1. |
- Davis, Jenny, et al.
(författare)
-
Time-dependent material flow analysis of iron and steel in the UK. : Part 2. Scrap generation and recycling
- 2007
-
Ingår i: Resources, Conservation and Recycling. - : Elsevier BV. - 0921-3449 .- 1879-0658. ; 51:1, s. 118-140
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents an analysis of the use of iron and steel in the UK and explores how much of the iron and steel is recycled when it becomes obsolete after use. The first part of this paper series investigated production and consumption trends of iron and steel in the UK, whereas this paper focuses on scrap generation and recycling. Information on the amounts of iron and steel going into different groups of goods, together with values for their estimated lifetimes, have enabled modelling of the annual release of iron and steel from the use phase in the form of end-of-life scrap. This is an application to material flow accounting of the theory of residence time distributions used routinely in chemical reaction engineering. By comparing modelled generation of scrap with actual scrap consumption in the UK, we obtain estimates of loss or accumulation of iron and steel scrap in the UK. The model indicates that as much as 30% of the scrap that was potentially available in 2001 as end-of-life scrap has either been accumulated within the economic system or lost to landfill. © 2006 Elsevier B.V. All rights reserved.
|
|
2. |
- Dingemanse, M., et al.
(författare)
-
Beyond Single-Mindedness: A Figure-Ground Reversal for the Cognitive Sciences
- 2023
-
Ingår i: Cognitive Science. - : Wiley. - 0364-0213 .- 1551-6709. ; 47:1
-
Tidskriftsartikel (refereegranskat)abstract
- A fundamental fact about human minds is that they are never truly alone: all minds are steeped in situated interaction. That social interaction matters is recognized by any experimentalist who seeks to exclude its influence by studying individuals in isolation. On this view, interaction complicates cognition. Here, we explore the more radical stance that interaction co-constitutes cognition: that we benefit from looking beyond single minds toward cognition as a process involving interacting minds. All around the cognitive sciences, there are approaches that put interaction center stage. Their diverse and pluralistic origins may obscure the fact that collectively, they harbor insights and methods that can respecify foundational assumptions and fuel novel interdisciplinary work. What might the cognitive sciences gain from stronger interactional foundations? This represents, we believe, one of the key questions for the future. Writing as a transdisciplinary collective assembled from across the classic cognitive science hexagon and beyond, we highlight the opportunity for a figure-ground reversal that puts interaction at the heart of cognition. The interactive stance is a way of seeing that deserves to be a key part of the conceptual toolkit of cognitive scientists.
|
|
3. |
- Geyer, R., et al.
(författare)
-
Time-dependent material fl{ligature}ow analysis of iron and steel in the UK. : Part 1: Production and consumption trends 1970-2000
- 2007
-
Ingår i: Resources, Conservation and Recycling. - : Elsevier BV. - 0921-3449 .- 1879-0658. ; 51:1, s. 101-117
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents a detailed account of the supply chain for iron and steel in the UK, using material fl{ligature}ow analysis. Due to the lack of a universally agreed methodology of material fl{ligature}ow analysis, we include an explanation of the accounting methodology employed in the study. Data for the supply chain has been collected reaching back three decades, enabling analysis of trends in production and consumption of iron and steel over the years. This fi{ligature}rst part of a series of two papers quantifi{ligature}es the iron and steel fl{ligature}ows through the UK economy including the annual amount of iron and steel embodied in all fi{ligature}nal goods that enter the use phase in the UK. The second part explores the more elusive fl{ligature}ows of scrap generation and recycling. In this fi{ligature}rst paper we show that the UK no longer has the capacity to recycle the scrap it collects and is increasingly relying on foreign economies to do so. We also observe that trade in iron and steel products and ferrous metal containing fi{ligature}nal goods has increased dramatically over the years, but remained relatively balanced. Today, one-half of UK's iron and steel production is exported, whereas one-half of the iron and steel entering the UK use phase comes from imported fi{ligature}nal goods. The efficiency with which the UK iron and steel industry transforms iron ore and scrap into iron and steel products has increased substantially. However, there is no significant downward trend in the absolute level of iron and steel use in the UK. Between 1970 and 1981 the annual amount of steel put to use dropped from 16.4 to 10.7 million metric tonnes but climbed back up to 15 million metric tonnes twice since then. © 2006 Elsevier B.V. All rights reserved.
|
|
4. |
- Wilson, Kenneth C., et al.
(författare)
-
Slurry transport using centrifugal pumps
- 2006. - 3.ed.
-
Bok (övrigt vetenskapligt/konstnärligt)abstract
- Vast tonnages of solid-liquid mixtures are pumped every year in dredging operations, mining and waste-disposal applications. Most of these systems are centrifugal pumps, and the resolution of problems encountered in slurry pumping requires both detailed scientific knowledge and judgment derived from practical experience. For many years the combination of up-to-date analysis and hands-on experimentation has been provided to interested engineers in a short course based at the GIW Hydraulic Laboratory. The lecturers in this course, who represent a broad background of international expertise, have prepared this widely-recognized text, Slurry Transport Using Centrifugal Pumps, Third Edition. This unique text is logically divided into two sections: the first part of the book concentrates on the behaviors of various sorts of slurry flow, and the second part deals with the behavior of centrifugal pumps handling slurries, and with how pumps and pipelines interact as a system.
|
|
5. |
- Clift, R., et al.
(författare)
-
The application of Life Cycle Assessment to Integrated Solid Waste Management - Part 1 - Methodology
- 2000
-
Ingår i: Process Safety and Environmental Protection. - 0957-5820 .- 1744-3598. ; 78:B4, s. 279-287
-
Tidskriftsartikel (refereegranskat)abstract
- Integrated Waste Management is one of the holistic approaches to environmental and resource management which are emerging from applying the concept of sustainable development. Assessment of waste management options requires application of Life Cycle Assessment (LCA). This paper summarizes the methodology for applying LCA to Integrated Waste Management of Municipal Solid Waste (MSW) developed for and now used by the UK Environment Agency, including recent developments in international fora. Particular attention is devoted to system definition leading to rational and clear compilation of the Life Cycle Inventory, with appropriate 'credit' for recovering materials and/or energy from the waste. LCA of waste management is best seen as a way of structuring information to help decision processes.
|
|
6. |
- Giosan, Liviu, et al.
(författare)
-
Fluvial landscapes of the Harappan civilization
- 2012
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 109:26, s. E1688-E1694
-
Tidskriftsartikel (refereegranskat)abstract
- The collapse of the Bronze Age Harappan, one of the earliest urban civilizations, remains an enigma. Urbanism flourished in the western region of the Indo-Gangetic Plain for approximately 600 y, but since approximately 3,900 y ago, the total settled area and settlement sizes declined, many sites were abandoned, and a significant shift in site numbers and density towards the east is recorded. We report morphologic and chronologic evidence indicating that fluvial landscapes in Harappan territory became remarkably stable during the late Holocene as aridification intensified in the region after approximately 5,000 BP. Upstream on the alluvial plain, the large Himalayan rivers in Punjab stopped incising, while downstream, sedimentation slowed on the distinctive mega-fluvial ridge, which the Indus built in Sindh. This fluvial quiescence suggests a gradual decrease in flood intensity that probably stimulated intensive agriculture initially and encouraged urbanization around 4,500 BP. However, further decline in monsoon precipitation led to conditions adverse to both inundation- and rain-based farming. Contrary to earlier assumptions that a large glacier-fed Himalayan river, identified by some with the mythical Sarasvati, watered the Harappan heartland on the interfluve between the Indus and Ganges basins, we show that only monsoonal-fed rivers were active there during the Holocene. As the monsoon weakened, monsoonal rivers gradually dried or became seasonal, affecting habitability along their courses. Hydroclimatic stress increased the vulnerability of agricultural production supporting Harappan urbanism, leading to settlement downsizing, diversification of crops, and a drastic increase in settlements in the moister monsoon regions of the upper Punjab, Haryana, and Uttar Pradesh.
|
|
7. |
- Nesti, Cedric, et al.
(författare)
-
Hemicolectomy versus appendectomy for patients with appendiceal neuroendocrine tumours 1-2 cm in size : a retrospective, Europe-wide, pooled cohort study
- 2023
-
Ingår i: The Lancet Oncology. - : Elsevier. - 1470-2045 .- 1474-5488. ; 24:2, s. 187-194
-
Tidskriftsartikel (refereegranskat)abstract
- BackgroundAwareness of the potential global overtreatment of patients with appendiceal neuroendocrine tumours (NETs) of 1–2 cm in size by performing oncological resections is increasing, but the rarity of this tumour has impeded clear recommendations to date. We aimed to assess the malignant potential of appendiceal NETs of 1–2 cm in size in patients with or without right-sided hemicolectomy.MethodsIn this retrospective cohort study, we pooled data from 40 hospitals in 15 European countries for patients of any age and Eastern Cooperative Oncology Group performance status with a histopathologically confirmed appendiceal NET of 1–2 cm in size who had a complete resection of the primary tumour between Jan 1, 2000, and Dec 31, 2010. Patients either had an appendectomy only or an appendectomy with oncological right-sided hemicolectomy or ileocecal resection. Predefined primary outcomes were the frequency of distant metastases and tumour-related mortality. Secondary outcomes included the frequency of regional lymph node metastases, the association between regional lymph node metastases and histopathological risk factors, and overall survival with or without right-sided hemicolectomy. Cox proportional hazards regression was used to estimate the relative all-cause mortality hazard associated with right-sided hemicolectomy compared with appendectomy alone. This study is registered with ClinicalTrials.gov, NCT03852693.Findings282 patients with suspected appendiceal tumours were identified, of whom 278 with an appendiceal NET of 1–2 cm in size were included. 163 (59%) had an appendectomy and 115 (41%) had a right-sided hemicolectomy, 110 (40%) were men, 168 (60%) were women, and mean age at initial surgery was 36·0 years (SD 18·2). Median follow-up was 13·0 years (IQR 11·0–15·6). After centralised histopathological review, appendiceal NETs were classified as a possible or probable primary tumour in two (1%) of 278 patients with distant peritoneal metastases and in two (1%) 278 patients with distant metastases in the liver. All metastases were diagnosed synchronously with no tumour-related deaths during follow-up. Regional lymph node metastases were found in 22 (20%) of 112 patients with right-sided hemicolectomy with available data. On the basis of histopathological risk factors, we estimated that 12·8% (95% CI 6·5 –21·1) of patients undergoing appendectomy probably had residual regional lymph node metastases. Overall survival was similar between patients with appendectomy and right-sided hemicolectomy (adjusted hazard ratio 0·88 [95% CI 0·36–2·17]; p=0·71).InterpretationThis study provides evidence that right-sided hemicolectomy is not indicated after complete resection of an appendiceal NET of 1–2 cm in size by appendectomy, that regional lymph node metastases of appendiceal NETs are clinically irrelevant, and that an additional postoperative exclusion of metastases and histopathological evaluation of risk factors is not supported by the presented results. These findings should inform consensus best practice guidelines for this patient cohort.
|
|
8. |
- Wilson, K.C., et al.
(författare)
-
Operating points for pipelines carrying concentrated heterogeneous slurries
- 2004
-
Ingår i: Powder Technology. - 0032-5910 .- 1873-328X. ; 123:1, s. 19-24
-
Tidskriftsartikel (refereegranskat)abstract
- Early studies of slurry pipeline systems were based on moderate volumetric concentrations of solids (say up to 18%), for which the excess pressure gradient caused by solids is proportional to concentration. Much larger concentrations now coming into common use show more complicated behaviour. An algebraic analysis is developed to determine desirable operating points and associated energy consumption for settling slurries. This deals initially with the simple proportional behaviour, and then is extended to other cases. Comparison is made to recent experiments using highly concentrated settling slurries with various particle gradings. It is found that near-uniform gradings tend to have high frictional losses, while very broad gradings can give rise to energy-efficient transport at high concentrations
|
|
9. |
- Zhong, Yi, et al.
(författare)
-
Humidification of Central Asia and equatorward shifts of westerly winds since the late Pliocene
- 2022
-
Ingår i: Communications Earth and Environment. - : Springer Science and Business Media LLC. - 2662-4435. ; 3:1
-
Tidskriftsartikel (refereegranskat)abstract
- The production, transport, and deposition of mineral dust exert major influences on climate change and Earth’s biogeochemical cycles. Furthermore, their imprint, as recorded in pelagic sediments, provides an avenue for determining past changes in terrestrial aridity and atmospheric circulation patterns in response to global climate change. Here, by examining geochemical and magnetic data obtained from a ferromanganese crust in the western Pacific Ocean, we investigate the eolian dust source-region conditions and dust transport mechanisms from the Asian interior to the Pacific Ocean since the Pliocene. We identify a gradual provenance change in the dust source regions, from a dominant Gobi Desert source during the early Pliocene to a mixed Gobi-Taklimakan Desert source during the late Pliocene and Pleistocene, alongside increasing chemical weathering in those source areas. Climate model simulations suggest that these changes were related to an equatorward shift of the westerly jet and humidification of Central Asia during the gradual transition from a warm Pliocene climate to the cool Pleistocene.
|
|