792 research outputs found
Evaluation of the effect of climate variability on the hydro-glaciological regime in the Upper Indus Basin
Full text linkIl ritiro dei ghiacciai osservato a scala planetaria e gli effetti del riscaldamento globale che accelererà la fusione dei ghiacciai e delle nevi stagionali andranno ad alterare alterare i regimi idrologici che interessano non solo i bacini montani, ma anche le aree a valle. Gran parte dell'approvvigionamento idrico del Pakistan è generato dalla fusione nivale e glaciale nelle regioni montuose del Karakoram. Tuttavia, il cambiamento climatico rappresenta un rischio elevato per questi bacini idrografici. Pertanto, quantificare questi cambiamenti prevedibili è una sfida importante per la gestione e la pianificazione delle risorse idriche. L'obiettivo di questa tesi è valutare l'effetto della variabilità climatica sul regime idrologico e glaciologico nell’Alto Bacino dell’Indo (nel seguito Upper Indus Basin-UIB).
Il primo capitolo di questa tesi di dottorato presenta la climatologia delle precipitazioni ad alta risoluzione nell’UIB basata sul metodo delle anomalie (1995-2017) e sviluppato utilizzando quattro set di dati su griglia (APHRODITE, CHIRPS, PERSIANN-CDR e ERA5) su scala stagionale e annuale. I risultati indicano le migliori prestazioni della precipitazione stimata con il dataset CHIRPS con correzione del bias seguito dalle rianalisi del modello ERA5; infatti il set di dati di precipitazione CHIRPS con correzione del bias ha ottenuto risultati migliori nella simulazione delle precipitazioni con RMSE, MAE, MAPE [%] e BIAS più piccoli seguiti da ERA5.
Sulla base dei risultati del Capitolo 1, nel Capitolo 2 si utilizza il modello distribuito di bilancio energetico Physically Based Distributed Snow Land and Ice Model (PDSLIM), già testato nelle Alpi da Ranzi e Rosso (1991), Ranzi et al. (2010) e Grossi et al. (2013) per il bacino del Naltar situato nel bacino del fiume Hunza, in Pakistan, per simulare i regimi idro-glaciologici attuali e futuri. I risultati hanno mostrato prestazioni molto soddisfacenti del modello verificato rispetto all'area di copertura nevosa (Snow Cover Area) stimata dalle immagini del sensore satellitare LANDSAT-TM e Terra/Aqua-MODIS per tutti gli anni simulati con coefficiente medio di determinazione R2 = 0,96 e Nash-Sutcliffe Efficiency NSE= 0,95. Le simulazioni di deflusso hanno rivelato un buon accordo con la portata giornaliera osservata ottenuta con NSE e Kling-Gupta Efficiency (KGE) medi di 0,90 e 0,89. L'analisi della composizione del deflusso ha rivelato che la componente sotterranea, con risposta lenta, è la componente principale, seguita dal deflusso del ghiacciaio e dal deflusso superficiale.
Nel Capitolo 3 si illustra l’impiego del modello PDSLIM calibrato per esaminare le proiezioni future dei regimi glaciologico-idrologici per i due periodi temporali (2040-2059) e (2080-2099) negli scenari RCP 2.6, RCP 4.5 e RCP 8.5. Le simulazioni previste del bilancio di massa ed energetico indicano che la progressione della fusione della neve e del ghiaccio aumenterà costantemente in entrambi i periodi di tempo futuri con un'anticipazione dei tempi della massima fusione nivale. Dalle stime del bilancio di massa attuale (-737 mm anno-1) e previsto (-887 mm anno-1 per lo scenario 2050_4.5; -2018 mm anno-1 per il 2050_8.5 e -1154 mm anno-1 entro il 2090_4.5 ; -2597 mm anno-1 per 2090_8.5) e dalle immagini satellitari MODIS e LANDSAT sembra che anche nel bacino del Naltar i ghiacciai stiano per ritirarsi rapidamente indicando un'eccezione alla cosiddetta 'anomalia del Karakoram', una congettura di un rallentamento del ritiro dei ghiacciai nella regione a causa dell'accumulo nivale indotto dalle precipitazioni ad alta quota. Nel complesso il modello PDSLIM mostra prestazioni molto buonei nel simulare le dinamiche glacio-idrologiche attuali e, probabilmente, anche quelle future e pone una solida base per il potenziale utilizzo dell'approccio del bilancio energetico distribuito nei bacini glaciali del Karakorum e del’Hymalaia.Projections of glaciers’ retreat and earlier snowmelt driven by global warming could alter the hydro-glaciological regimes affecting not only the upstream watershed but also downstream areas. A large portion of Pakistan's water supply is generated by the melting of snow and ice in the mountainous regions of the Karakoram. However, climate change poses a high risk to these watersheds. Thus, quantifying these changes at the right time is an important challenge for water resources planners. The objective of this dissertation is to assess the effect of climate variability on the hydro-glaciological regime in the Upper Indus Basin (UIB) in the present and future projected climate.
Chapter 1 compiles the high resolution precipitation climatology (1995-2017) of the UIB developed using the anomaly method and four gridded datasets (APHRODITE, CHIRPS, PERSIANN-CDR and ERA5) which are bias corrected with interpolated observations at seasonal and annual scale. The results indicate the better performance of bias corrected CHIRPS precipitation followed by ERA5; bias corrected CHIRPS precipitation datasets performed better in simulating precipitation with smaller RMSE, MAE, MAPE [%] and BIAS followed by ERA5. Precipitation and discharge revealed significant variability at the seasonal scale more than at annual scale. The rainfall and runoff relationship and annual runoff coefficients suggest the need of further investigation and monitoring about snow-glacier melt contribution in streamflow.
Based on Chapter 1 outcomes, Chapter 2 employs the Physically Based Distributed Snow Land and Ice Model (PDSLIM), already tested in the Alps by Ranzi and Rosso (1991), Ranzi et al. (2010) and Grossi et al. (2013); Ranzi and Rosso (1991) for the Naltar catchment situated in the Hunza river basin (Pakistan) to simulate current and future hydro-glaciological regimes. The results exhibited very satisfactory performances of the model verified against satellite-based snow cover area for all simulated years with average coefficient of determination R2 = 0.96 and Nash-Sutcliffe Efficiency NSE= 0.95. Runoff simulations revealed good agreement with observed daily discharge obtained with mean NSE and KGE of 0.90 and 0.89.
Chapter 3 employs the calibrated PDSLIM to examine future projections of glaciological-hydrological regimes for the two-time periods 2040-2059 and 2080-2099 under RCP 2.6, RCP 4.5 and RCP 8.5 scenarios. The projected simulations of the energy and mass balance indicate that snow and ice melt progression will consistently increase in both future time periods with an anticipation in the timing of the maximum snowmelt. Additionally, the rise in temperature is expected to have a substantial impact on peak hydrological regimes from one to two months earlier by 2090s over Naltar catchment. From the actual (-737 mm a-1) and projected mass balance estimates (-887 mm a-1 by 2050_4.5 scenario; -2018 mm a-1 for 2050_8.5 and -1154 mm a-1 by 2090_4.5; -2597 mm a-1 for 2090_8.5) and the MODIS and LANDSAT satellite images it appears that also in the Naltar catchment glaciers are going to retreat fast indicating an exception to the so-called ‘Karakoram anomaly’, a conjecture of a slower retreat of glaciers in the region because of accumulated precipitation at high altitudes . Overall, PDSLIM performs well for the current and, likely, future glacio-hydrological dynamics and sets a strong foundation for the potential usage of distributed energy balance approach in the glacierized catchments of High Mountain Asia (HMA) including Karakoram and Himalaya
Federated cloud resource management: review and discussion
No full textFederation of clouds is the future of cloud computing, mobile cloud computing, Internet of things, and big data applications. The utilization of federated resources is envisioned to increase the quality of service, cost benefits, and reliability. Resource management in the federation of multiple clouds is a pressing issue owing to the lack of cross-domain knowledge, security, trust, and administrative policies. This study classifies these resource management functions in the federated cloud environment into resource pricing, resource discovery, resource selection, resource monitoring, resource allocation, and disaster management. Each federated resource management function is discussed, and insights into state-of-the-art research are then provided. These resource management functions are also compared based on the performance metrics that are suitable for an individual function. Finally, we indicate the open challenges for further research with regard to each classified resource management function
Muhammad Shaikh's Views on Jesus (A.S) and Differences with Jamhūr Mufassirīn
Full text linkHazrat Jesus (A.S) was the son of Maryam who was a virgin mother and the daughter of Imran. He was the decedents of David, Isaac, and Abraham (A.S). The holy Qur’ān declared Him only the son of Maryam and enlisted in the decedents of the apostles. He spent a specific time period in the world and after that was uplifted towards the heavens. He will come down back near the day of resurrection and will make act upon the Sharī’ah of Muhammad (PBUH). He will kill the Dajjāl and after staying for a specific time period will die naturally and will be buried in city of Medina. Muhammad Shaikh who was born in Karachi established an institute named International Islamic Propagation Center for the teaching of the Qur’ān, He is totally against the authentic universal teaching of the Qur’ān concerning Jesus Christ. He vies that Jesus was born in Makah. It is universally acknowledge that he was given Gospel whereas Muhammad Shaikh rejects this completely. He insists that Muhammad is not the last prophet and the intercession in the Day of Judgment was not given to Muhammad but to Jesus and the Qur’ān is not only al-Kitāb, rather Gospel also the entitlement of al-Kitāb. He is of the view that right of intercession will be given to Jesus. Prophet-hood was not ended to Muhammad, it accedes further. In this article the thoughts of Muhammad Shaikh will be examined in the light of the Qur’ān, the Sunnah, and the views of Jamhūr Mufassirīn (majority of interpreters of the Qur’ān and the Sunnah)
Chameleon: A Multimodal Learning Framework Robust to Missing Modalities
No full textMultimodal learning has demonstrated remarkable performance improvements over unimodal architectures. However, multimodal learning methods often exhibit deteriorated performances if one or more modalities are missing. This may be attributed to the commonly used multi-branch design containing modality-specific components, making such approaches reliant on the availability of a complete set of modalities. In this work, we propose a robust multimodal learning framework, Chameleon, that adapts a common-space visual learning network to align all input modalities. To enable this, we present the unification of input modalities into one format by encoding any non-visual modality into visual representations thus making it robust to missing modalities. Extensive experiments are performed on multimodal classification task using four textual-visual (Hateful Memes, UPMC Food-101, MM-IMDb, and Ferramenta) and two audio-visual (avMNIST, VoxCeleb) datasets. Chameleon not only achieves superior performance when all modalities are present at train/test time but also demonstrates notable resilience in the case of missing modalities
Intumescence behaviour of bottom ash based geopolymer mortar through microwave irradiation – As affected by alkali activation
Full text linkEnergy balance modelling of snow and ice melt for the Naltar catchment (Karakoram, Pakistan) in future climate
Full text linkHigh Mountain Asia (HMA), including the Hindu Kush-Karakoram Himalayas (HKH) is one of the world's key “water towers”, with the resources supporting hundreds of millions of people. Currently, this region is experiencing significant demographic and socio-economic growth. Reliable hydrological projections of the future supply of water resources are essential, given the likelihood that water resources demand will continue to increase. In this study, CORDEX South Asia (CORDEX-WAS44) regional climate models (RCMs) and the Physically Based Distributed Snow Land and Ice Model, that was calibrated with hourly meteorological data and daily runoff over eight years of monitoring period, are employed in the Naltar catchment located in the Hunza river basin, Upper Indus Basin, Pakistan to project glacio-hydrological regimes in the future climate. For each of the CORDEX-WAS44 simulations, climate change signals for near future (2040–2059) and far future (2080–2099) under three Representative Concentration Pathways (RCPs) namely RCP2.6, RCP4.5, and RCP8.5 are presented with respect to the corresponding present climate (1991–2010). Results show overall significant increases in mean temperature between (+0.9 to + 6.0 °C, depending upon the scenario) and total precipitation (+6 to + 29 %) from April to September by the end of the century for RCP2.6, RCP4.5, and RCP8.5. The projected simulations of energy and mass balance indicate that snow and ice melt rate will increase consistently in both future periods with an earlier timing of the snowmelt as it appears in June in the near future (2040–2059) and in May in the far future (2080–2099) under the high emission scenario (RCP8.5). The increase in temperature, precipitation and winter snowpack changes are also expected to have a substantial impact on the hydrological regime in the Naltar catchment, with a peak flow occurring one to two months earlier and a total by 2090 and a decrease of total runoff in the monsoon season by –3 to –24 % in the near and far future, respectively, under RCP 8.5 scenario and more neutral changes (–2 to + 3 %) according to RCP 4.5. Based on these results and the discussion above, water availability in the Naltar catchment will be uncertain by the end of the century
Impacts of changing climate and snow cover on the flow regime of Jhelum River, Western Himalayas
No full textThis study examines the change in climate variables and snow cover dynamics and their impact on the hydrological regime of the Jhelum River basin in Western Himalayas. This study utilized daily streamflow records from Mangla dam, spanning a time period of 19 years (1995–2013), along with precipitation and temperature data over 52 years (1961–2013) from 12 different
climate stations in the catchment. Additionally, moderate-resolution imaging spectroradiometer (MODIS) remote sensing product MOD10A2 was utilized to analyze the change in snow cover dynamics during 2000–2013. The Pearson and Kendall rank correlation tests were used to scrutinize snow cover trends and correlation between temperature, precipitation, snow cover area (SCA) and streamflows records. Basin-wide trend analysis showed a slightly increasing tendency in temperature
(s = 0.098) and precipitation (s = 0.094), during the years 1961–2013. The changes in streamflow indicated a positive (r [0.12) relationship with respect to temperature but variable trends (r = -0.45–0.41) with respect to precipitation during both the winter and monsoon seasons. This indicates that temperature has a significant impact on the hydrological regime of the basin.
MODIS data-based investigations suggested an expansion in SCA during 2000–2013. The changes in SCA of highaltitude
zones ([2000 m a.s.l.) depicted a stronger positive correlation with climate variables and streamflow compared with those obtained for low-altitude regions (\2000 m a.s.l.). Overall, these results signify that highaltitude areas contribute to the streamflow largely in the form of snow- and glacier-melt during the early summer season. The streamflow is then further augmented by monsoon rainfall in the low-elevation regions during late summer
Green and Sustainable Synthesis of Silver and Gold Nanoparticles: A Stevia Leaf Extract Approach
No full text: Silver and gold nanoparticles were synthesized by reducing silver and gold ions using previously unexplored stevia extracts prepared with water, methanol, and ethanol as solvents. These extracts served as both reducing and stabilizing agents. The nanoparticles were characterized using ultraviolet-visible (UV-Vis) spectroscopy, which confirmed surface plasmon resonance (SPR) at 400-450 nm for AgNPs and 500-550 nm for AuNPs, with an additional peak at 650-700 nm. Zeta potential analysis revealed polydispersity index (PdI) values of 0.269, 0.328, and 0.184 for AgNPs, and 0.428, 0.366, and 0.408 for AuNPs in water, ethanol, and methanol extracts, respectively. The Z-average particle sizes were 68.66, 163.9, and 146.4 nm for AgNPs, and 207.2, 96.27, and 160.6 nm for AuNPs. TEM images confirmed that the nanoparticles were spherical and well-dispersed. FTIR analysis indicated that functional groups such as hydroxyl and carbonyl from the stevia extracts were involved in the reduction and stabilization of nanoparticles. This study highlights the potential of Stevia rebaudiana extracts as efficient, eco-friendly agents for the synthesis of metallic nanoparticles, offering a sustainable alternative to conventional chemical and physical methods with potential applications in antimicrobial and biomedical fields
لیاقت علی کے افسانوں میں مقامی معاشرت کا عکس
No full textLiaqat Ali is one of the emerging fiction writers of todays. He was born on September 13,1972 in Multan and grew up here. He studied in Multan and today he is serving as a Urdu professor in Islamia University Bahawalpur. Liaqat Ali is a Short Story writer who interprets locality. So far, two fictional collections have been published. In which, we can see the dynamic images of the culture and society of Multan. He has interpreted the life, problems and difficulties of a local man in his stories. He has made local life of Multan the subject of his stories and also created characters which is connected to his land. How much the stories of Liaqat Ali are under the impact and influence of localism? It is being analysis and explored in this article
Exploring the effective teaching aspects of the Seerah of Prophet Muhammad (PBUH)
Full text linkEducation and learning are crucial aspects of human life, and it is essential to select effective teaching methods to promote them. However, in many educational institutions, esteemed teachers are taught and encouraged to use European-imported teaching methods, whether they are inductive, deductive, kindergarten, or Montessori methods. Regrettably, the teaching method that is closest to human nature and was used by the Companions of the Prophet (peace be upon him) and subsequent generations of Muslims, such as Abu Bakr, Umar, Uthman, and Ali (may Allah be pleased with them), Umar ibn Abdul Aziz, Muhammad ibn Qasim, and Tariq ibn Ziyad, is often neglected. Highly educated teachers are not aware of how the Prophet (peace be upon him) taught, which is a heartbreaking situation. This series aims to address this issue
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