Effective and Simple NaOH-Modification Method to Remove Methyl Violet Dye via Ipomoea aquatica Roots

In this study, a simple chemical modification was applied to a sustainable and abundantly available resource, kangkong root (KR), to remove methyl violet 2B (MV) dye. The chemically modified adsorbent (NaOH-KR) was obtained using NaOH solution treatment. Batch adsorption experiments were carried out to investigate the effects of pH, ionic strength, contact time, adsorbent dosage, and initial dye concentration. A regeneration experiment was also carried out to assess the potential of reusability. The adsorption process was modelled using various kinetics and isotherm models, whereby the best-fitting models were evaluated by using the coefficient of determination ( R 2 ) and error functions. The Sips ( R 2 = 0.9714 , χ2 =0.16) and pseudo-second-order ( R 2 = 0.9996 , χ 2 = 0.007 ) models were identified to best represent the adsorption process. The Sips model predicted a maximum adsorption capacity at 551.5 mg g-1 for NaOH-KR, which is 55% improvement in performance when compared to nonmodified KR. Lastly, the regeneration experiment showed that NaOH-KR was able to maintain reasonable dye removal even after five consecutive cycles of regenerating and reusing.

Ponies, Joints, Complexity and the Method of Indifference

An important discipline in biomedical science is the repair of damaged organs by in vitro cultured differentaited stem cells. This article evaluates an article in this field, entitled "The complexity of joint regeneration", by Diloloksumpan et al. (2021), who described a regeneration experiment of artificial damage of the joint of ponies. The experiment failed an I describe the possible cause of this failure by discussing the design of the experiment in the light of J.S.Mill's Method of Difference, published in 1848. I continue with a discussion of the concept of complexity that was introduced by the authors of the paper, by pointing out that three types of complexity may be distinguished; one of these is complicatedness which characterizes the assumed complexity of the joint experiment. I propose that this complicatedness can be solved by the use of the method of difference.

Calcineurin subunit B is involved in shell regeneration in Haliotis diversicolor

Abalone shells are mainly composed of two major polymorphs of CaCO3 that are distributed in different layers of the shell. The process of shell biomineralization is controlled by genes and proteins expressed within the mantle epithelium. In this present paper, we conducted a shell regeneration experiment to study the role of HcCNA and HcCNB (individual subunits of calcineurin) in shell biomineralization in H. diversicolor. The results of qPCR showed that HcCNB is upregulated to a greater extent than HcCNA in the mantle after shell notching. In vivo study of the effects of rHcCNB injection showed a significantly higher percentage of regenerated shell length, but not area, in the injected group compared to the control group. In addition, SEM observation of the inner surface of the regenerated shells revealed three different zones including prismatic, nacreous, and a distinct transition zone. Changes in the crystal organization and ultrastructure are clearly evident in these three zones, particularly after 3 weeks of rHcCNB administration. We hypothesize that this is due to faster biomineralization rates in the rHcCNB treated group. Taken together, our results demonstrate that HcCNB participates in shell regeneration in H. diversicolor. As calcineurin subunits have also been implicated in shell formation in bivalves, these findings suggest that calcineurin subunits may play important roles in biomineralization in all conchiferans.

Study on the preparation of amine-modified silicate MCM-41 adsorbent and its H2S removal performance

A series of APTMS ((3-aminopropyl)trimethoxysilane)-modified silicate MCM-41 adsorbents ( x-APTMS/MCM-41, x is the volume of APTMS per 1 g of silicate MCM-41) with different APTMS contents was prepared, and the effects of APTMS content on the desulfurization performance of the APTMS/MCM-41 adsorbents were studied in a fixed adsorption bed using H2S and N2 mixture as a model gas. The as-prepared adsorbents were characterized by X-ray diffraction analysis, N2 adsorption–desorption, Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, and energy-dispersive spectroscopy. The results showed that all the APTMS-modified x-APTMS/MCM-41 adsorbents retained the mesoporous silica structure of MCM-41. The Brunauer–Emmett–Teller-specific surface area of x-APTMS/MCM-41 increased slightly with increasing x at first and then decreased with further increasing APTMS content. The H2S removal performances of x-APTMS/MCM-41 adsorbents decreased in the order 0.6-APTMS/MCM-41 > 0.7-APTMS/MCM-41 > 0.5-APTMS/MCM-41 > 0.4-APTMS/MCM-41 > 0.8-APTMS/MCM-41. At x = 0.6, the maximum H2S removal rate of 54.2% and H2S saturated capacity of 134.4 mg g−1 were observed. The regeneration experiment of 0.6-APTMS/MCM-41 adsorbent after three times regeneration at 423 K for 3 h in nitrogen confirmed that it possessed a good regenerability.

Study on coordinated control of the energy regeneration and the vibration isolation in a hybrid electromagnetic suspension

A type of hybrid electromagnetic suspension is proposed in this study to improve the reliability of a conventional active electromagnetic suspension. A motor with the proposed hybrid electromagnetic suspension linear can regenerate the vibration energy; the coordination relationship between the energy regeneration and the vibration isolation of the hybrid electromagnetic suspension is studied. A dynamic model is established, and a modified skyhook control strategy is designed. A passive energy regeneration control system and an active control system are developed. The effect of the damping on the energy regeneration and the vibration isolation is discussed. The best damping, which can consider the energy regeneration and the vibration isolation simultaneously, is determined. Comparative simulations of a passive suspension, a hybrid electromagnetic suspension and an active electromagnetic suspension are carried out, and the results verify the effectiveness of the control strategy. Finally, an energy regeneration experiment and an isolation comparative experiment of a quarter-suspension are conducted. The findings show that the hybrid electromagnetic suspension with a modified skyhook control strategy can efficiently facilitate coordination between the energy regeneration and the vibration isolation.

Dynamic Regeneration of D301f Anion Exchange Resin to Remove Nitrate Nitrogen in Wastewater

Nitrate nitrogen in wastewater poses serious threat. D301f anion exchange resin can remove nitrate nitrogen in wastewater, its regeneration is one of the most important procedures, because regeneration efficiency has a direct impact on exchange capacity, water quality and regeneration agent consumption. D301f exchange resin column simulated nitrogen fertilizer plant wastewater (nitrate nitrogen300mg/L) for dynamic regeneration experiment. The results showed that, NH4OH regeneration agent dosage selected 3 to 4 times of theoretical amount more reasonable; regeneration solution concentration and temperature separately used 20% and 30°C better.