Highly efficient resonant coupling of optical excitations in hybrid organic/inorganic semiconductor nanostructures

The integration of organic and inorganic semiconductors on the nanoscale offers the possibility of developing new photonic devices that combine the best features of these two distinct classes of material. Such devices could, for example, benefit from the large oscillator strengths found in organic materials and the nonlinear optical properties of inorganic species. Here we describe a novel hybrid organic/inorganic nanocomposite in which alternating monolayers of J-aggregates of cyanine dye and crystalline semiconductor quantum dots are grown by a layer-by-layer self-assembly technique. We demonstrate near-field photon-mediated coupling of vastly dissimilar optical excitations in the two materials that can reach efficiencies of up to 98% at room temperature. By varying the size of the quantum dots and thus tuning their optical resonance for absorption and emission, we also show how the ability of J-aggregates to harvest light can be harnessed to increase the effective absorption cross section of the quantum dots by up to a factor of ten. Combining organic and inorganic semiconductors in this way could lead to novel nanoscale designs for light-emitting, photovoltaic and sensor applications.     

A study regarding the environmental management system of ready mixed concrete production in Turkey

The construction industry as one of the leading industries of the Turkish economy makes up approximately 60% of total investments. Because of the widespread use of concrete building systems used in construction work in Turkey, concrete production is also quite high. In this study, the application levels of the methods of environmental management in regards to the ready mixed concrete production in Turkey were determined. In Turkey a wide ranging environmental laws about this subject exists. However, it is known that there are problems in its implementation. As a result of this study, it has been determined that there are differences between plants in their environmental applications of the ready mixed concrete production in Turkey, and despite the strides taken in this area; it has not achieved the desired levels. Therefore, inspections must be increased in order to strengthen the enforcement of the rules and regulations of the environmental laws in Turkey.     

Synthesis of High‐Temperature‐Stable TiO2 and its Application on Ag+‐Activated Ceramic Tile

The main purpose of study was to provide a common synergy using Ag⁺‐doped calcium phosphate powder and high‐temperature‐stable TiO₂ for antibacterial and photocatalytic tile applications. Thermally stable SiO₂‐modified TiO₂ active layer was deposited on Ag⁺‐activated ceramic tiles by spray coating. The results showed that a nearly 100% cleanability degree was detected for SiO₂‐modified TiO₂ (TS)‐coated antibacterial tiles when compared uncoated and unmodified TiO₂‐coated tiles. Antibacterial tests and colorimetric analyses indicated that ceramic tiles provide both antibacterial and photocatalytic properties simultaneously.     

The effect of cutting parameters and cutting tools on machining performance of carbon graphite material

Abstract

The present study focuses on the effects of cutting speed, feed rate and cutting tool material on the machining performance of carbon graphite material. Polycrystalline Diamond (PCD) cutting tools are used in machining experiments and its performance is compared with the tungsten carbide (WC) and Cubic Boron Nitride (CBN) tools. Machining performance criteria such as flank and nose wear and resulting surface topography and roughness of machined parts were studied. This study illustrates that feed rate and cutting tool material play a dominant role in the progressive wear of the cutting tool. The highest feed rate and cutting speed profoundly reduce the tool wear progression. The surface roughness and topography of specimens are remarkably influenced from the tool wear. Major differences are found in the wear mechanisms of PCD and WC and CBN cutting tools.     

Effects of various whey proteins on the physicochemical and textural properties of set type nonfat yoghurt

In this study, the changes during storage in the physicochemical, textural and sensory properties of nonfat yoghurts fortified with whey proteins, namely whey protein concentrates (WPC), whey protein isolates and whey protein hydrolysates, were investigated. Enrichment of nonfat yoghurt with the whey protein additives (1% w/v) had a noticeable effect on pH, titratable acidity, syneresis, water‐holding capacity, protein contents and colour values on the 14th day of storage (P < 0.01). The addition of whey proteins to the yoghurt milk led to increases in the hardness, cohesiveness and elasticity values, resulting in improved textural properties. The addition of WPC improved the texture of set‐type nonfat yoghurt with greater sizes in the gel network as well as lower syneresis and higher water holding capacity. This study suggests that the addition of whey protein additives used for fortification of yoghurt gave the best textural and sensory properties that were maintained constant during the shelf life.     

The effect of the strength and direction of magnetic field on the assembly of magnetic nanoparticles into higher structures

The self-assembly of magnetic nanoparticles into higher-order organizations upon external magnetic stimulation has critical importance for the fabrication of discrete microstructures. In this study, the tuning of self-assembly behavior of magnetic Fe3O4 nanoparticles (MNPs), with an average size of 6 nm, under the enhanced magnetic force upon changing the applied field strength and direction is explored. Upon evaporation of the solvent where the MNPs are suspended, formation of particular micrometer sized structures is achieved with a surface constructed from sub-micrometer size magnetic beads in between the applied magnetic field and MNPs. In this study, three different surfaces fabricated using sub-micrometer size magnetic beads in between the applied magnetic field and MNPs are used and the effect of the template pattern, applied field strength and direction are explored.     

Determining Rainwater Harvesting Storage Capacity with Particle Swarm Optimization

Water Resources Management - A reduction in the amount of available clean water is a universal problem, and the harvest of rainwater is one of the methods that can solve this issue. In this study,...     

CMHS data highlights on: availability of psychiatric beds, United States: selected years, 1970-1990

Despite the decrease from 474,190 to 250,541 between 1970 and 1990 in the overall number of non-Federal psychiatric beds (excluding "scatter" beds in non-Federal general hospitals), the trend was by no means constant over time. Between 1970 and 1982, a period of rapid deinstitutionalization of State mental hospitals, the number of beds in all organizations combined dropped precipitously from 474,190 to 222,666, led by State mental hospitals which decreased from 413,066 to 140,140 beds. This was the height of the community mental health center movement and the prevailing view of mental health administrators was that persons with mental illness could be cared for better in the community, rather than at State mental hospitals, far from their homes. Thus, some hospitals closed altogether, and many others closed wards and units as part of the downsizing process. Contrary to a decrease in the number of beds in State mental hospitals during the 1970-82 period, the number of beds in other organization types, in particular private psychiatric hospitals and separate psychiatric services of non-Federal general hospitals, remained relatively constant. The net result was a substantial decrease in the overall number of non-Federal psychiatric beds. In the 1982-90 period, a different phenomenon occurred. The number of beds in State mental hospitals was continuing to decline, but at a slower rate from 140,140 to 98,789, while the number of beds in other types of mental health organizations, particularly private psychiatric hospitals and separate psychiatric inpatient services of non-Federal general hospitals, expanded somewhat.(ABSTRACT TRUNCATED AT 250 WORDS)     

Staffing of mental health organizations, United States, 1988

Between 1986 and 1988, the number of full-time equivalent (FTE) staff employed in specialty mental health organizations in the United States increased 7 percent, from 494,515 to 531,067. Much of this increase could probably be attributed to the increase in number of mental health organizations during this period, from 4,747 to 4,930. With the exception of State mental hospitals and VA psychiatric organizations, all of the other types of mental health organizations showed varying amounts of increase in FTE staff with the most notable gains being reported by private psychiatric hospitals, residential treatment centers for emotionally disturbed children, and multiservice mental health organizations. Of the 531,067 FTE staff employed in mental health organizations in 1988, 72 percent were classified as patient care staff and 28 percent as administrative and support staff. State mental hospitals and VA psychiatric organizations had slightly higher percentages of administrative and support staff (35 and 32 percent, respectively). Seventy percent or more of the staff employed in the various types of specialty mental health organizations in 1988 worked on a full-time basis, the two exceptions being freestanding psychiatric outpatient clinics and non-Federal general hospital psychiatric services in which full-time staff represented only 52 percent and 69 percent, respectively, of all staff. For the most part, the majority (50 percent or more) of each of the staff disciplines employed in mental health organizations worked on a full-time basis. The major exceptions were psychiatrists and other physicians, most of whom worked either on a part-time or trainee basis.     

Synthesis of poly(butyl acrylate‐co‐methyl methacrylate)/montmorillonite waterborne nanocomposite via semibatch emulsion polymerization

Poly(butyl acrylate‐co‐methyl methacrylate)‐montmorillonite (MMT) waterborne nanocomposites were successfully synthesized by semibatch emulsion polymerization. The syntheses of the nanocomposites were performed in presence of sodium montmorillonite (Na‐MMT) and organically modified montmorillonite (O‐MMT). O‐MMT was used directly after the modification of Na‐MMT with dimethyl dioctadecyl ammonium chloride. Both Na‐MMT and O‐MMT were sonified to obtain nanocomposites with 47 wt % solids and 3 wt % Na‐MMT or O‐MMT content. Average particle sizes of Na‐MMT nanocomposites were measured as 110–150 nm while O‐MMT nanocomposites were measured as 200–350 nm. Both Na‐MMT and O‐MMT increased thermal, mechanical, and barrier properties (water vapor and oxygen permeability) of the pristine copolymer explicitly. X‐ray diffraction and transmission electron microscope studies show that exfoliated morphology was obtained. The gloss values of O‐MMT nanocomposites were found to be higher than that of the pristine copolymer. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42373.