The performance of beveled-edge large-area avalanche photodiodes (LAAPDs) produced by Advanced Photonix, Inc. (API), Hamamatsu SPL 2560 APDs, and APDs from the Institute of Electron Technology (ITE) ...was studied in scintillation detection using CsI(Tl), BGO, LSO, and YAP scintillators. Measurements covered DC gain characteristics, relative response to X-rays and light, and energy resolution for 5.9-keV X-rays from a /sup 55/Fe source. We also determined the electron-hole (e-h) pair numbers for the studied scintillators and the detector energy resolution for 662-keV /spl gamma/-rays from a /sup 137/Cs source. The highest numbers of e-h pairs were measured with the LAAPD equaling 33 800 e-h/MeV for CsI(Tl) and 10 200 e-h/MeV for the YAP crystal. In the case of the Hamamatsu APD, the respective numbers were 30 900 e-h/MeV and 4700 e-h/MeV. Finally, the APD from ITE measured 16 500 e-h/MeV with CsI(Tl). The best energy resolution of 4.9% for 662 keV was observed with CsI(Tl) coupled to the LAAPD. The second best resolution was with the Hamamatsu APD showing a result of 5.8%.
The performance of beveled-edge large area avalanche photodiodes (LAAPD) produced by Advanced Photonix, Inc. (API), Hamamatsu SPL 2560 APDs and APDs from Institute of Electron Technology (ITE) were ...studied in scintillation detection using CsI(Tl), BGO, LSO and YAP scintillators. Measurements covered DC gain characteristics, relative response to X-rays and light, energy resolution for 5.9 keV X-rays from /sup 55/Fe source, determination of electron-hole (e-h) pair number for the studied scintillators and their energy resolution for 662 keV /spl gamma/-rays from a /sup 137/Cs source. The highest number of e-h pairs was measured with the LAAPD from API equal to 33800 e-h/MeV for CsI(Tl) and 10200 e-h/MeV for YAP crystal. In the case of the Hamamatsu APD, the respective numbers were 30900 e-h/MeV and 4700 e-h/MeV. For the APD from ITE we measured 16500 e-h/MeV with CsI(Tl). The best energy resolution of 4.9% for 662 keV was observed with CsI(Tl) coupled to LAAPD from API, while the Hamamatsu APD showed somewhat worse result of 5.8%.
Spectrophotometric sequential injection system (SI) is proposed to automate the method of simultaneous determination of Fe(II) and Fe(III) on the basis of parameters of a single peak. In the ...developed SI system, sample and mixture of reagents (1,10-phenanthroline and sulfosalicylic acid) are introduced into a vessel, where in an acid environment (pH≅3) appropriate compounds of Fe(II) and Fe(III) with 1,10-phenanthroline and sulfosalicylic acid are formed, respectively. Then, in turn, air, sample, EDTA and sample again, are introduced into a holding coil. After the flow reversal, a segment of air is removed from the system by an additional valve and as EDTA replaces sulfosalicylic acid forming a more stable colorless compound with Fe(III), a complex signal is registered. Measurements are performed at wavelength 530nm. The absorbance measured at minimum of the negative peak and the area or the absorbance measured at maximum of the signal can be used as measures corresponding to Fe(II) and Fe(III) concentrations, respectively. The time of the peak registration is about 2min. Two-component calibration has been applied to analysis. Fe(II) and Fe(III) can be determined within the concentration ranges of 0.04–4.00 and 0.1–5.00mgL−1, with precision less than 2.8% and 1.7% (RSD), respectively and accuracy better than 7% (RE). The detection limit is 0.04 and 0.09mgL−1 for Fe(II) and Fe(III), respectively. The method was applied to analysis of artesian water samples.
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•Spectrophotometric sequential injection determination of Fe(II) and Fe(III) is proposed.•Determination is based on reaction with phenanthroline, sulfosalicylic acid and EDTA.•A single peak parameters technique is employed to the method implementation.•Absorbance measured at the negative peak minimum corresponds to Fe(II) concentration.•Area of the negative peak or signal maximum correspond to Fe(III) concentration.
This dissertation examines how critical thinking skills are addressed in university-level intensive language programs for international students in the United States. The theoretical framework for ...this study was built upon Vygotsky's sociocultural theory. Three research questions inquired about language instructors' ability to conceptualize critical thinking, integration of critical thinking into intensive language programs curricula and assessment tools, and obstacles in implementation of critical thinking in language instruction. Twenty-one instructors from intensive language programs for international students at six research universities in the Northeast part of the United States participated in this study. The data collection instruments were a questionnaire and follow-up interviews. A qualitative data analysis using a coding scheme revealed that the majority of the participants did not have a strong conceptualization of critical thinking and had difficulty in articulating critical thinking as a cultural construct. The analysis also revealed that the instructors from intensive language programs with re-designed curricula that included critical thinking as learning and instructional objectives reported a high success rate in preparing international students for academic challenges unlike the instructors from language programs that follow a traditional structure-oriented approach to language teaching. Some instructors from structure-oriented language programs reported that they developed their own critical thinking materials to infuse language instruction with critical thinking instruction. Other than their programs' focus on language assessment, obstacles in implementing critical thinking into language curricula listed by the instructors included a lack of textbooks encouraging critical thinking, resistance from administrators and other instructors to re-design language curricula, students' lack of motivation to learn critical thinking, and difficulty of teaching and evaluating critical thinking. With no other studies existing on teaching critical thinking in intensive language programs in universities in the U.S., this study offers pioneering evidence and implications for (a) stronger implementation of critical thinking skills in language support programs for international students planning to pursue academic degrees, (b) reconceptualization of the notion of academic literacy to include critical thinking, (c) development of critical thinking instructional materials and textbooks for language instruction, and (d) training in critical thinking instruction in teacher education programs and professional development initiatives. The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.
The RD48 (ROSE) collaboration has succeeded to develop radiation hard silicon detectors, capable to withstand the harsh hadron fluences in the tracking areas of LHC experiments. In order to reach ...this objective, a defect engineering technique was employed resulting in the development of Oxygen enriched FZ silicon (DOFZ), ensuring the necessary O-enrichment of about 2×10
17 O/cm
3 in the normal detector processing. Systematic investigations have been carried out on various standard and oxygenated silicon diodes with neutron, proton and pion irradiation up to a fluence of 5×10
14
cm
−2 (1
MeV neutron equivalent). Major focus is on the changes of the effective doping concentration (depletion voltage). Other aspects (reverse current, charge collection) are covered too and the appreciable benefits obtained with DOFZ silicon in radiation tolerance for charged hadrons are outlined. The results are reliably described by the “Hamburg model”: its application to LHC experimental conditions is shown, demonstrating the superiority of the defect engineered silicon. Microscopic aspects of damage effects are also discussed, including differences due to charged and neutral hadron irradiation.
The design and properties of 3
mm silicon avalanche photodiodes developed at ITE are presented. Their performance parameters within the spectral range applicable in scintillation detection (400–700
...nm) are discussed and compared to those for near infrared radiation.
This report summarises the final results obtained by the RD48 collaboration. The emphasis is on the more practical aspects directly relevant for LHC applications. The report is based on the ...comprehensive survey given in the 1999 status report (RD48 3rd Status Report, CERN/LHCC 2000-009, December 1999), a recent conference report (Lindström et al. (RD48), and some latest experimental results. Additional data have been reported in the last ROSE workshop (5th ROSE workshop, CERN, CERN/LEB 2000-005). A compilation of all RD48 internal reports and a full publication list can be found on the RD48 homepage (http://cern.ch/RD48/). The success of the oxygen enrichment of FZ-silicon as a highly powerful defect engineering technique and its optimisation with various commercial manufacturers are reported. The focus is on the changes of the effective doping concentration (depletion voltage). The RD48 model for the dependence of radiation effects on fluence, temperature and operational time is verified; projections to operational scenarios for main LHC experiments demonstrate vital benefits. Progress in the microscopic understanding of damage effects as well as the application of defect kinetics models and device modelling for the prediction of the macroscopic behaviour has also been achieved but will not be covered in detail.
Zjawisko migracji nierozerwalnie związane jest z procesem globalizacji gospodarki światowej, która ułatwia przemieszczanie ludności dzięki szerokiej sieci powiązań z rodzinami i znajomymi ...znajdującymi się za granicą i oddziaływaniu na tę sieć międzynarodowego rynku pracy.
Celem artykułu jest przedstawienie problemu migracji zagranicznych ze szczególnym uwzględnieniem Polski w latach 2016-2020.
W artykule przedstawione zostało pojęcie migracji, jej rodzaje oraz przyczyny i skutki. Zaprezentowano również statystyki będące wynikiem badań Głównego Urzędu Statystycznego związane ze skalą migracji w Polsce w latach 2016-2020 oraz głównymi kierunkami emigracji i imigracji na pobyt stały.
This dissertation examines how critical thinking skills are addressed in university-level intensive language programs for international students in the United States. The theoretical framework for ...this study was built upon Vygotsky's sociocultural theory. Three research questions inquired about language instructors' ability to conceptualize critical thinking, integration of critical thinking into intensive language programs curricula and assessment tools, and obstacles in implementation of critical thinking in language instruction. Twenty-one instructors from intensive language programs for international students at six research universities in the Northeast part of the United States participated in this study. The data collection instruments were a questionnaire and follow-up interviews. A qualitative data analysis using a coding scheme revealed that the majority of the participants did not have a strong conceptualization of critical thinking and had difficulty in articulating critical thinking as a cultural construct. The analysis also revealed that the instructors from intensive language programs with re-designed curricula that included critical thinking as learning and instructional objectives reported a high success rate in preparing international students for academic challenges unlike the instructors from language programs that follow a traditional structure-oriented approach to language teaching. Some instructors from structure-oriented language programs reported that they developed their own critical thinking materials to infuse language instruction with critical thinking instruction. Other than their programs' focus on language assessment, obstacles in implementing critical thinking into language curricula listed by the instructors included a lack of textbooks encouraging critical thinking, resistance from administrators and other instructors to re-design language curricula, students' lack of motivation to learn critical thinking, and difficulty of teaching and evaluating critical thinking. With no other studies existing on teaching critical thinking in intensive language programs in universities in the U.S., this study offers pioneering evidence and implications for (a) stronger implementation of critical thinking skills in language support programs for international students planning to pursue academic degrees, (b) reconceptualization of the notion of academic literacy to include critical thinking, (c) development of critical thinking instructional materials and textbooks for language instruction, and (d) training in critical thinking instruction in teacher education programs and professional development initiatives.
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