56 research outputs found

    Modeling Of Waste Material Costs On Road Construction Projects

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    Material waste is a term from the amount of waste material percentage and is one of the serious problems in the implementation of road construction project. The research objective is to calculate the average percentage of waste material in road construction projects and obtain waste material influencing profit and make a regression model of % material waste to % profit contractors. The data obtained are 158 projects in East and North Kalimantan divided into 51 road building projects and 107 road improvement projects. The percentage of waste material on road building project is B aggregate as the largest (26%) and ready mix concrete (5.3%) as the smallest. The percentage of waste material on road improvement project is B aggregate as the largest (24.2%) and ready mix concrete (6.14%) as the smallest. The influencing waste material on the road construction project is B aggregate, lean concrete and ready mix concrete with regression equation to determine the estimated % profit contractor as a function of % material waste is Y = 7.363 -0.032 X3 - 0.078 X4 - 0.066 X6. The influenced waste material on road improvement projects are cement, B aggregate, and Land Fill with the regression equation to determine the estimated % profit of contractor as a function of % material waste is Y = 8,702- 0,037 X4- 0,054 X5- 0,044 X7

    Modelling of waste material costs on road construction projects.

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    Material waste is a term from the amount of waste material percentage and is one of the serious problems in the implementation of road construction project. The research objective is to calculate the average percentage of waste material in road construction projects and obtain waste material influencing profit and make a regression model of % material waste to % profit contractors. The data obtained are 158 projects in East and North Kalimantan divided into 51 road building projects and 107 road improvement projects. The percentage of waste material on road building project is B aggregate as the largest (26%) and ready mix concrete (5.3%) as the smallest. The percentage of waste material on road improvement project is B aggregate as the largest (24.2%) and ready mix concrete (6.14%) as the smallest. The influencing waste material on the road construction project is B aggregate, lean concrete and ready mix concrete with regression equation to determine the estimated % profit contractor as a function of % material waste is Y = 7.363 -0.032 X3 - 0.078 X4 - 0.066 X6. The influenced waste material on road improvement projects are cement, B aggregate, and Land Fill with the regression equation to determine the estimated % profit of contractor as a function of % material waste is Y = 8,702- 0,037 X4- 0,054 X5- 0,044 X7.N.

    Hemostatic efficacy of an advanced bipolar sealer in open gynecologic, thoracic, and colectomy procedures: A prospective cohort study

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    Background An advanced bipolar (ABP) tissue sealer designed for division of major vessels in open procedures was evaluated in a prospective post-market study. The objective was to provide clinical data for assessment of vessel transection, hemostatic performance and ease of use of the ABP device during open colectomy, gynecologic, and thoracic operations. Materials and methods The ABP test device was used in colectomy (n = 36), gynecologic (n = 44), and thoracic (n = 21) procedure groups. Vessels transected with the ABP device were graded intraoperatively on a hemostasis scale of 1–4, defined as follows: Grade1, no bleeding; Grade 2, minor bleeding with no intervention; Grade 3, minor bleeding requiring touchup with the test device or monopolar cautery; and Grade 4, significant bleeding requiring intervention with any additional hemostatic product. The primary performance measure was the percentage of vessels that achieved hemostasis grades ≤3. The primary safety endpoint was the summarization of all ABP device-related adverse events (AEs). Results For all three procedure groups together, 302 (96.2%) of 314 total vessel transections were scored as hemostasis grades ≤ 3, including 270 (86.0%) that were rated Grade 1. Twelve transections (3.8%) were Grade 4, which included 9 vessels transected in the gynecologic group and 3 in the thoracic group. Three subjects experienced a total of 4 device-related AEs, consisting of hematoma, hypotension, procedural pain, and superficial thermal burn. All 4 device-related AEs were mild in severity. Conclusion The advanced bipolar device exhibited effective hemostasis, an acceptable safety profile, and ease of use during colectomy, thoracic, and gynecologic procedures

    Sustainable biosurfactant production from secondary feedstock—recent advances, process optimization and perspectives

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    Biosurfactants have garnered increased attention lately due to their superiority of their properties over fossil-derived counterparts. While the cost of production remains a significant hurdle to surpass synthetic surfactants, biosurfactants have been anticipated to gain a larger market share in the coming decades. Among these, glycolipids, a type of low-molecular-weight biosurfactant, stand out for their efficacy in reducing surface and interfacial tension, which made them highly sought-after for various surfactant-related applications. Glycolipids are composed of hydrophilic carbohydrate moieties linked to hydrophobic fatty acid chains through ester bonds that mainly include rhamnolipids, trehalose lipids, sophorolipids, and mannosylerythritol lipids. This review highlights the current landscape of glycolipids and covers specific glycolipid productivity and the diverse range of products found in the global market. Applications such as bioremediation, food processing, petroleum refining, biomedical uses, and increasing agriculture output have been discussed. Additionally, the latest advancements in production cost reduction for glycolipid and the challenges of utilizing second-generation feedstocks for sustainable production are also thoroughly examined. Overall, this review proposes a balance between environmental advantages, economic viability, and societal benefits through the optimized integration of secondary feedstocks in biosurfactant production

    Factors accounting for the association between anxiety and depression, and eczema: the Hordaland health study (HUSK)

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    <p>Abstract</p> <p>Background</p> <p>The association between anxiety and depression, and eczema is well known in the literature, but factors underlying this association remain unclear. Low levels of omega-3 fatty acids and female gender have been found to be associated with both depression and eczema. Somatization and health anxiety are known to be associated with anxiety and depression, further, somatization symptoms and health anxiety have also been found in several dermatological conditions. Accordingly, omega-3 fatty acid supplement, female gender, somatization and health anxiety are possible contributing factors in the association between anxiety and depression, and eczema. The aim of the study is to examine the relevance of proposed contributing factors for the association between anxiety and depression, and eczema, including, omega-3 fatty acid supplement, female gender, health anxiety and somatization.</p> <p>Methods</p> <p>Anxiety and depression was measured in the general population (n = 15715) employing the Hospital Anxiety and Depression Scale (HADS). Information on eczema, female gender, omega-3 fatty acid supplement, health anxiety and somatization was obtained by self-report.</p> <p>Results</p> <p>Somatization and health anxiety accounted for more than half of the association between anxiety/depression, and eczema, while the other factors examined were of minor relevance for the association of interest.</p> <p>Conclusions</p> <p>We found no support for female gender and omega-3 fatty acid supplement as contributing factors in the association between anxiety/depression, and eczema. Somatization and health anxiety accounted for about half of the association between anxiety/depression, and eczema, somatization contributed most. The association between anxiety/depression, and eczema was insignificant after adjustment for somatization and health anxiety. Biological mechanisms underlying the mediating effect of somatization are yet to be revealed.</p

    Gabapentin for chronic pelvic pain in women (GaPP2):a multicentre, randomised, double-blind, placebo-controlled trial

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    BackgroundChronic pelvic pain affects 2–24% of women worldwide and evidence for medical treatments is scarce. Gabapentin is effective in treating some chronic pain conditions. We aimed to measure the efficacy and safety of gabapentin in women with chronic pelvic pain and no obvious pelvic pathology.MethodsWe performed a multicentre, randomised, double-blind, placebo-controlled randomised trial in 39 UK hospital centres. Eligible participants were women with chronic pelvic pain (with or without dysmenorrhoea or dyspareunia) of at least 3 months duration. Inclusion criteria were 18–50 years of age, use or willingness to use contraception to avoid pregnancy, and no obvious pelvic pathology at laparoscopy, which must have taken place at least 2 weeks before consent but less than 36 months previously. Participants were randomly assigned in a 1:1 ratio to receive gabapentin (titrated to a maximum dose of 2700 mg daily) or matching placebo for 16 weeks. The online randomisation system minimised allocations by presence or absence of dysmenorrhoea, psychological distress, current use of hormonal contraceptives, and hospital centre. The appearance, route, and administration of the assigned intervention were identical in both groups. Patients, clinicians, and research staff were unaware of the trial group assignments throughout the trial. Participants were unmasked once they had provided all outcome data at week 16–17, or sooner if a serious adverse event requiring knowledge of the study drug occurred. The dual primary outcome measures were worst and average pain scores assessed separately on a numerical rating scale in weeks 13–16 after randomisation, in the intention-to-treat population. Self-reported adverse events were assessed according to intention-to-treat principles. This trial is registered with the ISRCTN registry, ISCRTN77451762.FindingsParticipants were screened between Nov 30, 2015, and March 6, 2019, and 306 were randomly assigned (153 to gabapentin and 153 to placebo). There were no significant between-group differences in both worst and average numerical rating scale (NRS) pain scores at 13–16 weeks after randomisation. The mean worst NRS pain score was 7·1 (standard deviation [SD] 2·6) in the gabapentin group and 7·4 (SD 2·2) in the placebo group. Mean change from baseline was −1·4 (SD 2·3) in the gabapentin group and −1·2 (SD 2·1) in the placebo group (adjusted mean difference −0·20 [97·5% CI −0·81 to 0·42]; p=0·47). The mean average NRS pain score was 4·3 (SD 2·3) in the gabapentin group and 4·5 (SD 2·2) in the placebo group. Mean change from baseline was −1·1 (SD 2·0) in the gabapentin group and −0·9 (SD 1·8) in the placebo group (adjusted mean difference −0·18 [97·5% CI −0·71 to 0·35]; p=0·45). More women had a serious adverse event in the gabapentin group than in the placebo group (10 [7%] of 153 in the gabapentin group compared with 3 [2%] of 153 in the placebo group; p=0·04). Dizziness, drowsiness, and visual disturbances were more common in the gabapentin group.InterpretationThis study was adequately powered, but treatment with gabapentin did not result in significantly lower pain scores in women with chronic pelvic pain, and was associated with higher rates of side-effects than placebo. Given the increasing reports of abuse and evidence of potential harms associated with gabapentin use, it is important that clinicians consider alternative treatment options to off-label gabapentin for the management of chronic pelvic pain and no obvious pelvic pathology.FundingNational Institute for Health Research

    Integrated motor drives: state of the art and future trends

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    With increased need for high power density, high efficiency and high temperature capabilities in Aerospace and Automotive applications, Integrated Motor Drives (IMD) offers a potential solution. However, close physical integration of the converter and the machine may also lead to an increase in components temperature. This requires careful mechanical, structural and thermal analysis; and design of the IMD system. This paper reviews existing IMD technologies and their thermal effects on the IMD system. The effects of the power electronics (PE) position on the IMD system and its respective thermal management concepts are also investigated. The challenges faced in designing and manufacturing of an IMD along with the mechanical and structural impacts of close physical integration is also discussed and potential solutions are provided. Potential converter topologies for an IMD like the Matrix converter, 2-level Bridge, 3-level NPC and Multiphase full bridge converters are also reviewed. Wide band gap devices like SiC and GaN and their packaging in power modules for IMDs are also discussed. Power modules components and packaging technologies are also presented
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