484 research outputs found

    Energy efficiency of a flat-plate solar collector using thermally treated graphene-based nanofluids: Experimental study

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    Ā© The Author(s) 2020. A covalent functionalization approach was utilized for the preparation of highly dispersed pentaethylene glycol-thermally treated graphene-water as the absorbing material inside a flat-plate solar collector. Four mass fractions of nanofluids were prepared (0.025, 0.05, 0.075, and 0.1 wt% pentaethylene glycol-thermally treated graphene-water). Graphene nanoparticles were characterized by energy dispersive X-ray analysis with a scanning electron microscope. Measurements of the thermophysical properties were subsequently carried out for the nanosuspensions. The raw investigation data were collected from an indoor flat-plate solar collector test setup. The experimental procedure included different sets of variables such as input temperatures of 303, 313, and 323 K; fluid mass flow rate of 0.00833, 0.01667, and 0.025 kg sāˆ’1; and heat flow density of 500, 750, and 1000 W māˆ’2. The thermophysical tests of pentaethylene glycol-thermally treated graphene-water nanofluids showed a proportional increase against weight concentrations, while the specific heat power was reduced. The tests showed an increment in energy efficiency by increasing the fluid mass flow rate and heat input. By comparison, the thermal efficiency decreased with the increasing temperature of the fluid supply. Relative to the base fluid, the energy efficiency of pentaethylene glycol-thermally treated graphene/water-based flat-plate solar collector increased to 10.6%, 11%, and 13.1% at the three fluid mass flow rates. In conclusion, an exponential form was used to derive the thermal effectiveness of flat-plate solar collector based on the experimental data

    Energy efficiency of a flat-plate solar collector using thermally treated graphene-based nanofluids: Experimental study

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    Ā© The Author(s) 2020. A covalent functionalization approach was utilized for the preparation of highly dispersed pentaethylene glycol-thermally treated graphene-water as the absorbing material inside a flat-plate solar collector. Four mass fractions of nanofluids were prepared (0.025, 0.05, 0.075, and 0.1 wt% pentaethylene glycol-thermally treated graphene-water). Graphene nanoparticles were characterized by energy dispersive X-ray analysis with a scanning electron microscope. Measurements of the thermophysical properties were subsequently carried out for the nanosuspensions. The raw investigation data were collected from an indoor flat-plate solar collector test setup. The experimental procedure included different sets of variables such as input temperatures of 303, 313, and 323 K; fluid mass flow rate of 0.00833, 0.01667, and 0.025 kg sāˆ’1; and heat flow density of 500, 750, and 1000 W māˆ’2. The thermophysical tests of pentaethylene glycol-thermally treated graphene-water nanofluids showed a proportional increase against weight concentrations, while the specific heat power was reduced. The tests showed an increment in energy efficiency by increasing the fluid mass flow rate and heat input. By comparison, the thermal efficiency decreased with the increasing temperature of the fluid supply. Relative to the base fluid, the energy efficiency of pentaethylene glycol-thermally treated graphene/water-based flat-plate solar collector increased to 10.6%, 11%, and 13.1% at the three fluid mass flow rates. In conclusion, an exponential form was used to derive the thermal effectiveness of flat-plate solar collector based on the experimental data

    Genotype x Environment interaction for quality traits in durum wheat cultivars adapted to different environments

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    The quality traits of durum wheat are important for the utilization by the industries. These traits may be influenced by genotype and interaction of genotype and environment (GxE). To evaluate the effects of genotype, environment and genotype x environment interaction on quality traits such as vitreousness, SDS sedimentation test, yellow pigment index, protein content and test weight, twelve Moroccan durum wheat cultivars representing a range of agronomic adaptation were tested in five locations representing a range of environments in three growing seasons. The results indicated significant effects of genotype, environment and GxE for all the quality traits. The extent of these effects differed; for SDSsedimentation volumes, yellow pigment and test weight, the component of variation due to genotype was larger than due to the environment, indicating the greater influence of genotypes on these traits. However, for vitreousness and protein content, the effect of environment was higher than the effect due to genotypes. Thus, these traits are controlled greatly by environmental effects than genetics. The variation due to GxE was higher than that of genotype for vitreousness and test weight, indicating high GxE interaction effect and less genotypic stability for these traits. For protein content, where the environmental effect was greater than that of genotype and GxE effect, multiple environmental trials are necessary in order to determine protein content of a cultivar. For other traits,  preliminary evaluations can be done in one environment and good performing ones can be selected for multiple environmental trials

    Perirhinal cortex and the recognition of relative familiarity

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    Spontaneous object recognition (SOR) is a widely used task of recognition memory in rodents which relies on their propensity to explore novel (or relatively novel) objects. Network models typically define perirhinal cortex as a region required for recognition of previously seen objects largely based on findings that lesions or inactivations of this area produce SOR deficits. However, relatively little is understood about the relationship between the activity of cells in the perirhinal cortex that signal novelty and familiarity and the behavioural responses of animals in the SOR task. Previous studies have used objects that are either highly familiar or absolutely novel, but everyday memory is for objects that sit on a spectrum of familiarity which includes objects that have been seen only a few times, or objects that are similar to objects which have been previously experienced. We present two studies that explore cellular activity (through c-fos imaging) within perirhinal cortex of rats performing SOR where the familiarity of objects has been manipulated. Despite robust recognition memory performance, we show no significant changes in perirhinal activity related to the level of familiarity of the objects. Reasons for this lack of familiarity-related modulation in perirhinal cortex activity are discussed. The current findings support emerging evidence that perirhinal responses to novelty are complex and that task demands are critical to the involvement of perirhinal cortex in the control of object recognition memory

    6-PACK programme to decrease fall injuries in acute hospitals: Cluster randomised controlled trial

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    Objective: To evaluate the effect of the 6-PACK programme on falls and fall injuries in acute wards. Design: Cluster randomised controlled trial. Setting: Six Australian hospitals. Participants: All patients admitted to 24 acute wards during the trial period. Interventions: Participating wards were randomly assigned to receive either the nurse led 6-PACK programme or usual care over 12 months. The 6-PACK programme included a fall risk tool and individualised use of one or more of six interventions: ā€œfalls alertā€ sign, supervision of patients in the bathroom, ensuring patientsā€™ walking aids are within reach, a toileting regimen, use of a low-low bed, and use of a bed/chair alarm. Main outcome measures: The co-primary outcomes were falls and fall injuries per 1000 occupied bed days. Results: During the trial, 46 245 admissions to 16 medical and eight surgical wards occurred. As many people were admitted more than once, this represented 31 411 individual patients. Patientsā€™ characteristics and length of stay were similar for intervention and control wards. Use of 6-PACK programme components was higher on intervention wards than on control wards (incidence rate ratio 3.05, 95% confidence interval 2.14 to 4.34; P<0.001). In all, 1831 falls and 613 fall injuries occurred, and the rates of falls (incidence rate ratio 1.04, 0.78 to 1.37; P=0.796) and fall injuries (0.96, 0.72 to 1.27; P=0.766) were similar in intervention and control wards. Conclusions: Positive changes in falls prevention practice occurred following the introduction of the 6-PACK programme. However, no difference was seen in falls or fall injuries between groups. High quality evidence showing the effectiveness of falls prevention interventions in acute wards remains absent. Novel solutions to the problem of in-hospital falls are urgently needed

    Can harmonisation of outcomes bridge the translation gap for pre-clinical research? A systematic review of outcomes measured in mouse models of type 2 diabetes

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    Background: In pre-clinical research, systematic reviews have the potential to mitigate translational challenges by facilitating understanding of how pre-clinical studies can inform future clinical research. Yet their conduct is encumbered by heterogeneity in the outcomes measured and reported, and those outcomes may not always relate to the most clinically important outcomes. We aimed to systematically review outcomes measured and reported in pre-clinical in vivo studies of pharmacological interventions to treat high blood glucose in mouse models of type 2 diabetes. Methods: A systematic review of pre-clinical in vivo studies of pharmacological interventions aimed at addressing elevated blood glucose in mouse models of type 2 diabetes was completed. Studies were screened for eligibility and outcomes extracted from the included studies. The outcomes were recorded verbatim and classified into outcome domains using an existing outcome taxonomy. Outcomes were also compared to those identified in a systematic review of registered phase 3/4 clinical trials for glucose lowering interventions in people with type 2 diabetes. Results: Review of 280 included studies identified 532 unique outcomes across 19 domains. No single outcome, or domain, was measured in all studies and only 132 (21%) had also been measured in registered phase 3/4 clinical trials. A core outcome set, representing the minimum that should be measured and reported, developed for type 2 diabetes effectiveness clinical trials includes 18 core outcomes, of these 12 (71%) outcomes were measured and reported in one or more of the included pre-clinical studies. Conclusions: There is heterogeneity of outcomes reported in pre-clinical research. Harmonisation of outcomes across the research pathway using a core outcome set may facilitate interpretation, evidence synthesis and translational success, and may contribute to the refinement of the use of animals in research. Systematic review registration: The study was prospectively registered on the PROSPERO Database, registration number CRD4201810683

    Long-term, prolonged-release tacrolimus-based immunosuppression in de novo kidney transplant recipients: 5-year prospective follow-up of the ADHERE study patients.

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    The objectives of this study were to assess long-term graft survival, patient survival, renal function, and acute rejections in de novo kidney transplant recipients, treated with once-daily prolonged-release tacrolimus-based therapy. The study was a 5-year non-interventional prospective follow-up of patients from the ADHERE study, a Phase IV 12-month open-label assessment of patients randomized to receive prolonged-release tacrolimus in combination with mycophenolate mofetil (MMF) (Arm 1) or sirolimus (Arm 2). From 838 patients in the randomized study, 587 were included in the long-term follow-up, of whom 510 completed the study at year 5. At 1 year post-transplant, graft and patient survival rates were 93.0% and 97.8%, respectively, and at 5 years were 84.0% and 90.8%, respectively. Cox proportional hazards analysis showed no association between graft loss, initial randomized treatment arm, donor age, donor type, or sex. The 5-year acute rejection-free survival rate was 77.4%, and biopsy-confirmed acute rejection-free survival rate was 86.0%. Renal function remained stable over the follow-up period: mean Ā± SD eGFR 4-variable modification diet in renal disease formula (MDRD4) was 52.3 Ā± 21.6 ml/min/1.73 m2 at 6 months and 52.5 Ā± 23.0 ml/min/1.73 m2 at 5 years post-transplant. These findings support the role of long-term once-daily prolonged-release tacrolimus-based immunosuppression, in combination with sirolimus or MMF, for renal transplant recipients in routine clinical practice. ispartof: TRANSPLANT INTERNATIONAL vol:33 issue:2 pages:161-173 ispartof: location:England status: publishe
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