Shandong jianzhu university 山東建築大學

About: Shandong jianzhu university 山東建築大學 is a education organization based out in Jinan, China. It is known for research contribution in the topics: Heat transfer & Microstructure. The organization has 5354 authors who have published 4402 publications receiving 27567 citations. The organization is also known as: Shandong University of Architecture and Engineering.

Vertical-borehole ground-coupled heat pumps: A review of models and systems

Abstract: A large number of ground-coupled heat pump (GCHP) systems have been used in residential and commercial buildings throughout the world due to the attractive advantages of high efficiency and environmental friendliness. This paper gives a detailed literature review of the research and developments of the vertical-borehole GCHP technology for applications in air-conditioning. A general introduction on the ground source heat pump system and its development is briefly presented first. Then, the most typical simulation models of the vertical ground heat exchangers currently available are summarized in detail including the heat transfer processes outside and inside the boreholes. The various design/simulation programs for vertical GCHP systems primarily based on the typical simulation models are also reviewed in this paper. Finally, the various hybrid GCHP systems for cooling or heating-dominated buildings are well described. It is found that the GCHP technology can be used both in cold and hot weather areas and the energy saving potential is significant.

Simulation and comparative study on the oxidation kinetics of atrazine by UV/H2O2, UV/HSO5− and UV/S2O82−

Abstract: This study comparatively investigated atrazine (ATZ) degradation by irradiation at the wavelength of 254 nm in the presence of peroxides including hydrogen peroxide (H2O2), peroxymonosulfate (HSO5−), and persulfate (S2O82−) at various initial ATZ concentrations and oxidant dosages. The effects of water matrix, such as carbonate/bicarbonate (HCO3−/CO32−), chloride ions (Cl−), and natural organic matter (NOM), were evaluated on these three advanced oxidation processes. A simple steady-state kinetic model was developed based on the initial rates of ATZ destruction, which could well describe the apparent pseudo-first-order rate constants (kapp, s−1) of ATZ degradation in these three processes. The specific roles of reactive species (i.e., HO, SO4−, CO3−, and Cl2−) under various experimental conditions were quantitatively evaluated based on their steady-state concentrations obtained from this model. Modeling results showed that the steady-state concentrations of HO and SO4− decreased with the increase of CO32−/HCO3− concentration, and the relative contribution of HO to ATZ degradation significantly decreased in UV/H2O2 and UV/HSO5− systems. On the other hand, the scavenging effect of HCO3−/CO32− on the relative contribution of SO4− to ATZ degradation was lower than that on HO. The presence of Cl− (0.5–10 mM) significantly scavenged SO4− but had slightly scavenging effect on HO at the present experimental pH, resulting in greater decrease of kapp in the UV/S2O82− than UV/H2O2 and UV/HSO5− systems. Higher levels of Cl2− were generated in the UV/S2O82− than those in the UV/H2O2 and UV/HSO5− systems at the same Cl− concentrations. NOM significantly decreased kapp due to its effects of competitive UV absorption and radical scavenging with the latter one being dominant. These results improve the understanding of the effects of water constituents for ATZ degradation in the UV-based oxidation processes.

A new model and analytical solutions for borehole and pile ground heat exchangers

Abstract: The ground-coupled heat pump (GCHP) systems have been identified as one of the best sustainable energy technologies for space heating and cooling in buildings. While the foundation piles of buildings are used to partly take the place of boreholes in the ground heat exchanger (GHE) in recent years, the classical approaches of the line heat source model and the “hollow” cylindrical heat source model for the borehole GHEs fail for thermal analysis and design of the pile GHEs. Evolved from the classical models, a new “solid” cylindrical source model is presented in this paper to consider both the radial dimension and the heat capacity of the borehole or pile. Expressions of the analytical solution are derived for 1-D and 2-D new models by means of the Green’s function method. Results obtained from the new 1-D model are compared with the classical line source and “hollow” cylindrical source models of the borehole GHE, and also validated by a numerical solution of the same model. While the 1-D and 2-D solid cylindrical source models can provide adequate tools for design and simulation of the pile GHEs, improvement can also be achieved in simulating the temperature response of the borehole GHEs, especially for short time steps.

Binary differential evolution with self-learning for multi-objective feature selection

Abstract: Feature selection is an important data preprocessing method. This paper studies a new multi-objective feature selection approach, called the Binary Differential Evolution with self-learning (MOFS-BDE). Three new operators are proposed and embedded into the MOFS-BDE to improve its performance. The novel binary mutation operator based on probability difference can guide individuals to rapidly locate potentially optimal areas, the developed One-bit Purifying Search operator (OPS) can improve the self-learning capability of the elite individuals located in the optimal areas, and the efficient non-dominated sorting operator with crowding distance can reduce the computational complexity of the selection operator in the differential evolution. Experimental results on a series of public datasets show that the effective combination of the binary mutation and OPS makes our MOFS-BDE achieve a trade-off between local exploitation and global exploration. The proposed method is competitive in comparison with some representative genetic algorithm-, particle swarm-, differential evolution-, and artificial bee colony-based feature selection algorithms.

Efficient Pb(II) removal using sodium alginate–carboxymethyl cellulose gel beads: Preparation, characterization, and adsorption mechanism

Abstract: Alginate–carboxymethyl cellulose (CMC) gel beads were prepared in this study using sodium alginate (SA) and sodium CMC through blending and cross-linking. The specific surface area and aperture of the prepared SA–CMC gel beads were tested. The SA–CMC structure was characterized and analyzed via infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Static adsorption experiment demonstrated that Pb(II) adsorption of SA–CMC exceeded 99% under the optimized conditions. In addition, experiments conducted under the same experimental conditions showed that the lead ion removal efficiency of SA–CMC was significantly higher than that of conventional adsorbents. The Pb(II) adsorption process of SA–CMC followed the Langmuir adsorption isotherm, and the dynamic adsorption model could be described through a pseudo-second-order rate equation. Pb(II) removal mechanisms of SA–CMC, including physical, chemical, and electrostatic adsorptions, were discussed based on microstructure analysis and adsorption kinetics. Chemical adsorption was the main adsorption method among these mechanisms.