169 research outputs found

    Suitabilty of Palm Kernel Shell As Coarse Aggregate In Lightweight Concrete Production

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    Palm kernel shell(PKS) is an agricultural waste which is environmental friendly. This research was focused on the assessment of characteristic strength of palm kernel shell concrete, with the view to be used as lightweight aggregate. This research is carried out to help in reducing construction cost in areas where lightweight concrete canbe considered. Various tests were carried out  in order to ascertain its use as lightweight aggregate. The aim was achieved by casting the beam and cubes with total replacement of granite with PKS and also casting an equivalent control to give a basis for comparison and a water cement ratio of 0.65 at a mix ratio of 1:2:4. A total of 24 beams and cubes each were cast  respectively . They were cured for 7, 14, 21 and 28days. Crushing of 3 each for the Palm Kernel Shell Concrete (PKSC) and Normal Weight Concrete (NWC) for each curing day upto the age of 28 days was carried out. The results of crushing values are as follows for 7, 14, 21 and 28 days; 14.47N/mm2, 18.49N/mm2, 20.33N/mm2 , 23.00N/mm2 and 7.40N/mm2, 9.20N/mm2; 11.30N/mm2 , 13.10 N/mm2, for NWC and PKSC respectively. The value for the flexural strength is as follow; 1.87, 0.91, 1.36, 1.81 and 0.34, 0.34, 0.40, 0.34 for NWC and PKSC respectively. The results showed that the compressive and flexural strength improved with age of curing, though the compressive and flexural strength of PKSC is low as compared to that of the NWC. It was concluded that the compressive and flexural strength of NWC is higher than that of PKSC. Therefore PKSC canbe used as lightweight concrete which should be designed with the corresponding design for NWC. It can therefore be concluded that palm kernel shell is a lightweight aggregate and can be used to produce lightweight concrete. Keywords: Palm kernel shell, lightweight aggregate, compressive strength, flexural strengt

    Which trial do we need? Evaluation of systemic antibiotics as primary prophylaxis in mechanically ventilated patients with burn injuries

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    Burn injury is a frequent source of morbidity and mortality worldwide, and infection is a leading cause of death. In mechanically ventilated patients who sustain a burn injury, ventilator-associated pneumonia (VAP) is common and associated with poor outcomes and a high risk of recurrence

    Burns from e-cigarettes and other electronic nicotine delivery systems

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    With increasing use of electronic cigarettes (e-cigarettes) and other electronic nicotine delivery systems (ENDS) globally, the debate surrounding the potential harms or benefits may shift to ensuring that the devices are manufactured, marketed, and sold according to standards that reduce harm and promote health

    Is there a maximum star formation rate in high-redshift galaxies?

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    We use the James Clerk Maxwell Telescope's SCUBA-2 camera to image a 400 arcmin2 area surrounding the GOODS-N field. The 850 ÎŒm rms noise ranges from a value of 0.49 mJy in the central region to 3.5 mJy at the outside edge. From these data, we construct an 850 ÎŒm source catalog to 2 mJy containing 49 sources detected above the 4σ level. We use an ultradeep (11.5 ÎŒJy at 5σ) 1.4 GHz image obtained with the Karl G. Jansky Very Large Array together with observations made with the Submillimeter Array to identify counterparts to the submillimeter galaxies. For most cases of multiple radio counterparts, we can identify the correct counterpart from new and existing Submillimeter Array data. We have spectroscopic redshifts for 62% of the radio sources in the 9' radius highest sensitivity region (556/894) and 67% of the radio sources in the GOODS-N region (367/543). We supplement these with a modest number of additional photometric redshifts in the GOODS-N region (30). We measure millimetric redshifts from the radio to submillimeter flux ratios for the unidentified submillimeter sample, assuming an Arp 220 spectral energy distribution. We find a radio-flux-dependent K – z relation for the radio sources, which we use to estimate redshifts for the remaining radio sources. We determine the star formation rates (SFRs) of the submillimeter sources based on their radio powers and their submillimeter fluxes and find that they agree well. The radio data are deep enough to detect star-forming galaxies with SFRs >2000 M ☉ yr–1 to z ~ 6. We find galaxies with SFRs up to ~6000 M ☉ yr–1 over the redshift range z = 1.5-6, but we see evidence for a turn-down in the SFR distribution function above 2000 M ☉ yr–1

    Helicopter tail rotor orthogonal blade vortex interaction

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    The aerodynamic operating environment of the helicopter is particularly complex and, to some extent, dominated by the vortices trailed from the main and tail rotors. These vortices not only determine the form of the induced flow field but also interact with each other and with elements of the physical structure of the flight vehicle. Such interactions can have implications in terms of structural vibration, noise generation and flight performance. In this paper, the interaction of main rotor vortices with the helicopter tail rotor is considered and, in particular, the limiting case of the orthogonal interaction. The significance of the topic is introduced by highlighting the operational issues for helicopters arising from tail rotor interactions. The basic phenomenon is then described before experimental studies of the interaction are presented. Progress in numerical modelling is then considered and, finally, the prospects for future research in the area are discussed

    Improving Research Enrollment of Severe Burn Patients

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    Enrolling severely burn injured patients into prospective research studies poses specific challenges to investigators. The authors describe their experience of recruiting adults with ≄20% TBSA burns or inhalation injury admitted to a single academic burn unit into observational research with minimally invasive specimen collection. The authors outline iterative changes that they made to their recruitment processes in response to perceived weaknesses leading to delays in enrollment. The primary outcome was the change in days to consent for enrolled patients or cessation of recruitment for nonenrolled patients before and after the interventional modifications. The authors assessed change in overall enrollment as a secondary outcome. Study enrollment was approximately 70% in both 4-month study periods before and after the intervention. Following the intervention, time to consent by surrogate decision maker decreased from a median of 26.5 days (interquartile range [IQR] 14-41) to 3 days (IQR 3-6) (P =.004). Time to initial consent by patient changed from a median of 15 days (IQR 2-30) to 3 days (IQR 2-6) (P =.27). Time to decline for nonenrolled patients decreased from a median of 12 days (IQR 6.5-27) to 1.5 days (IQR 1-3.5) (P =.026). Both the findings of the study and a brief literature review suggest that careful design of the recruitment protocol, increased experience of the study team, and broad time windows for both approach and enrollment improve the efficiency of recruiting critically injured burn patients into research

    Burn injury outcomes in patients with pre-existing diabetic mellitus: Risk of hospital-acquired infections and inpatient mortality

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    Background: Diabetes mellitus (DM) is a major cause of illness and death in the United States, and diabetic patients are at increased risk for burn injury. We therefore sought to examine the impact of pre-existing DM on the risk of inpatient mortality and hospital acquired infections (HAI) among burn patients. Methods: Adult patients (≄18 years old) admitted from 2004 to 2013 were analyzed. Weighted Kaplan–Meier survival curves – adjusting for patient demographics, burn mechanism, presence of inhalation injury, total body surface area, additional comorbidities, and differential lengths of stay – were used to estimate the 30-day and 60-day risk of mortality and HAIs. Results: A total of 5539 adult patients were admitted and included in this study during the study period. 655 (11.8%) had a pre-existing DM. The crude incidence of HAIs and in-hospital mortality for the whole burn cohort was 8.5% (n = 378) and 4.4% (n = 243), respectively. Diabetic patients were more likely to be older, female, have additional comorbidities, inhalational injury, and contact burns. After adjusting for patient and burn characteristics, the 60-day risk of HAI among patients with DM was significantly higher, compared to non-diabetic patients (RR 2.07, 95% CI 1.28, 6.79). However, no significant difference was seen in the 60-day risk of mortality (RR 1.34, 95% CI 0.44, 3.10). Conclusions: Pre-existing DM significantly increases the risk of developing an HAI in patients following burn injury, but does not significantly impact the risk of inpatient mortality. Further understanding of the immune modulatory mechanism of burn injury and DM is imperative to better attenuate the acquisition of HAIs

    Sex-Based Differences in Inpatient Burn Mortality

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    Background: Among burn patients, research is conflicted, but may suggest that females are at increased risk of mortality, despite the opposite being true in non-burn trauma. Our objective was to determine whether sex-based differences in burn mortality exist, and assess whether patient demographics, comorbid conditions, and injury characteristics explain said differences. Methods: Adult patients admitted with burn injury—including inhalation injury only—between 2004 and 2013 were included. Inverse probability of treatment weights (IPTW) and inverse probability of censor weights (IPCW) were calculated using admit year, patient demographics, comorbid conditions, and injury characteristics to adjust for potential confounding and informative censoring. Standardized Kaplan–Meier survival curves, weighted by both IPTW and IPCW, were used to estimate the 30-day and 60-day risk of inpatient mortality across sex. Results: Females were older (median age 44 vs. 41 years old, p < 0.0001) and more likely to be Black (32% vs. 25%, p < 0.0001), have diabetes (14% vs. 10%, p < 0.0001), pulmonary disease (14% vs. 7%, p < 0.0001), heart failure (4% vs. 2%, p = 0.001), scald burns (45% vs. 26%, p < 0.0001), and inhalational injuries (10% vs. 8%, p = 0.04). Even after weighting, females were still over twice as likely to die after 60 days (RR 2.87, 95% CI 1.09, 7.51). Conclusion: Female burn patients have a significantly higher risk of 60-day mortality, even after accounting for demographics, comorbid conditions, burn size, and inhalational injury. Future research efforts and treatments to attenuate mortality should account for these sex-based differences. The project was supported by the National Institutes of Health, Grant Number UL1TR001111

    Risk Factors for Healthcare-Associated Infections in Adult Burn Patients

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    OBJECTIVE Burn patients are particularly vulnerable to infection, and an estimated half of all burn deaths are due to infections. This study explored risk factors for healthcare-Associated infections (HAIs) in adult burn patients. DESIGN Retrospective cohort study. SETTING Tertiary-care burn center. PATIENTS Adults (≄18 years old) admitted with burn injury for at least 2 days between 2004 and 2013. METHODS HAIs were determined in real-Time by infection preventionists using Centers for Disease Control and Prevention criteria. Multivariable Cox proportional hazards regression was used to estimate the direct effect of each risk factor on time to HAI, with inverse probability of censor weights to address potentially informative censoring. Effect measure modification by burn size was also assessed. RESULTS Overall, 4,426 patients met inclusion criteria, and 349 (7.9%) patients had at least 1 HAI within 60 days of admission. Compared to 6 times as likely to acquire an HAI (HR, 6.38; 95% CI, 3.64-11.17); and patients with >20% TBSA were >10 times as likely to acquire an HAI (HR, 10.33; 95% CI, 5.74-18.60). Patients with inhalational injury were 1.5 times as likely to acquire an HAI (HR, 1.61; 95% CI, 1.17-2.22). The effect of inhalational injury (P=.09) appeared to be larger among patients with ≀20% TBSA. CONCLUSIONS Larger burns and inhalational injury were associated with increased incidence of HAIs. Future research should use these risk factors to identify potential interventions
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