemented. For this purpose, appropriate conditions for preparing and preserving healthy food should be provided as well as increasing the frequency of vegetable containing meals and providing fruits and salads in every meal at school cafeterias.

Magnetic field-dependent low-energy magnon dynamics in α-RuCl3

Ozel, Ilkem Ozge,Belvin, Carina A.,Baldini, Edoardo,Kimchi, Itamar,Do, Seunghwan,Choi, Kwang-Yong,Gedik, Nuh American Physical Society 2019 Physical Review B Vol.100 No.8