An Investigation of the Properties of Expanded Polystyrene Concrete with Fibers Based on an Orthogonal Experimental Design

The Controlled Release and Prevention of Abdominal Adhesion of Tannic Acid and Mitomycin C-Loaded Thermosensitive Gel

Postoperative abdominal adhesion is one of the most common complications after abdominal surgery. A single drug or physical barrier treatment does not achieve the ideal anti-adhesion effect. We developed a thermosensitive hydrogel (PPH hydrogel) consisting of poloxamer 407 (P407), poloxamer (P188), and hydroxypropyl methylcellulose (HPMC) co-blended. An injectable thermosensitive TA/MMC-PPH hydrogel was obtained by loading tannic acid (TA) with an anti-inflammatory effect and mitomycin C (MMC), which inhibits fibroblast migration or proliferation. The optimal prescriptions of PPH hydrogels with a suitable gelling time (63 s) at 37 °C was 20% (w/v) P407, 18% (w/v) P188, and 0.5% (w/v) HPMC. The scanning electron microscopy (SEM) revealed that the PPH hydrogel had a three-dimensional mesh structure, which was favorable for drug encapsulation. The PPH hydrogel had a suitable gelation temperature of 33 °C, a high gel strength, and complicated viscosity at 37 °C, according to the rheological analysis. In vitro release studies have shown that the PPH hydrogel could delay the release of TA and MMC and conform to the first-order release rate. Anti-adhesion tests performed on rats in vivo revealed that TA/MMC-PPH hydrogel significantly reduced the risk of postoperative adhesion. In conclusion, the TA/MMC-PPH hydrogel prepared in this study showed an excellent performance in both controlled drug release and anti-adhesive effects. It can be used as a protocol to prevent or reduce postoperative abdominal adhesion.

Research on energy-saving factors adaptability of exterior envelopes of university teaching-office buildings under different climates (China) based on orthogonal design and EnergyPlus

To achieve carbon neutrality in 2060 (China), building energy-saving has been highly concerned. University buildings have great energy-saving potential as part of energy consumption where 70% of energy loss is caused by heat transfer from the envelope. However, most of the research on energy-saving factors for envelopes is limited to a certain climate or a specific building type, and the optimal configuration of envelopes under different climatic regions has not been well solved. Therefore, the influence degree and appropriate parameters of each factor of the teaching-office building envelopes on energy consumption under different climates were analyzed in this paper by orthogonal design and numerical simulation. Results show that: (1) Solar heat gain coefficient (SHGC) and indoor air change rates (ACH) [the heat transfer coefficient of the exterior wall (K_wall) and ACH] are the main factors affecting the cooling [heating] load, the insulation form of the exterior wall (W_ins) and K_wall [W_ins and solar radiation absorption coefficient of exterior surface materials (ρ_s)] have less influence; (2) The important ranking and optimal level of the influence of each factor on the cooling (or heating) loads are related to local load demands; (3) For the annual load, K_wall and the heat transfer coefficient of the exterior window (K_win) is the focus of energy-saving in severe cold and cold zones, but their impact is not significant in Guangzhou and Kunming, and the high significance of SHGC is only shown in Hohhot, Lhasa, Guangzhou, and Haikou; (4) The annual load energy savings reach 39.64%–57.57% in different climates by optimizing all factors. The research results can provide directions and data references for the energy-saving design and renovation of educational building envelopes in different climates (China).

Development of a Formability Prediction Model for Aluminium Sandwich Panels with Polymer Core

In the present work, the compatibility relationship on the failure criteria between aluminium and polymer was established, and a mechanics-based model for a three-layered sandwich panel was developed based on the M-K model to predict its Forming Limit Diagram (FLD). A case study for a sandwich panel consisting of face layers from AA5754 aluminium alloy and a core layer from polyvinylidene difluoride (PVDF) was subsequently conducted, suggesting that the loading path of aluminium was linear and independent of the punch radius, while the risk for failure of PVDF increased with a decreasing radius and an increasing strain ratio. Therefore, the developed formability model would be conducive to the safety evaluation on the plastic forming and critical failure of composite sandwich panels.