7 research outputs found
Improving the sensitivity of radionuclide monitoring stations
Zsfassung in dt. SpracheDie Nachweisgrenze von Radionuklid Stationen des Internationalen Messsystemes (IMS) der CTBTO ist hauptsĂ€chlich durch den lokalen Rn-220 Hintergrund durch die Tochterprodukte Pb-212, Bi-212 und Tl-208 beeinflusst, die die Gammaspektroskopiemessungen dominieren. Obwohl der Rn-222 Hintergrund im selben Bereich des Rn-220 Hintergrundes sein kann, haben die Tochterprodukte Pb-214, Bi-214 und Pb-210 keinen nennenswerten Einfluss auf die Ergebnisse der gammaspektroskopischen Messungen von Aerosolproben und können vernachlĂ€ssigt werden.Die Emanation von Rn-220 aus dem Boden folgt einem Muster (Taggang) was direkten Einfluss auf die AktivitĂ€tskonzentrationen der Tochterprodukte hat.In dieser Arbeit wurde gezeigt, dass obwohl Pb-212 eine Halbwertszeit hat, die atmosphĂ€rischen Transport ĂŒber mehrere 100 km zulĂ€sst, die Ănderungen in der gesammelten AktivitĂ€t durch den (sehr) lokalen Hintergrund vollstĂ€ndig erklĂ€rt werden kann. Mögliche entfernte Hintergrundquellen haben daher nur einen kleinen Einfluss.Mit dem Wissen des Rn-220 Tagganges wurden die Effekte des Startzeitpunktes auf die gesammelte AktivitĂ€t untersucht.Der Unterschied zwischen "bestem" und "schlechtestem" Startzeitpunkt (niedrigste vs. höchste AktivitĂ€t am Filter zum Probennahmeende) in Bezug auf die gesammelte AktivitĂ€t an der Radionuklid Station RN09 Darwin, Australien, betrug wĂ€hrend des Untersuchungszeitraumes 9%. Mit Optimierung des Filterwechselzeitpunktes erreicht man eine Verbesserung der Nachweisgrenze fĂŒr CTBT relevante Radionuklide von zirka 4%.Weiters konnte gezeigt werden, dass obwohl in einer Region mit "hohem" Rn-220 Hintergrund und der daraus resultierenden Proben mit AktivitĂ€ten von mehreren kBq, die zusĂ€tzliche Ăquivialentdosis fĂŒr das Personal vernachlĂ€ssigbar gegenĂŒber der natĂŒrlichen Strahlenbelastung ist.The detection sensitivity of particulate radionuclide monitoring stations of the CTBTO International Monitoring System (IMS) is mainly affected by the local Rn-220 background through its progenies Pb-212, Bi-212 and Tl-208 which dominate the performed gamma spectroscopy measurements. Although the Rn-222 background could be in the same range of the Rn-220 background, its progenies Pb-214, Bi-214 and Pb-210 do not have a noteworthy effect on the gamma spectroscopy results of aerosol samples and can be disregarded.The release of Rn-220 from the soil does follow a regular pattern (diurnal variation) and this also affects the activity concentration of its progenies.This work showed that, although the Pb-212 has a half-life allowing atmospheric transport over several 100 km, the variations of the sampled activity can be fully explained by the (very) local background making it the dominating source. Thus possible distant high background sources do have limited effect.With the knowledge of the Rn-220 progenies diurnal variation, the effect of the sampling start time on the sampled radioactivity was assessed.The effect of the "best" to the "worst" collection start time (ie.maximum versus minimal amount of radioactivity on the filter at the end of sampling) in regard to the sampled radioactivity at the Radionuclide Station RN09 Darwin, Australia, was found to be 9%. By optimizing the filter change time the station sensitivity (capability for the detection of CTBT relevant nuclides) can be improved by app. 4%.It was also shown that, although being in a "high background" region resulting in samples with activities of several kBq the additional effective dose for the operators is not significant when comparing to the dose from natural sources.11
PENGARUH PENERAPAN MODEL THINK PAIRS SHARE (TPS) TERHADAP HASIL BELAJAR SISWA PADA MATA PELAJARAN IPA DI KELAS V MADRASAH IBTIDAIYAH WATHONIYAH PALEMBANG.[SKRIPSI]
Penelitian ini membahas tentang Pengaruh Model Think Pairs Share terhadap
hasil belajar Siswa Tentang Alat Pernapasan Manusia Pada Mata Pelajaran Ilmu
Pengetahuan Alam di MI Wathoniyah Palembang. Alasan peneliti ingin membahas
masalah ini karena MI ini jarang menggunakan model dalam proses belajar mengajar
dan tidak menggunakan model (TPS) dalam kegiatan pembelajaran. Jadi peneliti
berminat untuk mengadakan penelitian mengenai penggunaan TPS untuk melihat
pengaruh hasil belajar sesudah menggunakan model (TPS). Bagaimana pelaksanaan
model (TPS) pada mata pelajaran IPA materi alat pernapasan manusia siswa Kelas V
di MI Wathoniyah Palembang?Bagaimana hasil belajar siswa kelas Eksperimen yang
diterapkan model (TPS) dan hasil belajar siswa Kelas Kontrol yang tidak diterapkan
model (TPS) pada mata pelajaran IPA Kelas V di MI Wathoniyah
Palembang?Bagaimana pengaruh pelaksanaan model (TPS) terhadap hasil belajar
siswa Kelas Eksperimen sesudah diterapkan model (TPS) dan Kelas Kontrol yang
tidak menerapkan model (TPS) pada mata pelajaran IPA Kelas V di MI Wathoniyah
Palembang? Penelitian ini merupakan jenis penelitian eksperimen dan kontrol dengan
pendekatan kuantitatif. Populasi dalam penelitian ini berjumlah 50 orang yaitu kelas
V A eksperemen 25 dan kelas V B kontrol 25 orang yang terdiri dari 10 orang lakilaki
dan 15 orang perempuan masing-masing kelas. Teknik pengumpulan data yang
digunakan dalam penelitian ini adalah, tes (posttest), dokumentasi, dan observasi.
Sedangkan teknik analisa data yang digunakan adalah analisa uji âtâ.
Dari analisis tersebut maka diperoleh kesimpulan yaitu: pertama pelaksanaan
Model (TPS) pada mata pelajaran IPA Materi Alat Pernapasan Manusia di Kelas V
MI Wathoniyah Palembang dalam kategori baik, hasil ini terlihat dari soal post-tes
yang telah di berikan kepada siswa, model pembelajaran ini sangat menarik dan bisa
mengaktifkan siswa saat proses belajar. Kedua Hasil belajar siswa kelas eksperimen
menerapkan model TPS mendapatkan mean sebesar 82. Sedangkan presentase hasil
belajar siswa yang memperoleh skor tinggi ada 3 orang siswa (12%), skor sedang 15
orang siswa (60%), dan skor rendah ada 7 orang siswa (28%), Sedangkan hasil
belajar siswa kelas kontrol yang tidak menerapkan TPS yaitu memperoleh nilai ratarata
67, tergolong tinggi ada 7 orang siswa dengan persentase 28%, tergolong sedang
ada 12 orang siswa dengan persentase 48%, dan yang tergolong rendah ada 6 orang
siswa sebanyak 24%. Hal ini dapat dilihat dari nilai hasil posttest jumlah = 100%,
dengan demikian dapat dikategorikan baik. Ketiga Terdapat pengaruh yang signifikan
antara hasil belajar siswa kelas eksperimen yang diterapkan model (TPS) dan hasil
belajar siswa kelas kontrol yang tidak diterapkan model (TPS) kelas V pada mata
pelajaran IPA materi alat pernapasan manusia di Madrasah Ibtidaiyah Wathoniyah
Palembang, hal ini dapat dilihat hasil uji hipotesis menggunakan uji t yaitu:
perhitungan (to = 4,16) dan besarnya âtâ yang tercantum pada Tabel Nilai t (ttts 5% =
2,01 dan ttts 1% = 2,68) maka dapat diketahui bahwa to adalah lebih besar dari pada tt
yaitu 2,01 2,68
Ultra-low background measurements of decayed aerosol filters RID B-6012-2011 RID G-8809-2011
Aerosol samples collected on filter media were analyzed using HPGe detectors employing varying background-reduction techniques in order to experimentally evaluate the opportunity to apply ultra-low background measurement methods to samples collected, for instance, by the Comprehensive Test Ban Treaty International Monitoring System (IMS). In this way, realistic estimates of the impact of low-background methodology on the sensitivity obtained in systems such as the IMS were assessed. The current detectability requirement of stations in the IMS is 30 mu Bq/m(3) of air for (140)Ba, which would imply similar to 10(6) fissions per daily sample. Importantly, this is for a fresh aerosol filter. One week of decay reduces the intrinsic background from radon daughters in the sample allowing much higher sensitivity measurement of relevant isotopes, including (131)I. An experiment was conducted in which decayed filter samples were measured at a variety of underground locations using Ultra-Low Background (ULB) gamma spectroscopy technology. The impacts of the decay and ULB are discussed
Ultra-low background measurements of decayed aerosol filters
Aerosol samples collected on filter media were analyzed using HPGe detectors employing varying background-reduction techniques in order to experimentally evaluate the opportunity to apply ultra-low background measurement methods to samples collected, for instance, by the Comprehensive Test Ban Treaty International Monitoring System (IMS). In this way, realistic estimates of the impact of low-background methodology on the sensitivity obtained in systems such as the IMS were assessed. The current detectability requirement of stations in the IMS is 30 ÎŒBq/m3 of air for 140Ba, which would imply âŒ106 fissions per daily sample. Importantly, this is for a fresh aerosol filter. One week of decay reduces the intrinsic background from radon daughters in the sample allowing much higher sensitivity measurement of relevant isotopes, including 131I. An experiment was conducted in which decayed filter samples were measured at a variety of underground locations using Ultra-Low Background (ULB) gamma spectroscopy technology. The impacts of the decay and ULB are discussed. © 2009 AkadĂ©miai KiadĂł, Budapest, Hungary