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Indoor Radon Concentrations of School Buildings in Varna District, Bulgaria

Journal of Environmental Science and Engineering(B) 2022年第2期11卷 43-48页

作者： Desislava Djunakova Bistra Kunovska Jana Djounova Kremena Ivanova zdenka stojanovska National Centre of Radiobiology and Radiation Protection Sofia 1606Bulgaria Faculty of Medical Sciences Goce Delcev UniversityStip 2000Republic of North Macedonia

Radon is a radioactive gas that is naturally produced by the breakdown of uranium in soil,rock and *** International Commission on Radiological Protection(ICRP)and World Health Organization(WHO)requirements include controlling indoor radon exposure and settings of a reference level for the annual average activity concentration of up to 300 Bq/m3 for dwellings and public *** measurements in school buildings have long been carried out in many *** measurements in schools in Bulgaria have started and are *** study concerns the measurements of radon concentration(CRn)in all state school buildings in one of the Black Sea regions,Varna district,and the analysis of indoor *** survey of 1,185 premises of 107 schools was conducted from December 2019/January 2020 to March/May 2020 using a passive *** AM(Arithmetic Mean)of CRn in the premises of the studied schools on the territory of Varna district is 130 Bq/m^(3),and the geometric mean is 97 Bq/m^(3).The number of premises exceeding the national reference level of 300 Bq/m^(3) is 72 located in 38 schools(about 36% of schools).A statistically significant difference(KW(Kruskal-Wallis),p<0.0001)was found between the radon data,grouped by ***,the radon data were classified into two groups based on municipality location:on the Black Sea coast and *** located near the sea have a higher value of *** order to more accurately assess the exposure of pupils and teachers,the results are divided into four groups,depending on the type of use of the premises and the floor on which they are *** highest CRn value was found in the study rooms used for specialized education such as physics,chemistry,music etc.(AM=155 Bq/m3),which can be explained by their smaller size and less frequent use.A statistically significant difference(KW,p<0.0001)was found,which means that the radon exposure in the examined rooms depends on the type of use.T

关键词： Radon schools measurement classrooms Bulgaria

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Blending Ratio Analysis of Akund / Cotton Blended Yarn Based on Micro Projection

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Journal of Donghua University(English Edition) 2012年第6期29卷 520-523页

作者：蒋晓王芹俞建勇程隆棣 stojanovska Elena 范雯红 College of Textiles Donghua University Modern Textile Institute Donghua University Key Laboratory of Textile Science and Technology Ministry of EducationDonghua University Akund Research Institute Hunan Yunjin Group Co. Ltd.

A microscope method was developed for testing the blending ratio of akund/cotton blended yarns. Fiber characteristics such as diameter, longitudinal feature, and hollow structure were observed to identify akund and cotton. Therefore, the measurement of the blending ratio for akund/cotton blended yarns based on each fiber's amount, moisture regain, and metric count was available. The results show that using specimen's longitudinal section is more effective during the fiber counting than specimen's transverse section benefiting from the separation of the fibers.

关键词： calotropis gigantea akund fiber blending ratio micro projection feasibility

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Spinning Akund Fiber into Yarn and Analysis of Yarn Properties

Spinning Akund Fiber into Yarn and Analysis of Yarn Properti...

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作者：爱丽娜（Elena stojanovska）东华大学

学位级别：硕士

Akund floss referring to yellowish,thin and hollow seed fiber that is not unknown,but not enough *** few published information about it indicate that it is very fine,hollow,yellowish fiber with smooth surface whose structure is similar to that of kapok,and its tensile strength comparable to that of cotton *** characteristics make akund fiber an interesting target for research and increase the possibility for its application in textile *** master thesis had the objective of converting akund fiber into ring spun yarn with favorable properties that will enable production of weaving and knitting *** properties,such as friction coefficient and strength of akund fiber previously treated with different chcemicals were *** results obtained were statistically analyzed in order to identitfying the most accurate chemical treatment for preparation of akund fiber for *** akund cotton fiber mass was spun after identifying the most suitable parameters for carding,drawing,roving and *** final product was akund/cotton blended yarn in ratio 67/33,in count 32Ne,with braking tenacity of 6,86 cN/tex;twist:726 tpm;3.34%elongation at break;Zweigle hairiness index of 3,87;and coefficient of variation by mass of 16,8%-properties that enable its application in textile purposes.

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Simulations of Using Vectors in Natural Sciences Education

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Computer Technology and Application 2013年第9期4卷 455-459页

作者： Dijana Capeska Bogatinoska Linda Fahlberg stojanovska Biljana Janakievska University of Information Science and Technology St. Paul the Apostle Ohrid 6000 R. Macedonia Faculty of Technical Sciences Univ. St. Clement of Ohrid Bitola 7000 R. Macedonia Warehouse Skopsko JL Transport Bitola 7000 R. Macedonia

The implementation of ICT （information and communication technologies） into the educational process is becoming a reality in the 21st century. Today＇s students grow up with technology. To keep their attention, scientific problems should be solved through visualization, which is made possible using ICT in the educational process. In the modem educational process, students still have difficulties in learning science concepts. Also, it is a very common problem that students cannot apply mathematical language and concepts into other science areas such as physics, engineering, etc. For example, students start learning about vectors in mathematics in secondary school. Vectors are very important because they have a wide area of applications especially in physics, engineering and navigation to represent forces, tension, velocity, etc.. Using the free mathematical software GeoGebra, a simulation of using vectors in these areas is made. It will be shown that such simulations increase students＇ interest, keep their attention, and make this knowledge more real and more understandable and connected to the physical world and thus more applicable to their other studies.

关键词： Education GeoGebra ICT vectors.

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South Sudan Vehicle Workshop Hazardous Waste Management

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Journal of Traffic and Transportation Engineering 2017年第3期5卷 157-169页

作者： Zoran Chachorovski Drasko Atanasoski Micho Apostolov Aneta stojanovska-Stefanova Faculty of Tourism and Business Logistics University Goce Delcev Shtip 2000 Republic of Macedonia

All facility managers and fleet managers know how difficult it can be to effectively manage hazardous wastes and identify economic recycling opportunities. This report reviews the context surrounding GO＇s （global organization） vehicle workshops and environmental management in South Sudan, specifically relating to hazardous waste management. Potential recycling opportunities are identified and some preliminary suggestions for hazardous waste management are made.

关键词： Environment legislation policy management government private sector.

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Cardiac functional magnetic resonance imaging at 7T:Image quality optimization and ultra-high field capabilities

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World Journal of Radiology 2020年第10期12卷 231-246页

作者： El-Sayed H Ibrahim V Emre Arpinar L Tugan Muftuler Jadranka stojanovska Andrew S Nencka Kevin M Koch Department of Radiology Medical College of WisconsinMilwaukeeWI 53226United States Department of Neurosurgery Medical College of WisconsinMilwaukeeWI 53226United States Department of Radiology University of MichiganAnn ArborMI 48109United States

BACKGROUND 7T cardiac magnetic resonance imaging(MRI)introduces several advantages,as well as some limitations,compared to lower-field *** capabilities of ultra-high field(UHF)MRI have not been fully exploited in cardiac functional *** To optimize 7T cardiac MRI functional imaging without the need for conducting B1 shimming or subject-specific tuning,which improves scan *** this study,we provide results from phantom and in vivo scans using a multi-channel transceiver modular *** We investigated the effects of adding a dielectric pad at different locations next to the imaged region of interest on improving image quality in subjects with different body *** also investigated the effects of adjusting the imaging flip angle in cine and tagging sequences on improving image quality,B1 field homogeneity,signal-to-noise ratio(SNR),blood-myocardium contrast-to-noise ratio(CNR),and tagging persistence throughout the cardiac *** The results showed the capability of achieving improved image quality with high spatial resolution(0.75 mm×0.75 mm×2 mm),high temporal resolution(20 ms),and increased tagging persistence(for up to 1200 ms cardiac cycle duration)at 7T cardiac MRI after adjusting scan set-up and imaging *** the imaging flip angle was essential for achieving optimal SNR and myocardium-toblood *** a dielectric pad at the anterior left position of the chest resulted in improved B1 homogeneity compared to other positions,especially in subjects with small chest *** Improved regional and global cardiac functional imaging can be achieved at 7T MRI through simple scan set-up adjustment and imaging parameter optimization,which would allow for more streamlined and efficient UHF cardiac MRI.

关键词： Magnetic resonance imaging High-field Cardiac function Cine Tagging Strain

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Optimized cardiac magnetic resonance imaging inversion recovery sequence for metal artifact reduction and accurate myocardial scar assessment in patients with cardiac implantable electronic devices

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World Journal of Radiology 2018年第9期10卷 100-107页

作者： El-Sayed H Ibrahim Mason Runge Jadranka stojanovska Prachi Agarwal Maryam Ghadimi-Mahani Anil Attili Thomas Chenevert Chiel den Harder Frank Bogun Department of Radiology Medical College of Wisconsin Department of Radiology University of Michigan Department of Medical Physics Leiden University Medical Center

Late gadolinium enhancement(LGE) cardiovascular magnetic resonance(CMR) is the gold standard for imaging myocardial *** important application of LGE CMR is the assessment of the location and extent of the myocardial scar in patients with ventricular tachycardia(VT), which allows for more accurate identification of the ablation ***, a large percentage of patients with VT have cardiac implantable electronic devices(CIEDs), which is a relative contraindication for cardiac magnetic resonance imaging due to safety and image artifact *** studies showed that these patients can be safely scanned on 1.5 T scanners provided that an adequate imaging protocol is ***, imaging patients with a CIED result in metal artifacts due to the strong frequency off-resonance effects near the device; therefore, the spins in the surrounding myocardium are not completely inverted, and thus give rise to hyperintensity *** artifacts obscure the myocardial scar tissue and limit the ability to study the correlation between the myocardial scar structure and the electro-anatomical map during catheter *** this study, we developed a modified inversion recovery technique to alleviate the CIED-induced metal artifacts and improve the diagnostic image quality of LGE images in patients with CIEDs without increasing scan time or requiring additional *** developed technique was tested in phantom experiments and in vivo scans, which showed its capability for suppressing the hyperintensity artifacts without compromising myocardium nulling in the resulting LGE images.

关键词： Magnetic resonance imaging Heart Late gadolinium enhancement Viability imaging Inversion recovery Cardiac implantable electronic devices

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心外膜脂肪的增加与房颤发生、慢性房颤以及射频消融效果存在独立相关性

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国际医学放射学杂志 2015年第5期 503-503页

作者： J.stojanovska E.A.Kazerooni M.Sinno B.H.Gross K.Watcharotone S.Patel 宋茜 Department of Radiology Division of Cardiothoracic RadiologyUniversity of Michigan Health System

摘要目的确定胸内脂肪量与房颤(AF)发生、慢性房颤及射频消融(RFA)治疗效果是否存在相关性。方法此项回顾性研究遵循HIPAA,经机构伦理委员会批准并免除病人知情同意。169例AF病人(75例非阵发性和94例阵发性)和62例对照组病人进行了心脏C... 详细信息

摘要目的确定胸内脂肪量与房颤(AF)发生、慢性房颤及射频消融(RFA)治疗效果是否存在相关性。方法此项回顾性研究遵循HIPAA,经机构伦理委员会批准并免除病人知情同意。169例AF病人(75例非阵发性和94例阵发性)和62例对照组病人进行了心脏CT检查,在CT上测量心包外脂肪体积(EPFV)和心外膜脂肪体积(EFV),两者之和作为胸内总脂肪量。采用逻辑回归分析法评估这3种脂肪含量与

关键词：慢性房颤 RFA 心外膜脂肪射频消融相关性

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