3,195 research outputs found
Effects of the Interactions Between LPS and BIM on Workflow in Two Building Design Projects
Variability in design workflow causes delays and undermines the performance of building projects. As lean processes, the Last Planner System (LPS) and Building Information Modeling (BIM) can improve workflow in building projects through features that reduce waste. Since its introduction, BIM has had significant positive influence on workflow in building design projects, but these have been rarely considered in combination with LPS. This paper is part of a postgraduate research focusing on the implementation of LPS weekly work plans in two BIM-based building design projects to achieve better workflow. It reports on the interactions between lean principles of LPS and BIM functionalities in two building design projects that, from the perspective of an interaction matrix developed by Sacks et al. (2010a), promote workflow
Improving design workflow with the Last Planner System: two action research studies
Variability in workflow during the design stage of building projects has been widely acknowledged as a problem related to poor planning and control of design tasks and has been identified as a major cause of delay in building projects. The Last Planner system (LPS) of production planning and control helps to create predictable and reliable workflow by enabling the management of the range of relationships, interfaces and deliverables involved in a project. This paper presents results of implementing LPS in design to minimize variability in workflow within BIM-based building design projects. Action research was used to implement and evaluate the effectiveness of LPS weekly work planning (WWP) to improve workflow during the design development phase of two building design projects. The research was carried out with the collaboration between design practitioners at two building design firms in Florida and the researchers as facilitators. Overall PPC (Percent Plan Complete) measurements suggest that design workflow improved in both projects after WWP was implemented. However, efforts to use BIM in a lean way in the two projects (discussed in detail in an IGLC22 conference paper by the authors of this paper) were believed to be partly responsible for the improvement in design workflow.
KEYWORDS
Design workflow variability, LPS, BIM
A framework for evaluating an action research study on lean design management
There is no convention for evaluating action research (AR), and the one commonly used for evaluating research in general was deemed unsuitable for evaluating a postgraduate AR study on lean design management conducted by the researchers. The purpose of this paper is to present the framework developed by the researchers for evaluating the AR study, using criteria that are different from those traditionally used to evaluate research. It is hoped that this paper will contribute to lean construction research (LC) by highlighting the importance of using AR to measure the efficacy of LC production systems in their intended context of application and by letting future LC researchers know that they can develop their own criteria for evaluating their research rather than use generic criteria that may not be suitable
Aging and Post-Intensive Care Syndrome–Family (PICS-F): A Critical Need for Geriatric Psychiatry
Postintensive care syndrome–family (PICS-F) describes the psychological symptoms that affect the family members of patients hospitalized in the intensive care unit (ICU) or recently discharged from the ICU. Geriatric psychiatrists should be concerned about PICS-F for several reasons. First, ICU hospitalization in older adults is associated with higher rates of cognitive and physical impairment compared with older adults hospitalized in non-ICU settings or dwelling in the community. This confers a special burden on the caregivers of these older ICU survivors compared with other geriatric populations. Second, as caregivers themselves age, caring for this unique burden can be more challenging compared with other geriatric populations. Third, evidence for models of care centered on patients with multimorbidity and their caregivers is limited. A deeper understanding of how to care for PICS and PICS-F may inform clinical practice for other geriatric populations with multimorbidity and their caregivers. Geriatric psychiatrists may play a key role in delivering coordinated care for PICS-F by facilitating timely diagnosis and interdisciplinary collaboration, advocating for the healthcare needs of family members suffering from PICS-F, and leading efforts within healthcare systems to increase awareness and treatment of PICS-F. This clinical review will appraise the current literature about the impact of critical illness on the family members of ICU survivors and identify crucial gaps in our knowledge about PICS-F among aging patients and caregivers
Formulation optimization and in vitro characterization of rifampicin and ceftriaxone dual drug loaded niosomes with high energy probe sonication technique
The aim of the present study was to prepare niosomal formulations for dual drug therapy of ceftriaxone sodium and poorly water-soluble rifampicin by the ecological probe sonication method. Pluronic L121 and Span 60 were used as surface active agents and the optimization of the composition was made with the aid of Design of Experiment (DoE) concept. Concentration levels of charge inducing agent, dicetylphosphate (DCP), and Pluronic L121 were studied as variables. Prepared niosomes with varying concentrations of DCP and Pluronic L121 resulted in small sized niosomes with sizes ranging from 165 nm to 893 nm. During the four weeks stability testing, the particle sizes of the empty niosomes were reduced, while the particle sizes of the drug loaded niosomes were increased very slightly. The optimized formulations resulted in stable niosomes with high drug entrapment efficiencies: entrapment efficiency was 99% for rifampicin and 96% for ceftriaxone. All the niosomal formulations showed faster in vitro drug release rates as compared to bulk drug formulations. In conclusion, ceftriaxone and rifampicin loaded niosomes prepared with Pluronic L121 and Span 60 resulted in stable, small sized niosomes with high drug entrapment efficiencies and improved drug release profiles.Peer reviewe
Process optimization of ecological probe sonication technique for production of rifampicin loaded niosomes
The aim of the present study was to develop an optimized niosome formulation for the encapsulation of a poorly water-soluble drug by the ecological probe sonication method. Pluronic L121 and Span 60 were used as surface active agents and the optimization of the composition was made with the aid of Design of Experiment (DoE) concept. Rifampicin was used as a model drug. Concentration levels of charge inducing agent, dicetylphosphate (DCP), and Pluronic L121 were studied as variables. Prepared niosomes with varying concentrations of DCP and Pluronic L121 resulted in small sized niosomes with sizes ranging from 190 nm to 893 nm. During the four weeks stability testing, the particle sizes were reduced slightly. The formulation containing 2 mg of DCP resulted in most stable niosomes with 75.37% entrapment efficiency. All the niosomal formulations showed higher in vitro drug release rates as compared to bulk drug formulation. As a conclusion, rifampicin loaded niosomes prepared with Pluronic L121 and Span 60 resulted in stable, small sized niosomes with improved drug release profile.Peer reviewe
Utilization of Green Formulation Technique and Efficacy Estimation on Cell Line Studies For Dual Anticancer Drug Therapy With Niosomes
The aim of the present study was to prepare niosome formulations for the simultaneous encapsulation, dual drug therapy, of two anticancer drugs by the ecological probe sonication method. Poloxamer and sorbitan monostearate were used as surface active agents in niosomes, and the water soluble doxorubicin and poorly-water soluble paclitaxel were used as anticancer drugs. Thorough physicochemical analysis were performed for the niosomes, and their cytotoxicity and activity were evaluated on MCF-7 and PC3-MM2 cancer cell lines. Prepared niosomes were small in size with sizes ranging from 137 nm to 893 nm, and entrapment efficiencies were high, ranging from 91.24% to 99.99%. During the four weeks stability testing, the particle size remained stable. The niosomal formulations showed in vitro sustained drug release profiles for doxorubicin and clearly increased the dissolution rate of poorly water soluble paclitaxel. The incorporation of both the drugs into niosomes improved cell penetration and antiproliferative activity of the drugs PC3-MM2 cell lines. As a conclusion, doxorubicin and paclitaxel loaded niosome formulations resulted in relatively stable, small sized niosomes with improved drug release profiles, low toxicity, better cell penetration and antiproliferative activity. The niosomes showed synergistic effect due to the presence of both drugs, which can overcome multidrug resistance.Peer reviewe
Assessing Soil and Potential Air Temperature Coupling Using PALM-4U: Implications for Idealized Scenarios
Underground heat extremes amplified by e.g., underground infrastructure or badly adjusted geothermal systems have long been discussed in geosciences. However, there is little emphasis on the exchange between these subsurface heat extremes and the atmosphere. To address the issue, this study investigates the impact of varying soil temperatures on potential air temperatures in an idealized domain using the turbulence and building resolving large eddy simulation urban micro-climate model PALM-4U. This involves two steps: first we test if and how idealized domains can be simulated, second the coupling between surface and subsurface energy fluxes or rather temperatures in air and soil are in focus. We develop several scenarios, distinguishing between cyclic or Dirichlet/radiation boundary conditions along the x-axis, between summer and winter, as well as between various land cover types. Our results demonstrate that cyclic boundary conditions induce modifications of the potential air temperatures due to changes in the soil temperature. The magnitude of the impact varies with respect to the tested land covers, which primarily affect absolute temperatures. Daytime and season have a larger influence on the magnitude of the modifications. A 5 K increase in subsurface temperatures at 2 m depth results in a maximum of a 0.38 K increase for near surface potential air temperatures in winter between 09:00 and 10:00 local time after three days of simulation. When soil temperatures are decreased, we find predominantly inverse patterns. The least influence is found during summer at 09:00 local time where the elevated soil temperatures increase potential air temperatures by only 0.02 K over short- and tall grass, and 0.18 K over bare soil. When using Dirichlet/radiation boundary conditions, the atmosphere cannot develop freely and changing soil temperatures do not impact potential air temperatures. These results help to enhance our understanding of the coupling between soil- and atmospheric temperatures and also provide recommendations for the simulability of idealized but reality-oriented scenarios in PALM-4U. It is one of the first studies that demonstrates that heat and cold sources in the soil can affect atmospheric parameters
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