Possibilities of ultrasound methods in the diagnosis of decompression sickness

Aim of the work: to conduct a comparative analysis of methods of ultrasound examination of the right heart with audio and visual indication of intravascular decompression gas formation in divers after diving.Materials and methods. An examination of the right heart in divers after 152 man-descents was carried out. Intravascular decompression gas production was assessed by ultrasound using sound location based on the Doppler effect and transthoracic two-dimensional echocardiography.Results and discussion. Both methods make it possible to determine intravascular decompression gas formation after a diving descent, correlate with the clinical picture of acute decompression sickness and should be used in the medical support of diving descents. At the same time, the method of ultrasound examination based on transthoracic two-dimensional echocardiography turned out to be more sensitive in determining gas bubbles in the right heart as compared to auditory location with the Doppler effect.

Comparison of Z-Factor Correlations Using a Large PVT Dataset with Emphasis on the GERG-2008 EOS

The gas compressibility factor is an important property in reservoir simulation studies. It is directly linked to the gas formation volume factor and the gas density thereby impacting wellhead injection pressure, reservoir voidage, injectivity, as well as the tendency for gas gravity override to occur in the reservoir. ADNOC's PVT database contains experiments on almost 2,000 samples, of which more than 100 have been subject to advanced gas injection experiments. Z-factor data have been compiled from the liberated gas during DV experiments as well as from CCE experiments on reservoir gases, injection gases, and swollen fluid mixtures. Several of these mixtures are very rich in H2S, whereas pressure and temperature are in the range of 14.7-14,500 psia and 80-365 °F, respectively. We test several different methods for predicting the Z-factor, such as the industry-standard Hall-Yarborough method, in combination with various models for pseudo-critical pressure and temperature and including correction for non-hydrocarbon components. Other methods tested include the GERG-2008 model, considered to be state-of-the-art for predicting physical properties for well-described gas mixtures, as well as the well-known Peng-Robinson cubic equation of state. Based on close to 10,000 data points in our database, the GERG-2008 model typically predicts the Z-factor to be within 2% of the measured value, which is on par with the experimental uncertainty. However, for some rich gas condensate mixtures, the model gives larger errors because its parameters are only tuned to compositions with components up to C10. This is to our knowledge the first time that the GERG-2008 EOS has been compared to standard Z-factor correlations for such a large number of data points. If compositional information is available, we recommend using either the GERG-2008 model or the Hall-Yarborough model with pseudo-critical properties provided by Kay (1936). When compositions are not available, we find that the Standing correlation is more accurate than the Sutton model, also for sour mixtures.

BIOTECHNOLOGICAL FEATURES OF PRODUCTION AND QUALITY ASSESSMENT OF LACTOSE-FREE YOGHURT

Lactose-free dairy products play a significant role in the diet of people with lactose intolerance, as they are a source of prombiotics and highly nutrients that are readily available, are in balanced proportions and do not contain milk sugar (lactose). In the manufacture of lactose-free dairy products in the technological scheme provides for the extraction of milk sugar (lactose), which can lead to deterioration of their sensory and physicochemical properties. The aim of this work was to study the comparative aspect of biotechnological features of yogurts made by traditional and lactose-free technologies and to evaluate their organoleptic and physicochemical properties. The object of the study were organic drinking yogurt with "blueberry" filler (with probiotic) 2.5 % and lactose-free organic yogurt (with probiotic) 2.5 %. According to the results of research, organic drinking yogurt with "blueberry" filler (with probiotic) 2.5 % in taste was sour milk, without foreign tastes and odors moderately sweet, with a pronounced taste of "blueberry" filler, consistency - homogeneous, tender, dense, without gas formation, with particles of fresh blueberries, which are distributed throughout the mass of yogurt, color - with a shade that is characteristic of blueberries. Organic lactose-free yogurt (with probiotic) 2.5 % had a sour taste, sour milk, without foreign tastes and odors, color - white. According to the results of physico-chemical studies of experimental samples of organic drinking yogurt with "blueberry" filler and lactose-free organic yogurt, the titratable acidity was 80 and 85 oT, active acidity 4.7 and 4.5, respectively. The mass fraction of carbohydrates in drinking yogurt with "blueberry" filler was 9.8 g / 100 g at 4.4 g / 100 g in lactose-free yogurt, including sugar 5.8 and 0 g / 100 g, respectively. Energy value and caloric content was higher in the sample of yogurt with "blueberry" filling. The conditional viscosity of the test samples was 1 min 30 sec. and 59 sec. in accordance. The degree of syneresis in the experimental samples of organic drinking yogurt with the filler "blueberry" and lactose-free organic yogurt was 55 and 45 % moisture content - 44.07 and 39.49 %, respectively.

Identification of Breakout Behind Casing: Methodology to Obtain Openhole-Equivalent Caliper Measurements Through Slotted Liner Using the Density Tool

Growth in the coal seam gas industry in Queensland, Australia, has been rapid over the past 15 years, with greater than USD 70 billion invested in three liquified natural gas export projects supplied by produced coal seam gas. Annual production is of the order of 40 Bscm or 1,500 PJ, with approximately 80% of this coming from the Jurassic Walloon Coal Measures of the Surat Basin and 20% from the Permian Coal Measures of the Bowen Basin. The Walloon Coal Measures are characterized by multiple thin coal seams making up approximately 10% of the total thickness of the unit. A typical well intersects 10 to 20 m of net coal over a 200- to 300-m interval, interbedded with lithic-rich sandstones, siltstones, and carbonaceous mudstones. The presence of such a significant section of lithic interburden within the primary production section has led to a somewhat unusual completion strategy. To maximize connection to the gas-bearing coals, uncemented slotted liners are used; however, this leaves fluid-sensitive interburden exposed to drilling, completion, and produced formation fluids over the life of a well. External swellable packers and blank joints are therefore used to isolate larger intervals of interburden and hence minimize fines production. Despite these efforts, significant fines production still occurs, which leads to the failure of artificial lift systems and the need for expensive workovers or lost wells. Fines production has major economic implications, with anecdotal reports suggesting up to 40% of progressive cavity pump artificial lift systems in Walloon Coal Measures producers may be down at any one time. The first step in solving this problem is to identify the extent and distribution of fines production. The wellbore completion strategy above, however, precludes the use of mechanical calipers to identify fines-production-related wellbore enlargement. A new caliper-behind-liner technique has therefore been developed using a multiple-detector density tool. Data from the shorter-spacing detectors are used to characterize the properties of the liner as well as the density of the annular material. This is particularly important to evaluate as the annulus fill varies between gas, formation water, drilling and completion fluids, and accumulated fines. The longer-spacing detector measurements are then used in conjunction with pre-existing openhole formation density measurements to determine the thickness of the annulus, and hence hole size, compensating for liner and annulus properties.

Blue-LED Calibration on DOAS System to Measure Nitrogen Dioxide Emission Compared with USEPA Method 7B Standard

Air polution level measurement sometime needs tricky instrumentation, costly, and use chemical reagent that could bad impact to environment, it also time consuming for analysis. In other hand, air polution level measurement, include nitrogen dioxide (NO2) needs accuracy, rapid and environment friendly for its analysis and measurement. Differential Optical Absorption Spectroscopy (DOAS) develop as spectrum measurements both UV and visible, transmitted by specific canal using absorption Lambert Beer’s Law principal. On this basic method, NO2 measurement needs light source with 330 – 500 nm wavelength, it is possible to use cheap blue-LED for this measurement. This research intends to calibrate prototype instrumentation for measuring NO2 by DOAS based using Blue-LED (375 nm) passed in continual gas container. NO2 emission simulated in laboratory scale by reacting copper (Cu) with nitric acid (HNO3) result NO2 gas formation. Blue-LED spectrum analysed by compact CCD Spectrometer for its absorbance spectrum, then calibrated with NO2 measurement using USEPA Method 7B standard that is commonly used in testing laboratory as standard method for NO2 measurement. It has good corelation between spectrum absorbance in CCD Spectrometer to USEPA Method 7B with more than 95% linierity. As rapidity of this measurement and shown good accuracy, more development for this method could carry fast, accurate, cheap, also environmentally friendly method for NO2 measurement.

COMPARISON OF MODERN GEODYNAMIC MODES OF FRAMING OF THE EUROASIAN LITHOSPHERIC PLATE

The purpose of the work is to analyze the modern geodynamic mode of framing of the Eurasian lithospheric plate to determine the types of deformations in the structures of spreading, subduction and rift genesis and favorable conditions for oil and gas formation at certain stages of structure development. The authors have analyzed the Arctic spreading zone, the Kamchatka subduction zone, the southwestern part of Eurasia and the Baikal rift system. The author's development of calculation of slip vectors of rock masses in foci of earthquakes and methods of tensor analysis of mechanics of fractured media were used in the work. Differences and similarities between the Arctic spreading zone, the Kamchatka subduction zone, the southwestern part of Eurasia and the Baikal rift system are shown. All of the above structures have a complex layered-block structure. That is, in a layered-block medium in layers, and in individual blocks and in time, the stress-strain state of the lithosphere changes, which directly depends on the direction of the axes of compressive stresses

Biocompatibility Analyses of HF-Passivated Magnesium Screws for Guided Bone Regeneration (GBR)

Background: Magnesium (Mg) is one of the most promising materials for human use in surgery due to material characteristics such as its elastic modulus as well as its resorbable and regenerative properties. In this study, HF-coated and uncoated novel bioresorbable magnesium fixation screws for maxillofacial and dental surgical applications were investigated in vitro and in vivo to evaluate the biocompatibility of the HF coating. Methods: Mg alloy screws that had either undergone a surface treatment with hydrofluoric-acid (HF) or left untreated were investigated. In vitro investigation included XTT, BrdU and LDH in accordance with the DIN ISO 10993-5/-12. In vivo, the screws were implanted into the tibia of rabbits. After 3 and 6 weeks, degradation, local tissue reactions and bony integration were analyzed histopathologically and histomorphometrically. Additionally, SEM/EDX analysis and synchrotron phase-contrast microtomography (µCT) measurements were conducted. The in vitro analyses revealed that the Mg screws are cytocompatible, with improved results when the surface had been passivated with HF. In vivo, the HF-treated Mg screws implanted showed a reduction in gas formation, slower biodegradation and a better bony integration in comparison to the untreated Mg screws. Histopathologically, the HF-passivated screws induced a layer of macrophages as part of its biodegradation process, whereas the untreated screws caused a slight fibrous tissue reaction. SEM/EDX analysis showed that both screws formed a similar layer of calcium phosphates on their surfaces and were surrounded by bone. Furthermore, the µCT revealed the presence of a metallic core of the screws, a faster absorbing corrosion front and a slow absorbing region of corroded magnesium. Conclusions: Overall, the HF-passivated Mg fixation screws showed significantly better biocompatibility in vitro and in vivo compared to the untreated screws.

Kinetic Study of Gas Formation in Styrofoam Pyrolysis Process

This research aims to study the reaction kinetics of gas formation in the pyrolysis of styrofoam waste. Pyrolysis of styrofoam waste without a catalyst takes place at a constant temperature of 180°C. In contrast, the pyrolysis of styrofoam waste by adding a zeolite catalyst took place at a constant temperature of 170°C. The amount of styrofoam waste used in this research sample is 200 grams, and the natural zeolite catalyst is 5 grams. Pyrolysis of styrofoam waste without using a catalyst form a gas at a constant temperature of 180°C, the kinetics of the reaction takes place on the zero-order. This result follows the Arrhenius equation K = Ae10617/RT with an activation energy value (Ea) of 1.27x103 kJ.mol-1. Pyrolysis of styrofoam waste by adding a zeolite catalyst to gas formation at a constant temperature of 170°C also takes place on the zero-order. The equation follows Arrhenius K= Ae4711,5/RT and the activation energy value (Ea) is 5.66x102 kJ.mol-1.