Current-induced spin polarization in InGaAs and GaAs epilayers with varying doping densities

The current-induced spin polarization and momentum-dependent spin-orbit field were measured in In$_{x}$Ga$_{1-x}$As epilayers with varying indium concentrations and silicon doping densities. Samples with higher indium concentrations and carrier concentrations and lower mobilities were found to have larger electrical spin generation efficiencies. Furthermore, current-induced spin polarization was detected in GaAs epilayers despite the absence of measurable spin-orbit fields, indicating that the extrinsic contributions to the spin polarization mechanism must be considered. Theoretical calculations based on a model that includes extrinsic contributions to the spin dephasing and the spin Hall effect, in addition to the intrinsic Rashba and Dresselhaus spin-orbit coupling, are found to qualitatively agree with the experimental results.Comment: 16 pages, 8 figure

A component-level methodology to evaluate the seismic repair costs of infills and services for Italian RC buildings

The reliable estimation of seismic losses due to damage to buildings is paramount for the post-emergency management and the planning of recovery activities. For residential reinforced concrete (RC) infilled buildings, a significant role in the computation of seismic loss is played by non-structural components, above all infills, partitions and services, as shown in past earthquakes. In this work, a component-based methodology is proposed to assess seismic losses for residential RC buildings in Mediterranean region. The attention is focused on the repairing activities for masonry infills (typical enclosure or partitions elements in Italian and Mediterranean RC buildings), and for services (plumbing systems, electric equipment, floor/wall tiles…), commonly enclosed within the infill panels for the considered building typology. The described methodology can be used starting from the expected damage level to infills and partitions. It adopts given repair unit costs at different damage states of infills. The loss estimation methodology has been, first, validated by comparing predicted and actual repair costs for specific case-study buildings damaged by L’Aquila (Italy) 2009 earthquake. Then, the methodology has been applied to a wide dataset of RC buildings (about 2500 residential buildings) damaged by L’Aquila earthquake available from the literature, to show its possible application at a large-scale level. A good agreement between observed and predicted costs is obtained both for specific case-study buildings and for the wider building stock, especially when damage to structural components is very limited

A component-level methodology to evaluate the seismic repair costs of infills and services for Italian RC buildings

AbstractThe reliable estimation of seismic losses due to damage to buildings is paramount for the post-emergency management and the planning of recovery activities. For residential reinforced concrete (RC) infilled buildings, a significant role in the computation of seismic loss is played by non-structural components, above all infills, partitions and services, as shown in past earthquakes. In this work, a component-based methodology is proposed to assess seismic losses for residential RC buildings in Mediterranean region. The attention is focused on the repairing activities for masonry infills (typical enclosure or partitions elements in Italian and Mediterranean RC buildings), and for services (plumbing systems, electric equipment, floor/wall tiles…), commonly enclosed within the infill panels for the considered building typology. The described methodology can be used starting from the expected damage level to infills and partitions. It adopts given repair unit costs at different damage states of infills. The loss estimation methodology has been, first, validated by comparing predicted and actual repair costs for specific case-study buildings damaged by L'Aquila (Italy) 2009 earthquake. Then, the methodology has been applied to a wide dataset of RC buildings (about 2500 residential buildings) damaged by L'Aquila earthquake available from the literature, to show its possible application at a large-scale level. A good agreement between observed and predicted costs is obtained both for specific case-study buildings and for the wider building stock, especially when damage to structural components is very limited

Evolution of the seismic vulnerability of masonry buildings based on the damage data from L'Aquila 2009 event

AbstractThe purpose of this study is the analysis of vulnerability trends, with particular emphasis to the evolution of the seismic behaviour of masonry buildings over the years due to the improvements in construction practices and to the enhancement of building materials over the years, also related to the subsequent enactment of seismic prescriptions. To this aim, residential masonry buildings damaged after the 2009 L'Aquila earthquake are considered, coming from the online platform Da.D.O. (Database di Danno Osservato, Database of Observed Damage) recently released from the Italian Department of Civil Protection. General features of all the parameters available from the original database are thoroughly analysed, a selection of which is used for vulnerability analysis, namely the period of construction and the design type, the presence of structural interventions, the type of horizontal structure. Vulnerability curves are obtained through an optimization technique, minimizing the deviation between observed and predicted damage. PGA from ShakeMap is used for ground motion characterization. Damage levels defined according to the European Macroseismic Scale are considered, obtained from the observed damage for vertical structures collected during the inspections. Vulnerability curves are firstly obtained as a function of period of construction and horizontal structural types, limited to the irregular layout and bad quality vertical type only, highlighting their clear influence on seismic behaviour. Lastly, the effectiveness of retrofit intervention is evaluated comparing the vulnerability curves for strengthened masonry buildings compared to those not subjected to any retrofit interventions

Seismic Loss Estimation in Pre-1970 Residential RC Buildings: The Role of Infills and Services in Low–Mid-Rise Case Studies

The lessons learned after recent earthquakes have highlighted the key role played by infills and services in damage and loss of Reinforced Concrete (RC) buildings. Their influence in seismic performance and loss estimation of selected RC building case studies is thoroughly analyzed here. The case study selection aims to be representative of existing buildings built in Italy before 1970, and covers a different number of stories and design typologies. The seismic responses of the case-study buildings are numerically analyzed by means of non-linear static pushover analysis (PO) considering a lumped plasticity approach with a quadri-linear flexural response for beam/column elements (properly calibrated for RC elements reinforced with plain bars) and a tri-linear compressive-only axial response with diagonal concentric struts for infill panels (empirically derived from experimental data on hollow clay masonry walls). Economic loss estimation is carried out via a component-based methodology that relies on the main repairing activities and resultant costs required for the refurbishment of infills and services for different damage levels. Accordingly, a damage analysis is performed herein, given the intensity measure, based on a comparison between Interstory drift demand from PO analysis and drift-based fragility functions specific for masonry infills. Loss curves, relating the total building repair cost to peak ground acceleration (PGA), are presented and compared for the analyzed case study buildings to show their trends and quantify the incidence of infills and services with respect to the reconstruction cost. A comparison between these outcomes and those recently found in the literature emphasizes the robustness of the considered approach and the reliability of the hypotheses about damage and loss assessment

E-Defense 2015 ten-story building: beam–column joint assessment according to different code-based design

Recent devastating earthquakes worldwide pointed out the importance of seismic detailing and their influence on the observed damage and subsequent repairability of reinforced concrete buildings. Several studies and post-earthquake observations remarked the role of beam–column joints (BCJs) on the global building response and the effectiveness of transverse reinforcement in increasing the joint shear strength and the ultimate deformation. Although number of experimental and theoretical studies focused on the seismic response of BCJs, their mechanical behaviour is still a discussed topic. This resulted in number of design approaches available in worldwide code or standards that lead to different quantity of joint stirrups. This study focuses on the response of BCJs of a 10-story prototype building designed according to Japanese standards and tested in 2015 on the E-Defense shaking table. First the damage assessment at global (building) and local (joint) level is performed at increasing intensities and considering the building in the base slip and base fixed configurations. A refined numerical model is then developed and validated against global and local experimental results. Then, the joint stirrups are re-designed according to different international standards (ACI, EC8, NZS) and different numerical models are developed. The numerical results are then compared in terms of interstorey drift demand and joint shear strain. Finally, a comparison in terms of expected damage varying the design approach of joint stirrups is proposed

Clinical pathways of epileptic seizures and status epilepticus: results from a survey in Italy

Objective: Patients with seizures or status epilepticus (SE) access the hospital through emergency departments and may be admitted into different wards according to the level of care required. Clinicians with different expertise are in charge of taking critical therapeutic decisions. To date, very few studies have investigated the stage at which these patients are referred to neurologists or epileptologists and how guideline recommendations are applied in clinical practice. Methods: A survey was used to investigate how patients with epileptic seizures or SE are managed in emergency and in subsequent hospital pathways in Italy. Results: One hundred and seventy-seven physicians (mainly neurologists) from all parts of Italy filled in a questionnaire. Less than half of the participants (35%) answered that, in their hospital, patients with epilepsy were managed by epileptologists. The percentages were lower for patients presenting with acute seizures (21%) or SE (16%). Diagnostic, therapeutic, and assistance pathways (PDTA) for patients presenting with seizure(s) or SE were available for both conditions in about 50% of cases, while, in the rest of the hospitals, participants indicated informal agreements (about 25% of cases) or lack of any agreement (about 25% of cases) between clinicians. Professionals more often involved in PDTA were epileptologists/neurologists, emergency physicians, and intensivists. More than half ot the participants (55%) thought that organizational issues are the most important criticalities for such patients and need to be improved (61%). Significance: There is a high variability in hospital clinical pathways for epilepsy in Italy

Characterising plasticised cellulose acetate-based historic artefacts by NMR spectroscopy: a new approach for quantifying the degree of substitution and diethyl phthalate contents

As one of the first semi-synthetic plastics produced industrially, cellulose acetate (CA)-based artefacts represent valued items in museum collections and archives which, however, present stability issues. High temperature and relative humidity conditions have long been known to promote changes in CA properties, for instance, due to the deacetylation of CA polymer chains and the loss of plasticiser from the polymer matrix. However, there is a need for improved methods for the quantification of plasticiser loss and CA deacetylation. In this context, this contribution presents a new approach for enabling the investigation of plasticiser loss and deacetylation degradation processes in historic plasticised CA-based artefacts which is based on high-resolution proton nuclear magnetic resonance spectroscopy (1H NMR). The proposed methods allow for simple and fast quantification of diethyl phthalate contents and average degree of substitution (DS), while requiring no need for extractive separation between the plasticiser and the CA polymer matrix prior to analysis. Both methods are demonstrated by their application towards a series of reference samples, historic artefacts and artificially aged plasticised CA materials. Our analysis indicates that plasticiser content and DS can be accurately quantified by using high-resolution 1H NMR and both methods have been compared to analyses performed using infrared spectroscopy

Arthropods on Mars?

As presented in this report numerous fossils like forms resembling a variety of marine arthropods including crustaceans, sea spiders, scorpions, arachnids, nematodes, annelids, tube worms, sea snakes, Kimberlla, Namacalathus, Lophotrochozoa, armored trilobites and millipedes have been found in Gale Crater (on Sols 302, 553, 753, 781, 809, 869, 880, 905, 1032), and Meridiani Planum both of which have hosted rivers, lakes, and inland seas. Similar specimens are mixed within a variety of divergent fossillike forms and are also found on distant sediment and mud stone. All specimens are distinct from underlying substrate and there are no obvious patterns or repetitions typically produced by erosion or weathering. Although without extraction and direct examination it is impossible to precisely determine the identity of all these specimens, the same problems bedevil identification of Burgess Shale fossils some of which are presented in this report for comparative analysis. The discoveries presented here and in other reports supports the theory that metazoans and other marine organisms evolved in the lakes, oceans and inland seas of Mars

Aerodynamic Properties and Drug Solubility of Dry Powders Prepared by Spray Drying: Clarithromycin Versus its Hydrochloride Salt

Aerodynamic Properties and Drug Solubility of Dry Powders Prepared by Spray Drying: Clarithromycin Versus its Hydrochloride Salt. Russo P, Manniello M.D., Simonetti A., Petrone A.M., Porta A., Del Gaudio P., Aquino R.P. Department of Pharmacy (DIFARMA), University of Salerno, Fisciano (SA) – Italy; ([email protected]). Introduction and Objectives. The antibiotic therapy for a direct administration to the lung in cystic fibrosis patients has to provide suitable drug availability, possibly in the lower respiratory tract characterized by the presence of thick secretions. Apart from deposition, systemic or local pharmacological activity of an inhalation product depends on drug dissolution into the biological fluids lining the lung. Therefore, one of the crucial step in the therapeutic management of the respiratory disease is the drug solubilization in this site of action. Clarithromycin (CLA; fig.1) is a broad spectrum and a well know macrolide antibiotic usually prescribed particularly for the treatment of respiratory infections, interestingly showing an additional anti-inflammatory effect (Pukhalsky et al., 2004); CLA is characterized by a very poor water solubility (0.33 mg/L). One of the common strategy, for increasing drug solubility in aqueous medium is represented by the production of dry powders in amorphous form using the spray drying technique (Yonemochi et al., 1999). Moreover, CLA has a dimethylamino group, which can be salified for solubility/dissolution improvement (fig.1). Hence, the aim of the present study was to obtain respirable powders of clarithromycin, while improving drug aqueous solubility. Powders were produced with CLA or CLA hydrochloride and characterized in terms of drug content, aerodynamic properties and drug solubility. Finally, in order to assess the effect of the spray-drying process on the antibiotic activity of the engineered particles, microbiological tests were performed. Materials and Methods. Several batches of micronized particles were prepared by spray drying different feed solutions; critical process parameters were solvent composition (isopropyl alcohol/water ratio), drug concentration and pH of the liquid feeds (table 1). Saturated solubility measurements were carried out keeping an excess amount of CLA raw material (RM), CLA spray-dried suspension and hydrochloride spray-dried in phosphate buffer (0.05 M, pH 6.75) at 37°C for 72h. After filtration, the solubility was measured by HPLC method and expressed in mg/ml. The results were reported as mean of three measurements and standard deviation. Particle size distribution of Raw Material and engineered particles was determined using a light-scattering laser granulometer, while particle morphology was assessed by scanning electron microscopy (SEM). The in vitro deposition of the micronized powders was evaluate by means of a Single-Stage Glass Impinger (SSGI; apparatus A; European Pharmacopoeia 8.0), using a proper device for the aerosolization. The antibacterial assay was carried out in MHB by microdilution method using 96-well microtiter plates. Briefly, 200 µl of 1X107 CFU/ml of P. aeruginosa ATCC 27853 were incubated at 37°C with different concentration of drug (4, 6 and 8 µg/ml). Results and Discussion. Morphology and aerodynamic properties of spray-dried particles were strongly dependent on organic solvent concentration as well as on pH of the liquid feeds processed, both influencing drug solubility. Adding clarithromycin to hydroalcoholic mixtures, alkaline feeds (pH~10.5; #1, #2, tab.1) in form of suspensions were obtained.   The resulting spray-dried powders showed good process yield, but unsatisfactory aerodynamic properties, due to a high particle size (tab. 1) and the presence of residual drug crystals mixed to spherical particles (fig.2; #2). With the aim to obtain clear feeds in form of solutions, we tested clarithromycin in its hydrochloride salt form, obtained lowering pH values of feed solutions (pH 6.5). Micronized salified powders showed higher process yield and very interesting FPF values, thanks to smaller and wrinkled particles (fig.2 #4, #6; tab.1). Moreover, water solubility of spray-dried powders was strongly influenced by clarithromycin form. Powders obtained from alkaline feed suspensions showed lower solubility in a phosphate buffer 0.05 M, pH 6.75 (fig.3, # 1). A substantial increase in drug solubility was obtained, at the same conditions, with powders dried from feed solution containing clarithromycin hydrochloride (fig.3 #9-#5). To verify the ability of the produced formulations to was performed. Three different drug concentrations were tested in a multi-well plate. Clarithromycin raw material (RM, line C, figure 4) and #1 (line D, figure 4) showed a lower activity against P. aeruginosa growth compared to #4, #5, #6, containing the hydrochloride form. This different behavior against P. aeruginosa may be due to the lower CLA solubility; at higher concentration, clarithromycin precipitates in RM and #1 wells, becoming unavailable for antibiotic purpose. Conclusions. Clarithromycin inhalable powders containing the drug in its hydrochloride form showed good aerodynamic properties and higher water solubility. Thanks to a fine-tuning of the process parameters and liquid feed composition, no excipients were necessary to obtain respirable powders. The spray drying process of CLA hydrochloride not only preserved antimicrobial activity, but also, increasing drug solubility, improved drug efficacy against P. aeruginosa. References. Pukhalsky, A. L., Shmarina, G. V., Kapranov, N. I., Kokarovtseva, S. N., Pukhalskaya, D., & Kashirskaja, N. J. (2004). Anti-inflammatory and immunomodulating effects of clarithromycin in patients with cystic fibrosis lung disease. Mediators Inflamm, 13(2), 111-117. doi: 10.1080/09629350410001688495 Yonemochi, E., Kitahara, S., Maeda, S., Yamamura, S., Oguchi, T., & Yamamoto, K. (1999). Physicochemical properties of amorphous clarithromycin obtained by grinding and spray drying. Eur J Pharm Sci, 7(4), 331-338