Charge Carrier Dynamics in Cu2ZnSn S Se 4 Thin Film Solar Cells measured by Time Resolved Terahertz and Microwave Spectroscopy

We track charge carriers dynamics from femtoseconds to nanoseconds in Cu2ZnSn S Se 4 thin films by time resolved terahertz spectroscopy TRTS and time resolved micro wave conductivity measurements TRMC . This includes trapping of photo carriers into band tail states followed by recombination with a time constant of 9.1 ns. The relatively long life time is likely caused by the localization into long living trap states rather than by a low concentration of recombination center

How do we recognize the child with OSAS?

Obstructive sleep-disordered breathing includes a spectrum of clinical entities with variable severity ranging from primary snoring to obstructive sleep apnea syndrome (OSAS). The clinical suspicion for OSAS is most often raised by parental report of specific symptoms and/or abnormalities identified by the physical examination which predispose to upper airway obstruction (e.g., adenotonsillar hypertrophy, obesity, craniofacial abnormalities, neuromuscular disorders). Symptoms and signs of OSAS are classified into those directly related to the intermittent pharyngeal airway obstruction (e.g., parental report of snoring, apneic events) and into morbidity resulting from the upper airway obstruction (e.g., increased daytime sleepiness, hyperactivity, poor school performance, inadequate somatic growth rate or enuresis). History of premature birth and a family history of OSAS as well as obesity and African American ethnicity are associated with increased risk of sleep-disordered breathing in childhood. Polysomnography is the gold standard method for the diagnosis of OSAS but may not be always feasible, especially in low-income countries or non-tertiary hospitals. Nocturnal oximetry and/or sleep questionnaires may be used to identify the child at high risk of OSAS when polysomnography is not an option. Endoscopy and MRI of the upper airway may help to identify the level(s) of upper airway obstruction and to evaluate the dynamic mechanics of the upper airway, especially in children with combined abnormalities. Pediatr Pulmonol. 2017;52:260–271. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc

Leasing development in Latvia

Visizplatītākais un efektīvākais kreditēšanas veids Latvijā ir līzings. Līzinga daudzpusējā ietekme uz ekonomiku ir saistīta ar to, ka tas vienlaicīgi piesaista privātā kapitāla investīcijas ražošanas sfērā, uzlabo tiešo ražotāju finansiālo stāvokli un uzlabo to konkurētspēju. Par pāris gadu desmitiem , tas ir kļuvis ļoti pieejams gan privātpersonām, gan juridiskām personā. Tomēr pagaidām Latvijā vēl pastāv problēmas un to atrisinājuma iespējas. Bakalaura darba mērķis ir balstoties uz literatūras teorētiskajiem aspektiem, izpētīt un iepazīties ar līzinga veidiem, kā arī izanalizēt pašreizējo situāciju Latvijas līzingu tirgū, rezultātus apkopot secinājumos un atsevišķos priekšlikumos. Mērķu sasniegšanai tiek izvirzīti dažādi uzdevumi, līzinga būtības veidu un klasifikāciju izpēte, līzinga darījuma noslēgšanas kartības izvērtēšana, veikt līzinga darījumu tiesiskās bāzes izpēti Latvijā , kā arī analizēt lielākos līzinga uzņēmumus Latvijā un salīdzināt to ar kopējo Latvijas līzinga tirgu. Novērtēt līzinga darījuma riskus, izstrādāt secinājumus un priekšlikumus par līzinga attīstības iespējām Latvija. Pēc veiktajiem uzdevumiem, var secināt, ka līzingu attīstību Latvijā varētu stimulēt un uzlabot atsevišķa līzinga likuma izveide. Bakalaura darba nosaukums ir „līzinga attīstība Latvijā”. Darba apjoms sastāda 64 lappuses. Darbā tiek izmantoti 49 literatūras un informācijas avoti. Bakalaura darbs satur 4 tabulas un 16 attēlus.The most common and the most efficient form of lending in Latvia is lease. Multilateral impact of lease on the economic concerned with the fact that it attracts private capital investment in the manufacturing sector, improves the financial situation of the direct manufacturers and improves their competitiveness simultaneously. It has become very accessible for individuals and entities during the last few decades. However, there are still problems and opportunities of its solution in Latvia. The target of Bachelor's work is not only to research and to learn the types of lease using the theoretical aspects of literature, but also to analyze the current situation of the Latvian leasing market and to make the conclusions and some proposals. There are pursued different tasks for achieving the target: researching the substance and classification of lease, assessment of procedure of closing the deal of lease, researching the legal basis of lease in Latvia, as well as the analysis of the major Latvian leasing companies and its comparison with the total Latvian leasing market; estimating of the leasing transaction risks, making conclusions and proposals for leasing development in Latvia. After the pursued tasks fulfillment it can be concluded that the development of the Latvian leasing could be stimulated and improved by creation of leasing law. Bachelor's work title is "Development of Latvian leasing." Work consists of 64 pages. There are 49 sources of literature and information used in work. Bachelor's work consists of 4 tables and 16 images

Intragrain charge transport in kesterite thin films-Limits arising from carrier localization

Intragrain charge carrier mobilities measured by time-resolved terahertz spectroscopy in state of the art Cu2ZnSn(S,Se)(4) kesterite thin films are found to increase from 32 to 140 cm(2) V-1 s(-1) with increasing Se content. The mobilities are limited by carrier localization on the nanometer-scale, which takes place within the first 2 ps after carrier excitation. The localization strength obtained from the Drude-Smith model is found to be independent of the excited photocarrier density. This is in accordance with bandgap fluctuations as a cause of the localized transport. Charge carrier localization is a general issue in the probed kesterite thin films, which were deposited by co-evaporation colloidal inks, and sputtering followed by annealing with varying Se/S contents and yield 4.9\%-10.0 efficiency in the completed device. (C) 2016 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/)