Establishing which metallic materials are suitable to be used for the protection of operators and machinery, when subjected to stress impact in the drilling industry, for surface exploitation, mines ...and quarries, is a complex process. Due to the harsh operating conditions, a careful evaluation of the various materials used is of utmost importance. This paper addresses the issues relating to the methodology of determining the appropriate homogenous materials to be used, based on a correspondence between their characteristics and applications. Starting with a list of specific operating conditions, one has established a set of requirements and has assessed the market; the recommended materials for the job are alloy steels and aluminum alloys.
An analysis of the verification approach used for the SCOMP hardware is presented herein. Although the SCOMP approach is informal it is extensive and thorough. In general, it provides sufficient ...evidence to conclude that the SCOMP hardware forms a sound basis for the development of a security kernel. However, the SCOMP approach presents a number of problems which are common to most informal verification approaches. These problems include: (1) incomplete formal top-level specification of the hardware functions that are visible at the TCB interface, and (2) incomplete coverage of design (and implementation) analysis and testing. The existence of verification problems does not imply that design/implementation flaws are left undiscovered and uncorrected in the SCOMP system. However, it does require that complete confidence in the hardware design (and implementation) be gained in alternate ways; e.g., by careful review of all possible implications of the verification omissions, and, possibly, by penetration analysis. All concerns raised along these lines with the system designers were answered in a satisfactory way.
We investigate k-connectivity in secure wireless sensor networks under the random pairwise key predistribution scheme with unreliable links; a network is said to be k-connected if it remains ...connected despite the failure of any of its (k - 1) nodes or links. With wireless communication links modeled as independent on-off channels, this amounts to analyzing a random graph model formed by intersecting a random K-out graph and an Erdös-Rényi graph. We present conditions on how to scale the parameters of this intersection model so that the resulting graph is k-connected with probability approaching to one (resp. zero) as the number of nodes gets large. The resulting zero-one law is shown to improve and sharpen the previous result on the 1-connectivity of the same model. We also provide numerical results to support our analysis and show that even in the finite node regime, our results can provide useful guidelines for designing sensor networks that are secure and reliable.
The aim of this study was to identify possible influences of extraction methods as well as extraction parameters on the phytochemical and biological profiles of Xanthium spinosum L. extracts. ...Extraction methods were chosen as follows: classical methods, maceration and Soxhlet extraction; innovative extraction methods, turboextraction, ultrasound-assisted extraction, and a combination of the latter two. Extracts were subjected to total polyphenolic and flavonoid content spectrophotometric analysis. The phytochemical profile was determined for the best-yielding extracts using HPLC-MS analysis. Following the newly acquired data, another sorting of the extracts was performed. Biological activities such as antimicrobial and anti-inflammatory actions were evaluated, as well as oxidative stress reduction potential, on a Wistar rats inflammation model. Comparable results were achieved with Soxhlet extraction and ultrasound-assisted extraction, both surpassing all other tested methods in terms of yields. Bioactive compound concentrations tended to increase with the increase in extraction time and temperature. These maximal values lowered once the degradation points of the bioactive compounds were reached. Extracts demonstrated good protection against Gram-negative bacteria. Additionally, they provided good cellular protection and increased the antioxidant defense in the analyzed rat plantar tissue.
•The first theoretical vibrational spectra predictions are in line with the experiment.•Essentially, all bands in the experimental spectra are tentatively assigned.•The number of bands in the ...OH-region is equal to the number of independent OH-groups.•Employed harmonic approximation is valid particularly in the lower-frequency region.
The arsenate hydroxyl-bearing minerals sarkinite and adamite were studied with vibrational spectroscopic (IR and Raman) and quantum theoretical methods. The observed IR bands in the higher (1100–600cm−1) and especially lower (600–450cm−1) frequency region of AsO4 vibrations could clearly discriminate between the studied analogues. The differences between their crystal structures are much pronounced in both IR and Raman OH-stretching regions. Namely, a single strong band is found in the case of orthorhombic adamite compared to four weaker bands observed in corresponding IR and Raman spectral regions of monoclinic sarkinite. Essentially all bands in the experimental spectra, collected at both room and liquid nitrogen temperature, were tentatively assigned. To support the tentative assignment of bands in the vibrational spectra of the mentioned minerals, periodic pseudopotential plane wave density functional theory calculations were carried out. Geometry optimizations of the 3D periodic systems included both optimizations of the atomic positions within the unit cell and of the unit cell itself. In most cases, the assignments were either supported or implied by the obtained theoretical data. It is worth mentioning that this is the first experimental and theoretical study of the vibrational spectra of the very-rare sarkinite mineral.
Introduction: Cervical necrotizing fasciitis is a rare but very severe infection that affects the soft-tissues of the cephalic extremity. Cervical necrotizing fasciitis most frequently occurs ...secondarily to inflammatory odontogenic disorders and represents the most severe infection of maxillofacial spaces, with a high lethal potential.
Materials and Methods: In this study, we selected 55 patients with confirmed cervical necrotizing fasciitis of odontogenic origin, treated in the Clinic of Oral and Maxillofacial Surgery in Cluj-Napoca during January 1996-December 2012.
Results: In the majority of cases, the disease evolved without the presence of associated systemic disorders (60% 45.49-72.69), the rest of the patients having 1-4 types of systemic disorders; type 2 diabetes mellitus was the most frequent type of underlying systemic disorder. From the appearance of the first symptoms until the presentation for treatment, a time interval of 2-30 days elapsed. During this time period, 78.18% (95% confidence interval CI 65.49-89.06) of the patients received antibiotic treatment, but without results. Mandibular molars were the most frequent starting point of the disease, and the submandibular space was the first affected by the disease, 47.27% (95% CI 32.76-61.79). Bacteriological exams showed that facultatively aerobic/anaerobic G + bacteria were the most frequently identified (72.22% 58.21-83.60).
Conclusion: The odontogenic lesions of the lower molars, complicated by submandibular space infections, are the most frequent starting point of odontogenic cervicofacial necrotizing fasciitis. Delayed surgical treatment and strict antibiotic therapy play an important role in favoring the development of odontogenic necrotizing fasciitis.
The reference development pathway of the Macedonian energy sector highlights the important role that lignite and hydro power play in the power sector, each accounting for 40% of total capacity in ...2021. In 2030, this dominance continues, although hydro has a higher share due to the retirement of some of the existing lignite plants. Three sensitivity runs of the MARKAL-Macedonia energy system model have been undertaken to explore the importance of these technologies to the system, considering that their resource may be reduced with time: (1) Reducing the availability of lignite from domestic mines by 50% in 2030 (with limited capacity of imports), (2) Removing three large hydro options, which account for 310 MW in the business-as-usual case, and (3) Both of the above restrictions. The reduction in lignite availability is estimated to lead to additional overall system costs of 0.7%, compared to hydro restrictions at only 0.1%. With both restrictions applied, the additional costs rise to over 1%, amounting to 348 Mcurrencysymbol over the 25 year planning horizon. In particular, costs are driven up by an increasing reliance on electricity imports. In all cases, the total electricity generation decreases, but import increases, which leads to a drop in capacity requirements. In both, the lignite and the hydro restricted cases, it is primarily gas-fired generation and imports that "fill the gap". This highlights the importance of an increasingly diversified and efficient supply, which should be promoted through initiatives on renewables, energy efficiency, and lower carbon emissions.
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