Search results for "Horizon"
showing 10 items of 600 documents
Design of a sun tracker for the automatic measurement of spectral irradiance and construction of an irradiance database in the 330-1100 nm range
2007
Abstract An automatic global and direct solar spectral irradiance system has been designed based on two LICOR spectroradiometers equipped with fibre optics and remote cosine sensors. To measure direct irradiance a sun tracker based on step motors has been developed. The whole system is autonomous and works continuously. From the measurements provided by this system a spectral irradiance database in the 330–1100 nm range has been created. This database contains normal direct and global horizontal irradiances as well as diffuse irradiance on a horizontal plane, together with total atmospheric optical thickness and aerosol optical depth.
Modeling of light pipes for the optimal disposition in buildings
2019
A light pipe is an excellent solution to transport and distribute daylight into environments without or with little lighting, guaranteeing comfort inside the rooms. As stated in the literature, the evaluation of the performances of light pipes presents numerous complexities, making the work very difficult for technicians and designers. This study is aimed to present a methodology that is able to identify the potential of light pipes using indices such as daylight autonomy (DA), continuous daylight autonomy (DAc), and useful daylight illuminance (UDI). This paper presents an analysis of daylight obtained by several configurations of simple models of light pipes installed into a 5 ×
Bioindicators and nutrient availability through whole soil profile under orange groves after long-term different organic fertilizations
2019
We investigated long-term (18 years) effects of three organic (cow manure (CM), poultry manure (PM), compost from agro-industry orange wastes (OW)) and one inorganic fertilization (IF) on various soil biological indicators (microbial biomass C, soil respiration, total phospholipid fatty acids (PLFAs), total bacteria, Gram-positive and Gram-negative bacteria and fungi) and nutrient contents (total and extractable organic C, total and mineral N, available P and K) along the profile of a Typic Haplustept under orange Mediterranean orchards. All fertilizers were added on the same N content basis (190 kg N ha−1 per year). Variables related to carbon cycling gradually worsened with depth, regardl…
Vehicles, replicators, and intercellular movement of genetic information: evolutionary dissection of a bacterial cell.
2012
Prokaryotic biosphere is vastly diverse in many respects. Any given bacterial cell may harbor in different combinations viruses, plasmids, transposons, and other genetic elements along with their chromosome(s). These agents interact in complex environments in various ways causing multitude of phenotypic effects on their hosting cells. In this discussion I perform a dissection for a bacterial cell in order to simplify the diversity into components that may help approach the ocean of details in evolving microbial worlds. The cell itself is separated from all the genetic replicators that use the cell vehicle for preservation and propagation. I introduce a classification that groups different r…
The importance of horizontal-fit of university student jobs for future job quality
2019
Purpose The purpose of this paper is to gain a better understanding of the antecedents of the quality of graduates’ jobs when they enter the job market after university graduation. Design/methodology/approach Survey data collected from 173 Spanish bachelor and master’s degree university graduates at two time points (two months before and six months after graduation, approximately) were analyzed by means of path analysis. Findings A moderated mediation model was tested, where the relationship between the horizontal fit (HF) between the university degree subject and the student’s job and the quality of the graduate’s job after graduation is mediated by self-perceived employability and modera…
Knowledge construction about port performance evaluation: An international literature analysis
2017
Purpose: This study aims to identify and analyze the characteristics of international scientific research that addresses the segment of literature referring to port performance evaluation, in order to identify the existence of a theoretical alignment between the concept of performance evaluation, as an area of knowledge, and the practical application of port performance evaluation. Design/methodology: For the approach to the problem, this paper makes use of qualitative research, analyzing bibliographical portfolio characteristics related to port performance evaluation. An action research strategy was adopted, according to which the authors selected the bibliographical portfolio based on ana…
Differentiation in knowledge‐creating organizations
2007
PurposeThe purpose of this paper is to focus on the analysis of the influence of organizational design variables on the creation of knowledge within the organization. The impact that enablers have on knowledge creation has been widely demonstrated and established in the relevant literature. Using this assumption as a starting‐point, the main aim of this study is to consider and explore the role of differentiation – horizontal and vertical – in knowledge creation using enablers as mediator variables.Design/methodology/approachThe paper has created a model of relations of the design variables that correspond to differentiation – horizontal job specialization, vertical job specialization and n…
Implant-supported overdenture manufactured using CAD/CAM techniques to achieve horizontal path insertion between the primary and secondary structure:…
2015
This report describes the case of an edentulous patient with an atrophic maxilla and severe class III malocclusion. Prosthetic rehabilitation was performed using CAD/CAM techniques for manufacturing an implant-supported overdenture with horizontal insertion. A vestibulo-lingual insertion overdenture is a precision prosthesis with a fixation system affording a good fit between the primary and secondary structure. Both structures exhibit passive horizontal adjustment. This treatment option requires the same number of implants as implant-supported fixed dentures. The horizontal assembly system prevents the prosthesis from loosening or moving in response to axial and non-axial forces. The techn…
In situ Mössbauer spectroscopy: Evidence for green rust (fougerite) in a gleysol and its mineralogical transformations with time and depth
2005
Abstract A miniaturized Mossbauer spectrometer, adapted to the Earth’s conditions from the instrument developed for Mars space missions, has been used for the first time to study in situ variations with depth and transformations with time of iron minerals in a gleysol. The instrument is set into a PVC tube and can be moved up and down precisely (±1 mm) at the desired depth. Mossbauer spectra were obtained from 15 to 106 cm depth and repeated exactly at the same point at different times to follow mineralogical transformations with time. X-ray diffraction (XRD) and selective extraction techniques were performed on soil samples. The piezometric level of the water table was measured and the com…
Chemical weathering of volcanic rocks at the island of Pantelleria, Italy: Information from soil profile and soil solution investigations
2007
Abstract Concentrations of major, minor and trace elements were determined in soil profiles and soil solutions from the island of Pantelleria, Sicily Channel, to evaluate the weathering extent of soils evolved on trachytic and pantelleritic rocks and the aqueous transport of elements by their soil solutions. The chemical index of alteration (CIA) indicates a low-to-moderate degree of weathering; consistently, the mineralogical and geochemical imprints of the parent rocks are generally preserved. The chemical weathering appears to be incongruent, owing to primary minerals and glass dissolving to a variable degree while secondary minerals have formed. Based on the calculated saturation state …