1,159 research outputs found
Assessment of the Nexus between Groundwater Extraction and Greenhouse Gas Emissions Employing Aquifer Modelling
AbstractOne of the main sources of Greenhouse Gas Emissions (GHG) is electricity consumption which is getting used for different purposes.Water pumping, especially, pumping from deep groundwater resources consumes a lot of energy. In arid and semi-arid areas, in which groundwater is the only source of water, water pumping is done for different purposes such as agricultural, industrial and urban uses. Kerman plain is one of these arid and semi-arid areas which is located in South East of Iran. Groundwater reliance and aquifer decline are the most prominent challenges that this area is faced with in recent years. This challenges increase the demand for more electricity consumption to pump water from the aquifer so that CO2 emissions will be increased. A large percentage of water extraction from the aquifer is used for agricultural purposes. In this paper, by modelling Kerman plain aquifer with MODFLOW software by using Geographical Information System (GIS) database and also studying height of groundwater table from 1999 to 2012, electricity energy consumption of groundwater extraction for agricultural, industrial and urban water supply is calculated and the CO2 emissions trends resulted from electricity energy consumption is evaluated. Then model results are examined for a business as usual (BAU) scenario of changes in water resources. As a result the amount of CO2 emitted from groundwater abstraction by three mentioned sectors is calculated for specified time horizon. Finally, some suggestions are presented for reducing greenhouse gas emissions for the time horizon
The unique Wolverine HREE deposit, Browns Range area, Western Australia
The Wolverine deposit is the largest of a number of REE ore bodies located in the Browns Range area of the Tanami region, Western Australia. These deposits collectively represent one of the worlds’ richest sources of dysprosium and other critical HREE. The Wolverine deposit consists of xenotime [(Y,REE)PO4] and minor florencite [(REEAl3(PO4)2(OH)6] mineralisation in hydrothermal lodes within massive arkosic sandstones. Small alkali granite and pegmatite bodies also intruded the sandstone in the region. Steeply dipping mineralisation is associated with silicification at major fault junctions, and occurs mostly as; 1) high grade, low tonnage lodes with large (>10m long and 1m wide) veins and chaotic breccias of massive, anhedral xenotime (±quartz, ±hematite, ±sericite), and; 2) low grade, probably higher tonnage disseminated mm-scale xenotime-quartz veins and crackle breccias in which xenotime grains occur in a number of morphological types, mainly blade-like and pyramidal overgrowth on pre-existing xenotime grains.
U-Pb dating and isotopic analysis of detrital zircon grains from arkose samples from across the district yielded a single age population of ~3.1 (±~0.1) Ga (corrected for lead loss), which is interpreted to be the maximum depositional age of the sandstones. This age is significantly older than the granitic rocks in the region ( ca. 1.8 to 2.5 Ga), indicating that there is (previously unknown) Mesoarchean basement within the North Australian Craton. Highly unradiogenic Hf isotope data for these zircons combined with unradiogenic Nd isotope values for ore xenotime indicate that old (Early Archean or Hadean?) crustal components contributed to the formation of ~3.1 Ga basement rocks and potentially the xenotime ore bodies.
Work is ongoing to understand the temporal evolution of the deposit, the source of the REE (i.e., mantle versus old crustal) and the processes of transport and precipitation of HREE to form the deposit
Learning inguinal hernia repair? A survey of current practice and of preferred methods of surgical residents
Purpose: During surgical residency, many learning methods are available to learn an inguinal hernia repair (IHR). This study aimed to investigate which learning methods are most commonly used and which are perceived as most important by surgical residents for open and endoscopic IHR. Methods: European general surgery residents were invited to participate in a 9-item web-based survey that inquired which of the learning methods were used (checking one or more of 13 options) and what their perceived importance was on a 5-point Likert scale (1 = completely not important to 5 = very important). Results: In total, 323 residents participated. The five most commonly used learning methods for open and endoscopic IHR were apprenticeship style learning in the operation room (OR) (98% and 96%, respectively), textbooks (67% and 49%, respectively), lectures (50% and 44%, respectively), video-demonstrations (53% and 66%, respectively) and journal articles (54% and 54%, respectively). The three most important learning methods for the open and endoscopic IHR were participation in the OR [5.00 (5.00–5.00) and 5.00 (5.00–5.00), respectively], video-demonstrations [4.00 (4.00–5.00) and 4.00 (4.00–5.00), respectively], and hands-on hernia courses [4.00 (4.00–5.00) and 4.00 (4.00–5.00), respectively]. Conclusion: This study demonstrated a discrepancy between learning methods that are currently used by surgical residents to learn the open and endoscopic IHR and preferred learning methods. There is a need for more emphasis on practising before entering the OR. This would support surgical residents’ training by first observing, then practising and finally performing the surgery in the OR
Standardized videos in addition to the surgical curriculum in Medical Education for surgical clerkships:a cohort study
BACKGROUND: Medical students are expected to translate the theoretical knowledge gained during their study to practical knowledge during the clerkships. A surgical educational platform with standardized videos may be the solution. However, the effects of a structured online video-based platform in addition to the standard curriculum on students’ self-reported and tested surgical knowledge during the surgical clerkship must be assessed. METHODS: Fourth-year medical students (n = 178) participated in a 6-week course of theoretical and practical training followed by a 10-week in-hospital clerkship in the Erasmus University Medical Center (Erasmus MC), Rotterdam, The Netherlands and 11 affiliated general hospitals. Ninety students followed the usual surgical curriculum (control group), followed by 88 students who were given voluntary access to a video-based surgical educational platform of Incision Academy (video group). At the start (T0) and end (T1) of the clerkship, both groups filled out a surgical knowledge test and a survey regarding their self-reported surgical knowledge and their access to available study sources. Supervisors were blinded and surveyed concerning students’ performance and their acquired knowledge. We analyzed the data using paired and unpaired student t-tests and linear regression. RESULTS: At the end of the clerkship, students in the video group indicated that they had better resources at their disposal than the control group for surgical procedures (p = 0.001). Furthermore, students in the video group showed a greater increase in self-reported surgical knowledge during their clerkship (p = 0.03) and in more objectively tested surgical knowledge (p < 0.001). CONCLUSIONS: An online surgical educational platform with standardized videos is a valuable addition to the current surgical curriculum according to students and their supervisors. It improves their test scores and self-reported surgical knowledge. Students feel better prepared and more able to find the information necessary to complete the clerkship. TRIAL REGISTRATION: Registry not necessary according to ICMJE guidelines. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12909-022-03314-w
Effect of elevated in-service temperature on the mechanical properties and microstructure of particulate-filled epoxy polymers
In civil engineering applications, epoxy-based polymers are subject to different environmental conditions including in-service temperature, which might accelerate their degradation and limit their application ranges. Recently, different particulate fillers were introduced to enhance the mechanical properties and reduce the cost of epoxy-based polymers. This paper addresses the effect of in-service elevated temperature (from room temperature to 80o C) in particulate-filled epoxy based resin containing up to 60% by volume of fire retardant and fly ash fillers through a deep understanding of the microstructure and analysis of their mechanistic response. An improvement in the retention of mechanical properties at in-service elevated temperature was achieved by increasing the percentages of fillers. The retention of compressive and split tensile strength at 80o C for the mix containing 60% fillers was 72% and 52%, respectively, which was significantly higher than the neat epoxy. Thermo-dynamic analysis showed an increase in glass transition temperature with the inclusion of fillers, while these mixes also experienced less weight loss compared to neat epoxy, indicating better thermal stability. Scanning electron microscopy images showed the formation of dense microstructures for particulate-filled epoxy based resin at elevated temperatures. This indicates that the particulate filled epoxy resin exhibits better engineering properties at in-service elevated temperatures, increasing their durability and therefore their suitability for civil engineering applications. A simplified prediction equation based on power function was proposed and showed a strong correlation to the experimental compressive and splitting tensile strength at different levels of in-service elevated temperature
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