Formulation and Comparative Characterization of Chitosan,Gelatin, and Chitosan–Gelatin-Coated Liposomes of CPT-11–HCl

Liposomes containing phosphatidylcholine and cholesterol (uncoated) and coated by chitosan, gelatin, and combination of chitosan and gelatin were prepared by the modified ethanol injection method. The aim of this work was to formulate and characterize liposomes of camptothecin (CPT)-11–HCl (Irinotecan HCl) containing chitosan, gelatin, and both polymers as coating materials; and also to increase its circulation longevity when compared with the free drug while maintaining the agent in its active lactone form. Size, shape, zeta potential, encapsulation efficiency, stability study, in vitro, and in vivo release study were used for characterization of liposomes. The size of liposomes was in the order of uncoated?<?chitosan coated?<?gelatin coated?<?combination of chitosan and gelatin coated. The zeta potential of liposomes was in the order of combination of chitosan and gelatin coated?>?chitosan coated?>?gelatin coated?>?uncoated. The formulations showed the long-term stability. The encapsulation efficiency of liposomes was in order of combination of chitosan and gelatin coated?>?gelatin coated?>?chitosan coated?>?uncoated. The in vitro and in vivo release of drug was observed in the order of combination chitosan and gelatin coated?>?gelatin coated?>?chitosan coated?>?uncoated.     

Size Distribution of SnO2 Quantum Dots Studied by UV–Visible, Transmission Electron Microscopy and X-Ray Diffraction

Measuring the size of the quantum dots (QDs) with accuracy is crucial considering its effect on the physical and chemical properties. Size determination of SnO₂ QDs prepared by a soft chemical method using various techniques and their correlation is reported here. Direct method like high resolution transmission electron microscopy (HRTEM), and indirect method like X-ray diffraction and ultra violet–visible (UV–Vis) techniques used for size determination and then correlated. Effective crystallite size found from TEM morphological analysis is 2.4 ± 0.1 nm, which matches closely with the crystallite size of 2.3 ± 0.1 nm as calculated using Williamson–Hall plot. Particle size is also calculated from UV–Vis spectroscopy following quantum confinement effect in SnO₂. The obtained slopes from the Tauc’s plot provide a distribution of particle sizes which matches well with the result from TEM analysis.     

Characterization of Ge–Bi–S glass by thermal, electrical, switching and optical measurements

A study of the synthesized Ge22.5Bi7S70.5 glassy system has been carried out. Differential thermal analysis data indicate the retention in the as-quenched sample of two amorphous phases. Thermal conductivity, , measurements on bulk sample reveal that the main contribution to is due to phonon thermal conductivity. Thermal evaporation of the synthesized ingot gives films with Ge20.7Bi6.8S72.5 as composition. The values of the activation energy and the pre-exponential factor calculated from the direct current electrical conductivity above 53 °C suggest that carrier conduction occurred between extended states in these films. The I–V characteristics in the off-state and the switching phenomenon are investigated. A memory switch with a threshold voltage decreasing with temperature is detected for the studied films. Optical parameters such as absorption coefficient, optical gap and refractive index are also determined. Comparison with binary Ge–S glass reveals that the addition of Bi introduces additional absorbing states at band edges. © 1998 Kluwer Academic Publishers     

Deciphering the Superior Electronic Transmission Induced by the Li–N Ligand Pairs Boosted Photocatalytic Hydrogen Evolution

Atomic level decoration route is designated as one of the attractive methods to regulate both the charge density and band structure of photocatalysts. Moreover, to enable more efficient separation and transport of photocarriers, the construction of novel active sites can enhance both the reactivity and electrical conductivity of the crystal. Herein, an Li–N ligand is constructed via co-doping lithium and nitrogen atoms into ZnIn₂S₄ lattice, which achieves a promoted photocatalytic H₂ evolution at 9737 µmol g⁻¹ h⁻¹. The existence of Li–N ligand pairs and the behaviors of photocarriers on L₄₀N₅ZIS are determined systematically, which also provides a unique insight into the mechanism of the improved photocarrier migration rate. With the introduction of Li–N dual sites, the vacancy form of ZnIn₂S₄ has changed and the photocatalytic stability is significantly improved. Interestingly, the change of charge density around Li–N ligand in ZnIn₂S₄ is determined by theoretical simulations, as well as the regulated energy barrier of photocatalytic water splitting caused by Li–N dual sites, which act as both adsorption site for H₂O and stronger reactive sites. This work helps to extend the understanding of ZnIn₂S₄ and offers a fresh perspective for the creation of a Li–N co-doped photocatalyst.     

High-Temperature Pyrometric Measurement of Thermal Diffusivity by a Flash Method: Co–Si and Co–Ge Systems

The paper deals with an automated system for measuring the thermal diffusivity of metals and alloys by a flash method involving the use of a contactless technique of recording the superheat temperature of a specimen. The solution of the heat equation for a cylinder with due regard for the Gaussian distribution of energy over the laser beam cross section forms the basis of the measurement method. The structural scheme of the experimental facility is described using an IBM PC and a GOR-100M type laser. The results of measuring the thermal diffusivity of Co–Si and Co–Ge systems in the temperature range of 300–1650 K are presented. The polytherms of the thermal diffusivity in the vicinity of the Curie point and in structural transitions exhibit anomalies. These anomalies are smoothed out as the concentrations of Si and Ge increase, and are not observed at a concentration of admixtures higher than 10 at. %. The obtained results are in satisfactory agreement with the diagrams of state for Co–Si and Co–Ge alloys.     

Characterization of corrosion phenomena of Zr–Ti–Cu–Al–Ni metallic glass by SEM and TEM

Corrosion phenomena are investigated for a Zr₅₉Ti₃Cu₂₀Al₁₀Ni₈ metallic glass immersed in hydrofluoric acid (HF) in open-circuit conditions and by means of electron microscopies (SEM and TEM). Several morphologies develop on the corroded surface and especially large and deep pits. TEM study demonstrates that Cu-rich nanocrystals of 5–10 nm are formed inside the corrosion pits (on their walls) during the corrosion process. These nanocrystals are not only by-products of the corrosion process but they very likely play a role in the development of the corrosion pitting morphology. They could have a dual role: (i) protecting the capped areas against dissolution and (ii) speeding the dissolution of neighboring uncapped areas by the creation of local galvanic cells.     

ZnO–TiO 2 nanocomposite: Characterization and moisture sensing studies

This paper reports morphological and relative humidity sensing behaviour of ZnO?CTiO ₂ nanocomposite powder pellets obtained through solid-state reaction route. Resistance of the pellets is observed to decrease with increase in relative humidity in the 10?C90% range. Sensing element with 15 wt % of TiO ₂ in ZnO shows best results with a sensitivity of 9 $\boldsymbol{\cdot}$ 08?M $\boldsymbol{\Omega} $ /%RH in 10?C90% relative humidity range. This sensing element manifests crystallite size of 71?nm as measured from XRD and average grain size of 207?nm calculated from SEM micrograph. This sensing element manifests low hysteresis, less effect of ageing and good reproducibility. Response and recovery times of this sensing element are measured to be 84?s and 396?s, respectively.     

Phosphogypsum:Part Ⅰ:Mineralogical,Thermogravimetric,Chemical and Infrared Characterization

1-IntroductionPGisanimportantindustrialby-productderivedfromphosphoricacidandphosphatefertilizerman-ufacturesbydihydrateprocess.Theamountofthiswasteexceedsconsiderablythanthemassoftheprod-uct,becausetheamountofthewastePGbeingpro-ducedintheacidrangesfrom4.5to5.5tpertonofPzOsintermsofdrymatter.ThePGissepa-ratedfromthemediumofdissolvedphosphateoreinsulphuricacidbyfiltration.WhereasthemajorpartofthepureP2O5isobtainedfromthesedimentbymeansofacountercurrentwashingwithwater[1'2l.Theobtainedfilter…     

Modifying a dental ceramic by bioactive glass via the sol–gel route: Characterization and bioactivity investigation

The modification of a widely used dental ceramic by a bioactive glass via sol–gel method resulted in the fabrication of novel dental ceramic composites with bioactive behavior. The presence of leucite (Lt), apatite (Ap), various calcium silicate phases (CS) and a glassy aluminosilicate matrix were detected, while after sintering the predominance of wollastonite (W) among the other calcium silicate phases was observed, along with further crystallization of apatite. Concerning the bioactivity, the onset of the apatite formation was directly dependent on the bioactive glass amount, while a delay of the sintered specimens compared to the raw powders was also observed.     

Characterization of Cu–Ni alloy electrodeposition and synthesis of nanoparticles by pulsed sonoelectrochemistry

Binary alloy Cu–Ni nanoparticles were synthesized by sonoelectrochemical technique from aqueous bath in presence of Na-citrate as complexing agent, to allow co-deposition of Cu and Ni. Alloy Pulsed Electro-Deposition (PED) was carried out to study nucleation kinetic and the effects of pH and surfactant on the final product physical and chemical properties, with the aim to determine optimized parameters for subsequent sonoelectrosyntheses of nanoparticles. Role of pH and Na-citrate in the synthesis process was investigated and it was found that i) pH is the main parameter affecting the stability of synthesis solutions, ii) Na-citrate content influences the sonoelectrochemical process efficiency but at the same time iii) the complexing agent is necessary to obtain Cu and Ni co-deposition; iv) produced nanoparticles are made of CuNi alloy with a fcc crystalline structure and v) pH is weakly responsible of increase in mean grain size of produced nanoparticles.     

Characterization of Erbium,Indium, and Erbium–Indium co-doped 8%mol Yttria-stabilized Zirconia

Journal of Materials Science: Materials in Electronics - In this work, the cubic structure of Yttria-stabilized Zirconia (8YSZ) and Indium and Erbium co-doped 8YSZ nanopowders have been prepared by...     

Characterization of silicon phases in spray-formed and extruded hypereutectic Al–Si alloys by image analysis

The silicon phases in the spray-formed and extruded hypereutectic Al–Si alloys (AlSi18, AlSi25 and AlSi35) have been quantitatively evaluated by means of image analysis technique. The influence of silicon content in the alloys, thermal conditions during spray forming of the alloys and hot extrusion of the spray-formed alloys on the size, shape, dispersion and orientation of the silicon phases have been studied and discussed. In general, the silicon phases are greatly refined and uniformly distributed in the spray-formed Al–Si alloys. This improvement in the silicon phases is further facilitated by low thermal input as well as fast cooling conditions during spray forming. The silicon particles in the as-extruded Al–Si alloys appear more homogeneous and regular than those in the as-deposited Al–Si alloys but exhibit a certain amount of anisotropy and a tendency to preferred orientation. The silicon particles, depending on the particle size and shape, may fracture or coarsen during extrusion.     

Synthesis and Characterization of Nanocrystalline Ni-Ti and Ni-Cr Powders by Mechanical Alloying

Nanocrystalline powders in the Ni-Ti and Ni-Cr systems were prepared by mechanical alloying (MA) of elemental crystalline powders in an inert atmosphere. The microstructure of the mechanically alloyed powders were characterized by XRD and TEM. The ball-milling process results in a drastic decrease of the crystallite size to the nanometer scale. X-ray diffraction analysis reveals that in the Ni-Cr system, no diffraction peaks from NiCr compound were observed even after 20 h of ball milling; while the lattice parameter of Ni increased with the milling time. In the Ni-Ti system, amorphous alloy was formed. Crystalline intermetallic compounds were obtained by post heat treatment of the amorphous alloy.The crystallization temperature of the amorphous NiTi alloy was obtained be DSC measurement.     

Characterization of hydroxyapatite– and bioglass–316L fibre composites prepared by spark plasma sintering

To improve the mechanical properties of pure hydroxyapatite (HA) ceramics and pure 45S5 bioglasses, HA–316L fibre composites and bioglass 45S5–316L fibre composites were produced by spark plasma sintering (SPS) at 950 and 850 °C, respectively. While the HA phase in the HA–316L fibre composites did not decompose after the SPS process, microcracks were found around the 316L fibres in the composites. Consequently, the HA–316L fibre composites could not effectively improve the mechanical properties of the pure HA ceramics. In contrast, the bioglass 45S5–316L fibre composites showed no microcracks around the 316L fibres and thus exhibited bending strengths of up to 115 MPa.     

Cyber–Physical Production Systems for Data-Driven,Decentralized, and Secure Manufacturing—A Perspective

With the concepts of Industry 4.0 and smart manufacturing gaining popularity, there is a growing notion that conventional manufacturing will witness a transition toward a new paradigm, targeting innovation, automation, better response to customer needs, and intelligent systems. Within this context, this review focuses on the concept of cyber–physical production system (CPPS) and presents a holistic perspective on the role of the CPPS in three key and essential drivers of this transformation: data-driven manufacturing, decentralized manufacturing, and integrated blockchains for data security. The paper aims to connect these three aspects of smart manufacturing and proposes that through the application of data-driven modeling, CPPS will aid in transforming manufacturing to become more intuitive and automated. In turn, automated manufacturing will pave the way for the decentralization of manufacturing. Layering blockchain technologies on top of CPPS will ensure the reliability and security of data sharing and integration across decentralized systems. Each of these claims is supported by relevant case studies recently published in the literature and from the industry; a brief on existing challenges and the way forward is also provided.     

High Pressure Phase Equilibria in the Systems Ammonia+Potassium Iodide, +Sodium Iodide, +Sodium Bromide, and +Sodium Thiocyanate: Solid–Liquid–Vapor and Liquid–Liquid–Vapor Equilibria

Solid salt–liquid–vapor equilibria and liquid–liquid–vapor equilibria were determined experimentally for the binary system NH₃+KI in the temperature range 333 to 673 K and at pressures up to 80 MPa. It is found that the system NH₃+KI belongs to Type V of fluid phase behavior according to the classification of van Konynenburg and Scott. The pressure of the three-phase curve solid salt–liquid–vapor is monotonically increasing in the temperature range investigated and reaches a value of 76 MPa at 670 K. The three-phase liquid–liquid–vapor curve starts in a lower critical end point at 407.3 K and 11.59 MPa and ends in an upper critical end point at 408.8 K and 11.92 MPa. For the systems NH₃+NaI, NH₃+NaBr, and NH₃+NaSCN, Type V fluid phase behavior is also found. In the system NH₃+NaI, the lower critical end point is found at 406.8 K and 11.52 MPa and the upper critical end point at 408.5 K and 11.86 MPa. For the system NH₃+NaBr, these coordinates are 404.6 K, 11.03 MPa and 408.8 K, 11.90 MPa, respectively, and, for the system NH₃+NaSCN, 409.2 K, 11.99 MPa and 409.6 K, 12.06 MPa.     

Characterization and corrosion behavior of NiTi–Ti2Ni–Ni3Ti multiphase intermetallics produced by vacuum sintering

An in-situ synthesis method was employed to produce NiTi–Ti₂Ni–Ni₃Ti multiphase intermetallics. In this regard, the amorphous/nanocrystalline Ni–Ti powders were sintered at 1300 °C for 2 hrs to obtain Ni–Ti alloys with dense structure. Tafel polarization tests were employed to study corrosion behavior of multiphase materials in 3.5% NaCl and 0.1 M H₂SO₄ corrosive media. The results indicated that the microstructure of sintered samples consists of NiTi(Fe) and Ti₂Ni/Ti₄Ni₂O_x phases embedded in a Ni₃Ti matrix. The synthesized multiphase materials had microhardness up to 873 HV1 kg.Further investigations showed the corrosion performance of multiphase samples in 3.5% NaCl solution was inferior to that of wrought NiTi alloy. In contrast, the corrosion resistance of multiphase samples in 0.1 M H₂SO₄ solution was comparable to that of wrought NiTi alloy.     

Development and Characterization of Cr3C2–NiCr Coated Superalloy by Novel Cold Spray Process

The coating deposition by cold spray process depends upon the mechanical properties of both the coating and substrate materials. This results in variation of the coating microstructure for different coating–substrate system materials. In this study cold sprayed 75%Cr₃C₂–25%(Ni–20%Cr) coating–superalloy system is developed. The microstructure of the coating obtained is suitable for restricting the penetration of corrosive species toward the substrate. The techniques of X-ray diffraction (XRD), scanning electron microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDX), and elemental X-ray analysis were used for characterization of the newly developed cold spray coated superalloy.     

Characterization of hollow silica–polyelectrolyte composite nanoparticles by small-angle X-ray scattering

Hollow silica–polyelectrolyte composite nanoparticles were prepared using templates of spherical polyelectrolyte brushes which consist of a polystyrene (PS) core and a densely grafted linear poly(acrylic acid) shell. The obtained hollow particles were systematically studied by small-angle X-ray scattering (SAXS) in combination with other characterization methods such as transmission electron microscopy and dynamic light scattering. The hollow structure formed by dissolving the PS core was confirmed by the reduction of electron density to zero in the cavity through fitting SAXS data. SAXS revealed both the inward and outward expansions of the hollow silica–polyelectrolyte composite particles upon increasing pH from 3 to 9, while further increasing pH led to the partial dissolution of silica layer and even destruction of the hollow structure. SAXS was confirmed to be a unique and powerful characterization method to observe hollow silica nanoparticles, which should be ideal candidates for controlled drug delivery.