Perkembangan Teori Sewa Tanah dalam Perspektif Pemikiran Ekonomi

A history of Land Rent Theorities have several opinions, as mazhab of Physiocratic, classical tradition, and new. The different opponions can be understanding for knowing two factors that land value increasingly location to central bussines and fertile soil

Direct <i>in Situ</i> Determination of the Mechanisms Controlling Nanoparticle Nucleation and Growth

Although nanocrystal morphology is controllable using conventional colloidal synthesis, multiple characterization techniques are typically needed to determine key properties like the nucleation rate, induction time, growth rate, and the resulting morphology. Recently, researchers have demonstrated growth of nanocrystals by <i>in situ</i> electron beam reduction, offering direct observations of single nanocrystals and eliminating the need for multiple characterization techniques; however, they found nanocrystal morphologies consistent with two different growth mechanisms for the same electron beam parameters. Here we show that the electron beam current plays a role analogous to the concentration of reducing agent in conventional synthesis, by controlling the growth mechanism and final morphology of silver nanocrystals grown via <i>in situ</i> electron beam reduction. We demonstrate that low beam currents encourage reaction limited growth that yield nanocrystals with faceted structures, while higher beam currents encourage diffusion limited growth that yield spherical nanocrystals. By isolating these two growth regimes, we demonstrate a new level of control over nanocrystal morphology, regulated by the fundamental growth mechanism. We find that the induction threshold dose for nucleation is independent of the beam current, pixel dwell time, and magnification being used. Our results indicate that <i>in situ</i> electron microscopy data can be interpreted by classical models and that systematic dose experiments should be performed for all future <i>in situ</i> liquid studies to confirm the exact mechanisms underlying observations of nucleation and growth

Direct Observation of Aggregative Nanoparticle Growth: Kinetic Modeling of the Size Distribution and Growth Rate

Direct observations of solution-phase nanoparticle growth using in situ liquid transmission electron microscopy (TEM) have demonstrated the importance of “non-classical” growth mechanisms, such as aggregation and coalescence, on the growth and final morphology of nanocrystals at the atomic and single nanoparticle scales. To date, groups have quantitatively interpreted the mean growth rate of nanoparticles in terms of the Lifshitz–Slyozov–Wagner (LSW) model for Ostwald ripening, but less attention has been paid to modeling the corresponding particle size distribution. Here we use in situ fluid stage scanning TEM to demonstrate that silver nanoparticles grow by a length-scale dependent mechanism, where individual nanoparticles grow by monomer attachment but ensemble-scale growth is dominated by aggregation. Although our observed mean nanoparticle growth rate is consistent with the LSW model, we show that the corresponding particle size distribution is broader and more symmetric than predicted by LSW. Following direct observations of aggregation, we interpret the ensemble-scale growth using Smoluchowski kinetics and demonstrate that the Smoluchowski model quantitatively captures the mean growth rate and particle size distribution

Direct Observation of Aggregative Nanoparticle Growth: Kinetic Modeling of the Size Distribution and Growth Rate

Direct observations of solution-phase nanoparticle growth using in situ liquid transmission electron microscopy (TEM) have demonstrated the importance of “non-classical” growth mechanisms, such as aggregation and coalescence, on the growth and final morphology of nanocrystals at the atomic and single nanoparticle scales. To date, groups have quantitatively interpreted the mean growth rate of nanoparticles in terms of the Lifshitz–Slyozov–Wagner (LSW) model for Ostwald ripening, but less attention has been paid to modeling the corresponding particle size distribution. Here we use in situ fluid stage scanning TEM to demonstrate that silver nanoparticles grow by a length-scale dependent mechanism, where individual nanoparticles grow by monomer attachment but ensemble-scale growth is dominated by aggregation. Although our observed mean nanoparticle growth rate is consistent with the LSW model, we show that the corresponding particle size distribution is broader and more symmetric than predicted by LSW. Following direct observations of aggregation, we interpret the ensemble-scale growth using Smoluchowski kinetics and demonstrate that the Smoluchowski model quantitatively captures the mean growth rate and particle size distribution

<i>P. falciparum</i>-derived uric acid induces TNF, IL-6 and IL-1β release from PBMCs.

<p>PBMCs were incubated with media alone (control), uninfected erythrocytes (RBCs) or <i>P. falciparum</i>-infected erythrocytes (iRBCs) at a ratio of (5∶1; erythrocyte∶PBMC) for 6 h (24 h for IL-10) in the absence (black bars) or presence (white bars) of 2 mM allopurinol (A–D) or 0.1 mg/ml uricase (E–H). Incubation media were collected and TNF (A,E), IL-6 (B,F), IL-1β (C,G) and IL-10 (D,H) concentrations were determined by flow cytometry using cytometric bead array. Data represent the average of triplicated samples with standard deviations. *, indicates significant differences (<i>p</i><0.05) in cytokine release by PBMCs incubated with iRBCs when compared to IRBCs in the presence of allopurinol or uricase.</p

Mature <i>P. falciparum</i> infected erythrocytes accumulate high levels of hypoxanthine.

<p>Hypoxanthine was analyzed in the soluble fraction of lysates of human erythrocytes infected with <i>P. falciparum</i> at different times after infection in a synchronized culture. Lysates of uninfected erythrocytes cultured for the same times were used as controls. Shown are GC - selected reaction monitoring MS ion plots using the m/z 365.2 to m/z 251.2 product ion MS/MS transition. Hypoxanthine accumulated in cultured uninfected erythrocytes (red lines) and <i>P. falciparum</i> infected erythrocytes (black lines) is shown. Infected erythrocytes at 33 h (mature trophozoites, thick lines) and 40 h (schizonts, think lines) were purified from synchronized cultures of 2% parasitemia.</p

Analysis of existing approaches at the bank's competitiveness

Викладений аналіз найпоширеніших сучасних підходів до аналітичного оцінювання конкурентоспроможності банку.The article analyzes the most common approaches of building the model of the bank's competitiveness

Mature <i>P. falciparum</i> infected erythrocytes induce TNF, IL-6 and IL-1β from PBMCs.

<p>(A–C) PBMCs were incubated with mature <i>P. falciparum</i> infected erythrocytes (squares) or uninfected erythrocytes (circles) at the indicated ratio of erythrocyte to PBMC for 6 h. Data represent the average of triplicated samples with standard deviations. Incubation media were collected and TNF (A), IL-6 (B), or IL-1β (C) concentrations were determined by flow cytometry using cytometric bead array. (D) <i>P. falciparum</i> infected erythrocytes were cultivated alone or in the presence of 2 mM allopurinol. Synchronized cultures were seeded at 0.5% rings and the culture media was changed daily. The percentage of infected erythrocytes was calculated after 0 h (black bars), 24 h (white bars) and 48 h (grey bars) of culture.</p

Re-Electrospraying Splash-Landed Proteins and Nanoparticles

FITC-albumin, Lsr-F, or fluorescent polystyrene latex particles were electrosprayed from aqueous buffer and subjected to dispersion by differential electrical mobility at atmospheric pressure. A resulting narrow size cut of singly charged molecular ions or particles was passed through a condensation growth tube collector to create a flow stream of small water droplets, each carrying a single ion or particle. The droplets were splash landed (impacted) onto a solid or liquid temperature controlled surface. Small pools of droplets containing size-selected particles, FITC-albumin, or Lsr-F were recovered, re-electrosprayed, and, when analyzed a second time by differential electrical mobility, showed increased homogeneity. Transmission electron microscopy (TEM) analysis of the size-selected Lsr-F sample corroborated the mobility observation

Direct <i>in Situ</i> Observation of Nanoparticle Synthesis in a Liquid Crystal Surfactant Template

Controlled and reproducible synthesis of tailored materials is essential in many fields of nanoscience. In order to control synthesis, there must be a fundamental understanding of nanostructure evolution on the length scale of its features. Growth mechanisms are usually inferred from methods such as (scanning) transmission electron microscopy ((S)TEM), where nanostructures are characterized after growth is complete. Such <i>post mortem</i> analysis techniques cannot provide the information essential to optimize the synthesis process, because they cannot measure nanostructure development as it proceeds in real time. This is especially true in the complex rheological fluids used in preparation of nanoporous materials. Here we show direct <i>in situ</i> observations of synthesis in a highly viscous lyotropic liquid crystal template on the nanoscale using a fluid stage in the STEM. The nanoparticles nucleate and grow to ∼5 nm particles, at which point growth continues through the formation of connections with other nanoparticles around the micelles to form clusters. Upon reaching a critical size (>10–15 nm), the clusters become highly mobile in the template, displacing and trapping micelles within the growing structure to form spherical, porous nanoparticles. The final products match those synthesized in the lab <i>ex situ</i>. This ability to directly observe synthesis on the nanoscale in rheological fluids, such as concentrated aqueous surfactants, provides an unprecedented understanding of the fundamental steps of nanomaterial synthesis. This in turn allows for the synthesis of next-generation materials that can strongly impact important technologies such as organic photovoltaics, energy storage devices, catalysis, and biomedical devices