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The Pst indicator is one of parameters used in the power quality evaluation. The IEC flickermeter with a complex signal chain structure is used to Pst measurements. The occurrence for Pst values greater than the limit value indicates the occurrence of flicker severity caused by voltage fluctuation. This paper presents the analysis of the influence of he sampling rate on Pst measurement results. For analysis purpose, the analytical model of the IEC flickermeter signal chain has been prepared, considering the sampling rate of input voltage. Based on the prepared model, the possible effects of incorrect sampling rate selection in Pst measurements have been presented. The model test results have been compared with laboratory measurement results for two AMI energy meters with built-in IEC flickermeter. The obtained laboratory measurement results indicate the occurrence of aliasing for tested energy meters, which causes Pst measurement disturbance.

Historically, benzene has been widely used in a large variety of applications. Occupational exposure limits (OELs) were set for benzene as it was found to be acutely toxic, causing central nervous system depression at high exposures. OELs were lowered when it was discovered that chronic exposure to benzene could cause haematotoxicity. After confirmation that benzene is a human carcinogen causing acute myeloid leukaemia and possibly other blood malignancies, OEL were further lowered. The industrial application of benzene as solvent is almost completely discontinued but it is still used as feedstock for the production of other materials, such as styrene. Occupational exposure to benzene may also occur since it is present in crude oil, natural gas condensate and a variety of petroleum products and because benzene can be formed in combustion of organic material. In the past few years, lower OELs for benzene in the range of 0.05–0.25 ppm have been proposed or were already established to protect workers from benzene-induced cancer. The skin is an important potential route of exposure and relatively more important at lower OELs. Consequently, human biomonitoring–which integrates all exposure routes–is routinely applied to control overall exposure to benzene. Several potential biomarkers have been proposed and investigated. For compliance check of the current low OELs, urinary S-phenylmercapturic acid (S-PMA), urinary benzene and blood benzene are feasible biomarkers. S-PMA appears to be the most promising biomarker but proper validation of biomarker levels corresponding to airborne benzene concentrations below 0.25 ppm are needed.

OBJECTIVE The immunological factors have role in the development of preeclampsia. The thymus is one of the main organs of the fetal immune system. The aim of this prospective clinical study was to investigate the association between fetal thymus volume and preeclampsia by adding the 3-dimensional measurement of thymus volume to the routine fetal ultrasound scan at 11-14 week of gestation. STUDY DESIGN Totally 72 pregnant women in their first trimester of pregnancy were included and 3-D fetal thymus volume was measured with sonographic VOCAL programme. All women gestational period was followed. The data of women with preeclampsia (n = 10, study group) and without preeclampsia (n = 62, control group) were compared. MAIN OUTCOME MEASURES Fetal thymus volume, preeclampsia development. RESULTS Fetal thymus volume, mean gestational age at birth and newborn birthweight were found to be statistically lower in cases with preeclampsia compared with those without any complications. When the fetal thymus volume measured by the VOCAL programme in the study group was used as a marker for preeclampsia development, the limit value was 0.0375 cm3; sensitivity was 87.1% and specificity was 50% (AUC 85.3%, P

Bu Yüksek Lisans tezi çalışması mevcut mobil iletişim spektrumundaki frekans band gruplarının ve teknolojilerinin (2G, 3G, 4G) ve 5G teknolojisinde kullanılacak olan frekans ve teknolojilerle birlikte elektromanyetik alan değerleri ölçümü ve karşılaştırılmasını içermektedir.Hayatımızda çok etkin rol oynayan kablosuz iletişim teknolojileri yakın zamanda hayata geçecek olan 5G teknolojisiyle önemini ve işlevini arttırarak varlığını sürdürecektir. Bugün kullandığımız 4.5G teknolojisinin çok ötesinde hızları mümkün kılacak olan 5G ile yeni ve daha geniş band frekanslar kullanılmaya başlanacaktır. Elektromanyetik dalgaların insan sağlığına etkisinin merak edildiği ve araştırıldığı bu dönemde yeni frekanslar farklı ve daha kısa dalgaboylarıyla bu bağlamda nasıl etkiler oluşturacağı yeni bir merak konusudur. Bu tezde bugün kullanmakta olduğumuz 2G, 3G, 4.5G teknolojileri ile ve yakın gelecekte hayatımıza girecek olan 5G teknolojisinin oluşturduğu elektromanyetik alanın uzaklıkla değişen değerleri ölçülüp incelenmiştir. Tezdeki çalışma, Ülkemizdeki düzenleme krtierleri referans alınarak frekans band grubu, iletişim teknolojisi ve çıkış gücüne göre yapılmıştır. Burada elde etmek istediğimiz sonuç, yakın bir süreçte ülkemizde de hizmete girecek olan 5G teknolojisi ile birlikte gerek Uluslararası İyonlaşmamış Radyasyondan Korunma Kurulu (ICNIRP), gerekse Türkiye’deki Düzenleyici Kurum (BTK) tarafından yönetmelikle belirlenen elektrik ve elektromanyetik alan limit değerleri referans alınarak belirlenmiş ve uyulmakla yükümlü olunan limit değerlerin aşılıp aşılmayacağını görülmesidir. Bu kapsamda yine Uluslararası ve yerel standartlar doğrultusunda 5G’nin mobil iletişim noktalarındaki (baz istasyonları) kaynaklarında yapacağımız ölçümlerle elektrik ve elektromanyetik alan değerlerinin durumu ve etkisi ile, ülkemizde belirlenen sınır değerlerin aşılıp aşılmayacağını görerek olası etki analizini yapılması ve bir çıktı oluşturulması hedeflenmiştir. This graduation thesis includes the measurement and comparison of the frequency band groups and technologies (2G, 3G, 4G) in the current mobile communication spectrum and the frequency and technologies to be used in 5G technology, as well as the electromagnetic field values.Wireless communication technologies, which play a very active role in our lives, will continue to exist by increasing their importance and function with the 5G technology which will be implemented in the near future. With 5G, which will enable speeds far beyond the 4.5G technology we use today, new and wider band frequencies will be used. In this period when the effects of electromagnetic waves on human health are being wondered and investigated, how new frequencies will create different and shorter wavelengths in this context creates a new curiosity. In this thesis, the changing values of the electromagnetic fields created by the 2G, 3G, 4.5G technologies we use today and the 5G technology that will enter our lives in the near future have been measured and examined. The study in the thesis has been made according to the frequency band group, communication technology and output power by taking the regulation criteria in our country as a reference. The result we want to achieve here is determined by reference to the electrical and electromagnetic field limit values determined by the regulation by both the International Non-Ionized Radiation Protection Board (ICNIRP) and the Regulatory Authority in Turkey (BTK), together with 5G, which will be put into service in our country in a short time. It’s aimed to see if limit values can be exceeded. In this context, again in line with international and local standards, It’s aimed to make an impact analysis and create an output by seeing whether the limit values determined in our country will be exceeded with the condition and effect of the electrical and electromagnetic field values with the measurements we will make at the sources of mobile communication points (base stations) of 5G.

Available data of the indoor airborne culturable bacteria and fungi at schools’ environments is very limited in the peninsula of Qatar. This study aims to determine the microbial load in indoor and outdoor air at three schools utilizing two types of air sampling methods: (i) six-stage Andersen cascade impactor for cultivable microbes and (ii) air filtration method for non-cultivable microbes. The maximum levels of airborne culturable bacteria were 971 CFU/m3 in indoor and 334 CFU/m3 in outdoor air samples in the morning in a private (international) school. Lower concentrations of airborne culturable bacteria were recorded in indoor (348 CFU/m3) and outdoor areas (261 CFU/m3) in the afternoon. High CFU numbers (971 CFU/m3) were observed at the food court area during breakfast time, exceeding the WHO indoor air quality limit value. The size distribution of the bacteria had maximum in the 1.1 - 2.3 μm size bin. The most frequently isolated fungal genera were Aspergillus and Penicillium, and their concentration was higher during winter. The prevalence and concentration of airborne microbes were altering spatially (indoors versus outdoors), temporally (morning versus afternoon) and seasonally (winter versus summer). The results indicate that airborne bacterial and fungal spores must be considered as important biological pollutants. Our findings might contribute to the implementation of preventative public health programs and creation of recommendations aimed at providing healthier school environments. We declare that the research reported in this manuscript received supported grant funding from the Qatar National Research Fund (QNRF)-Qatar.

Hydrogen sulfide (H2S) emissions from municipal solid waste (MSW) management facilities have been linked to odor nuisance and human health effects both for workers and people living in the surrounding areas. Two field campaigns were conducted to characterize H2S concentrations in the ambient air of MSW management facilities in Portugal: a mechanical-biological treatment (MBT) plant with an associated landfill of residual waste; and a sealed landfill. H2S concentration exhibited a similar spatial distribution during both monitoring campaigns. The highest values were recorded in the mechanical treatment hall of the MBT plant and the lowest were consistently found in the sealed landfill, indicating that fresh waste, containing a high load of fermentable organic matter, was a major source of H2S to the ambient air. 50 % of the data obtained in the MBT plant were higher than the limit value recommended by the Portuguese regulation on occupational health, and therefore emphasize the importance of conducting routine H2S monitoring and equipment maintenance programs in MSW management facilities, in order to promote a safe and healthy work environment.