258 research outputs found

    Antimicrobial effect of natural antimicrobial agents against foodborne pathogens

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    Risk Assessment of Microbial Problems and Preventive Actions in Food Industry - 2nd Open Seminar Arranged by SAFOODNET - Food Safety and Hygiene Networking Within New Member States and Associated Candidate Countries; Istanbul; Turkey; 22 October 2007 through 23 October 2007Besides that foodborne infections and intoxications cause great danger for human health they have also adverse impact on the economics. Alternative food preservation techniques to produce safer foods e.g. systems containing natural antimicrobial agents have recently gained popularity. The consumers prefer foods with no chemical additives without shortened shelf-life. In this sense, natural antimicrobials have become promising alternatives for hurdle technology. However, most of the natural antimicrobials have limited spectrum of activity

    Effect of biopolymers containing natamycin against Aspergillus niger and Penicillium roquefortii on fresh kashar cheese

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    Fungal spoilage during refrigerated storage is one of the main safety and quality-related problems for dairy products. The effect of wheat gluten (WG) and methyl cellulose (MC) biopolymers containing natamycin (NA) on the growth of Aspergillus niger and Penicillium roquefortii on the surface of fresh kashar cheese during storage at 10 C for 30 days was investigated. Wrapping of A. niger-inoculated cheese with MC films containing 5–20 mg NA per 10 g resulted in approximately 2-log reductions in spore count. Two mg NA per 10 g included into WG films was sufficient to eliminate A. niger on the surface of cheese. However, MC and WG films containing NA did not cause any significant decrease in P. roquefortii count on the cheese surface. Therefore, especially use WG films in dairy applications could be an effective way of controlling A. niger growth on these products.The Scientific and Technological Research Council of Turkey (TUBITAK-TOVAG Project No: 104O543

    Turizm için Mesleki Almanca Ders Kitapları

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    Turizmin çeşitli meslek kollarında çalışanlar ve çalışan adayları için mesleki Almanca öğrenimine yönelik çeşitli ders materyalleri mevcuttur. Ağırlıklı olarak ders kitabı biçiminde hazırlanan materyaller, günümüzün teknolojik gelişmeleri ile birlikte çeşitlilik kazanmıştır. Örgün öğrenimin yanı sıra çalışanlar için uzaktan öğrenim ve%252Fveya bireysel öğrenim imkânı sağlayan öğrenme materyalleri de ön plana çıkmıştır. Öğrenen grubun veya bireyin ihtiyaçlarına ve özelliklerine uygun ders kitabını belirlemek, öğrenim sürecinin sağlıklı işleyebilmesi ve hedeflenen dilsel bilgi ve becerilerin edinilebilmesi için kilit öneme sahiptir. Satış odaklı kitap tanıtımları ve broşürler öğrenen ve öğretenleri uygun ders kitabını seçme konusunda yanılgıya düşürebilmektedir. Her kitabı satın alıp ayrıntılı olarak incelemek ise oldukça masraflı ve zaman alıcı bir süreçtir. Bu çalışmada turizme yönelik mesleki Almanca öğretiminde kullanılmak üzere hazırlanmış olan ders kitapları ve yardımcı materyaller incelenmiş, kitaplarla ilgili ayrıntılı öğretimsel ve yöntembilimsel bilgiler ortaya konmuştur. Böylece ilgili öğrenci ve öğreticilere bu alanda ders kitabı seçiminde kolaylık sağlanması hedeflenmiştir

    Some Non-Destructive Testing Methods: A Comparative Complitation Work

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    Bu çalışmada, materyallerin kusur analizini gerçekleştirerek güvenli materyal kullanımı sağlayan tahribatsız test yöntemleri incelenmektedir. Tahribatsız test işleminde kullanılacak yöntemin, çalışma şartları açısından test edilecek materyal üzerinde uygulanabilir olması gerekmektedir. Örneğin girdap akımları yöntemi, çalışma şartları gereği ferromanyetik metalleri test edemezken, ferro olmayan metalleri test edebilmektedir. Bu şartlar göz önüne alınarak seçilen test yöntemi ile materyal düzenli aralıklarla tahribatsız muayene edilerek kusurlu materyal bölgeleri tespit edilmektedir. Bu şekilde güvenli materyal kullanımı sağlanarak büyük maddi kayıplar önlenmiş olur. Tahribatsız test yöntemlerinin bir kısmı güvenilir sonuçlar üretmesi açısından endüstride yaygın olarak kullanılmaktadır. Bu bağlamda manyetik kaçak akı, akustik emisyon, ultrasonik, girdap akımları ve radyografi yöntemleri bu çalışmada incelenmiştir. Yöntemlerin işleyiş prensipleri, literatürde yapılmış çalışmalar ve gerçekleştirilmiş deneyler incelenerek açıklanmıştır. Yöntemler karşılaştırmalı olarak seçilen kriterlere göre sınıflandırılmıştır. Bu çalışma ile geniş içeriğe sahip bir derleme ortaya çıkarılmıştır.In this study, nondestructive testing methods, which sustain safe material usage are analyzed by doing defect analysis of material. Method that is used in nondestructive testing process, need to be applicable on testing material in terms of working conditions. For instance; eddy currents method can test nonferrous metals while it cannot test ferromagnetic metals because of working conditions. Considering these conditions, defective material parts are identified by examining chosen testing method and material in regular intervals. Thanks to this way, major financial losses are avoided by sustainig safe material usage. Some parts of nondestructive testing methods are widely used in industry with regard to producing dependable results. In this context, magnetic flux leakage, acoustik emission, eddy currents, and radiography methods are analyzed in this study. Methods’ process principle, works that have done in literature, performed experiments are analyzed and explained. Methods are classified by regarding comperatively selected criteria. With this study, a compilation, having broad content is presented

    Thermal kinetic analysis, theoretical thermodynamic calculations and antimicrobial activity of three new energetic materials

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    WOS: 000425965400096Three new energetic agents were synthesized using 3,5-dinitro-4-chlorobenzonitrile, sodium azide and hydrazine, which were 2,6-dinitro-4-cyano-azidobenzene (I), N-2,6-dinitro-cyanophenyl-hydrazine (II) and bis-N,N'(2,6-dinitro-4-cyanophenyl)hydrazine (III). These energetic substances were first characterized by elemental analysis, IR, mass, H-1 NMR and C-13 NMR spectroscopic methods. The energetic substances were studied by thermogravimetry, and it was understood that the mechanism of the thermal decomposition reactions consists of two successive exothermic thermal reactions. In the first thermal reaction, the energetic material was converted to furoxane compounds, and then, these furoxane compounds were decomposed by the second thermal reaction. Activation energies and Arrhenius pre-exponential factors of thermal responses were determined by using isothermal (Coats-Redfern) and nonisothermal/isoconvertional (Kissinger-Akahira-Sunose, Ozawa-Flynn-Wall) methods with thermogravimetry and differential scanning calorimetry (DSC) data. With these calculated values, other thermodynamic parameters reaction enthalpy, entropy changes and free energy were calculated. Formation enthalpies of the elements of the energetic substances were theoretically calculated using the CBS-4M algorithm in the Gaussian 09 program for the synthesized energetic substances. In the thermal decomposition reactions, the products were estimated with the aid of literature data and the enthalpies of explosion reactions were theoretically calculated according to the Hess Law. Besides, the exothermic energies in the first and second thermal reactions of the energetic substances were measured by DSC. The results measured by DSC were compared with the calculated theoretical results and were found to be very close to each other. In the study, antimicrobial activity was estimated to be high because energetic molecules are strained molecules, and it is possible this tension can affect the medium. According to this thought, antimicrobial activity was determined by using five different bacteria and a fungus. Antimicrobial activity values were determined by "agar dilution" method, and results were found as minimum inhibition concentration. Among the three energetic substances, 2,6-dinitro-4-cyano-azidobenzene was found to have the most active compound.Scientific Research Fund of the University of Ankara [16H0430004]; Scientific Research Fund of the Ahi Evran University [FEF.A4.17.001]This work was supported by the Scientific Research Fund of the University of Ankara (project no. 16H0430004) and Scientific Research Fund of the Ahi Evran University (grant no: FEF.A4.17.001)

    Tip 1 diabetes mellitus hastalarında tanı mevsimi değişiyor mu?

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    Objective: By the effect of global warming, climate model of Turkey is suggested to evolve through semi-arid seasons and to the tropical climate. This study aimed to determine the seasonability for clinical onset of Type 1 diabetes mellitus (T1DM). Method: T1DM patients newly diagnosed between 2014 and 2019 in our pediatric endocrinology department located in Istanbul were included in this study. Clinical onset date and age of diagnosis of diabetes were recorded for each patient. Using the worldwheatheronline.com website, regional average rainy days, cloudy days, sunny days, temperature, and ultraviolet index (UVI) were calculated per month for the past 6 years. Results: A total of 659 patients with the new onset T1DM included in this study. A number of new diagnosed patients were 29.1% (192) in winter, 22.8% (150) in spring, 17.6% (116) in summer, and 30.5% (201) in autumn, respectively. No significant effect of the rainy day, cloudy day, sunny day, temperature, and UVI average of the month of diagnosis could be detected on this seasonal shift. Similar results were obtained when 132 patients whose under 4 years of age at the time of diagnosis were excluded from the study data. Conclusion: Although weather conditions seemed to have no considerable effect on this seasonal shift, the T1DM onset in the autumn season was seen to be shifted to the spring season, partially. Further studies including large number of participants are needed for a better understanding of the seasonality of T1DM worldwide.Amaç: Küresel ısınma ile birlikte Türkiye’de mevsimlerin yarı kurak ve tropik iklim özelliklerine doğru evrildiği, son yıllarda sonbahar ve ilkbahar hava koşullarının yarısının kışa, yarısının da yaza benzer seyrettiği düşünülmektedir. Bu çalışmada, tip 1 diabetes mellitus klinik tanı zamanında mevsim değişikliğinin ve bu duruma hava koşullarının olası etkisinin incelenmesi amaçlandı. Yöntem: Çalışmaya İstanbul’daki çocuk endokrinoloji kliniğimizde 2014 ile 2019 yılları arasında yeni tanı almış 18 yaş altı tip 1 diabetes mellitus hastaları dahil edildi. Her hasta için klinik belirti başlangıç tarihi ve diyabet tanı mevsimi ile demografik veriler kaydedildi. Worldwheatheronline.com web sitesi kullanılarak İstanbul ilinin son beş yılındaki tip 1 diabetes mellitus tanı ayına ait aylık ortalama yağışlı gün, bulutlu gün, güneşli gün sayısı, sıcaklık ve ultraviyole indeks ortalaması saptandı. Hastaların tanı yaşı ile tanı mevsimi ve hava koşulları arasındaki ilişki istatistiksel olarak değerlendirildi. Bulgular: Çalışmaya 659 yeni tanı almış tip 1 diabetes mellitus hastası alındı. Çalışmaya alınan hastaların %50,4’ü kız (n=332), %49,6’sı (n=327) erkek idi. Mevsimlere göre yeni tanı konulan hasta sayısı sırasıyla kışın %29,1 (n=192), ilkbaharda %22,8 (n=150), yazın %17,6 (n=116) ve sonbaharda %30,5 (n=201) idi. Çalışma süresince tip 1 diabetes mellitus klinik başlangıcının kış ve sonbahar aylarında yüksek ilkbahar ve yaz aylarında düşük olduğu görülmekle beraber istatistiksel anlamı olacak şekilde 2016 yılı ve sonrasında sonbahar mevsimindeki diyabet başlangıç ağırlığının bir kısmının ilkbahar mevsiminekaymış olduğu izlendi. Ancak mevsimsel bu kayma üzerinde tanı ayına ait yağışlı gün, bulutlu gün, güneşli gün, sıcaklık ve ultraviyole indeks ortalamasının anlamlı bir etkisi saptanmadı. Tanı sırasında dört yaşın altında olan 132 hasta çalışma verilerinden çıkarılarak yapılan istatistiksel değerlendirmede sonuçların değişmediği görüldü. Sonuç: Çalışmamız ile sonbahar mevsimindeki diyabet başlangıç ağırlığının bir kısmının ilkbahar mevsimine kaymış olduğu tespit edilmiş olup bu mevsimsel kaymaya hava koşullarının etkisinin olmadığı görüldü. T1DM tanısında mevsimsel özelliklerin etkisini daha iyi değerlendirebilmek için daha çok sayıda hasta içeren geniş kapsamlı çalışmalara gereksinim duyulmaktadır

    A Review of Commercial Electric Vehicle Charging Methods

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    Electric Vehicles (EVs) are rapidly becoming the forerunners of vehicle technology. First electric vehicles were overlooked because of not having adequate battery capacity and because of low efficiency of their electric motors. Developing semiconductor and battery technologies increased the interest in the EVs. Nevertheless, current batteries still have insufficient capacity. As a result of this, vehicles must be recharged at short distances (approximately 150 km). Due to scheduled departure and arrival times EVs appear to be more suitable for city buses rather than regular automobiles. Thanks to correct charging technology and the availability of renewable energy for electric buses, the cities have less noise and CO2 emissions. The energy consumption of internal combustion engines is higher than of the electric motors. In this paper, studies on the commercial electric vehicle charging methods will be reviewed and the plug-in charging processes will be described in detail. This study strives to answer the questions of how plug-in charging process communication has performed between the EV and Electric Vehicle Supply Equipment (EVSE).</p

    The Reasons of Renal Transplant Recipients’ Admission to the Emergency Department; a Case Series Study

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    Introduction:  Renal transplantation are admitted to emergency department (ED) more than normal population. The present brief report aimed to determine the reasons of renal transplant patients’ ED visits.Methods: This retrospective case series study analyzed the reasons of renal transplant recipients’ admission to one ED between 2011 and 2014. The patient data were collected via a checklist and presented using descriptive statistics tools.Results: 41 patients with the mean age of 40.63 ± 10.95 years were studied (60.9% male). The most common ED presenting complaints were fever (36.6%) and abdominal pain (26.8%). Infections were the most common final diagnosis (68.3%). Among non-infectious causes, the most common was acute renal failure (9.7 %). 73.2% of the patients were hospitalized and no cases of graft loss and mortality were seen.Conclusion: The most common reason for ED admission was fever, and infections were the most common diagnosis. Acute gastroenteritis being the most frequent infection and among non-infectious problems, acute renal failure was the most frequent one.
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