29 research outputs found
Value added utilization of by-product electric furnace ferronickel slag as construction materials: A review
This paper reviews the potential use of electric furnace ferronickel slag (FNS) as a fine aggregate and binder in Portland cement and geopolymer concretes. It has been reported that the use of FNS as a fine aggregate can improve the strength and durability properties of concrete. Use of some FNS aggregates containing reactive silica may potentially cause alkali-silica reaction (ASR) in Portland cement concrete. However, the inclusion of supplementary cementitious materials (SCM) such as fly ash and blast furnace slag as partial cement replacement can effectively mitigate the ASR expansion. When finely ground FNS is used with cement, it shows pozzolanic reaction, which is similar to that of other common SCMs such as fly ash. Furthermore, 20% FNS powder blended geopolymer showed greater strength and durability properties as compared to 100% fly ash based geopolymers. The utilization of raw FNS in pavement construction is reported as a useful alternative to natural aggregate. Therefore, the use of by-product FNS in the construction industry will be a valuable step to help conservation of natural resources and add sustainability to infrastructures development. This paper presents a comprehensive review of the available results on the effects of FNS in concrete as aggregate and binder, and provides some recommendations for future research in this field
Towards molecular breeding of reproductive traits in cereal crops
The transition from vegetative to reproductive phase, flowering per se, floral organ development, panicle structure and morphology, meiosis, pollination and fertilization, cytoplasmic male sterility (CMS) and fertility restoration, and grain development are the main reproductive traits. Unlocking their genetic insights will enable plant breeders to manipulate these traits in cereal germplasm enhancement. Multiple genes or quantitative trait loci (QTLs) affecting flowering (phase transition, photoperiod and vernalization, flowering per se), panicle morphology and grain development have been cloned, and gene expression research has provided new information about the nature of complex genetic networks involved in the expression of these traits. Molecular biology is also facilitating the identification of diverse CMS sources in hybrid breeding. Few Rf (fertility restorer) genes have been cloned in maize, rice and sorghum. DNA markers are now used to assess the genetic purity of hybrids and their parental lines, and to pyramid Rf or tms (thermosensitive male sterility) genes in rice. Transgene(s) can be used to create de novo CMS trait in cereals. The understanding of reproductive biology facilitated by functional genomics will allow a better manipulation of genes by crop breeders and their potential use across species through genetic transformation
In-situ transition of amorphous gels to Na-P1 zeolite in geopolymer: Mechanical and adsorption properties
Turning amorphous gels of fly ash-based geopolymers into zeolite(s) can improve their adsorption properties for the potential use of wastewater treatment. This study investigates the optimal crystallization conditions under which Na-P1 zeolite forms and the relationship between the extent of crystallization, the resulting microstructure, and the compressive strength. The results indicate that a curing temperature of 90 °C is more effective when forming Na-P1 zeolite in geopolymers than a curing temperature of 60 °C. The most suitable alkali concentration (wt% Na2O/fly ash) and alkali activator modulus (n(SiO2)/n(Na2O)) are 15 and 1.5, respectively. The transition of amorphous gels into crystalline zeolites, i.e., more ordered structures, leads to a certain loss of compressive strength. However, the optimal matrix still retains 13.5 MPa of compressive strength. The cation exchange capacity (CEC) of the geopolymer matrix is demonstrated to be a function of the crystalline extent, and the highest CEC occurs in the optimal in-situ transformed geopolymer
Optical coherence tomography biomarkers as predictors of transition to chronic central serous chorioretinopathy after retinal laser photocoagulation
Objectives: To explore the optical coherence tomography (OCT) biomarkers to predict the transition to chronic central serous chorioretinopathy (cCSC) after retinal laser photocoagulation. Methods: Patients enrolled in this study were from a 12-week clinical trial comparing the efficacy and safety of subthreshold micropulse laser (SML) with threshold conventional laser (TCL) for CSC and had extended follow-up for more than 1 year. They were divided into two groups, transited to cCSC group (cCSC group) and did not transited to cCSC group (non-cCSC group) according to fundus examination at the extended follow-up. Collect the best-corrected visual acuity (BCVA) and OCT characteristics of patients at baseline and 12 weeks after laser treatment. Results: Twenty-seven patients were enrolled (42.6 ± 7.7 years old), and duration of follow-up was 178.9 ± 88.8 (57.0–312.0) weeks. Nine patients (33.3%) were assigned to cCSC group, and the other 18 patients (66.7%) were assigned to the non-cCSC group. Twelve weeks after the laser treatment, subretinal fluid (SRF) of 15 patients (83.3%) in non-cCSC group and 5 patients (55.6%) in cCSC group absorbed completely; the height of SRF had statistical difference between two groups ( p  = 0.035); rough RPE was less common in cCSC group ( p  = 0.030); hyper reflective mass (HRM) was more common in cCSC group ( p  = 0.024); more number of hyper reflective foci (HRF) in outer segment of photoreceptor layer were detected in cCSC group ( p  = 0.035). From baseline to 12 weeks after laser treatment, the number of HRF in outer segment photoreceptor layer did not change significantly in cCSC group ( p  = 0.665) but decreased significantly in non-cCSC group ( p  = 0.000). A total of five patients suffered binocular CSC, three of them in the non-cCSC group occurred later than the other two in the cCSC group (129.9–278.3 weeks vs 96.1–114.9 weeks after baseline). Conclusion: SRF, rough RPE, HRM, and number of HRF in outer segment photoreceptor layer 12 weeks after laser treatment, and change in the number of HRF in outer segment photoreceptor layer from baseline to 12 weeks after laser treatment may predict the transition to cCSC
Soft Lattice Implication Subalgebras
In this paper, we introduce the concepts of soft lattice implication subalgebras, endow a parameter set as a lattice implication algebra, and further discuss its equivalent characterization. Then, new operations of soft lattice implication subalgebras are introduced, under which two soft lattice implication subalgebras is also a soft lattice implication subalgebra. Finally, the concepts of image and preimage of a soft lattice implication subalgebra and their properties are presented
Risk-Association of DNMT1 Gene Polymorphisms with Coronary Artery Disease in Chinese Han Population
Recently, a significant epigenetic component in the pathogenesis of Coronary Artery Disease (CAD) has been realized. Here, we evaluated the possible association of candidate Single Nucleotide Polymorphisms (SNPs) in the epigenetic-regulatory gene, DNA methyltransferase 1 (DNMT1), with CAD in Chinese Han population. Five tag SNPs (rs16999593, rs2336691, rs2228611, rs4804494, rs7253062) were analyzed by High Resolution Melt (HRM) method in 476 CAD patients and 478 controls. Overall, there were significant differences in the genotype and allele distributions of rs2228611 and rs2336691, between patients and controls. The minor A allele of rs2228611 was associated with a lower risk of CAD (p = 0.034); modest effect in the additive analysis but also marginal significance was found in the recessive model [ORadditive = 0.404 (0.184, 0.884), p = 0.023 and ORrecessive = 0.452 (0.213, 0.963), p = 0.040] after adjusting for confounders. While the rs2336691 A allele were associated with a higher risk of developing CAD (p = 0.037); borderline significant association in both additive and dominant models [ORadditive = 1.632 (1.030, 2.583), p = 0.037 and ORdominant = 1.599 (1.020, 2.507), p = 0.040]. In conclusion, these data provide the first evidence that occurrence of CAD may be moderated by genetic variation in the gene involved in the epigenetic machinery
A knowledge graph-aided concept–knowledge approach for evolutionary smart product–service system development
In order to meet user expectations and to optimize user experience with a higher degree of flexibility and sustainability, the Smart product–service system (Smart PSS), as a novel value proposition paradigm considering both online and offline smartness, was proposed. However, conventional manners for developing PSS require many professional consultations and still cannot meet with the new features of Smart PSS, such as user context-awareness and ever-evolving knowledge management. Therefore, aiming to assist Smart PSS development cost-effectively, this paper adopted the knowledge graph (KG) technique and concept–knowledge (C-K) model to propose an evolutionary design approach. Two knowledge graphs are firstly established with open-source knowledge, prototype specifications, and user-generated textual data. Then, triggered by personalized requirements, four KG-aided C-K operators are conducted based on graph-based query patterns and computational linguistics algorithms, thus generating innovative solutions for evolving Smart PSS. To validate the performance of the proposed approach, a case study of a smart nursing bed fulfilling multiple personalized requirements is conducted, and the evaluation result of its knowledge evolution is acceptable. It hopes that this work can offer insightful guidance to industrial organizations in their development of Smart PSS.National Research Foundation (NRF)This work is conducted within the Delta-NTU Corporate Lab for Cyber-Physical Systems with funding support from Delta Electronics Inc and the National Research Foundation (NRF) Singapore under the Corporate Laboratory @ University Scheme (Ref. RCA-16/434; SCO-RP1) at Nanyang Technological University, Singapore, and National Natural Science Foundation of China (No. 71671113). The authors are also grateful for the contributions from members of the nursing bed project at Shanghai Jiao Tong University and the medical suggestions from physicians in Huashan Hospital, Shanghai
Chloride diffusion in alkali-activated fly ash/slag concretes: Role of slag content, water/binder ratio, alkali content and sand-aggregate ratio
The widespread application of alkali-activated fly ash/slag (AAFS) concrete requires the satisfaction of a series of performance criteria both from its early age properties (e.g. workability, strength) and long-term stability. In this study, long-term (till 180 days) natural chloride diffusion tests were conducted to evaluate the chloride diffusion in AAFS concretes prepared with different slag content, water/binder (w/b) ratio, alkali content, and sand-aggregate ratio. The results revealed that AAFS concretes obtained in this study were generally regarded as flow/high flow concretes (slump > 100 mm) with compressive strength > 50 MPa at 28 day. The free chloride diffusion coefficient (Df) of AAFS concretes was between 0.4 and 1.8 × 10-12 m2/s. The slag content and w/b were found as dominant parameters affecting the long-term chloride transport in AAFS concretes, while the sand-aggregate ratio presented a limited effect. The formation of more C-A-S-H gels (by increasing slag content ≥ 50%), and lower w/b (≤0.45) at Na2O content of ∼ 5% was preferred for AAFS concretes with good workability, strength and durability. MIP results indicated that capillary pores in AAFS reached percolation and became disconnected after 180 days. The long-term chloride diffusivity of AAFS concretes was closely related to the threshold pore diameter and volume of pores > 5 nm. The more larger pores, the higher chloride diffusion coefficient was
Evaluation of a dynamic navigation system for endodontic microsurgery: study protocol for a randomised controlled trial
Introduction Endodontic microsurgery is a very important technique for preserving the natural teeth. The outcomes of endodontic microsurgery largely depend on the skill and experience of the operators, especially for cases in which the apices are located far away from the labial/buccal cortical bone. A dynamic navigation system (DNS) could provide a more accurate and efficient way to carry out endodontic microsurgery. This study is devoted to comparing the clinical outcomes of the DNS technique with those of the freehand technique.Methods and analysis Sixteen patients will be randomly assigned to one of two groups. For the experimental group, the osteotomy and root-end resection will be performed under the guidance of dynamic navigation. For the control group, these procedures will be performed freehand by an endodontist. The required time to perform these procedures will be used to evaluate the efficiency of the DNS technique. A Visual Analogue Scale will be used to evaluate pain at 1, 3 and 7 days after endodontic microsurgery. Preoperative and postoperative cone beam CT scans will be obtained to evaluate the accuracy of the DNS technique. The global coronal deviations, the apical deviations and the angular deflection will be measured. The root-end resection length deviation, the root-end resection angle deviations, the extent of the osteotomy and the volume change of the buccal cortical bone will also be measured. Periapical radiographs will be obtained to evaluate the outcome at 1 year after microsurgery. The time to execute the study, including follow-ups, will last from 1 June 2022 to 31 December 2025.Ethics and dissemination The present study has received approval from the Ethics Committee of Peking University School and Hospital of Stomatology. The results will be disseminated through scientific journals.Trial registration number ChiCTR2200059389