The focusing effect of graded index photonic crystals

Cataloged from PDF version of article.We describe an approach to implement graded index (GRIN) structures using two- dimensional photonic crystals (PCs). The lattice spacing along the transverse direction to propagation is altered and we show, both theoretically and experimentally, that such a spatial perturbation is an effective way to obtain GRIN PC. The response of the structure to spatially wide incident beams is investigated and strong focusing behavior is observed. The large spot size conversion ratio can be attainable and is mainly limited by the finite size of the structure. The designed GRIN PC shows promise for use in optical systems that require compact and powerful focusing elements compared to the traditional bulky lenses. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.3009965

High efficiency of graded index photonic crystal as an input coupler

Cataloged from PDF version of article.A graded index photonic crystal (GRIN PC) configuration was placed at the input side of a photonic crystal waveguide (PCW) in order to efficiently couple the light waves into the waveguide. We compared the transmission efficiencies of light in the absence and presence of the GRIN PC structure. We report a significant improvement in coupling when the GRIN PC is incorporated with the PCW. The intensity profiles were obtained by carrying out the experiments at microwave frequencies. Finite difference time domain based simulations were found to be in good agreement with our experimental results

Cultivation of Agaricus bisporus on wheat straw and waste tea leaves based composts and locally available casing materials Part III: Dry matter, protein, and carbohydrate contents of Agaricus bisporus

This study was performed to determine the effects of composts and casing materials on dry matter, protein, and carbohydrate contents of the fruit bodies of Agaricus bisporus. Results showed that Agaricus bisporus cultivated on group I and group II casing soil groups showed remarkably higher dry matter and carbohydrate contents compared to other casing groups. No significant differences were found among casing soil groups in terms of protein content of Agaricus bisporus cultivated on wheatstraw. But, there were significant differences between casing soil groups in terms of protein content of Agaricus bisporus cultivated on waste tea leaves

Yield response of mushroom (Agaricus bisporus) on wheat straw and waste tea leaves based composts using supplements of some locally available peats and their mixture with some secondary casing materials

The study was conducted to investigate yields of mushroom (Agaricus bisporus) on wheat straw and waste tea leaves based composts. Mixtures (50:50, v/v) of some locally available peats including peat ofBolu (PB), peat of Agacbasi (PA), peat of Caykara (PC) and their mixture (80:20; v/v) with which piece of mosaic and sand were used. Also, some activator materials such as wheat bran, wheat chaff, chickenmanure, pigeon manure, and poplar leaves were used for A. bisporus cultivation. The results on wheat straw based composts provided the highest mushroom yield (23.01%) that was obtained on wheat strawand pigeon manure based compost using a mixture of PA with PC (50+50; v/v) as casing material. For waste tea leaves based composts, the highest mushroom yield (24.90%) were recorded on wheat straw and pigeon manure based compost using a mixture of PC with sand (80+20; v/v) as casing material

Cultivation of Agaricus bisporus on wheat straw and waste tea leaves based compost formulas using wheat chaff as activator material

This study was designed to determine the pin head formation time and yield values of Agaricus bisporus on some casing materials. Composts were prepared basically from wheat straw and waste tea leaves by using wheat chaff as activator substance. Temperatures of the compost formulas were measured during composting at various depths in order to determine the compostability level. Results showed that in both compost types, maximum temperature values were recorded in the second turning stage. Composting was completed in 21 days for both composts. While the fastest pin head formation (12.50 days) was obtained on wheat straw based compost using peat of Bolu (PB) and peat of Agacbasi (PA) (50+50; in volume); waste tea leaves based compost using peat of Caykara (PC) and forest soil (FS) mixture (50+50; in volume) as casing material gave the fastest pin head formation (13.25 days). In terms of yield, a mixture of peat of Bolu and peat of Agacbasi (PA) (50+50; in volume) gave the highest yieldfor wheat straw based compost, a mixture of peat of Agacbasi and perlite (P) (80+20; involume) had the highest yield for waste tea leaves based compost

Cultivation of Agaricus bisporus on some compost formulas and locally available casing materials. Part II: Waste tea leaves based compost formulas and locally available casing materials

Three compost formulas (formula I, formula II, and formula III) based waste tea leaves and using some activator materials such as wheat bran, chicken manure and pigeon manure were studied for Agaricusbisporus cultivation. Some locally available peats such as peat of Bolu, peat of Agacbasi, peat of Caykara and theirs mixture (80:20; volume : volume) with perlite were used. Temperature values of allcompost formulas during composting process were measured to determine the compostability level. According to results, compost temparature steadily increased until the 8th, 9th, and 9th day ofcomposting for formula I, formula II, and formula III, respectively. The maximum compost temperature values were measured for all compost formulas at the second turning stage of composting process.The highest compost temperature values were measured prepared from a mixture of waste tea leaves and wheat bran (formula I). The best mushroom yield was obtained by a mixture of waste tea leaves andpigeon manure with the peat of Caykara and perlite mixture as casing material. Peat of Caykara gave higher mushroom yield than those of other peats

An investigation on pin head formation time of Agaricus bisporus on wheat straw and waste tea leaves based composts using some locally available peat materials and secondary casing materials

This study was designed to determine pin head formation time of Agaricus bisporus on wheat straw and waste tea leaves based composts. Locally available peat materials such as peat of Bolu (PB), peat of Agacbasi (PA), peat of Caykara (PC), and their mixture (80:20; v:v) with piece of mosaic (PM), perlite (P), and sand (S) were used as secondary casing materials. Also, some activator materials such aswheat bran, chicken manure, and pigeon manure were used for A. bisporus cultivation. For wheat straw based composts, the fastest pin head formation times were observed with a mixture of PA with PMcasing material on wheat straw and chicken manure based compost and with PA casing material on wheat straw and pigeon manure based compost. For waste tea leaves based composts, the fastest pinhead formation times were obtained with a mixture of PA with PM and PC with PM on waste tea leaves and chicken manure based compost. Generally, when peat materials were used in combination witheach other, the period of pin head formation times shortened compared to their individual use. A mixture of forest soil with sand (80 + 20; in volume) gave the worst results in terms of pin head formation times for both composts. In secondary casing materials, PM gave the best results in terms of pin head formation time for both composts

Cultivation of Agaricus bisporus on some compost formulas and locally available casing materials. Part I: Wheat straw based compost formulas and locally available casing materials

Three compost formulas; wheat straw based and using different activator materials such as wheat brain, chicken manure, and pigeon manure were used for Agaricus bisporus cultivation. Locallyavailable casing materials such as peat of Bolu, peat of Agacbasi, peat of Caykara, and their mixture (80:20; v:v) with perlite were used. Temperature degrees of all of compost formulas were measuredduring composting at various depth in order to determine the compostability level. Results showed that inner compost temparature increased until the 8th and 9th day of composting for formula I, formula II, and formula III composts, respectively. The maximum inner compost temperature degrees were measured for all compost formulas at the second turning stage of composting. The highest mushroom yield (1707.2 g) was recorded by wheat straw mixed with pigeon manure with the peat of Caykara and perlite mixture as casing material

La cantidad de madera muerta y sus tasas de descomposición asociadas en reservas forestales y bosques manejados en el noroeste de Turquía

This study describes the state of coarse dead wood (CDW) in the Forest Reserve and the Managed Forest zones of northern conifer-broadleaved mixed forest. The results showed mean total CDW volumes in the ranges 30,05±11,06 m3/ha in the Forest Reserve (6,33±2,98% of the LW volume), and 9,31±2,84 m3/ha in the Managed Forest (1,96±0,84% of the LW volume). The total CDW volume was 3,22 times higher in the Forest Reserve than in the Managed Forest. The CDWlog1 and CDWsnag1 were the most abundant CDW decay classes, whilst CDWlog2 and CDWsnag2 were the lowest. Comparisons of ratios between the Managed Forest and the Forest Reserve with abundant decay classes CDWlog1 and CDWsnag1 indicated large differences. The CDWlog1 volume was 4,09 times higher, and the CDWsnag1 volume was 3,68 times greater in the Forest Reserve than in the Managed Forest. The ratio of different CWD classes in the Managed Forest to CWD classes in the Reserve Forest confirms the pattern. In both Managed and Reserve Forest zones there is balance between total CDWlogs and total CDWsnags, but the differences between total CDWlogs and total CDWsnags was not statistically significant. The total CDW volume was significantly dependent on the forest management system. The system influenced amount and diversity of CDW. In commercially managed forest the abundance and structure of CDW retained is a compromise between the needs of timber production and nature conservation.Este estudio describe el estado de la madera muerta en la zona de reserva forestal y zonas de bosques manejados de coníferas del norte de bosques mixtos de frondosas. Los resultados mostraron que la media total de los volúmenes de madera muerta es igual a 30,05 ± 11,06 m3 / ha en la Reserva Forestal (6,33 ± 2,98% del volumen de madera en pie), y 9,31 ± 2,84 m3 / ha en los bosques manejados (1,96 ± 0,84% del volumen de LW). El volumen total de madera muerta fue de 3,22 veces mayor en la Reserva Forestal de que en el bosque administrado. Las clases de decaimiento de madera muerta más abundantes eran CDWlog1 y CDWsnag1, mientras que CDWlog2 y CDWsnag2 fueron los menos abundantes. Las comparaciones de las proporciones entre el bosque manejado y la Reserva Forestal con las clases de decaimiento más abundantes (CDWlog1 y CDWsnag1) indican grandes diferencias ente las dos zonas. El volumen CDWlog1 fue 4,09 veces mayor, y el volumen CDWsnag1 fue 3,68 veces mayor en la Reserva Forestal de que en el bosque manejado. La relación de las diferentes clases de decaimiento entre los bosques manejados y la Reserva Forestal confirma el patrón. En ambos casos, bosque manejado y zonas de reserva forestal, existe un equilibrio entre CDWlogs total y CDWsnags total, pero las diferencias entre CDWlogs total y CDWsnags total no fue estadísticamente significativa. El volumen total de madera muerta depende significativamente del sistema de gestión forestal. El sistema de manejo influye sobre la cantidad y diversidad de madera muerta. En una gestión comercial de los bosques, la abundancia y estructura de madera muerta presente es un compromiso entre las necesidades de la producción de madera y la conservación de la naturaleza

Cultivation of Agaricus bisporus on wheat straw and waste tea leaves based composts using poplar leaves as activator material

This study was carried out to determine pin head formation time and mushroom yield of Agaricus bisporus on some casing materials. Composts were prepared basically from wheat straw and waste tealeaves using poplar leaves as activator material. In this study, moreover, in order to follow the evolution of the composting process, daily temperature measurements were taken. According to the results of the study, in both compost types, maximum temperature values were observed in the second turning stage. While in the first and second turning stages, inner-pile temperature of the compost was in atendency of exhibiting steady increase, they are prone to decrease in the following turning stages. In both composts, the period of composting has finished in 19 days. While the fastest pin head formation(13 days) was obtained on wheat straw based compost using peat of Caykara (PC) and forest soil (FS) (50+50; in volume); waste tea leaves based compost using peat of Bolu (PB) and peat of Caykara (PC)mixture (50+50; in volume) as casing material gave the fastest pin head formation (13.30 days). While, a mixture of peat of Agacbasi (PA) and perlite (P) gave the highest yield for wheat straw based compost,peat of Bolu shows the highest yield for waste tea leaves based compost