Characterization and physiological effect of tapioca maltodextrin colloid plasma expander in hemorrhagic shock and resuscitation model

Plasma expanders (PEs) are administered fluids to replace blood volume when massive blood loss has occured. Maltodextrin from tapioca starch was selected as a study candidate to prepare a colloid PE due to an uncomplicated production process. The formulations of mixture between tapioca maltodextrin and 0.9 % sodium chloride solution were prepared and then characterized. This was to investigate the effects of a dextrose equivalent (DE) and the concentration on the physical properties. Storage stability of each formulation was also determined and compared with clinically used PE [6 % hydroxyethyl starch (HES), 130/0.4]. The effects on the circulatory system in hamsters with hemorrhagic shock and resuscitation using prepared PE were also investigated. The results showed that low DE value led to high retrogradation, turbidity and viscosity but low colloid osmotic pressure and poor solubility. Among the prepared solutions, tapioca maltodextrin with DE6 at 10 % w/v concentration had comparable properties with 6 % HES 130/0.4. Animals resuscitated with 10 % DE6 PE had improved mean arterial blood pressure similar to those resuscitated with 6 % HES 130/0.4. However, several parameters in animals resuscitated with 10 % DE6 PE were lower than those resuscitated with 6 % HES 130/0.4, i.e., heart rate, functional capillary density. Therefore, if using tapioca maltodextrin for PE, some properties have to be considered and efficiently optimized.     

Risk-constrained design of autonomous hybrid refueling station for hydrogen and electric vehicles using information gap decision theory

The proposed autonomous hybrid charging station in this paper is energized by a photovoltaic (PV) system, which should provide electric vehicles (EVs), and water electrolyzer (WE) with electricity. The WE operates by using electricity to produce and store hydrogen to feed hydrogen vehicles (HVs). Moreover, a fuel cell (FC) is allocated to the system, which uses the stored hydrogen to regenerate electricity the PV system is beyond reach. A supplementary diesel generator is also installed in the charging station to avoid power shortage as a conservative measurement. The hydrogen and electric demand of the station is accompanied by uncertainties, which should be taken into account in designing the charging station. Therefore, information-gap decision theory (IGDT) is employed to deal with the uncertainties. This approach provides the investor with three different strategies of risk-averse strategy (RAS), risk-neutral strategy (RNS), and risk-seeker strategy (RSS), which can help the investor with making a better decision. The outcome of the simulation proved that in RAS if the investor decides to invest 13.9% more capital, based on the robustness function, the charging station withstands the 9.6% deviation of uncertain parameters’ fraction error. However, should the investor decide to take risks in the construction of the charging station, by paying 13.9% less, the system is 10.7% fragile to the information-gap of uncertainties. Besides, the rated power of the PV system reaches from 1612 kW in RNS to 1731 kW in RAS while it decreased to 1479 kW in RSS.     

Health care service delivery based on the Internet of things: A systematic and comprehensive study

Today, the Internet of Things (IoT) becomes a heterogeneous and highly distributed structure which can respond to the daily needs of people and different organizations. With the fast development of IT‐based technologies such as IoT and cloud computing, low‐cost health services and their support, efficient supervision of the centralized management, and monitoring of public health can be realized. Therefore, there has been increasing attention in the integration of IoT and health care both in academic and the business world. However, while the health care service industry fully holds the welfares of information systems for its personnel and patients, there is a need for an improved understanding of the issues and opportunities related to IoT‐based health care systems. But, as far as we know, the detailed review and deep discussion in this field are very rare. Hence, in this paper, we presented a literature review on the IoT‐based health care services from papers published until 2018. Moreover, the drawbacks and benefits of the reviewed mechanisms have been discussed, and the main challenges of these mechanisms are highlighted for developing more efficient IoT techniques over health care services in the future. The results of this paper will be valuable for both practitioners and academicians, and it can provide visions into future research areas in this domain. By providing comparative information and analyzing the current developments in this area, this paper will directly support academics and working professionals for better knowing the progress in IoT mechanisms. As a general result, we found that IoT could help the governments to improve health services in society and commercial interactions.     

Response of reinforced concrete piles including soil–pile interaction effects

This paper discusses the importance of modeling soil–pile interaction in the response of reinforced concrete (RC) piles. A displacement-based, RC beam–column fiber model with distributed lateral deformable supports is presented first. The formulation is general and applies to both monotonic and cyclic loads. The proposed model is simple, computationally efficient and capable of representing the salient features of the soil–pile interaction, including dragging force and gap formation along the pile–soil interfaces as well as hysteretic responses of piles and surrounding soils. Two applications are presented to illustrate the model characteristics, to show the model capabilities, and to discuss the importance of modeling the pile–soil system. The first application deals with a single end-bearing pile embedded in a cohesionless soil. The proposed beam–column model is used to investigate the effects of different model parameters on the pile–soil response, including pile length, pile diameter, and pile and soil nonlinearities. The second application validates the accuracy of the proposed model with the experimental results of a cyclic test on a RC pile/shaft system where the influence of the pile–soil interaction is essential. Results from the correlation studies indicate that the proposed model can represent well both global and local responses of the pile–soil system. The effects of the interfacial characteristics between pile and soil on the system response are also studied.     

Correlation between beam on Winkler-Pasternak foundation and beam on elastic substrate medium with inclusion of microstructure and surface effects

A novel beam-elastic substrate element with inclusion of microstructure and surface energy effects is proposed in this paper. The modified couple stress theory is employed to account for the microstructure-dependent effect of the beam bulk material while Gurtin-Murdoch surface theory is used to capture the surface energy-dependent size effect. Interaction mechanism between the beam and the surrounding substrate medium is represented by the Winkler foundation model. The governing differential equilibrium and compatibility equations of the beam-elastic substrate system are consistently derived based on virtual displacement and virtual force principles, respectively. Both essential and natural boundary conditions of the system are also obtained. Two modified Tonti’s diagrams are presented to provide the big picture of both displacement-based and force-based formulations of the system. Due to similarity between the current problem and the one related to the beam on Winkler-Pasternak foundation, the so-called “natural” beam-Winkler-Pasternak foundation element coined by the authors is employed to perform two numerical simulations to study the characteristics and behaviors of a beam-substrate system with inclusion of microstructure and surface effects.     

Corrosion Fatigue Study of 6061 Aluminum Alloy: The Effect of Coatings on the Fatigue Characteristics

Metallurgical and Materials Transactions A - This study proposes a method for protecting 6061 aluminum alloy from corrosion fatigue. Corrosion fatigue can reduce fatigue strength at the endurance...