Ultrabroadband THz spectroscopy of disordered materials

We perform THz spectroscopic investigations of the dielectric function of disordered materials in the THz region. Specifically, we consider amorphous materials and perform ultrabroadband THz spectroscopy of chalcogenide glasses where we observe the transition from universal scaling of the absorption at low frequencies to medium-range order and local order at higher frequencies

A Site Evaluation Campaign for a Ground Based Atmospheric Cherenkov Telescope in Romania

Around the world, several scientific projects share the interest of a global network of small Cherenkov telescopes for monitoring observations of the brightest blazars - the DWARF network. A small, ground based, imaging atmospheric Cherenkov telescope of last generation is intended to be installed and operated in Romania as a component of the DWARF network. To prepare the construction of the observatory, two support projects have been initiated. Within the framework of these projects, we have assessed a number of possible sites where to settle the observatory. In this paper we submit a brief report on the general characteristics of the best four sites selected after the local infrastructure, the nearby facilities and the social impact criteria have been applied.Comment: 6 pages, 5 Postscript figure

Ultrabroadband terahertz spectroscopy of chalcogenide glasses

Chalcogenide glasses are receiving a lot of attention due to their unique optical properties. In this paper we study the optical properties of As2S3 and GaLaS glasses in a broad terahertz (THz) frequency range (0.2-18 THz). Complex dispersion behavior with drastic changes of refractive index and absorption coefficient is found for both glasses. We observe the breakdown of the universal power-law dependence of the absorption coefficient due to atomic vibrations observed at low THz frequencies in disordered materials, and see the transition to localized vibrational dynamics for the As2S3 compound at higher frequencies. In addition, As2S3 displays two transparency regions, at 7-8 THz and 12.2 THz, of potential interest for future nonlinear applications in the THz rang

Acute idiopathic polyradiculoneuritis with secondary arterial hypertension in a 5-year-old male Siberian Husky

Acute canine idiopathic polyradiculoneuritis (ACIP) is one of the most common generalised neuromuscular diseases affecting dogs. In this report, we describe a 5-year-old, 25-kg, male, intact, Siberian Husky dog with ACIP with secondary induced arterial hypertension fsystolic blood pressure [mean (m) ± standard deviation (sd)], 214 ± 19mmHg; mean blood pressure (m ± sd), 164 ± 6.36mmHg; and diastolic blood pressure (m ± sd), 137 ± 0.7mmHgg and sinus tachycardia. Heart rate variability analysis indicated decreased vagal activity (low root-meansquare values of successive RR interval differences and percentages of the RR intervals differing by more than 50ms in the entire recording) and predominance of sympathetic activity. Arterial hypertension was treated with amlodipine but remained greater than the upper limit for 51 days until the dog recovered ambulation. This is the first case report of ACIP and secondary arterial hypertension in a dog. Routine blood pressure measurements should be included in the monitoring of patients with ACIP if arterial hypertension might interfere with patient prognosis

A rare case of intracardiac fibrosarcoma with myxoid features inducing venous occlusion in a dog – a case report

Abstract Background In both humans and animals, cardiac fibrosarcoma is rare among primary cardiac malignant neoplasia. The overall prevalence of cardiac neoplasia in dogs is low, reported to be between 0.17% and 0.19% of hospital admissions. The aim of this report is to describe the clinical and pathological findings of a dog presenting signs of right sided congestive heart failure due to an intracardiac and venous obstructing mass, diagnosed by histopathology as cardiac fibrosarcoma with myxoid features. Case presentation A 7 years old male mix breed Husky weighing 23 kg was presented to our Veterinary Teaching Hospital the owner reporting weight loss, inappetence and exercise intolerance and on presentation exhibited breathlessness and an enlarged abdomen. A 5 minutes six leads electrocardiogram and cardiac ultrasonography were performed using standard, established techniques. Complete blood count, serum liver enzyme activities and renal parameters were assessed. Shortly after the cardiologic examination, the dog died and necropsy examination of the cardiovascular system revealed an elongated and branched mass attached dorsally to the endocardial insertion of the septal tricuspid valve leaflet. This mass extended retrogradely into the lumen of the cervical veins, obstructing the venous flow. Histological diagnosis of the mass was cardiac fibrosarcoma with myxoid features. Multiple metastases were found inside the lungs only. Conclusion This is the first report describing a right cardiac fibrosarcoma with myxoid features and venous obstruction in a dog. Cardiac fibrosarcoma is a rare finding, however should be considered when an intracardiac mass is diagnosed

Metamaterials modelling, fabrication, and characterisation techniques

Metamaterials are artificially designed media that show averaged properties not yet encountered in nature. Among such properties, the possibility of obtaining optical magnetism and negative refraction are the ones mainly exploited but epsilon-near-zero and sub-unitary refraction index are also parameters that can be obtained. Such behaviour enables unprecedented applications. Within this work, we will present various aspects of metamaterials research field that we deal with at our department. From the modelling part, we will present tour approach for determining the field enhancement in slits that have dimensions in the 10 4 times smaller than the incident wavelength. This huge difference makes it almost impossible for commercial software to handle thus analytical approached have to be employed. From the fabrication point of view, various 2D and 3D high resolution patterning techniques are used. The talk will describe the ones available within our group. We will present the electron-beam lithography approach for fabricating nano-antennae to be used in coupling of plasmonics waveguides to/from free space. Also, a 3D technique based on twophoton-polymerisation and isotropic metal deposition to fabricate metal-covered 3D photonic crystals will be discussed. From the measuring side we will present two THz based setups for obtaining material's characteristics, both in the low as well as in the high THz range, thus having the possibility of describing a material from 0.1 to 10THz. © 2012 SPIE