scholarly journals Rehydroxylation of Fired‐Clay Ceramics: Factors Affecting Early‐Stage Mass Gain in Dating Experiments

Archaeometry ◽  
2013 ◽  
Vol 56 (4) ◽  
pp. 689-702 ◽  
Author(s):  
M. A. Wilson ◽  
S. Clelland ◽  
M. A. Carter ◽  
C. Ince ◽  
C. Hall ◽  
...  
2020 ◽  
Vol 53 (12) ◽  
pp. 5473-5487 ◽  
Author(s):  
Andrea Rispoli ◽  
Anna Maria Ferrero ◽  
Marilena Cardu

AbstractTunnel boring machine (TBM) performance prediction is often a critical issue in the early stage of a tunnelling project, mainly due to the unpredictable nature of some important factors affecting the machine performance. In this regard, deterministic approaches are normally employed, providing results in terms of average values expected for the TBM performance. Stochastic approaches would offer improvement over deterministic methods, taking into account the parameter variability; however, their use is limited, since the level of information required is often not available. In this study, the data provided by the excavation of the Maddalena exploratory tunnel were used to predict the net and overall TBM performance for a 2.96 km section of the Mont Cenis base tunnel by using a stochastic approach. The preliminary design of the TBM cutterhead was carried out. A prediction model based on field penetration index, machine operating level and utilization factor was adopted. The variability of the parameters involved was analysed. A procedure to take into account the correlation between the input variables was described. The probability of occurrence of the outcomes was evaluated, and the total excavation time expected for the tunnel section analysed was calculated.


Author(s):  
Jinbao Zhang ◽  
Jaeyoung Lee

Abstract This study has two main objectives: (i) to analyse the effect of travel characteristics on the spreading of disease, and (ii) to determine the effect of COVID-19 on travel behaviour at the individual level. First, the study analyses the effect of passenger volume and the proportions of different modes of travel on the spread of COVID-19 in the early stage. The developed spatial autoregressive model shows that total passenger volume and proportions of air and railway passenger volumes are positively associated with the cumulative confirmed cases. Second, a questionnaire is analysed to determine changes in travel behaviour after COVID-19. The results indicate that the number of total trips considerably decreased. Public transport usage decreased by 20.5%, while private car usage increased by 6.4%. Then the factors affecting the changes in travel behaviour are analysed by logit models. The findings reveal significant factors, including gender, occupation and travel restriction. It is expected that the findings from this study would be helpful for management and control of traffic during a pandemic.


Author(s):  
Andrea Petetta ◽  
Massimo Virgili ◽  
Stefano Guicciardi ◽  
Alessandro Lucchetti

AbstractStock overexploitation, bycatch, discards and gear impacts on the environment are outstanding issues for Mediterranean fisheries. The adoption of alternative fishing gears is an appealing solution to ensure a more sustainable exploitation of resources. We discuss the pros and cons of pots as alternative gears by reviewing their main designs, spatial distribution and target species in the Mediterranean basin. We assessed the technical factors affecting the catch efficiency of the different pot designs for four target species: spiny lobster, Palinurus elephas; Norway lobster, Nephrops norvegicus; common octopus, Octopus vulgaris and pandalid shrimps, Plesionika spp. We found that pot volume is important to catch Octopus; mesh size to catch Nephrops and Plesionika; entrance surface to catch Octopus, Nephrops and Plesionika; pot shape/colour and entrance shape/position to catch Octopus and Plesionika; and bait type to catch Octopus and Nephrops. The literature review shows that pot fisheries have several considerable advantages over conventional gears, especially in terms of discards, bycatch, seabed impacts (particularly compared with bottom trawls and passive set nets), size and species selectivity, gear depredation, catch quality and gear cost, besides saving time and labour. Disadvantages hampering their wider diffusion include ghost fishing, a low catch of finfish species, the narrow range of species targeted by each pot design and the current early stage of research. These data make a clear case for using pots as alternative gears to traditional ones in the Mediterranean Sea in some areas and seasons to catch certain target species.


2016 ◽  
Vol 29 (7) ◽  
pp. 721-732 ◽  
Author(s):  
Ahmed Essmat Shouman ◽  
Nahla Fawzy Abou El Ezz ◽  
Nivine Gado ◽  
Amal Mahmoud Ibrahim Goda

Purpose – The purpose of this paper is to measure health-related quality of life (QOL) among patients with early stage cancer breast under curative treatment at department of oncology and nuclear medicine at Ain Shams University Hospitals. Identify factors affecting QOL among these patients. Design/methodology/approach – A cross-sectional study measured QOL among early stage female breast cancer (BC) patients and determined the main factors affecting their QOL. Three interviewer administered questionnaires were used. Findings – The physical domain mostly affected in BC patients and the functional domain least. Socio-demographic factors that significantly affected BC patients QOL scores were patient age, education, having children and family income. Specific patient characteristics include caregiver presence – a factor that affected different QOL scores. Age at diagnosis, affection in the side of the predominant hand, post-operative chemotherapy and difficulty in obtaining the medication were the disease-related factors that affected QOL scores. Originality/value – The final model predicting QOL for early stage female BC patients included age, education and difficulty in obtaining the medication as determinants for total QOL score. Carer presence was the specific patient characteristic that affected different QOL scores.


1990 ◽  
Vol 41 (6) ◽  
pp. 1093 ◽  
Author(s):  
JL Wheeler ◽  
C Mulcahy ◽  
JJ Walcott ◽  
GG Rapp

The effect of seven factors, namely genotype, plant maturity, nitrogen fertilizer, phosphorus fertilizer, water stress, light intensity and temperature, on the hydrogen cyanide potential (HCNp) of forage sorghum was studied in three pot experiments. Fivefold differences occurred between genotypes in HCNp, with a breeder's line, X45106, selected for low HCNp having a maximum of 520 mg HCN kg-1 DM (dry matter) compared with 2300 and 2450 mg kg-1 DM for cvs Zulu and Silk respectively. In X45 106, HCNp (mg HCN kg-1 DM) declined curvilinearly with age d (days from sowing) (HCNp=8460- 320d+ 3.1d2) and linearly in Silk (HCNp = 9020 - 110d), but the decline in Zulu was not statistically significant. Nitrogen (equivalent to 200 kg ha-1 of N) increased HCN, (P< 0.001), but more so in full light (100 mg kg-1 compared with 1430 mg kg-1) than in 50% shade (190 mg kg-1 compared with 690 mg kg-1). In one experiment, acute water stress appeared to reduce HCNp, but this was confounded with the strong decline due to aging. In another study, acute water stress had no effect on HCNp. Neither the application of superphosphate nor change in light intensity, nor change in temperature had a direct significant effect on HCNp in these studies. Breeding and selection for low HCNp appears a promising approach to ensuring that sorghum plants will provide non-toxic forage from an early stage of growth.


2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Erin Treanore ◽  
Etya Amsalem

Abstract In the face of insect declines, identifying phases of the life cycle when insects are particularly vulnerable to mortality is critical to conservation efforts. For numerous annual insect groups, diapause is both a key adaptation that allows survival of inhospitable conditions and a physiologically demanding life stage that can result in high rates of mortality. As bees continue to garner attention as a group experiencing high rates of decline, improving our understanding of how annual bees prepare for diapause and identifying factors that reduce survival is imperative. Here, we studied factors affecting diapause survival length and their underlying mechanisms using an economically and ecologically important annual bee species, Bombus impatiens. We examined how age and mass upon diapause onset correlate with diapause survival length, and the mechanistic role of nutrient acquisition and oxidative stress post pupal eclosion in mediating these effects. Our findings show that both age and mass were strong predictors of diapause survival length. Heavier queens or queens in the age range of ~6–17 days survived longer in diapause. Mass gain was attributed to increases in lipid, protein and glycerol amounts following pupal eclosion, and the ability to deal with oxidative stress was significantly compromised in older pre-diapause queens. Our results demonstrate that age-related shifts in bee physiology and timing of nutrient acquisition may both be critical factors driving diapause survival.


2002 ◽  
Vol 53 (11) ◽  
pp. 1197 ◽  
Author(s):  
G. M. Lodge

Studies were conducted in 1993–94 on 2 native grass cultivars, Austrodanthonia richardsonii (Link) H.P.�Linder (syn. Danthonia richardsonii Cashmore) cv. Taranna and A. bipartita (Link) H.P. Linder (syn. D. linkii Kunth) cv. Bunderra, to quantify the important morphological factors affecting seed production (as measured by seed weight, g/plant). Experiments also examined the influence of nitrogen (N) application and investigated the effects of time and method of harvest on seed production and subsequent germination. For both cultivars, inflorescence and floret number accounted for the highest proportion of the variation in seed production per plant (R2 = 0.873 and 0.686 for Taranna and Bunderra, respectively). Although N applied (0, 25, and 50 kg/ha) at the late vegetative or early flowering stage, or split applications at both times, had no significant effect (P > 0.05) on the seed production per plant of Taranna and Bunderra, further studies of N effects are required. In 1993 and 1994, time of inflorescence harvest and method of harvest had no significant effect on inflorescence number and seed production of Taranna and Bunderra and no significant effect on the subsequent germination of Bunderra seed. However, in 1993, harvesting at an early stage of flowering (10% of florets white and fluffy) reduced Taranna seed production by 17% compared with the mean and decreased (P < 0.05) seed germination by about 10%. In 1994, harvesting at early flowering (5% florets white and fluffy) reduced Taranna seed production by a mean of around 55% compared with harvesting at 50% maturity, and subsequent seed germination was also lower (P < 0.05) for the early harvest time. Application of 1 L/ha of paraquat (a.i. 200 g/L of paraquat dichloride) at mid-flowering to desiccate the crop in 1993 had no significant effect on the germination of Taranna and Bunderra caryopses. The implications of these data for commercial seed production are discussed.


2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Lei Wang ◽  
Heng Wen

Abstract Proppant flowback is a significant issue in the field of fractured well production. In order to investigate the influencing relationships among the parameters affecting proppant flowback, the weight of proppant flowback within different conditions was tested by applying a fracture simulation experiment device. During the experiments, the flowback velocity of the fracturing fluid, the viscosity of the fracturing fluid, the proppant particle size, and the effective closure pressure were studied. The experimental results indicated that the flowback velocity of the fracturing fluid is critical for proppant flowback. The weight of the flowback proppant increases as the fracturing fluid flowback velocity increases. Proppant flowback mainly occurs in the early stage of fracturing fluid flowback; more than 75% of the flowback volume of the proppant was carried by 33.33% of the fracturing fluid flowback volume. The weight of the flowback proppant decreases as the flowback fracturing fluid viscosity decreases. Using a larger particle size proppant or upon increasing effective closure pressure also can decrease the weight of the flowback proppant.


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