3-D Statistical Channel Model for Millimeter-Wave Outdoor Mobile Broadband Communications

This paper presents an omnidirectional spatial and temporal 3-dimensional statistical channel model for 28 GHz dense urban non-line of sight environments. The channel model is developed from 28 GHz ultrawideband propagation measurements obtained with a 400 megachips per second broadband sliding correlator channel sounder and highly directional, steerable horn antennas in New York City. A 3GPP-like statistical channel model that is easy to implement in software or hardware is developed from measured power delay profiles and a synthesized method for providing absolute propagation delays recovered from 3-D ray-tracing, as well as measured angle of departure and angle of arrival power spectra. The extracted statistics are used to implement a MATLAB-based statistical simulator that generates 3-D millimeter-wave temporal and spatial channel coefficients that reproduce realistic impulse responses of measured urban channels. The methods and model presented here can be used for millimeter-wave system-wide simulations, and air interface design and capacity analyses.Comment: 7 pages, 6 figures, ICC 2015 (London, UK, to appear

28 GHz and 73 GHz Millimeter-Wave Indoor Propagation Measurements and Path Loss Models

This paper presents 28 GHz and 73 GHz millimeter- wave propagation measurements performed in a typical office environment using a 400 Megachip-per-second broadband sliding correlator channel sounder and highly directional steerable 15 dBi (30 degrees beamwidth) and 20 dBi (15 degrees beamwidth) horn antennas. Power delay profiles were acquired for 48 transmitter-receiver location combinations over distances ranging from 3.9 m to 45.9 m with maximum transmit powers of 24 dBm and 12.3 dBm at 28 GHz and 73 GHz, respectively. Directional and omnidirectional path loss models and RMS delay spread statistics are presented for line-of-sight and non-line-of-sight environments for both co- and cross-polarized antenna configurations. The LOS omnidirectional path loss exponents were 1.1 and 1.3 at 28 GHz and 73 GHz, and 2.7 and 3.2 in NLOS at 28 GHz and 73 GHz, respectively, for vertically-polarized antennas. The mean directional RMS delay spreads were 18.4 ns and 13.3 ns, with maximum values of 193 ns and 288 ns at 28 GHz and 73 GHz, respectively.Comment: 7 pages, 9 figures, 2015 IEEE International Conference on Communications (ICC), ICC Workshop

Enhance Nurse-Physician Communication

Abstract Communication is the soul of healthcare, without it, the microsystem cannot survive. There are many disciplines in healthcare, in order for safe and effective care to be delivered strong communication is key. With initiatives taken, there is always room for improvement where gaps can be identified. In particular, a gap in communication between night shift nurses and primary care physicians. According to the CRICO Strategies (2015) there has been a $1.7 billion-dollar loss and 2,000 deaths in healthcare nationally as a result of miscommunication. Poor communication has serious devastating effects if it is not corrected promptly. The duty of a clinical nurse leader (CNL) quickly becomes apparent that change is in order, to bridge this gap and ensure patient safety. A CNL has a distinct role in designing, implementing and evaluating patient care. This is done by collaborating, delegating, and overseeing the success of care. With the use of evidence-based practice and innovation, a CNL ensures the best care is provided for patients within the microsystem (GraduateNursingEDU.org, 2018). A long-term acute care medical-surgical unit was assessed, which revealed under efficient scores from Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) that only 20 percent of staff felt efficiency in communication between nurses and primary care physicians. The goal of this project is to create a standardized communication tool to improve efficiency in communication in three months’ time. After the implementation of this project, efficiency in communication improved and nurse satisfaction was achieved in the process

Walking at the edge: How tempo-spatial nexus forms HRM practices in project-based organizations

Introduction: Research has scrutinized the role of different HRM practices in Project-based Organizations (PBOs) mostly in terms of project success and articulated the challenges of traditional HRM to reconcile with the project context. Nevertheless, HRM practices have been addressed less in PBOs with a practice-based research lens. Particularly, the role of tempo-spatial nexus in shaping such practices in this organizational form has been under-researched, although PBOs provide a very suitable context for doing so. Methods: Drawing upon a comparative case study in the oil and gas industry of Scotland and adopting a practice-based approach, this research aims to shed light on how HRM practices are shaped and re-shaped in the project-based context. The study, specifically, scrutinizes the role of temporality and space in the formation, adoption and adaptation of HRM practices in these organizational forms. Results and discussion: The findings reveal that project characteristics, specifically their duration, size and technical properties, induce different temporalities that along with different work locations and inter-organizational relationships, impact HRM practices as a threefold structure

A self-adaptive cohesive zone model for interfacial delamination

Interfacial failure in the form of delamination, often results in malfunction or failure of laminated structures. Different numerical approaches have been proposed for the simulation of this process. Due to the appealing feature of predicting both the delamination onset and its growth, cohesive zone models have been widely used to simulate delamination as a result of a gradual degradation of the adhesion between two materials when they become separated. Application of cohesive zone models for the modelling of delamination in brittle interfaces in a quasi-static finite element framework suffers froman intrinsic discretization sensitivity. A large number of interface elements are needed for the discretization of the process zone of a cohesive crack. Otherwise, a sudden release of energy in large cohesive zone elements results in a sequence of snap-through or snap-back points to appear in the global load-displacement response of the system which compromises the numerical efficiency. While computationally expensive path-following techniques can be used to follow the oscillatory path, the efficiency and robustness of brittle cohesive zone models can be significantly increased by reducing the oscillations observed in the global load-displacement behaviour without a further mesh refinement. In line with this purpose, the separation approximation in the process zone is enriched with an adaptive hierarchical extension. The linear separation approximation throughout the cohesive zone element is enriched with a bi-linear function, where the enrichment peak position and the magnitude of the enrichment are regarded as additional degrees of freedom obtained by minimization of the total potential of the global system. The mobility of the peak of the enrichment function within individual cohesive zone elements locally adapts the discretization to the physics governing the problem. Important numerical aspects of the proposed enrichment strategy such as its mobility and uniqueness have been thoroughly investigated while its limitations are addressed. The efficiency and robustness of the enrichment are shown through numerical examples which prove the general applicability of the methodology. In fact, application of the elaborated enrichment eliminates the need for a further mesh refinement while keeping the standard Newton-Raphson approach applicable in the case of a relatively coarse mesh which saves considerable computational costs. Extension of the proposed enrichment scheme to delamination in a threedimensional finite element framework has been carried out as well. Planar interix face elements have been enriched along all edges by bi-linear functions with mobile peaks. The effect of the proposed methodology on reducing discretization-induced oscillations is quantitatively evaluated. To deal with planar crack growth where the crack front is oblique with respect to element edges, a non-hierarchical enrichment strategy is also developed and its performance is compared with its hierarchical counterpart. The self-adaptive finite element formulation is extended to a framework suitable for large deformations and is applied to interfaces in microelectronics under realistic mixed-mode loading conditions. In particular, the material/interface systems used in miniaturized mixed-mode bending tests, which are conducted for a wide range of mode angles, are modelled to make a direct comparison with experimental results. The interface constitutive lawthat is used takes the dependence of fracture toughness on mode-mixity into account. Thereby, the enhanced cohesive zone model can be used for the simulation of the behaviour of brittle interfaces in an accurate, effective, and efficient manner

Acetyl Rb1 Ginsenoside from North American Ginseng: Extraction and Application

North American ginseng is a unique medicinal plant which is believed to show several biological activities including: anti-stress, anti-angiogenic, immunosuppressive, and anti-oxidant activity. Components previously isolated from North American ginseng include ginsenosides, polysaccharides, peptides, polyacetylenic alcohols, and fatty acids. The biological and pharmacological effects of ginseng are mainly related to the ginsenoside components, making their extraction and characterization of interest in order to identify them, and study their biological activities. This thesis focused on the extraction of ginsenosides from North American ginseng by an ultrasonication method with methanol and DMSO as solvents and their aqueous mixtures. Quantitative analysis of individual ginsenosides from the extracts was measured by HPLC, which demonstrated that ultrasonication significantly enhanced the extraction efficiency, with the best efficiency found using 80% solvent (methanol, and DMSO) and 20% water. Immunosuppressive activity of these ginseng extracts was tested in LPS-induced macrophage cells showing that the 80% DMSO and 80% methanol extracts gave significant potency toward immunosuppressive activity in a dose-dependent manner. Moreover, significant quantities of 6”-O-acetylginsenoside Rb1 were obtained using DMSO as the extraction solvent during ultrasonication, and identified using MS, FTIR, and 1D (1H and 13C) and 2D (gCOSY, gHSQC, and gHMBC) NMR. Also, subsequent bioassay experiments confirmed that acetyl ginsenoside Rb1 demonstrated additional immunosuppressive activity towards inhibiting the production of nitric oxide (NO) and tumor necrosis factor (TNF)-α in LPS-induced macrophage cells in a dose-dependent manner using murine macrophages. In addition, acetyl ginsenoside Rb1 gave significant anti-angiogenic activity and exhibited enhanced potency towards inhibiting tube-like structure formation of endothelial cells. Supercritical fluid chromatography (SFC) using supercritical carbon dioxide which is considered as a “green” separation method and believed as a promising technique for separation, isolation, and identification of herbal and medicinal plants, was used to separate and isolate ginseng extracts obtained by supercritical CO2 extraction (SFE). The effect of temperature and pressure on the separation of ginsenosides was studied with methanol being added to the CO2 mobile phase. Acidic, basic, and ionic additives were introduced to the mobile phase, respectively, to study their effect on the separation of ginsenosides. The best separation condition was obtained by adding 0.05% v/v trifluoroacetic acid in methanol. A high-concentration component in the extracts from the supercritical fluid extraction of North American ginseng was isolated by SFC and identified as sucrose using NMR, HPLC, and ESI-MS. Because of it\u27s unique biological activities, development of a suitable delivery system for acetyl ginsenoside Rb1 (ac-Rb1) was investigated for the first time in this research. PLGA microspheres were used to encapsulate ac-Rb1,examining both a double emulsion and a microfluidic technique. The size and morphology of the ac-Rb1 loaded PLGA microspheres were characterized by SEM and ZEISS light microscopy, showing unimodal 50-65 µm size diameters, respectively using the microfluidic technique. Also, another delivery system of PLGA in gelatin hydrogel was prepared in order to achieve a localized delivery method, overcoming drawbacks such as PLGA removal by macrophages and a high initial burst effect from gelatin hydrogel that can damage tissues around the injection site. The ac-Rb1 loaded microspheres were incorporated into the gelatin hydrogels to form a new delivery system examining gluteradlehyde crosslinking concentrations from 10-100µl. FTIR, DSC and TGA confirmed the formation and chemical stability of the gelatin encapsulated composites. Release profiles were studied and quantified by UV-Vis spectrophotometry with the results showing that the release of ac-Rb1 from the unimodal microspheres prepared by the microfluidic technique showed a lower initial burst effect than those from the double emulsion method. The burst effect was followed by a slow release profile which can be used for long term drug delivery applications to maintain the ginsenoside concentration for an extended time period. It should be mentioned that although the large burst effect could release a therapeutic agent relatively fast, it can also damage tissues around the treatment site. Hence, a combination delivery system was developed using cross-linked gelatin. The release of ac-Rb1 from the cross-linked gelatin encapsulated microspheres was effected by the pH of the releasing medium as well as the crosslinker concentration. Then, the in vitro cumulative release data of the core and core-composite systems was analyzed using empirical equations in Matlab. The results showed that the in vitro release kinetics data followed Fickian diffusion with the best fit observed using the Weibull model, for all investigated cases. Moreover, the released ac-Rb1 from delivery systems showed a significant immunosuppressive effect on LPS-induced macrophages indicating the novel delivery systems for ac-Rb1 have potential for next-generation biomedical agents in drug-release devices

The effect of grain size on shearing strength of sand

The object of this study is to determine experimentally the effect of definite grain size on the shearing characteristics of sandy soils. As it will be discussed in detail under the article - The Mechanics of Shear, the shearing characteristics of sandy soils depends on many factors such as grain size and shape, soil structure and relative density, the water content of soil. An attempt is made throughout the entire investigation to determine the effect of definite grain size on the shearing value and the angle of internal friction under the dry and saturated conditions. Furthermore, the results of shear tests on saturated soils as well as dry soils depend to a large extent on the rate at which the shearing force is increased, the dimensions of the specimen, and other details of the testing procedure. Therefore, all the features of the testing procedure described fully in detail to avoid misleading interpretation of the data -- Object And Scope Of Investigations, page 4