2,371 research outputs found

    Detention Properties of Subsurface Stormwater Modules Under Tropical Climate

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    Subsurface stormwater module is one of the components of a sustainable drainage system. However, the performance of subsurface stormwater module as on-site detention under tropical climate like Malaysia has not been extensively studied in the literature. The current study involves on-site installation of pilot scale subsurface stormwater modules exposed to tropical climate to simulate real conditions to evaluate the detention performance. Rainfall together with the changes in water level and volume of water detained in the installation were observed for six months between April 2021 to October 2021. The subsurface stormwater module used in the current study has a porosity of 94%. It was found that the subsurface stormwater module setup was able to detain between 35.2% to 95.6% of the rainfall volume generated from total rainfall between 11.1 mm to 56.8 mm. The findings can be used as design consideration for using subsurface stormwater module under tropical climate

    Detention Properties of Subsurface Stormwater Modules Under Tropical Climate

    Get PDF
    Subsurface stormwater module is one of the components of a sustainable drainage system. However, the performance of subsurface stormwater module as on-site detention under tropical climate like Malaysia has not been extensively studied in the literature. The current study involves on-site installation of pilot scale subsurface stormwater modules exposed to tropical climate to simulate real conditions to evaluate the detention performance. Rainfall together with the changes in water level and volume of water detained in the installation were observed for six months between April 2021 to October 2021. The subsurface stormwater module used in the current study has a porosity of 94%. It was found that the subsurface stormwater module setup was able to detain between 35.2% to 95.6% of the rainfall volume generated from total rainfall between 11.1 mm to 56.8 mm. The findings can be used as design consideration for using subsurface stormwater module under tropical climate

    A review on the economic feasibility of composting for organic waste management in Asian countries

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    The rising rate of population growth and industrial development mainly in urban areas have led to significant increase in municipal solid waste (MSW) production. It has been a challenge to materialise a sustainable solid waste management notably in many developing countries. Organic portion represents a significant component in the municipal solid waste across countries with different level of income, ranging from about 25 to 70 %. Composting can be a viable option to manage waste sustainably by transforming waste into value-added fertiliser. Large-scale operation of composting is confronted with concern over feasible economic performance, which varied following different mode of operation. This study aims to review the economic feasibility (EF) on two different composting systems, which are the in-vessel and windrow system, implemented in several developed and developing countries. The review considered the cost factors for both composting systems, including the capital cost and operating cost. The return on investment (ROI) is estimated for both composting systems based on the potential cost benefits from the compost sale and the saving of waste tipping fee. This review provides a better insight into the desirability and applicability of both composting systems as an alternative to the landfilling practice. It is expected that the review of the various composting system could be very useful for improving the sustainable composting technology in the developing countries

    Investigating the driving mechanisms of coronal mass ejections

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    The objective of this investigation was to first examine the kinematics of coronal mass ejections (CMEs) using EUV and coronagraph images, and then to make a comparison with theoretical models in the hope to identify the driving mechanisms of the CMEs. We have studied two CMEs which occurred on 2006 Dec. 17 (CME06) and 2007 Dec. 31 (CME07). The models studied in this work were catastrophe, breakout, and toroidal instability models. We found that after the eruption, the accelerations of both events exhibited a drop before increasing again. Our comparisons with the theories suggested that CME06 can be best described by a hybrid of the catastrophe and breakout models while CME07 is most consistent with the breakout model.Comment: 9 pages 7 figure

    Mini-review on substrate & inoculum loadings for anaerobic co-digestion of food waste

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    Increasing production of food waste can lead to major environmental pollution if it is disposed without proper control in many countries. Food waste can be regarded as a resource rather than unwanted discard due to its high potential for resource recovery. Anaerobic digestion of food waste has shown promising potential for food waste treatment and valorisation by producing biogas as a renewable energy and digestate as fertiliser. Food waste has high biogas potential due to the presence of highly labile organic matter but this can lead to process instability. The process instability is often linked to the imbalance of process intermediates that affects the microbial community. Common parameters that are crucial for ensuring optimal metabolic activity of anaerobes includes temperature, pH, carbon-nitrogen ratio, organic loading rate, retention time and nutrient concentration. Co-digestion of food waste with other feedstocks are increasingly being practiced for better nutrient balance and reducing chances for rapid acidfication. The optimum conditions for the process has been shown to vary following different microbial inoculants and loadings of the respective substrates. This study aims to review only the effect of substrate and inoculum used during the AD of food waste, including the type of co-digested substrate, the mixing ratio, the microbial inoculant used and the substrate to inoculum ratio

    Period Integrals of CY and General Type Complete Intersections

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    We develop a global Poincar\'e residue formula to study period integrals of families of complex manifolds. For any compact complex manifold XX equipped with a linear system VV^* of generically smooth CY hypersurfaces, the formula expresses period integrals in terms of a canonical global meromorphic top form on XX. Two important ingredients of our construction are the notion of a CY principal bundle, and a classification of such rank one bundles. We also generalize our construction to CY and general type complete intersections. When XX is an algebraic manifold having a sufficiently large automorphism group GG and VV^* is a linear representation of GG, we construct a holonomic D-module that governs the period integrals. The construction is based in part on the theory of tautological systems we have developed in the paper \cite{LSY1}, joint with R. Song. The approach allows us to explicitly describe a Picard-Fuchs type system for complete intersection varieties of general types, as well as CY, in any Fano variety, and in a homogeneous space in particular. In addition, the approach provides a new perspective of old examples such as CY complete intersections in a toric variety or partial flag variety.Comment: An erratum is included to correct Theorem 3.12 (Uniqueness of CY structure

    An insight into curcumin-based photosensitization as a promising and green food preservation technology

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    Consumer awareness on the side effects of chemical preservatives has increased the demand for natural preservation technologies. An efficient and sustainable alternative to current conventional preservation techniques should guarantee food safety and retain its quality with minimal side effects. Photosensitization, utilizing light and a natural photosensitizer, has been postulated as a viable and green alternative to the current conventional preservation techniques. The potential of curcumin as a natural photosensitizer is reviewed in this paper as a practical guide to develop a safe and effective decontamination tool for industrial use. The fundamentals of the photosensitization mechanism are discussed, with the main emphasis on the natural photosensitizer, curcumin, and its application to inactivate microorganisms as well as to enhance the shelf life of foods. Photosensitization has shown promising results in inactivating a wide spectrum of microorganisms with no reported microbial resistance due to its particular lethal mode of targeting nucleic acids. Curcumin as a natural photosensitizer has recently been investigated and demonstrated efficacy in decontamination and delaying spoilage. Moreover, studies have shown the beneficial impact of an appropriate encapsulation technique to enhance the cellular uptake of photosensitizers, and therefore, the phototoxicity. Further studies relating to improved delivery of natural photosensitizers with inherent poor solubility should be conducted. Also, detailed studies on various food products are warranted to better understand the impact of encapsulation on curcumin photophysical properties, photo-driven release mechanism, and nutritional and organoleptic properties of treated foods

    Association of age with perioperative morbidity among patients undergoing surgical management of minor burns

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    INTRODUCTION: Burn injuries are associated with significant morbidity, often necessitating surgical management. Older patients are more prone to burns and more vulnerable to complications following major burns. While the relationship between senescence and major burns has already been thoroughly investigated, the role of age in minor burns remains unclear. To better understand differences between elderly and younger patients with predominantly minor burns, we analyzed a multi-institutional database. METHODS: We reviewed the 2008-2020 ACS-NSQIP database to identify patients who had suffered burns according to ICD coding and underwent initial burn surgery. RESULTS: We found 460 patients, of which 283 (62%) were male and 177 (38%) were female. The mean age of the study cohort was 46 ± 17 years, with nearly one-fourth (n = 108; 23%) of all patients being aged ≥60 years. While the majority (n = 293; 64%) suffered from third-degree burns, 22% (n = 99) and 15% (n = 68) were diagnosed with second-degree burns and unspecified burns, respectively. An average operation time of 46 min, a low mortality rate of 0.2% (n = 1), a short mean length of hospital stay (1 day), and an equal distribution of in- and outpatient care (51%, n = 234 and 49%, n = 226, respectively) indicated that the vast majority of patients suffered from minor burns. Patients aged ≥60 years showed a significantly prolonged length of hospital stay (p0.0001), creatinine (p>0.0001), white blood cell count (p=0.02), partial thromboplastin time (p = 0.004), and lower levels of albumin (p = 0.0009) and hematocrit (p>0.0001) were identified as risk factors for the occurrence of any complication. Further, complications were more frequent among patients with lower body burns. DISCUSSION: In conclusion, patients ≥60 years undergoing surgery for predominantly minor burns experienced significantly more complications. Minor lower body burns correlated with worse outcomes and a higher incidence of adverse events. Decreased levels of serum albumin and hematocrit and elevated values of blood urea nitrogen, creatinine, white blood count, and partial thromboplastin time were identified as predictive risk factors for complications

    Reliability testing of tendon disease using two different scanning methods in patients with rheumatoid arthritis

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    Objective. To assess the intra- and interobserver reliability of musculoskeletal ultrasonography (US) in detecting inflammatory and destructive tendon abnormalities in patients with RA using two different scanning methods.Methods. Thirteen observers examined nine patients with RA and one healthy individual in two rounds independently and blindly of each other. Each round consisted of two consecutive examinations, an anatomy-based examination and a free examination according to personal preferences. The following tendons were evaluated: wrist extensor compartments 2, 4 and 6, finger flexor tendons 3 and 4 at MCP level, tibialis posterior tendon and both peronei tendons. Overall, positive and negative agreements and \u3ba-values for greyscale (GS) tenosynovitis, peritendinous power Doppler (PPD) signal, intratendinous power Doppler (IPD) signal and GS tendon damage were calculated.Results. Intraobserver \u3ba-value ranges were 0.53-0.55 (P < 0.0005) for GS tenosynovitis, 0.61-0.64 (P < 0.0005) for PPD signal, 0.65-0.66 (P < 0.0005) for IPD signal and 0.44-0.53 (P < 0.0005) for GS tendon damage. For interobserver reliability, substantial overall agreement ranged from 80 to 89% for GS tenosynovitis, 97 to 100% for PPD signal, 97 to 100% for IPD signal and 97 to 100% for GS tendon damage. Results were independent of scanning technique.Conclusion. Intraobserver reliability for tenosynovitis and tendon damage varied from moderate for GS to good for PD. Overall interobserver reliability for tenosynovitis and tendon damage was excellent both for GS and PD. This qualitative scoring system may serve as the first step to a semi-quantitative score for tendon pathology. \ua9 The Author 2012. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved
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