71 research outputs found
INNOVATIONS AND SUSTAINABILITY ISSUES INVOLVED IN GREEN PROJECT MANAGEMENT
The paper describes the attempt made in the direction of innovative approach to management and sustainability of Green projects concept. Green project concept involved the practice of increasing the efficiency with which building use resources-energy, water, materials, while reducing building impact on human health and the environment. Atmosphere above the earth has suffered high degree of pollution from buildings in recent times resulting in destabilization of ecosystem and ozone layer depletion which culminates in global warming phenomenon. In order to curtail the effect of negative impact of building on human health and environment, the complete building life cycle from design to post construction period should be thoroughly monitored. To this end, this study attempt, to describe innovative approaches to a sustainable Green project development including the attendant sustainability issues
Effect of rapid solidification on the microstructure and microhardness of BS1452 grade 250 hypoeutectic grey cast iron
Containerless solidification of low alloyed commercial grey cast iron in two different cooling media (N2 and He) using a 6.5 m high vacuum drop-tube have been investigated. Both the conventionally cooled, as-cast alloy and the rapidly cooled drop-tube samples were characterized using SEM, XRD and Vickers microhardness apparatus. The estimated range of cooling rates are 200 K sâ1 to 16,000 K sâ1 for N2 cooled droplets and 700 K sâ1 to 80,000 K sâ1 for He cooled droplets (in each case for 850 ÎŒm and 38 ÎŒm diameter droplets respectively). Microstructural analysis reveals that the as-received bulk sample displayed a graphitic structure while the rapidly cooled samples display decreasing amounts of α-Fe as the cooling rate increases. At moderate cooling rates α is replaced with Îł and Fe3C, while at higher cooling rates with αâČ. Microhardness increase with cooling rate but cannot be mapped uniquely onto cooling rate, suggesting undercooling also influences the mechanical properties
Maternal exposure to carbon monoxide in the first trimester (7-13+6 weeks) of pregnancy in the core Niger Delta
Background: Irrespective of the fact that the Niger Delta was known for its environmental pollution, neither organized environmental assessment nor human biomonitoring, including that of carbon monoxide (CO) had been performed in the region. The aim of the study therefore was to establish the severity of maternal impact on exposure to CO in the first trimester of pregnancy by quantifying the exhaled CO concentrations (ECOC) and to assess the effect of maternal age, body mass index (BMI) and parity on the severity of the impact.Methods: The study was of cross-sectional design carried out at the Rivers State University Teaching Hospital (RSUTH) in Rivers State. 490 consecutive pregnant women in the first trimester were recruited from the antenatal clinic from January 2021 to January 2022. Gestational age was estimated with the aid of ultrasound scan. Demographic, social and obstetric characteristics were taken. Exhaled carbon monoxide concentration (ECOC) was measured with the aid of a smokerlyzer. Data was analyzed, using the statistical package for social sciences (SPSS) version 25.0 (Armonk, NY) software. Ethical approval was obtained from the RSUTH ethics committee.Results: The mean value of ECOC 3.25±2.51 ppm was more than that obtained in other studies. Out of the total 490 patients that were assessed, 335 (68.37%) had mild impact from CO exposure (ECOC=1-3 ppm), 129 (26.33%) â moderate impact (ECOC=4-6 ppm) and 26 (5.31%) had severe impact (ECOC=more than 6 ppm). Moderate and severe impacts were more prominent in women of age groups 25-39 years and the differences in various age groups were statistically significant [X2=20.671, p<0.036, 95% CI (0.032, 0.040)]. Patients with higher BMI were more likely to have moderate and severe impact than those with lower BMI- 6 (33.33%) and 4 (22.22%) out of the 18 patients with class III obesity had moderate and severe impacts respectively. The differences in the impact at various BMI were statistically significant [X2=20.671, p<0.001, 95% CI (0.001, 0.002)]. There was inverse relationship between parity and the severity of the impact and the differences in various parity groups were statistically significant [X2=10.580, p<0.012, 95% CI (0.101, 0.113)]. There was also a paradoxical finding of 3 smokers having only mild impact.Conclusions: The mean value of ECOC 3.25±2.51 ppm was more than that obtained in other studies in non-pregnant women. Mild, moderate and severe impact from maternal CO exposure were established with the moderate and severe impact more prominent at maternal ages of 25-39 years, at higher BMI and at lower parity
Impact testing to determine the mechanical properties of articular cartilage in isolation and on bone
The original publication is available at www.springerlink.comNon peer reviewedPostprin
From Monodisciplinary via Multidisciplinary to an Interdisciplinary Approach Investigating Air-Sea Interactions â a SOLAS Initiative
Understanding the physical and biogeochemical interactions and feedbacks between the ocean and atmosphere is a vital component of environmental and Earth system research. The ability to predict and respond to future environmental change relies on a detailed understanding of these processes. The Surface Ocean-Lower Atmosphere Study (SOLAS) is an international research platform that focuses on the study of ocean-atmosphere interactions, for which Future Earth is a sponsor. SOLAS instigated a collaborative initiative process to connect efforts in the natural and social sciences related to these processes, as a contribution to the emerging Future Earth Ocean Knowledge-Action Network (Ocean KAN). This is imperative because many of the recent changes in the Earth system are anthropogenic. An understanding of adaptation and counteracting measures requires an alliance of scientists from both domains to bridge the gap between science and policy. To this end, three SOLAS research areas were targeted for a case study to determine a more effective method of interdisciplinary research: valuing carbon and the oceanâs role; air-sea interactions, policy and stewardship; and, air-sea interactions and the shipping industry
Rapid solidification morphologies in Ni3Ge: Spherulites, dendrites and dense-branched fractal structures
Single-phase ÎČ-Ni3Ge has been rapidly solidified via drop-tube processing. At low cooling rates (850â300Â ÎŒm diameter particles, 700â2800Â KÂ sâ1) the dominant solidification morphology, revealed after etching, is that of isolated spherulites in an otherwise featureless matrix. At higher cooling rates (300â75Â ÎŒm diameter particles, 2800â25,000Â KÂ sâ1) the dominant solidification morphology is that of dendrites, again imbedded within a featureless matrix. As the cooling rate increases towards the higher end of this range the dendrites display non-orthogonal side-branching and tip splitting. At the highest cooling rates studied (25,000Â KÂ sâ1), dense-branched fractal structures are observed. Selected area diffraction analysis in the TEM reveals the spherulites and dendrites are a disordered variant of ÎČ-Ni3Ge, whilst the featureless matrix is the ordered variant of the same compound. We postulate that the spherulites and dendrites are the rapid solidification morphology and that the ordered, featureless matrix grew more slowly post-recalescence. Spherulites are most likely the result of kinetically limited growth, switching to thermal dendrites as the growth velocity increases. It is extremely uncommon to observe such a wide range of morphologies as a function of cooling rate in a single material
Dynamics of coreâshell particle formation in drop-tube processed metastable monotectic alloys
We examine the apparent size of the core and shell as a function of cooling rate in coreâshell particles of the metastable monotectic alloy Co-50 at% Cu, finding that the volume fraction of the core systematically increases with cooling rate and hence undercooling. A model for this variation is proposed. A Monte-Carlo simulation is used to correct for sectioning effects allowing the true core:shell volume ratio to be estimated. From this, and the observation of a second, spinodal, episode of liquid phase separation we are able to estimate the undercooling at solidification. This permits a calculation of the time available following liquid phase separation for the migration giving rise to the observed coreâshell structure to occur and hence the required Marangoni velocity required to such migration
Microstructural Evolution and Phase Transformation in Laser Cladding of Cr and Mo Powder on Grey Cast Iron: Mixture Design of Experiment (DOE)
Metastable monotectic phase separation in CoâCu alloys
The liquid phase separation behaviour of metastable monotectic CoâCu alloys was investigated as a function of cooling rate using a 6.5 m drop-tube facility. A range of liquid phase separated morphologies were observed including stable two-layer coreâshell, evolving coreâshell and dendritic structures. It was found that in the coreâshell structures the core was always in the higher melting point (Co-rich) phase, irrespective of the core and shell volume fraction. In Cuâ50 at% Co alloy, high cooling rates were observed to yield two episodes of liquid phase separation, corresponding to binodal, followed by spinodal decomposition. The resulting structure comprised a coreâshell structure in which the Co-rich core contained a very fine dispersion of Cu-rich particles with a Cu-rich shell which may, or may not, contain a similar dispersion of Co-rich particles
Are identities oral? Understanding ethnobotanical knowledge after Irish independence (1937-1939)
BACKGROUND: The Schools' Folklore Scheme (1937-1939) was implemented at a pivotal time in Irelands' political history. It resulted in a body of ethnological information that is unique in terms of when, why and how it was collected. This material consists of over 700,000 pages of information, including ethnomedicinal and ethnobotanical traditions, reflecting an oral identity that spans generations and that in many cases was not documented in writing until the 1930s. The intention of this study is to highlight the importance of the Schools' Folklore Scheme and to demonstrate an ethnographic approach based on recollections of original participants of the scheme, to further understand the material in the collection and the impact it had on the participants. METHODS: This study involves an analysis of both oral and archival data. Eleven semi-structured interviews with original participants of the scheme were carried out between April and September 2016. Their corresponding schools' archival contributions to the scheme were located, and ethnomedicinal information was analysed and compared with the participants' recollections. RESULTS: The majority of participants' stated the scheme had a positive impact on them. Five participants' recalled collecting ethnomedicinal information, and there was a direct correlation between three of the participants' ethnomedicinal recollections and their entries in the archives. One third of all the ethnomedicinal entries analysed included the use of a plant. There were 191 plant mentions and 64 plant species named. CONCLUSIONS: Contacting the original participants offers a novel approach of analysing this archival material. It provides a unique first-hand account of this historical initiative, an insight into how the scheme was implemented and how it impacted upon the children. The ethnomedicinal and ethnobotanical information provides an understanding of the medicinal practices in Ireland during the 1930s. The plant species that were both orally recalled by participants and documented in the archives are in keeping with key ethnomedicinal systems throughout the world
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