Review on recent advances of zinc substituted cobalt ferrite nanoparticles: Synthesis characterization and diverse applications

Researchers have taken a prodigious consideration in characterizing and synthesizing zinc substituted cobalt ferrite nanoparticles because of their substantial applications across diverse technological and industrial fields. Zinc substituted cobalt ferrite nanoparticles are a class of lenient magnetic nanomaterials, which have potentially high magnetic, optical, electrical, and dielectric properties. These properties include a high value of permeability, low power losses, permittivity, saturation magnetization, coercivity, resistivity, and other beneficial properties that make them promise candidates for applications in various fields. These ferrites are also used in biomedical areas such as MRI and cancer treatments. In electronic fields, zinc substituted cobalt ferrite nanoparticles are used to make transducers, transformers, biosensors, and sensors. Apart from these advantages, they are found in our everyday electronic and electrical appliances like LED bulb, refrigerator, mobile charger, TV, microwave oven, juicer, washing machine, mixer, iron, printer, laptop, mobile, desktop, etc. Hence, the current review reports some properties of these spinel ferrites and emphasizes the different synthesis techniques that can be used to prepare them. Afterward, the impact of dopant on the materials' properties, the characterization techniques, and the momentous application in the present era have been well discussed.     

科帕卡格拉纳建筑 奥地利维亚纳

正科帕卡格拉纳位于新多瑙河12.5公里处,毗邻Reichsbrücke大桥。出于同旧有设计保持协调性考虑,力求能让大楼融入当地环境,迎合自身功能性需要,GERNER GERNER PLUS团队充分考虑现有周边环境,对大楼重新规划设计。新的设计突显建筑的特殊性和重要性,面向河流的立面是科帕卡格拉纳大楼最重要的部分,所以设计的重点也放在了这里。现有的城市中轴线是一个参照物,为了视觉上和氛围上形成一体化城市的感     

An Organoid for Woven Bone

Bone formation (osteogenesis) is a complex process in which cellular differentiation and the generation of a mineralized organic matrix are synchronized to produce a hybrid hierarchical architecture. To study the mechanisms of osteogenesis in health and disease, there is a great need for functional model systems that capture in parallel, both cellular and matrix formation processes. Stem cell-based organoids are promising as functional, self-organizing 3D in vitro models for studying the physiology and pathology of various tissues. However, for human bone, no such functional model system is yet available. This study reports the in vitro differentiation of human bone marrow stromal cells into a functional 3D self-organizing co-culture of osteoblasts and osteocytes, creating an organoid for early stage bone (woven bone) formation. It demonstrates the formation of an organoid where osteocytes are embedded within the collagen matrix that is produced by the osteoblasts and mineralized under biological control. Alike in in vivo osteocytes, the embedded osteocytes show network formation and communication via expression of sclerostin. The current system forms the most complete 3D living in vitro model system to investigate osteogenesis, both in physiological and pathological situations, as well as under the influence of external triggers (mechanical stimulation, drug administration).     

One-pot synthesis of gelatin-based,slow-release polymer microparticles containing silver nanoparticles and their application in anti-fouling paint

Gelatinous polymer matrix microparticles containing silver nanoparticles (AgNPs) were prepared by a novel method to obtain quasi non-swelling anti-fouling paint additives with slow-release characteristics. A w/o type dispersion were elaborated with the aqueous phase of gelatin, urea, silver-nitrate and formaldehyde dispersed in linseed oil. Gelatin was cross-linked by formaldehyde, together with urea for limiting the swelling of the product. Silver-nitrate was reduced with the assistance of gelatin and formaldehyde into homogenously dispersed AgNPs. The microparticles and embedded AgNPs were visualized by scanning and transmission electronmicroscopy. Encapsulated AgNPs with ∼18 nm crystallite size were identified by X-ray powder diffraction. Characterization of gelatin–urea–formaldehyde polymer matrices was carried out by attenuated total reflectance FTIR spectroscopy. Silver dissolution from microparticles and paints with AgNP-containing microparticles was measured by inductively coupled plasma spectrometer and resulted in highly sustained release, compared to unmodified gelatin microparticles and paints containing uncapsulated silver salts. A 7-month-long fouling experiment run in natural sweetwater media showed that solvent-based acrylic paint with AgNPs-containing gelatinous microparticles as additives offered resistance against biofouling at low Ag-release ratio.     

Experimentelle und numerische Untersuchungen von Brandszenarien vor Fassaden unter Berücksichtigung verschiedener Abstände

Experimental and numerical investigations of fire scenarios in front of façades considering various distances Constructional boundary conditions, e. g. walls or façades, close to ignition sources affect the fire formation and the plume. It is already known, that boundaries (e. g. walls) constrain the entrainment of air and oxygen into the plume and the combustion of gas or flammable products is completed at larger heights. How far the location of the fire sources, the building geometry and the heat release rate affect the characteristics of a flame is investigated at the Institut für Baustoffe, Massivbau und Brandschutz (iBMB) of TU Braunschweig in line with a series of experiments with a square gas burner. For the implementation of the fire tests the test rig in Braunschweig is provided with extensive measurement techniques to determine heat flux, wall‐bounded temperatures, temperatures for plume measurements and upward velocity. In this paper the data of the fire tests are discussed and compared with the results of a CFD‐Model and selected empirical calculation approaches.     

Enhanced selectivity to benzaldehyde in the liquid phase oxidation of benzyl alcohol using nanocrystalline ZSM-5 zeolite catalyst

In the present paper, nanocrystalline hierarchical ZSM-5 zeolites were successfully synthesized by the hydrothermal method in the presence of tetrapropylammonium hydroxide as a single template with the gel composition of 58SiO₂:Al₂O₃:20TPAOH:1,500H₂O. The prepared zeolite catalysts were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Nitrogen adsorption–desorption (BET), scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HR-TEM) techniques. The formation of pure and highly crystalline ZSM-5 zeolite phase is confirmed by XRD. The IR vibration band at 550 cm^?1 is assigned to the double 5-rings of MFI-type zeolites. N₂ adsorption–desorption isotherms showed that the synthesized product had high BET surface area and possessed composite pore structures with both micro and mesopores. The catalytic performance of hierarchical ZSM-5 zeolite was investigated in the selective oxidation of benzyl alcohol (BzOH) with hydrogen peroxide (H₂O₂) under mild conditions. The results showed that the conversion of BzOH and the selectivity to benzaldehyde were about 94 and about 99 % respectively, when using 0.08 g ZSM-5 catalyst with acetonitrile as the solvent and H₂O₂ as the oxidant at 90 °C. This catalyst can be retrieved and reprocessed for five times without a significant loss in its activity and selectivity.