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1.
Massive stars exploding in a He-rich circumstellar medium - X : flash spectral features in the Type Ibn SN 2019cj and observations of SN 2018jmt
Z.-Y. Wang, A. Pastorello, K. Maeda, A. Reguitti, Y.-Z. Cai, D. Andrew Howell, S. Benetti, Mateusz Bronikowski, E. Concepcion, Tanja Petrushevska, 2024, izvirni znanstveni članek

Opis: We present optical and near-infrared observations of two Type Ibn supernovae (SNe), SN\,2018jmt and SN\,2019cj. Their light curves have rise times of about ten days, reaching an absolute peak magnitude of $M_g$(SN\,2018jmt) = $-$19.07 pm 0.37 and $M_V$(SN\,2019cj) = $-$18.94 pm 0.19 mag, respectively. The early-time spectra of SN\,2018jmt are dominated by a blue continuum, accompanied by narrow (600$-$1000 km $) He i lines with the P-Cygni profile. At later epochs, the spectra become more similar to those of the prototypical SN Ibn 2006jc. At early phases, the spectra of SN\,2019cj show flash ionisation emission lines of C iii N iii and He ii superposed on a blue continuum. These features disappear after a few days, and then the spectra of SN\,2019cj evolve similarly to those of SN\,2018jmt. The spectra indicate that the two SNe exploded within a He-rich circumstellar medium (CSM) lost by the progenitors a short time before the explosion. We modelled the light curves of the two SNe Ibn to constrain the progenitor and the explosion parameters. The ejecta masses are consistent with either what is expected for a canonical SN Ib (sim 2 odot $) or for a massive Wolf Rayet star ($>$ sim 4 M$_ odot $), with the kinetic energy on the order of $10^ $ erg. The lower limit on the ejecta mass ($>$ sim 2 M odot $) argues against a scenario involving a relatively low-mass progenitor (e.g. $M_ ZAMS $ sim 10 M$_ odot $). We set a conservative upper limit of sim 0.1 M$_ odot $ for the 56Ni masses in both SNe. From the light curve modelling, we determined a two-zone CSM distribution, with an inner, flat CSM component and an outer CSM with a steeper density profile. The physical properties of SN\,2018jmt and SN\,2019cj are consistent with those expected from the core collapse of relatively massive envelope-stripped stars.
Ključne besede: supernovae
Objavljeno v RUNG: 06.11.2024; Ogledov: 315; Prenosov: 3
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2.
Tunable emissive ▫$CsPbBr_3 /Cs_4PbBr_6$▫ quantum dots engineered by discrete phase transformation for enhanced photogating in field-effect phototransistors
Han Xiao, Siyuan Wan, Lin He, Junlong Zou, Andraž Mavrič, Yixi Wang, Marek Piotrowski, Anil Kumar Bandela, Paolo Samorì, Zhiming M. Wang, 2024, izvirni znanstveni članek

Opis: Precise control of quantum structures in hybrid nanocrystals requires advancements in scientific methodologies. Here, on the design of tunable CsPbBr3/Cs4PbBr6 quantum dots are reported by developing a unique discrete phase transformation approach in Cs4PbBr6 nanocrystals. Unlike conventional hybrid systems that emit solely in the green region, this current strategy produces adjustable luminescence in the blue (450 nm), cyan (480 nm), and green (510 nm) regions with high photoluminescence quantum yields up to 45%, 60%, and 85%, respectively. Concentration‐dependent studies reveal that phase transformation mechanisms and the factors that drive CsBr removal occur at lower dilutions while the dissolution–recrystallization process dominates at higher dilutions. When the polymer‐CsPbBr3/Cs4PbBr6 integrated into a field‐effected transistor the resulting phototransistors featured enhanced photosensitivity exceeding 105, being the highest reported for an n‐type phototransistor, while maintaining good transistor performances as compared to devices consisting of polymer‐CsPbBr3 NCs.
Ključne besede: crystallization mechanisms, dilution-induced kinetic trapping, photogating effect, phototransistors, quantum dots
Objavljeno v RUNG: 26.06.2024; Ogledov: 962; Prenosov: 11
.pdf Celotno besedilo (4,02 MB)
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3.
Exhaled volatile organic compounds and respiratory disease : recent progress and future outlook
Maria Chiara Magnano, Waqar Ahmed, Ran Wang, Martina Bergant Marušič, Stephen J. Fowler, Iain R. White, 2024, pregledni znanstveni članek

Opis: The theoretical basis of eVOCs as biomarkers for respiratory disease diagnosis is described, followed by a review of the potential biomarkers that have been proposed as targets from in vitro studies. The utility of these targets is then discussed based on comparison with results from clinical breath studies. The current status of breath research is summarised for various diseases, with emphasis placed on quantitative and targeted studies. Potential for bias highlights several important concepts related to standardization, including practices adopted for compound identification, correction for background inspired VOC levels and computation of mixing ratios. The compiled results underline the need for targeted studies across different analytical platforms to understand how sampling and analytical factors impact eVOC quantification. The impact of environmental VOCs as confounders in breath analysis is discussed alongside the potential that eVOCs have as biomarkers of air pollution exposure and future perspectives on clinical breath sampling are provided.
Ključne besede: breath analysis, disease diagnosis, exhaled volatile organic compounds, respiratory disease, environmental exposure analysis, breath analysis
Objavljeno v RUNG: 06.05.2024; Ogledov: 1439; Prenosov: 9
.pdf Celotno besedilo (1,36 MB)
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Strategy for rural heritage regeneration in China : integrating community and government in governance: a case study of traditional villages in Luoning county :
Wendi Wang, 2024, doktorska disertacija

Opis: The Chinese countryside has long been associated with cultural continuity, albeit in contradictory ways. It has been marginalized for several decades, while all development efforts have focused on urbanization. However, as the tensions and paradoxes of modern urban life become increasingly obvious, the countryside is once again recognized as an enduring symbol of authentic national values. Chinese traditional cultural heritage is rooted in Chinese traditional villages. In fact, being built before the coming of the Republic of China, those villages nowadays still possess a great deal of very important material and immaterial forms of cultural heritage, as a historical record of the Chinese nation development. Through the examination and study of traditional villages in Luoning, and the perspective of theories of architectural conservation theory, community co-construction, and private-public partnership, the dissertation proposes a hybrid county governance model to maximize the stakeholder's functions roles, and operational procedures in the preservation and development of the traditional villages. Thus, through the integration of three stability perspectives—cultural, economic, and social —the dissertation provides the government's optimization strategy for heritage preservation. In the first case study, the governance of Zhangzhuang's traditional village is examined. The village's residents share responsibility for one another and are frequently connected by strong family ties and regular community organization in decision-making. Unfortunately, this thriving community-led government is insufficiently prepared to deal with the expanding tourism industry, it fails when it comes to overarching development objectives, and it lacks substantial experience in the preservation of historic structures. The Second case study investigates the government-led traditional types of villages. These are characterized by low public and community participation, and underdeveloped commodity economies, but being usually of outstanding importance, they result rich in traditional material and intangible cultural resources and have great potential for developing a tourism sector. Government-led efforts to reactivate the development of these villages have the advantages of credibility and authority, preferential policy formulation, and government short-term funding. However, these villages face severe problems in terms of community involvement, complementary market economies, and insufficient long-term government funding. This condition is investigated in the second case of the government's conception and promotion of the "Hou Shangzhuang Village Traditional Village Restoration" project. Despite some initial success, the project came to a standstill due to the competing interests of businesses, the government, and the community. The third case study looks into traditional villages where the primary development component is driven by businesses, creating conditions for the growth of a market economy. The analysis demonstrates that enterprise investments benefit from complementary capital input, resource integration, and effective management. However, the issue of uneven income and benefit distribution, as well as excessive consumption of public resources, pose a serious threat to both: the authenticity and integrity of cultural heritage, as well as the fair and sustainable development of local communities. This situation is examined in the case study of Qianhe Village, where the tourism industry has grown through multiple investment operations by private enterprises. The dissertation examines diverse hybrid governance models for each of these three different cultural, social, and economic heritage contexts. In specific it points to the role of government to efficiently design, validate, and promote responsive solutions for the resilience of cultural heritage of traditional villages in China.
Ključne besede: Heritage, Traditional Chinese village preservation, planning and management, Government, Governance, Participation, Community Co-construction
Objavljeno v RUNG: 11.03.2024; Ogledov: 1587; Prenosov: 27
.pdf Celotno besedilo (9,17 MB)

6.
Performance analysis of high-spectral-resolution lidar with/without laser seeding technique for measuring aerosol optical properties
Fengjia Gao, Fei Gao, Gaipan Li, Fan Yang, Li Wang, Song Yuehui, Dengxin Hua, Samo Stanič, 2024, izvirni znanstveni članek

Opis: High-spectral-resolution lidar (HSRL) is a powerful tool for aerosol measurements. With/without laser seeding technique in the transmitted laser, the HSRL can be distinguished as the single-longitudinal-mode (SLM) HSRL or the multi-longitudinal-mode (MLM) HSRL, and the Mach-Zehnder interferometer (MZI) with periodic transmittance function can be used as the spectral discriminator in both the SLM HSRL and MLM HSRL. To in-depth knowledge of the respective advantages of the SLM HSRL and MLM HSRL for measuring aerosol optical properties, the working principle, optimal parameter setting, and detection performance of the SLM HSRL and MLM HSRL are analyzed and discussed in detail, respectively. The working principle of the SLM HSRL and MLM HSRL indicate that the effective transmittance of MZI is the important parameter of data retrieval, the main source of retrieval uncertainties, and the key factor of MZI optical path difference (OPD) settings. To ensure that the MZI can achieve the preferable separation for aerosol Mie scattering signals and molecular Rayleigh scattering signals, the optimal OPDs of MZI are set at 165 mm and 1000 mm in the SLM HSRL and MLM HSRL from the aspects of the effective transmittance of MZI and the spectral discrimination ratio (SDR). Besides, to analyze the influence of frequency difference and divergence angle for the detection performance of HSRL, the effective transmittance of MZI and SDR are simulated and the results show that the MLM HSRL has higher requirements for the environmental parameters and the echo beam collimation than the SLM HSRL. Moreover, the HSRLs with SLM and MLM transmitted lasers are constructed in Xi'an for measuring aerosol optical properties. The preliminary measurement results show that the range square corrected signal (RSCS) of Rayleigh channel is smaller than that of Mie channel in both the SLM HSRL and MLM HSRL, while the difference between RSCS of Rayleigh channel and RSCS of Mie channel in the SLM HSRL is larger than that in the MLM HSRL, and the detection range of the SLM HSRL is lower than that of the MLM HSRL.
Ključne besede: aerosol optical properties, high-spectral-resolution lidar, single-longitudinal-mode, multi-longitudinal-mode, spectral discrimination ratio
Objavljeno v RUNG: 28.02.2024; Ogledov: 1468; Prenosov: 3
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7.
Changes in exhaled volatile organic compounds following indirect bronchial challenge in suspected asthma
Adam Peel, Ran Wang, Waqar Ahmed, Iain R. White, Maxim Wilkinson, Yoon K. Loke, Andrew M. Wilson, Stephen J. Fowler, 2023, izvirni znanstveni članek

Opis: Background Inhaled mannitol provokes bronchoconstriction via mediators released during osmotic degranulation of inflammatory cells, and, hence represents a useful diagnostic test for asthma and model for acute attacks. We hypothesised that the mannitol challenge would trigger changes in exhaled volatile organic compounds (VOCs), generating both candidate biomarkers and novel insights into their origin. Methods Participants with a clinical diagnosis of asthma, or undergoing investigation for suspected asthma, were recruited. Inhaled mannitol challenges were performed, followed by a sham challenge after 2 weeks in participants with bronchial hyper-responsiveness (BHR). VOCs were collected before and after challenges and analysed using gas chromatography–mass spectrometry. Results Forty-six patients (mean (SD) age 52 (16) years) completed a mannitol challenge, of which 16 (35%) were positive, and 15 of these completed a sham challenge. Quantities of 16 of 51 identified VOCs changed following mannitol challenge (p<0.05), of which 11 contributed to a multivariate sparse partial least square discriminative analysis model, with a classification error rate of 13.8%. Five of these 16 VOCs also changed (p<0.05) in quantity following the sham challenge, along with four further VOCs. In patients with BHR to mannitol distinct postchallenge VOC signatures were observed compared with post-sham challenge. Conclusion Inhalation of mannitol was associated with changes in breath VOCs, and in people with BHR resulted in a distinct exhaled breath profile when compared with a sham challenge. These differentially expressed VOCs are likely associated with acute airway inflammation and/or bronchoconstriction and merit further investigation as potential biomarkers in asthma.
Ključne besede: asthma, exhaled volatile organic compounds, pulmonology, breath metabolomics
Objavljeno v RUNG: 31.07.2023; Ogledov: 1995; Prenosov: 4
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