Search results for "Lead"

Lead isotopic fingerprint in human scalp hair: The case study of Iglesias mining district (Sardinia, Italy)

2017

The Sulcis-Iglesiente district (SW Sardinia, Italy) has been, until recently, one of the most important Italian polymetallic mining areas for the extraction of lead. Epidemiological studies conducted over several decades have indicated this site at high risk of environmental crisis with possible adverse effects on the public health. In the present paper we discuss Pb isotope signatures in human scalp hair and road dust collected from the Sulcis-Iglesiente area in order to trace the exposure of populations to potential Pb sources. A total of 23 determinations (20 on hair samples and 3 on road dust samples) of lead isotope ratios (206Pb/207Pb and 208Pb/206Pb) were carried out. The obtained re…

Il lato oscuro della leadership: Framework concettuale e contributo esplorativo

2015

Introduzione: La letteratura sulla leadership, storicamente, si è focalizzata sugli elementi che rendono la relazione capo-collaboratore efficace, cercando di individuare i fattori funzionali a una leadership di successo, dedicando poco spazio a una riflessione su cosa rende un leader inefficace o distruttivo. Solo di recente, diversi studiosi hanno provato a fare chiarezza sul tema del lato oscuro della leadership, proponendo diversi costrutti, come ad esempio “leader repulsivo” (Pearce e Sims, 2002), “leader bullo” (Ferris, 2007), “leader tossico” (Lipman-Blumen, 2005), “manager compromesso” (Lubit, 2004). Tuttavia queste ed altre definizioni sono spesso orientate solo su alcuni comportam…

Uncertainty at Work How to Regulate it through Leadership in order to improve the Quality of Work Life?

2022

This thesis manuscript focuses on factors able to regulate the uncertainty of people at work. Due to the constant evolution of the organizational world, uncertainty is increasingly becoming a factor with which to combine in different contexts about work. This factor constitutes a risk for individuals due to its aversive nature. In this perspective we have been interested, on the one hand, about theories concerning the concept of uncertainty. This allowed us to better understand and delimit the concept. On the other hand, we looked for ways to regulate uncertainty through the concept of leadership. This led us to consider this regulation as being either potentially possible through a directi…

Interactive Multiobjective Optimization in Lot Sizing with Safety Stock and Safety Lead Time

2021

In this paper, we integrate a lot sizing problem with the problem of determining optimal values of safety stock and safety lead time. We propose a probability of product availability formula to assess the quality of safety lead time and a multiobjective optimization model as an integrated lot sizing problem. In the proposed model, we optimize six objectives simultaneously: minimizing purchasing cost, ordering cost, holding cost and, at the same time, maximizing cycle service level, probability of product availability and inventory turnover. To present the applicability of the proposed model, we consider a real case study with data from a manufacturing company and apply the interactive NAUTI…

Evaluation of the effect of transcutaneous electrical nerve stimulation (TENS) on whole salivary flow rate

2015

Background: Saliva plays a critical role in maintaining oral homeostasis; it modulates the ecosystem through lubrication of the alimentary bolus, protection against microorganisms, buffer and repair of the oral mucosa, and helps in dental re-mineralization. Various local and systemic factors such as medications, radiation therapy, systemic conditions, etc. can lead to reduction in salivary flow. A decrease in salivary function, known as Xerostomia, increases a patient's risk for caries and other oral infections. Palliative management of Xerostomia includes wetting agents such as ice chips, drugs and saliva substitutes. Systemic agents stimulate salivary flow but often have unfavorable side …

SU-FF-T-62: Dosimetric Evaluation of An Internal Shielding Used with a HDR Skin Applicator

2009

Purpose: The Valencia HDR skin applicators are accessories of the microSelectron HDR afterloading system (Nucletron) cup shaped to limit the dose to the irradiation area. Applicators sizes are: diameter 2 and 3 cm. The typical prescription depth is 3 mm. This work aims to evaluate the backscatter and electron contamination of an internal shielding used to reduce the dose to the ocular globe when the lesion is located at the eyelid. Monte Carlo(MC) and experimental methods have been used. Method and Materials: The geometry has been: the Valencia applicator (2 cm diameter) on the surface of a solid polystyrene slab phantom; inside, a 2 mm lead slab located at 3 mm depth. MC simulation charact…

Upper secondary school organisations : a case study of two Norwegian schools

2001

Teachers’ Evidence-Based Actions

2013

Currently, there is a dynamic development in the German school system. It is a new governance model which has been designed to have measurable effects on the political regulation of education.

Bronze Sculptures and Lead Objects Tell Stories About Their Creators: Investigation of Renaissance Sculptures and Ancient Ingots by Means of Neutron …

2016

Renaissance bronze objects from the Rijksmuseum (Amsterdam) col- lection and lead ingots from ancient roman shipwrecks found near Sicily (Italy) were studied by means of neutron tomography. This was done with the aim to visualize and to measure the inner structures of the objects. In this way information about the manufacturing processes in the 16th century and the conservation status from the inside of the bronze sculptures was gained. Inscriptions found under the corrosion layer of the lead ingots gave hints about the trade routes in the past. Neutron imaging was proven perfect to transmit the relatively thick layers of Pb and Cu alloys while ceramic remains, soldering connections and cor…

Relationships between core self-evaluation, leader empowering behavior, and job security among Jordan University Hospital nurses

2021

Nurses are facing real stressors due to patients’ needs and leaders’ demands. The aim of this study is to explore the perceived level of core self-evaluation (CSE), leader empowering behavior (LEB), and job security among Jordan University Hospital nurses in Amman, the capital of Jordan. Furthermore, it investigates the relationship between the selected variables. Differences of gender, educational level, experience, and site of work are also examined with job security. Moreover, it evaluates the contribution of CSE, LEB, gender, educational level, experience, and site of work in predicting job security among Jordan University Hospital nurses. A descriptive cross-sectional design was adopte…