85 research outputs found

    Reduction of pavement thickness using a subgrade layer treated by different techniques

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    A range of stabilisers for poor quality subgrade soils have been developed to promote road constructions. Many of them are becoming more popular depending on their effectiveness. The purpose behind this research is to identify the relative efficacy of many physical and chemical stabilisation techniques for enhancing the properties of three types of local Iraqi subgrade soils. The comparison of the samples is based on the CBR tests. The AASHTO (1993) flexible pavement design was used to compute the pavement thickness requirements. The soil samples A, B and C have a natural CBR values of 3.8, 3.9 and 4, respectively, on which the physical stabilisers of Powdered rock (PR), grained recycled concrete (GRC), and recycled crumb rubber grains (CR) were employed, while Quicklime (QL) and activated fly ash (AFA) were both utilised as chemical stabilisers. The stabilisation with 15 % of AFA proved to be the most applicable method for soil types A and B for reducing the pavement thickness requirements by 51 % and 32 %, respectively, with a reasonable financial feasibility for both. The same feasibility is proven when stabilising soil type C with 15 % of GRC, which reduces the pavementthickness by 25.7 %

    Outcome of Quality of Life for Women Undergoing Autologous versus Alloplastic Breast Reconstruction following Mastectomy:A Systematic Review and Meta-Analysis

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    Background: This review aimed to meta-analyze the quality of life of alloplastic versus autologous breast reconstruction, when measured with the BREAST-Q. Methods: An electronic PubMed and EMBASE search was designed to find articles that compared alloplastic versus autologous breast reconstruction using the BREAST-Q. Studies that failed to present BREAST-Q scores and studies that did not compare alloplastic versus autologous breast reconstruction were excluded. Two authors independently extracted data from the included studies. A standardized data collection form was used. Quality was assessed using the Newcastle-Ottawa Scale. The mean difference and 95 percent confidence intervals between breast reconstruction means were estimated for each BREAST-Q subscale. Forest plots and the I2statistic were used to assess heterogeneity and funnel plot publication bias. The Z test was used to assess overall effects. Results: Two hundred eighty abstracts were found; 10 articles were included. Autologous breast reconstruction scored significantly higher in the five subscales than alloplastic breast reconstruction. The Satisfaction with Breasts subscale indicated the greatest difference, with a mean difference of 6.41 (95 percent CI, 3.58 to 9.24; I2= 70 percent). The Satisfaction with Results subscale displayed a mean difference of 5.52. The Sexual Well-Being subscale displayed a mean difference of 3.85. The Psychosocial Well-Being subscale displayed a mean difference of 2.64. The overall difference in physical well-being was significant, with high heterogeneity (mean difference, 3.33; 95 percent CI, 0.18 to 6.48; I2= 85). Conclusion: Autologous breast reconstruction had superior outcomes compared with alloplastic breast reconstruction as measured by the BREAST-Q

    Structural changes in FeOx/γ-Al2O3 catalysts during ethylbenzene dehydrogenation

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    The structural changes that occur in a FeOx/γ-Al2O3 catalyst during the dehydrogenation of ethylbenzene in a fluidized CREC Riser Simulator have been investigated. Chemical and morphological changes are observed to take place as a result of reaction. Electron microscopy reveals the formation of needle-like alumina structures apparently enclosing iron oxide particles. The formation of such structures at relatively low temperatures is unexpected and has not previously been reported. Additionally, X-ray diffraction and Mössbauer spectroscopy confirmed the reduction of the oxidation state of iron, from Fe2O3 (haematite) to Fe3O4 (magnetite). Iron carbides, Fe3C and ɛ-Fe2C, were detected by electron microscopy through electron diffraction and lattice fringes analysis. Carbon deposition (coking) on the catalyst surface also occurs. The observed structural changes are likely to be closely correlated with the catalytic properties of the materials, in particular with catalyst deactivation, and thereby provide important avenues for future study of this industrially important reaction. Fe2O3/Al2O3 catalyst undergoes chemical and morphological changes during ethylbenzene dehydrogenation forming Al2O3 needles which appear to contain reduced Fe3O4 particles. Fe3C also forms during reaction

    Time scale analysis for fluidizedbedmeltgranulation-II: binder spreading rate

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    The spreading time of liquid binder droplet on the surface a primary particle is analyzed for Fluidized Bed Melt Granulation (FBMG). As discussed in the first paper of this series (Chua et al., in press) the droplet spreading rate has been identified as one of the important parameters affecting the probability of particles aggregation in FBMG. In this paper, the binder droplet spreading time has been estimated using Computational Fluid Dynamic modeling (CFD) based on Volume of Fluid approach (VOF). A simplified analytical solution has been developed and tested to explore its validity for predicting the spreading time. For the purpose of models validation, the droplet spreading evolution was recorded using a high speed video camera. Based on the validated model, a generalized correlative equation for binder spreading time is proposed. For the operating conditions considered here, the spreading time for Polyethylene Glycol (PEG1500) binder was found to fall within the range of 10-2 to 10-5 s. The study also included a number of other common binders used in FBMG. The results obtained here will be further used in paper III, where the binder solidification rate is discussed

    Formulation and evaluation of ciprofloxacin as a topical gel

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    Ciprofloxacin is an antibacterial agent belong to floroquinolones group, it has broad spectrum activity against Gram positive and Gram negaitive bacteria. Ciprofloxacin – HCl was formulated as a gel dosage form using two different bases, a 5% methylcellulose and 5% sodium croboxy-methyl-cellulose gel base. The concentration of (1% w/w) of the drug in each base was prepared. In vitro availability of ciprofloxacin – HCl from these bases was studied, in addition the diffusion of the drug using excised mouse skin technique were also evaluated. The results indicated that the extent of ciprofloxacin – HCl release was higher from methylcellulose gel base than that from sodium caroboxy-methylcellulose gel base. While the data revealed that the diffusion of the ciprofloxacin through the excised mouse skin was higher from sodium croboxy-methyl-cellulose gel base than that from methylcellulose. According to these results, 5% methylcellulose gel base was selected for further studies. The influence of storage time and temperature on the stability of the drug, as well as physical properties and pH, for the selected formula over a period of 45 days was studied. The concentration of ciprofloxacin was found to decrease with time and temperature and no changes in the physical properties were noticed. The shelf life of the drug in the selected gel base was determined using exaggerated temperature techinque and it was equal to 2.5 years. The overall results of this study suggest that the selected formula could be used in the preparation of ciprofloxacin gel as a topical dosage form to be used in the treatment of some dermatological infections

    Biocidal activity of Ziziphora hispanica L and Satureja calamintha Scheele L essential oils against the Callosobruchus maculatus (Fabricius) pest on cowpea seeds during storage

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    IntroductionThe post-harvest period of cowpea [Vigna unguiculata (L) Walp] is marked by substantial losses due to the insect pest Callosobruchus maculatus (Fabricius). The primary goal of the current study is to identify environmentally appropriate substitutes for synthetic pesticides in the management of stored seed pests. Thus, in a laboratory setting, the insecticidal activity of essential oils (EOs) from Ziziphora hispanica and Satureja calamintha against the cowpea weevil C. maculatus was assessed.MethodsThe fumigant effects of these two EOs were tested with concentrations (4, 8, 12, 16, and 20 μL L−1 of air per 10 g of cowpea seeds) on four biological parameters of C. maculatus: adult mortality, fecundity, fertility, and adult emergence, while concentrations of 4, 12, 16, and 20 μL/cm2 of air were used for the repulsion test.Results and discussionThe fumigant effects of these two EOs were tested with concentrations (4, 8, 12, 16, and 20 μL L−1 of air per 10  g of cowpea seeds) on four biological parameters of C. maculatus: adult mortality, fecundity, fertility, and adult emergence, while concentrations of 4, 12, 16, and 20  μL/cm2 of air were used for the repulsion test. The results of fumigation tests showed a remarkable efficacy of both essential oils against adult C. maculatus after 24  h of exposure. Z. hispanica EO yielded a mortality rate of 80 ± 20%, with an LC50 of 2.77 μL L−1 for males and 66.66 ± 11.54% with an LC50 of 3.57  μL L-1 for females at 4 μL L−1 of air. However, the S. calamintha EO resulted in a mortality rate of 100% for males and 86.66 ± 23.09% with an LC50 of 2.17  μL L−1 for females at low doses. The fecundity was 1.33 ±  0.57 eggs per female. In contrast, this parameter was absent with S. calamintha EO at the low dose, while fertility and emerging adults were missing for both EOs. Furthermore, both EOs showed highly repellent activity towards C. maculatus adults, with 81.66% for Z. hispanica and 91.67% for S. calamintha EO. According to the results of the GC–MS analysis, the primary components of Z. hispanica EO were found to be pulegone (28.17%), alpha-naphtonitrite (10.77%), and 3-(3-thienyl) pro-2-enoic acid (10.62%). Similarly, the main constituents of S. calamintha EO were pulegone (21.48%), piperitenone oxide (17.71%), and eucalyptol (11.99%). Hence, these substances are regarded as the volatile compounds accountable for controlling C. maculatus activities. The study reports that Z. hispanica and S. calamintha show promising fumigant and repellent efficacy and offer new avenues for their potential use as an alternative to synthetic pesticides against stored seed pests

    A global perspective on the trophic geography of sharks

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    Sharks are a diverse group of mobile predators that forage across varied spatial scales and have the potential to influence food web dynamics. The ecological consequences of recent declines in shark biomass may extend across broader geographic ranges if shark taxa display common behavioural traits. By tracking the original site of photosynthetic fixation of carbon atoms that were ultimately assimilated into muscle tissues of 5,394 sharks from 114 species, we identify globally consistent biogeographic traits in trophic interactions between sharks found in different habitats. We show that populations of shelf-dwelling sharks derive a substantial proportion of their carbon from regional pelagic sources, but contain individuals that forage within additional isotopically diverse local food webs, such as those supported by terrestrial plant sources, benthic production and macrophytes. In contrast, oceanic sharks seem to use carbon derived from between 30° and 50° of latitude. Global-scale compilations of stable isotope data combined with biogeochemical modelling generate hypotheses regarding animal behaviours that can be tested with other methodological approaches.This research was conducted as part of C.S.B.’s Ph.D dissertation, which was funded by the University of Southampton and NERC (NE/L50161X/1), and through a NERC Grant-in-Kind from the Life Sciences Mass Spectrometry Facility (LSMSF; EK267-03/16). We thank A. Bates, D. Sims, F. Neat, R. McGill and J. Newton for their analytical contributions and comments on the manuscripts.Peer reviewe

    Using the community-based breeding program (CBBP) model as a collaborative platform to develop the African Goat Improvement Network—Image collection protocol (AGIN-ICP) with mobile technology for data collection and management of livestock phenotypes

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    Introduction: The African Goat Improvement Network Image Collection Protocol (AGIN-ICP) is an accessible, easy to use, low-cost procedure to collect phenotypic data via digital images. The AGIN-ICP collects images to extract several phenotype measures including health status indicators (anemia status, age, and weight), body measurements, shapes, and coat color and pattern, from digital images taken with standard digital cameras or mobile devices. This strategy is to quickly survey, record, assess, analyze, and store these data for use in a wide variety of production and sampling conditions.Methods: The work was accomplished as part of the multinational African Goat Improvement Network (AGIN) collaborative and is presented here as a case study in the AGIN collaboration model and working directly with community-based breeding programs (CBBP). It was iteratively developed and tested over 3 years, in 12 countries with over 12,000 images taken.Results and discussion: The AGIN-ICP development is described, and field implementation and the quality of the resulting images for use in image analysis and phenotypic data extraction are iteratively assessed. Digital body measures were validated using the PreciseEdge Image Segmentation Algorithm (PE-ISA) and software showing strong manual to digital body measure Pearson correlation coefficients of height, length, and girth measures (0.931, 0.943, 0.893) respectively. It is critical to note that while none of the very detailed tasks in the AGIN-ICP described here is difficult, every single one of them is even easier to accidentally omit, and the impact of such a mistake could render a sample image, a sampling day’s images, or even an entire sampling trip’s images difficult or unusable for extracting digital phenotypes. Coupled with tissue sampling and genomic testing, it may be useful in the effort to identify and conserve important animal genetic resources and in CBBP genetic improvement programs by providing reliably measured phenotypes with modest cost. Potential users include farmers, animal husbandry officials, veterinarians, regional government or other public health officials, researchers, and others. Based on these results, a final AGIN-ICP is presented, optimizing the costs, ease, and speed of field implementation of the collection method without compromising the quality of the image data collection

    Identifying forest ecosystem regions for agricultural use and conservation

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    ABSTRACT Balancing agricultural needs with the need to protect biodiverse environments presents a challenge to forestry management. An imbalance in resource production and ecosystem regulation often leads to degradation or deforestation such as when excessive cultivation damages forest biodiversity. Lack of information on geospatial biodiversity may hamper forest ecosystems. In particular, this may be an issue in areas where there is a strong need to reassign land to food production. It is essential to identify and protect those parts of the forest that are key to its preservation. This paper presents a strategy for choosing suitable areas for agricultural management based on a geospatial variation of Shannon's vegetation diversity index (SHDI). This index offers a method for selecting areas with low levels of biodiversity and carbon stock accumulation ability, thereby reducing the negative environmental impact of converting forest land to agricultural use. The natural forest ecosystem of the controversial 1997 Ex-Mega Rice Project (EMRP) in Indonesia is used as an example. Results showed that the geospatial pattern of biodiversity can be accurately derived using kriging analysis and then effectively applied to the delineation of agricultural production areas using an ecological threshold of SHDI. A prediction model that integrates a number of species and families and average annual rainfall was developed by principal component regression (PCR) to obtain a geospatial distribution map of biodiversity. Species richness was found to be an appropriate indicator of SHDI and able to assist in the identification of areas for agricultural use and natural forest management
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