High Pressure Raman Spectroscopic Study of the Effects of n‐Ethylamines and Water on the 2‐Nitropropane/Nitric Acid System

High pressure Raman spectroscopy measurements in a diamond anvil cell (0–10 GPa) on 2‐nitropropane/nitric acid/X (X=triethylamine, diethylamine, and water) ternary systems and 2‐nitropropane/nitric acid/water/Y (Y=triethylamine and diethylamine) quaternary systems are reported. The modifications of the chemical behavior of the 2‐nitropropane/nitric acid model system, induced by the presence of triethylamine, diethylamine, and/or water, were studied at ambient and high pressure. At ambient pressure, the ionization of the nitric acid has been observed with each of the additives. Moreover, in the case of ethylamines, new peaks have been observed and the hypothesis of a 2‐nitropropane/ethylamine complex is advanced. At high pressure, the decomposition of the 2‐nitropropane/nitric acid system, with an oxygen balance near zero, has been observed only in presence of triethylamine. The role of each additive to the 2‐nitropropane/nitric acid system in the modification of the respective reducing and oxidizing character of the components, and in the reactivity of the system, is discussed. Several hypotheses are advanced concerning the sensitizing effect of the additives on the 2‐nitropropane/nitric acid system.     

MIL-100(Fe) Sub-Micrometric Capsules as a Dual Drug Delivery System

Nanoparticles of metal–organic frameworks (MOF NPs) are crystalline hybrid micro- or mesoporous nanomaterials that show great promise in biomedicine due to their significant drug loading ability and controlled release. Herein, we develop porous capsules from aggregate of nanoparticles of the iron carboxylate MIL-100(Fe) through a low-temperature spray-drying route. This enables the concomitant one-pot encapsulation of high loading of an antitumor drug, methotrexate, within the pores of the MOF NPs, and the collagenase enzyme (COL), inside the inter-particular mesoporous cavities, upon the formation of the capsule, enhancing tumor treatment. This association provides better control of the release of the active moieties, MTX and collagenase, in simulated body fluid conditions in comparison with the bare MOF NPs. In addition, the loaded MIL-100 capsules present, against the A-375 cancer cell line, selective toxicity nine times higher than for the normal HaCaT cells, suggesting that MTX@COL@MIL-100 capsules may have potential application in the selective treatment of cancer cells. We highlight that an appropriate level of collagenase activity remained after encapsulation using the spray dryer equipment. Therefore, this work describes a novel application of MOF-based capsules as a dual drug delivery system for cancer treatment.     

Use of FT-NIR and XPS techniques to distinguish cell hull fractions prepared by autolysis or HPH from Saccharomyces cerevisiae and Brettanomyces bruxellensis strains

Yeast hulls can be used to adsorb undesirable compounds such as volatile phenols that may be present in wine. To understand this adsorption process, the properties of the cell walls and their chemical composition need to be better understood. A study was conducted using four different yeast fractions of either autolysed or high-pressure homogeniser (HPH)-crushed yeast biomasses of Saccharomyces cerevisiae and Brettanomyces bruxellensis. Near-infrared spectroscopy (FT-NIR) coupled with X-ray photoelectron spectroscopy (XPS) was used and analysed by principal component analysis (PCA). The FT-NIR spectral region of Saccharomyces and Brettanomyces statistically analysed by PCA showed a clear discrimination accounting for 76% of the variation in the data for PC1; moreover, yeast hulls prepared from the same strain and subjected to two different treatments were also separated. These methods classify yeast cell hulls (YCH) according to strain, composition and treatment applied. Our results indicate that yeast hulls obtained by autolysis are less rich in proteins than those resulting from HPH treatment due to the high pressure that releases more proteins and exposes them on the surface of the cell wall. The composition of YCH at the extreme surface is similar to that found deeper in the wall.     

An experimental and numerical study of the suppression of jets,counterflow, and backflow in vortex units

Vortex units are commonly considered for various single and multiphase applications due to their process intensification capabilities. The transition from gas-only flow to gas–solid flow remains largely unexplored nonetheless. During this transition, primary flow phenomenon, jets, and secondary flow phenomena, counterflow and backflow, are substantially reduced, before a rotating solids bed is established. This transitional flow regime is referred to as the vortex suppression regime. In the present work, this flow transition is identified and validated through experimental and computational studies in two vortex units with a scale differing by a factor of 2, using spherical aluminum and alumina particles. This experimental data supports the proposed theoretical particle monolayer solids loading that allows estimation of vortex suppression regime solids capacity for any vortex unit. It is shown that the vortex suppression regime is established at a solids loading theoretically corresponding to a monolayer being formed in the unit for 1g-Geldart D- and 1g-Geldart B-type particles. The model closely agrees with experimental vortex suppression range for both aluminum and alumina particles. The model, as well as the experimental data, shows that the flow suppression regime depends on unit dimensions, particle diameter, and particle density but is independent of gas flow rate. This combined study, based on experimental and computational data and on a theoretical model, reveals the vortex suppression to be one of the basic operational parameters to study flow in a vortex unit and that a simple monolayer model allows to estimate the needed solids loading for any vortex device to induce this flow transition.     

HOUSING AND LAND POLICIES IN DELHI

ABSTRACT: Land and housing policies in New Delhi have great significance in urban policy. When the Delhi Development Authority was given substantial powers to purchase land and plan its use, it had the potential to innovate and create an example of “best practice” in urban development in developing countries. For a variety of situational, political, and managerial reasons, the opportunity was lost. This paper offers an explanation, evaluates the loss of potential, and indicates the reforms which are necessary to achieve better results.     

A mixed valence compound in the two dimensional MPS3 family: V0.78PS3 structure and physical properties

The non stoichiometric compound V_0.78PS₃ has been obtained as single crystals from a preparation corresponding to the atomic ratio V/P/S = 1/1/3. It cristallizes with monoclinic symmetry, space group C2/m, with the unit cell parameters $\text{a}\text{= 5.867(1)}\text{A}\text{?}\text{,}\text{b}\text{= 10.160(2)}\text{A}\text{?}\text{,}\text{c}\text{= 6.657(1)}\text{A}\text{?}\text{, β = 107.08(2)°,}\text{V}\text{= 379.3(1)}\text{A}\text{?}{}^3$ and Z =4. The structure refinement was made down to a reliability factor value R = 3.3% from 445 reflexions (I > 3 σ (I)) and 31 variables. The material has same layer structure as FePS₃ with the occurrence of the thiophosphate anion (P₂S₆)^4?-including a P₂ pair. In V_0.78PS₃, the charge equilibrium implies the following developped formula : V_0.34^II V_0.44^III □_0.22 P^IV S₃^?II. The phase is a semi-conductor with a small activation energy of 0.24 eV, in accord with a vanadium mixed valence, and it presents, at low temperature, an antiferromagnetic order (T_N = 62 K).     

Structural determination of some MPS3 layered phases (M = Mn,Fe, Co,Ni and Cd)

The structures of most of the MPS₃ phases (M = Mn, Fe, Co, Ni, Cd) were determined from single crystal analysis. They show the expected CdCl₂ structural type, some weak disorder on the cationic sites being detected on NiPS₃ and CoPS₃. Fair stoichiometry is inferred for the phases since no interslab cation could be seen in the Van der Waals' gap of the structures. Polytypism may occur in the case of NiPS₃.     

用于433 MHz ISM频带的低功耗超再生接收器

设计师经常选择超再生接收器(super-regenerative receiver)——尽管它的频率不稳定,选择性较差——用于那些以功耗为主要问题的电池供电短距离无线应用,例如远程无钥匙进入系统,汽车警报、生物医学监视器、传感器网络、计算机外设     

2.36 /spl mu/m diode pumped VCSEL operating at room temperature in continuous wave with circular TEM/sub 00/ output beam

Operation of a diode-pumped AlGaAsSb/GaInAsSb type-I quantum-well vertical cavity surface emitting laser emitting near 2.36 /spl mu/m is reported. The epitaxial structure, grown on GaSb by molecular beam epitaxy consists of a GaSb/AlAsSb Bragg reflector and a GaInAsSb/AlGaAsSb active region. A circular TEM/sub 00/ low-divergence laser operation is demonstrated in continuous-wave mode operation from 268 up to 308K. A threshold of 5.5 kW/cm/sup 2/ at 268K has been measured.     

Mesure des circuits monolithiques hyperfréquences base d’une bonne conception

The aim of this article is to show how important are the measurements to design Microwave Monolithic Integrated Circuits. The following items will be discussed : the existing links between tests and modeling of linear devices, the creation of a measurement station, the use of an on-wafer accurate calibration procedure, and the utilization of these tests for circuit design. Corresponding results will be compared to those provided by a standard calibration and also to computation of models, for passive and active devices. The efforts made during caracterization of elements allow thus a better understanding and design, thanks to a very precise modeling.