Diagnosis of weaknesses in modern error correction codes: a physics approach

One of the main obstacles to the wider use of the modern error-correction codes is that, due to the complex behavior of their decoding algorithms, no systematic method which would allow characterization of the Bit-Error-Rate (BER) is known. This is especially true at the weak noise where many systems operate and where coding performance is difficult to estimate because of the diminishingly small number of errors. We show how the instanton method of physics allows one to solve the problem of BER analysis in the weak noise range by recasting it as a computationally tractable minimization problem.Comment: 9 pages, 8 figure

Inferior Mesenteric Artery Aneurysm: Case Report and Review of the Literature

Aneurysms of the inferior mesenteric artery are very rare. We report a new case associated with aorto-iliac occlusive disease and occlusion of the superior mesenteric artery, as well as review the pertinent literature

Debye relaxation in high magnetic fields

Dielectric relaxation is universal in characterizing polar liquids and solids, insulators, and semiconductors, and the theoretical models are well developed. However, in high magnetic fields, previously unknown aspects of dielectric relaxation can be revealed and exploited. Here, we report low temperature dielectric relaxation measurements in lightly doped silicon in high dc magnetic fields B both parallel and perpendicular to the applied ac electric field E. For B//E, we observe a temperature and magnetic field dependent dielectric dispersion e(w)characteristic of conventional Debye relaxation where the free carrier concentration is dependent on thermal dopant ionization, magnetic freeze-out, and/or magnetic localization effects. However, for BperpE, anomalous dispersion emerges in e(w) with increasing magnetic field. It is shown that the Debye formalism can be simply extended by adding the Lorentz force to describe the general response of a dielectric in crossed magnetic and electric fields. Moreover, we predict and observe a new transverse dielectric response EH perp B perp E not previously described in magneto-dielectric measurements. The new formalism allows the determination of the mobility and the ability to discriminate between magnetic localization/freeze out and Lorentz force effects in the magneto-dielectric response.Comment: 19 pages, 6 figure

Forward with Active Clamp for space applications: clamp capacitor, dynamic specifications and EMI filter impact on the power stage design

The impact of the clamp capacitor design, the dynamic specifications and the EMI filter design on the power stage design of a 28V 50W Forward with Active Clamp converter for space applications is analyzed along this paper. Clamp capacitor is designed by considering the ECSS standards limitations for the semiconductors and saturation of the magnetic components, and considering the influence of the resonance between this capacitance and the magnetizing inductance on the input impedance of the converter. Dynamic specifications influence are analyzed. Additionally, the EMI filter design process is described. Singlestage and Multi-stage approaches are proposed. All these features make an increase of 2:4W losses and 1:6 higher area of the converter, compared with a preliminary design of the power stage, before considering these aspects

VARIATIONS OF CLIMATE PARAMETERS AND THEIR IMPACT ON CABERNET SAUVIGNON AND SAUVIGNON BLANC PHENOLOGY IN CONDITIONS OF CENTRAL SERBIA

Research carried out in vineyard of King Peter I Karadjordjevic-Royal Winery at Oplenac-Topola municipality, on Sauvignon blanc and Cabernet sauvignon. Vineyard planted with Sauvignon blanc is geographically positioned at GPS coordinates N 44° 14' 4" and E 20° 41' 15" and Cabernet sauvignon is geographically positioned at GPS coordinates N 44° 14' 35" and E 20° 41' 22". Climat parameters (series from 1982-2011 year) included following parameters: mean monthly, vegetation (april-october) and annual temperature, active and effective temperature, precipitation distribution (annual and vegetation) and wind direction. Phenological observation included beginning and end of following phenophases: bleeding, budbreakt, shoot growing, flowering, berry development and ripening. The greatest variation Sauvignon blanc manifested in duration of grape ripening which is in 2010. lasted 46 days while in 2011. lasted 34 days. Cabernet sauvignon in 2011. had a lower number of days that have passed from bleeding to full maturity (209 days) compared to 2010., when it passed 217 days

Kaemika app, Integrating protocols and chemical simulation

Kaemika is an app available on the four major app stores. It provides deterministic and stochastic simulation, supporting natural chemical notation enhanced with recursive and conditional generation of chemical reaction networks. It has a liquid-handling protocol sublanguage compiled to a virtual digital microfluidic device. Chemical and microfluidic simulations can be interleaved for full experimental-cycle modeling. A novel and unambiguous representation of directed multigraphs is used to lay out chemical reaction networks in graphical form

Effect of Consecutive Cut and Vegetation Stage on Cncps Protein Fractions in Alfalfa (Medicago Sativa L.)

Crude protein (CP) of forages can be separated into fractions of differentiated abilities to provide available amino acids in the lower gut of ruminants. This knowledge is critical to develop feeding systems and to predict animal responses. The objective of this research was to asses whether CP concentrations and the relative proportion of CP fractions by CNCPS in alfalfa (Medicago sativa L.) cv K-28 were affected by different cuts and vegetation stages. Fraction B2, which represents true protein of intermediate ruminal degradation rate, was the largest single fraction in all cuts except in the third cut. Soluble fraction A was less than 400 g kg-1 CP in all cuts except in the third cut, while the unavailable fraction C ranged from 56 g kg-1 CP in the first cut to 134.8 g kg-1 CP in the fourth cut. The remaining fraction B3 (true protein of very low degradation rate) only represented less than 60 g kg-1 of total CP. Results showed that undegraded dietary protein represented a small proportion of total CP in alfalfa from the first to the fourth cut

Comparative Structural and Optical Properties of Different Ceria Nanoparticles

Herein a comparative study of five nanocrystalline cerium oxides (CeO2-delta) synthesised by different methods and calcined at 500 degrees C is reported. XRPD analysis showed that stoichiometry parameter delta, crystallite size/strain and lattice constant were only slightly affected by the method utilized. All ceria nanoparticles are nearly spherical in shape with faceted morphology, free of defects and with a relatively uniform size distribution. The average microstrain was found to be approximately 10 times higher than that of bulk counterpart. The absorption edge of nanocrystalline materials was shifted towards a higher wavelengths (red shift) in comparison with bulk counterpart, and band gap values were in the range 2.7-3.24 eV (3.33 eV for bulk counterpart)

Diagnosis and treatment of carotid body paraganglioma: 21 years of experience at a clinical center of Serbia

BACKGROUND: The carotid body paraganglioma (chemodectoma) is a relatively rare neoplasm of obscure origin. These are usually benign and commonly present as asymptomatic cervical mass. PATIENTS AND METHODS: Records of 12 patients (9 female and 3 male) with carotid body tumors treated between 1982 and 2003, treated at our center were retrospectively reviewed. Data on classification, clinical presentation, and surgical treatment were extracted from the case records. Surgical complications and treatment outcome were noted and survival was calculated by actuarial method. The literature on carotid body paraganglioma was reviewed. RESULTS: The average age of the patients was 52 years (range 30–78 years). Eight of these cases presented as a large asymptomatic non-tender neck mass, and two each presented with dysphagia, and hoarseness of voice. As per Shamblin classification seven of tumors were type II and 5 were types III. In 7 cases subadventitial tumor excision was performed, while in 5 associated resection of both external and internal carotid arteries was carried out. The artery was repaired by end-to-end anastomosis in one case, with Dacron graft in one case, and with saphenous vein graft in 3 cases. There was no operative mortality. After a mean follow-up of 6.2 years (range 6 months to 20 years), there were no signs of tumor recurrence in any of the cases. CONCLUSIONS: Surgical excision is the treatment of choice for carotid body paragangliomas although radiation therapy is an option for patients who are not ideal candidates for surgery. For the tumors that are in intimate contact with carotid arteries, the treatment by vascular surgeon is recommended

Facile synthesis of layered hexagonal MoS2

In this work synthesis of layered molybdenum sulphide (MoS2) through a temperature-controlled thermal evaporation approach is reported. Simultaneous co-evaporation of molybdenum trioxide (MoO3) and sulphur in an argon environment is employed. The as-deposited thin films are characterized by diffraction and microscopy