A Three-Dimensional Transient Model for Evaluating the Performance of Cement-Based Thermoelectric Module

The thermoelectric module (TEM) is a device that integrates multiple thermoelectric (TE) elements to realize the mutual conversion of heat and power. Due to the advantages of no moving parts and flexible expansion, the application of conventional Bi2Te3-based TEM in buildings has attracted the attention of researchers. On the other hand, the TE behavior of hardened cement composites was found by combining conductive additives with cement. Therefore, a new study on cement-based TEM for building energy harvesting and temperature control is proposed. To simulate the performance of cement-based TEM, a three-dimensional heat transfer model considering temperature-dependent TEM characteristics was established. The validity of the model is verified by comparing the results with commercial simulation software and experiments. Different from the existing analytical models and commercial software, the customized model has greater scalability, optimization, and control flexibility. Through parametric studies, the model can guide the design of TEM and the development of TE cement

Characteristics of Graphite and MnO2 Enhanced Cement-Based Thermoelectric Composite for Low-Temperature Applications

Thermoelectric (TE) cement composite is a new type of TE material. Unlike ordinary cement, TE cement can mutually convert thermal energy to electrical energy due to the addition of carbon fibers, metal oxide nanoparticles, etc. In hot summer or cold winter, the significant temperature difference between indoor and outdoor can be used by TE cement to generate electricity. On the other hand, given power input, the same material can provide cooling/ heating to adjust room temperature. Therefore, TE cement has certain energy-saving potential in the application of building enclosures and energy systems. Its ability to convert different forms of energy and use low-grade energy is conducive to the operation of net-zero buildings. In this study, a novel TE cement composite, MnO2 and graphite enhanced cement, was firstly fabricated. The surface morphology of the composites was analyzed by scanning electron microscopy. The performance indicators of TE materials include the power factor and dimensionless figure of merit ZT, which are calculated by Seebeck coefficient, thermal conductivity, and electrical conductivity. The values of these five TE properties were measured and calculated by a Physical Property Measurement System at different temperatures. Compared with the cement reinforced by graphite alone, it is confirmed that MnO2 nanoparticles have a positive effect on the enhancement of the TE performance for cement composites. The highest ZT of 5wt.% graphite and 10wt.% MnO2 enhanced cement composite prepared by the dry method is about 6.2 × 10-6 at 350 K

A selective cascade reaction-based probe for colorimetric and ratiometric fluorescence detection of benzoyl peroxide in food and living cells

A novel colorimetric and ratiometric fluorescent probe (Cou-BPO) was readily prepared for specific detection of harmful benzoyl peroxide (BPO). The probe Cou-BPO reacted with BPO via a selective oxidation cleavage-induced cascade reaction of the pinacol phenylboronate group, which resulted in an observable colorimetric and ratiometric fluorescence response towards BPO with a fast response time (o15 min) and a low detection limit (56 nM). For practical application, facile, portable and sensitive test paper of Cou-BPO has been prepared for visual detection of BPO. Furthermore, we employed Cou-BPO as a probe to determine BPO in food samples and living cells.info:eu-repo/semantics/publishedVersio

A Preliminary Experimental Study on the Performance of a Membrane-based Air Dehumidifier Using Ionic Liquid

Liquid desiccant air dehumidification (LDAD) is a promising alternative to the dehumidification systems that use mechanical cooling. However, its use in the market is still very limited due to its high installation cost, intensive carryover, and maintenance issues associated with the corrosion resulting from conventional liquid desiccants. The research reported in this paper aimed at addressing these challenges by applying membrane technology and ionic liquids in LDAD. This paper introduces a design of a membrane-based ionic liquid desiccant air dehumidification (MILDAD). A small-scale prototype of the MILDAD was built and tested in controlled conditions to characterize its performance. The preliminary experimental results indicate that the MILDAD can effectively dehumidify the air and the ionic liquid desiccant can be regenerated at 40ºC temperature. However, the latent effectiveness is relatively small compared with conventional LDAD systems and the current design is prone to leakage, especially when the flow rate of air and/or ionic liquid is high

Backstepping-based Robust Control for WMR with A Boundary in Prior for the Uncertain Rolling Resistance

In this study, we focus on the trajectory tracking control problem ofa wheeled mobile robot (WMR) in an uncertain dynamic environment. Concerningthe fact that the upper boundary may be usually achieved in prior according to thephysical properties of the terrain, this crucial message is utilized to construct thecontrollers. Firstly, a dynamic model for WMR including the rolling resistance ispresented, whose state variables are longitudinal and rotational velocities, as well asthe rotational angle of the mobile platform. Secondly, with the aid of backsteppingtechnique, the robust controllers based on the upper boundary are proposed and theglobally asymptotic stability of the closed-loop system is proven by the Lyapunovtheory in the following. Lastly, a saturation function is applied to replace the signumfunction, by which the inherent chattering can be suppressed greatly. Numericalsimulation results demonstrate that the proposed controllers with upper bound inprior possess robustness characteristics which yields potentially valuable applicationsfor the mobile robot, especially in the unstructured environment

A dual-analytes responsive fluorescent probe for discriminative detection of ClO− and N2H4 in living cells

Hydrazine (N2H4) and ClO− are very harmful for public health, hence it is important and necessary to monitor them in living cells. Herein, we rationally designed and synthesized a dual-analytes responsive fluorescent sensor PTMQ for distinguishing detection of N2H4 and ClO−. PTMQ underwent N2H4-induced double bond cleavage, affording colorimetric and green fluorescence enhancement with good selectivity and a low detection limit (89 nM). On the other hand, PTMQ underwent ClO−-induced sulfur oxidation and displayed red fluorescence lighting-up response towards ClO− with good selectivity, rapid response (<0.2 min) and a low detection limit (58 nM). Moreover, PTMQ was successfully employed for in-situ imaging of N2H4 and ClO− in living cellsinfo:eu-repo/semantics/publishedVersio

Data mining on varieties, therapeutic uses and medicinal characteristics of Traditional Chinese Medicine preparations for treating hair loss

Purpose: To review the varieties, therapeutic uses, and medicinal characteristics of traditional Chinese medicine (TCM) preparations for treating hair loss, and to provide a reference for research and development of new drugs.Methods: For this review, literature from the last 50 years pertaining to the treatment of hair loss via TCM were collected mainly from China National Knowledge Infrastructure database and Wanfang Data Resource System database. Information on Chinese traditional patent medicines and ethnomedicines for treating hair loss was drawn from books.Results: A total of 322 preparations were identified, including 135 preparations made by medical institutions, 108 Chinese traditional patent medicines, 60 preparations produced by doctors themselves, and 19 ethnomedicines. The forms of dosage included&nbsp; decoctions, pills, capsules, tablets, granules, tinctures, liniments, and powders. These preparations are traditionally used in the treatment of skin and subcutaneous tissue diseases. A total of 400 medicinal materials were used in preparations, including 339 from plants, 40 from animals, 14 from minerals. The most commonly used Chinese medicinal materials in order of frequency were Rehmannia glutinosa (Gaertn.) DC., Fallopia multiflora (Thunb.) Haraldson, Angelica sinensis (Oliv.) Diels, Ligustrum lucidum W.T. Aiton and Ligusticum chuanxiong Hort.Conclusion: TCM preparations for treating hair loss are abundant in variety. They are mainly decoctions, and primarily botanical medicinal materials. Most of the preparations are composed of Chinese medicinal materials for ‘toning the kidneys’ and ‘nourishing the liver’. They are used mainly in the treatment of seborrheic alopecia and alopecia areat

La-containing SBA-15/H2O2 systems for the microwave assisted oxidation of a lignin model phenolic monomer

A convenient and efficient application of heterogeneous Lanthanum-containing SBA-15 systems for the microwave assisted oxidation of a lignin model phenolic monomer, 3-methoxy- 4-hydroxybenzyl alcohol, is reported. Environmental friendly and low-cost H2O2 was used as the oxygen atom donor. The catalyst was prepared by immobilizing Lanthanum species on to the periodic mesoporous channels of siliceous SBA-15. Powder X-ray diffraction data and Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) revealed that the host retains its hexagonal mesoporous structure after immobilization and most of the lanthanum species are better dispersed in the calcined materials. The surface area and pore size of La/SBA-15 was considerably decreased indicating the intrapore confinement of the Lanthanum species. The activity of the La/SBA-15 was investigated in the oxidation of 3-methoxy-4-hydroxybenzyl alcohol in the presence of hydrogen peroxide as oxidant. 68% conversion of 3-methoxy-4-hydroxybenzyl alcohol to vanillin or other undetectable by-products was obtained after 30 min of reaction under 200W microwave irradiation, compared to a poor 25% degradation after 24 h under conventional heating. The possibility of recycling the catalyst was studied

STUDIES ON THE IDENTIFICATION OF CONSTITUENTS IN ETHANOL EXTRACT OF RADIX GLYCYRRHIZAE AND THEIR ANTICANCER ACTIVITY

Background: The main functions of Radix Glycyrrhizae include regulating middle warmer, moistening lung, relieving toxicity, harmonizing property of drugs which is a traditional Chinese medicine widely used in clinical settings. The objective of the paper is to isolate and identify the constituents in ethanol extract of Radix Glycyrrhizae, and to study their anticancer activity. Materials and Methods: Column chromatography, ODS column chromatography, preparative thin layer chromatography and NMR spectroscopy techniques were used to isolate compounds from ethanol extract of Radix Glycyrrhizae; optical microscopy and flow cytometry were used to determine the anticancer effect of Radix Glycyrrhizae extract. Results: Four compounds were isolated from the ethanol extract of Radix Glycyrrhizae, namely oleanolic acid, isoliquiritin, glycyrrhetinic acid and licochalcone A. Optical microscopic observation showed that the growth of gastric cancer cell line SGC-7901 was inhibited in the experimental groups, and apoptotic morphological changes were observed in adherent cells; flow cytometry with PI staining showed that Radix Glycyrrhizae extract could induce SGC-7901 cell apoptosis within a concentration range of 0.5-1.5 mg/mL, compared with the control group, the apoptosis was positively correlated with the drug concentration, which exhibited an apparent dose-dependence. Conclusion: We conclude Ethanol extract of Radix Glycyrrhizae has an anti-proliferative activity on SGC-7901 cells