The particularities of the calculation and of the cost reduction in lignite production

In the market economy, the entities are, in an objective way, obliged to be preoccupied with the reduction of costs, taking into consideration the relationship of independence and indirect proportionality between the level of production costs and profit. The laws of competition oblige to the limitation of the waste channels, to the introduction of performant tehnological and tehnical solutions, to the systematic development of the work productivity. Because of this, we appreciated that is advisable that also in the extraction of lignite, we should determine a correct production cost, according to which should be possible the identification of the cost optimization possibilities. On the other hand, the effective cost of the lignite has a major importance because it represents the price which is registered in the accountancy, and, at the same time, through its size, concreted in stocks, it influences the total of the circulant actives and the net active, and the financial result of the exercise. These aspects can be arguments for the option of approaching this work’s theme, in which there are analised the following problems: the general structure and the particularities of the production cost in lignite extraction and the directions for the minimization of the effective production cost, including for the applying of the standard-cost method.lignite stocks, production costs, actual cost, standard cost, cost reduction.

Low Temperature MOCVD-Processed Alumina Coatings

We first present a Review about the preparation of alumina as thin films by the technique of MOCVD at low temperature (550°C and below). Then we present our results about thin films prepared by the low pressure MOCVD technique, using aluminium tri-isopropoxide as a source, and characterized by elemental analysis (EMPA, EDS, ERDA, RBS), FTIR, XRD and TGA. The films were grown in a horizontal, hot-wall reactor, with N2 as a carrier gas either pure or added with water vapour. The deposition temperature was varied in the range 350-550°C. The films are amorphous. Those prepared at 350°C without water added in the gas phase have a formula close to AlOOH. Those deposited above 415°C are made of pure alumina Al2O3. When water is added in the gas phase, the films are pure alumina whatever the deposition temperature

Radioimaging Diagnosis of Vaterian Ampulloma: Technique, Semiology, and Differential Diagnosis - Review

The lining of the Vater papilla represents a complex set of folds of the mucous membrane which acts as an anti-reflux valve and participates in regulating the flow in pancreatic and biliary secretion. The constitutive smooth muscles of the Oddi sphincter differ both anatomically and especially embryologically from the parietal duodenal muscles. This is one of the reasons why some authors believe that the vaterian ampulloma is a distinct oncologic entity from the rest of the duodenal or pancreatic primitive neoplasia. The variations of the implantation manner in the papilla of the common bile duct and pancreatic one simultaneously determine different ways of surgical approach of malignancies of this region. Radioimaging diagnostic methods in suspected vaterian ampulloma require a more special technique. The purpose of this paper is to determine the potential semiological, radiological, and imaging characteristics that will allow a diagnosis of vaterian ampulloma, considering that the surgical therapy, as well as the survival rate in patients, is different from the other neoplasm of the region

Protective Alumina Coatings by Low Temperature Metalorganic Chemical Vapour Deposition

Alumina thin films were processed from aluminium tri-iso-propoxide in a horizontal, with N2 as a carrier gas, occasional addition of water in the gas phase, deposition temperature in the range 350-700°C, total pressure 0.67 kPa (2 kPa when water was used). The films do not diffract X-ray when prepared below 700°C. At 700°C, they start to crystallize as γ-alumina. EDS, EPMA, ERDA, RBS, FTIR and TGA revealed that films prepared in the range 350- 415°C, without water in the gas phase, have an overall composition Al2O3-x(OH)2x, with x tending to 0 with increasing temperature. Al2O3 is obtained above 415°C. When water is added in the vapour phase, the film composition is Al2O3, even below 415°C. Coatings deposited in these conditions show promising protection properties

Phase Transformations of Metallorganic Chemical Vapor Deposition Processed Alumina Coatings Investigated by In Situ Deflection

Phase transformations of Al2O3 films, deposited by metallorganic chemical vapor deposition from aluminium tri-isopropoxide on AISI 301 stainless steel, were investigated using an original technique of deflection associated with X-ray diffraction and electron microscopy. The samples were first oxidized at 1123 K in air to obtain a 0.9 m thick Cr2O3 protective oxide film on one side of the samples. Then, 1 m thick amorphous Al2O3 films were deposited on the opposite side at 823 K and 2 kPa. The deflection of such dissymmetrical samples was recorded during anisothermal treatments, consisting in slow heating to 1173 K in Ar atmosphere. The coefficient of thermal expansion of both the Cr2O3 and the amorphous Al2O3 films was determined to be 710−6 K−1 and 14.7 10−6 K−1, respectively. Crystallization kinetics of amorphous to mainly –Al2O3 become significant at temperatures equal or greater than 983 K. Transformation of metastable Al2O3 to –Al2O3 is initiated below 1173 K. It is demonstrated that deflection is a powerful tool for investigating the behavior of thin films deposited on a substrate and especially to reveal transformations occurring in these films during heat-treatments

PERSISTENCE AND SURVIVAL ASPECTS OF FLUCTUATION PHENOMENA IN SURFACES

Controlling the stability of nanostructures is an important fundamental issue in nanoscience. A key problem in this respect is the random stochastic interface dynamics associated with equilibrium nanometer scale thermal fluctuations, which can be understood by applying first--passage statistical concepts, such as the temporal persistence [survival] probability $P(t)$ [$S(t)$]. $P(t)$ [$S(t)$] measures the probability of the step height $not$ returning to the original [average] value within a given time interval. In this study, we measure the persistence exponent $\theta$ associated with the power--law decay of $P(t)$ at large time scale and also the survival time scale, $\tau_s$, describing the exponential decay of $S(t)$ for several nonequilibrium surface growth processes and fluctuating steps on solid surfaces. We show that for growth models in the Molecular Beam Epitaxy universality class, the nonlinearity of the underlying equation is clearly reflected in the difference between the measured values of the positive and negative persistence exponents. We also find that the survival time scale provides useful information about the physical mechanism underlying step fluctuations. An exact relation between long-time behaviors of the survival probability and the autocorrelation function is established and numerically verified. The dependencies of the persistence and survival probabilities on the system size and the sampling time are shown to be described by simple scaling forms. We introduce the generalizations of the persistence and survival probabilities for surface fluctuations. Our measurements of the persistent large deviations probability and associated family of exponents show good agreement with the corresponding quantities measured experimentally using scanning tunneling microscopy dynamical images of step fluctuations. The spatial persistence and survival probabilities are also theoretically analyzed. Finally, we investigate the connection between the generalizations of the spatial and temporal persistence probabilities

Aluminium tri-iso-propoxide: Shelf life, transport properties, and decomposition kinetics for the low temperature processing of aluminium oxide-based coatings

Aluminium tri-iso-propoxide (ATI) is a common precursor for the MOCVD of alumina coatings. However, little is known on its long term stability while its saturated vapour pressure in function of the temperature is controversial. The present contribution deals with these questions through FTIR, TGA and vapour pressure measurements. Low pressure MOCVD from ATI was performed in the temperature range 250–700 °C. Whereas the pyrolytic decomposition of ATI leads to hydroxo species free alumina films above 415 °C, it is shown in this paper that the thermal decomposition of ATI in the presence of water vapour yields pure alumina films at temperatures as low as 300–350 °C. The films prepared in the range 250–700 °C do not diffract X-rays. Arrhenius plots for both pyrolytic (Ea∼12 kJ/mole) and water assisted (Ea∼9 kJ/mole) decomposition reveal diffusion-limited processes with higher growth rate values in the former case

POSSIBILITIES OF INITIAL ESTIMATION AND FURTHER VALIDATION OF INSIDE CONTROL RISK

The approach option of the theme of this essay had in mind the distinguished importance of the objective of inside control regarding the segmentation with maximum exigency of the risks which can disadvantageously influence the fulfillment of the entity objectives. We considered essential the use of adequate procedures regarding the estimation and documentary validation of inside control risk. Regarding the initial estimation we analyzed the phases that are justified to be followed (four) and the proper steps which are followed (ten), starting with the assessment of audit objectives on types of operations and ending with reporting to the competent institutions. Regarding initial risk validation we examined the subsequent circumstances of this operation which are influencing the forecasted risk level, like: adjourning of control mechanisms applications, the apparition of new legal procedures, the alterations of the entity’s politics, etc.critical; inside control, initial risk estimation, subsequent risk validation, risk estimation procedure.

Role of in vivo reflectance confocal microscopy in the analysis of melanocytic lesions

No abstract available</p