Single Oil Research Articles

Determination of volatile ‘restricted substances’ in flavourings and their volatile raw materials by GC‐MS

AbstractMany flavour regulations around the world contain a list of so‐called ‘restricted substances’ (RS), i.e. substances that occur naturally in source materials for flavourings and food ingredients with flavouring properties, but whose presence in certain foods is restricted and/or for which maximum levels are set, for example, the European regulation 1334/2008. Only a few publications refer to the determination of RS in compound flavourings or their raw materials, and the latter only concern the analysis of one or two individual RS in single essential oils. The Working Group on Methods of Analysis of the International Organization of the Flavor Industry (IOFI) has developed a method for the rapid routine determination of β‐asarone, coumarin, menthofuran, methylchavicol, methyleugenol, pulegone, safrole and α‐ and β‐thujones in flavourings and their raw materials by gas chromatography‐mass spectrometry (GC‐MS), using selected‐ion monitoring and internal standards. The method has been evaluated by nine flavour‐industry laboratories using a complex surrogate flavouring containing all of the above analytes, at concentrations that would be likely to produce levels in finished foods of around typical maximum limits for these RS. Results were obtained from a total of 15 columns and sets of analytical conditions, using 11 GC/MS instruments, with in each case a determination of the analyte in two versions of the flavouring. With reproducibility relative standard deviations (RSDR) of less than about 20%, and recoveries of 80–120%, the method performance can be considered as satisfactory for rapid routine checks on the levels of restricted substances in compound flavourings. The method is intended for flavour‐industry laboratories in order for them to fulfil their obligation to inform food‐industry clients of the amounts of these substances in commercial flavourings, but is not intended for their analysis in finished foods. Copyright © 2014 John Wiley & Sons, Ltd.

Synergistic repellent and irritant effect of combined essential oils on Aedes aegypti (L.) mosquitoes.

This study was designed to compare the behavioral responses of Aedes aegypti to a single essential oil and to a mixture of two or three essential oils using an excito-repellency test chamber. Mixtures were prepared from essential oils extracted from Litsea cubeba (LC), Litsea salicifolia (LS), and Melaleuca leucadendron (ML). In general, the mixture of essential oils produced a much stronger escape response by Ae. aegypti, regardless of the test conditions. No significant difference in escape responses was seen when the mixture of oils was compared with a standard commercial product containing DEET. Greater contact irritancy was seen from mixed oils of LC and LS than with other mixed oils. Mixtures of LC and LS at 0.075% showed the highest synergistic action (65.5% escaped) compared to that with unmixed oil alone at the same concentration (LC/20% and LS=32.2%). In addition, mixtures of LC and LS at 0.075% demonstrated the highest non-contact repellency (62.7%) and showed a greater effect than the use of LC (20%) or LS (20.3%) alone. We conclude that mixtures of two essential oils show potential as active ingredients for mosquito repellents.

Effect of surfactant on the dynamics of a crude oil droplet in water column: Experimental and numerical investigation

AbstractIn this study we have investigated the effect of surfactant, sodium dodecyl sulfate (SDS), on the dynamics of a single crude oil droplet, rising in a quiescent water column. Experiments were conducted in a tank, in which an oil droplet was released into a stagnant water column through a nozzle. The droplets ranging from 0.3 to 0.85 cm were produced from three different sized nozzles. The shape adopted by the emanating droplets varied from spherical to oblate. SDS concentrations were varied from 0 to 750 ppm in water. The adsorption of surfactant reduced the interfacial tension at oil‐water interface which resulted in generation of smaller sized droplets at the nozzle and caused the droplet to flatten. Consequently, the rise velocities of droplets decreased.A numerical model based on finite volume method was developed using commercial CFD package ANSYS Fluent®. The model employed volume of fluid method, suggested by Hirt and Nichols (Journal of Computational Physics 1981, 39, 201), with an interface reconstruction technique based on piecewise linear representation for tracking the oil‐water interface. The influence of surface tension on the droplet dynamics was captured by including Continuum Surface force (CSF) approach suggested by Brackbill, Kothe, and Zemach (Journal of Computational Physics 1992, 100, 335). The shape and rise velocities predicted from model were in good agreement with experimental data. The results from simulations were used, to analyze the wake structure and pressure distribution around the droplet. It was found that the smaller droplets which ascended in rectilinear path were associated with an axisymmetric wakes whereas larger and intermediate sized droplets in high SDS concentration wobbled as they ascended because of asymmetric wakes.

Simultaneous Detection of Single Attoliter Droplet Collisions by Electrochemical and Electrogenerated Chemiluminescent Responses

AbstractWe provide evidence of single attoliter oil droplet collisions at the surface of an ultra‐microelectrode (UME) by the observation of simultaneous electrochemical current transients (i–t curves) and electrogenerated chemiluminescent (ECL) transients in an oil/water emulsion. An emulsion system based on droplets of toluene and tri‐n‐propylamine (2:1 v/v) emulsified with an ionic liquid and suspended in an aqueous continuous phase was formed by ultrasonification. When an ECL luminophore, such as rubrene, is added to the emulsion droplet, stochastic events can be tracked by observing both the current blips from oxidation at the electrode surface and the ECL blips from the follow‐up ECL reaction, which produces light. This report provides a means of studying fundamental aspects of electrochemistry using the attoliter oil droplet and offers complementary analytical techniques for analyzing discrete collision events, size distribution of emulsion systems, and individual droplet electroactivity.

Simultaneous detection of single attoliter droplet collisions by electrochemical and electrogenerated chemiluminescent responses.

We provide evidence of single attoliter oil droplet collisions at the surface of an ultra-microelectrode (UME) by the observation of simultaneous electrochemical current transients (i-t curves) and electrogenerated chemiluminescent (ECL) transients in an oil/water emulsion. An emulsion system based on droplets of toluene and tri-n-propylamine (2:1 v/v) emulsified with an ionic liquid and suspended in an aqueous continuous phase was formed by ultrasonification. When an ECL luminophore, such as rubrene, is added to the emulsion droplet, stochastic events can be tracked by observing both the current blips from oxidation at the electrode surface and the ECL blips from the follow-up ECL reaction, which produces light. This report provides a means of studying fundamental aspects of electrochemistry using the attoliter oil droplet and offers complementary analytical techniques for analyzing discrete collision events, size distribution of emulsion systems, and individual droplet electroactivity.

Application of a semi-detailed soot modeling approach for conventional and low temperature diesel combustion – Part II: Model sensitivity

In Part-II of the current study, a detailed sensitivity analysis was performed on the soot model that was described in Part-I. The performance of the soot model, which was implemented in the 3-D CFD code KIVA-CHEMKIN, was evaluated by conducting a sensitivity analysis of the soot sub-model formation and oxidation rates and soot precursor chemistry. In terms of soot precursor chemistry, a detailed poly-aromatic hydrocarbon (PAH) chemistry mechanism from the literature was reduced in two stages: (1) using the directed related graph with error propagation (DRGEP) method and (2) using sensitivity analysis, and integrated into primary reference fuel (PRF) chemistry mechanism for simulating different diesel combustion cases. It was seen that the model-predicted soot mass was more sensitive to the acetylene and propargyl chemistry (C2–C3 chemistry) as compared to the aromatic and PAH chemistry. In terms of the soot sub-models, the rates of soot surface growth through acetylene and OH-induced soot oxidation sub-models were modified to understand their effects on the predicted net in-cylinder soot mass, since the net soot mass is understood to be predominantly affected by these sub-models. The pre-exponential rate of the acetylene assisted surface growth rate had to be reduced by a factor of 2.5 (at baseline OH-induced oxidation rate) in order to match the exhaust soot mass of conventional diesel and premixed charge compression ignition (PCCI) experiments at various levels of EGR in a Caterpillar single cylinder oil test heavy-duty diesel engine. Similar results were also obtained when the OH-induced oxidation rate was increased (at baseline soot surface growth rate). It was found that the same sub-model constants were sufficient to yield good exhaust soot mass predictions with respect to the engine experiments operated under varied combustion modes, including single injection conventional diesel combustion at different levels of EGR and multiple injection PCCI experiments at no EGR and high EGR conditions.

Oil pollution detection using spectral fluorescent signatures (SFS)

Marine oil spills can be highly dangerous given that the wind, waves and currents can scatter an oil spill over a wide area within just a few hours in the open sea. Remote sensing can effectively be used for detecting and monitoring of oil spills. Optical sensors provide important information for oil spill contingency planning. Remote sensing techniques have contributed a great extent to the development of oil pollution monitoring systems. However, the available detection methods, mainly designed for spaceborne and airborne long-distance inspection, are too expensive and complex to be used in an operational way by relatively unskilled personnel. In the framework of DEOSOM project (European AMPERA project), an innovative water inspection method was investigated, based on the analysis of suspicious water samples in laboratory using the spectral fluorescent signature (SFS) technique. The SFS technique is based on the fluorescence properties of the oil compounds. Different oil products were analyzed in the laboratory, using eight LED light sources with wavelengths ranging from 270 to 850 nm to excite the samples and a USB4000-FL fluorescence spectrometer to register the fluorescence spectra. Finally, an algorithm to identify oil products in polluted water samples with known substances was developed. The mean of the 16 replicas was calculated for each point and used to calculate the Euclidean distance with respect to a known sample constituted by distilled water and single oil. Finally, the percentage of similarity referred to every oil was determined.

Single Oil Drop Electrochemistry on a Screen‐Printed Electrode Surface

AbstractThe use of a contaminated single oil drop on a screen‐printed carbon electrode is described for the first time here. The simple methodology developed herein opens the possibility of conducting such measurements. R‐(+)‐limonene oil, some samples of which were contaminated with 4‐nitrophenol (4‐NP), was used as the oil phase, and BrittonRobinson (BR) buffer was used as the aqueous phase. An oxidation peak at approximately 0.8 V vs. Ag was obtained when the system comprised an oil/water interface. The charge transfer resistance decreased by a factor of approximately 7.1 when an interfacial system composed of two immiscible liquids was used as an electrochemical tool.

Research on Distributed Power Quality Monitoring System of Oilfield

For the specific requirements of power quality in the process of oil exploration,this paper designs a distributed intelligent monitoring systems,including oilfield power quality monitoring center and single oil well monitoring terminal.Among them,Single well terminal hardware is composed of high precision meter chip ATT7022C and ARM9 processor, it can complete the accurate measurement of the electrical parameters.The monitoring center is designed with LabVIEW as the carrier of the power quality comprehensive platform.Using ethernet for data transmission between the terminal and monitoring center. The results show that the system is comprehensive, it can effectively detect multiple power quality parameters and harmonic variation of the grid side,and also can provide technical support for oilfield power quality monitorng automation.

How Thirsty is Shale Gas?

Beyond the Headlines Editor’s note: Professionals in the oil and gas industry often receive questions about how industry operations affect public health, the environment, and the communities in which they operate. Of particular concern today is the impact of hydraulic fracturing on the environment. In this new column, JPT is inviting energy experts to put those questions and concerns about industry operations into perspective. Additional information about the oil and gas industry, how it affects society, and how to explain industry operations and practices to the general public is available on SPE’s Energy4me website at www.energy4me. org. The New York Times reported on 15 May 2014 that Butte County in California banned hydraulic fracturing because of concerns regarding freshwater consumption in a drought year. Shale oil and gas opponents have seized this issue even in parts of the country not suffering any significant drought. The perception of being deprived of drinking water has strong imagery. The facts beyond the headlines are decidedly not so dire. A single shale oil or gas well will use between 3 and 5 million gal of water for drilling and completion operations. This sounds like a lot and, in some sense, it is a lot. But then you realize that the average golf course uses that much every 25 days, about the length of time it takes to drill a single well and start producing from it. It is also the amount of water that New York City uses every 4 minutes! Not a fair comparison, you say. Well, why don’t we compare it against other forms of energy? Such comparisons are best made on the basis of liters of water per megawatt hour of energy. Shale gas production uses about 38 liters. In comparison, corn ethanol on average uses 32,000 to 370,000 liters (the higher end of the range is for irrigated corn), and the real shocker is soybean diesel, which comes in at 180,000 to 960,000 liters. In other words, corn ethanol uses more than 1,000 times more water per unit of energy compared with shale gas. Other sources suggest an even greater disparity in water usage (Science 2009). Conventional fracturing fluid uses freshwater as the base fluid. Fresh is defined as 500 parts per million (ppm) or less of dissolved solids. The fluid returning to the surface after use, known as flowback water, is always saltier than what went in. Salinities of 200,000 ppm are not uncommon. As a frame of reference, seawater runs about 35,000 ppm. Recent advances in fracturing fluid chemistry allow for such flowback water to be reused without removing the salt down to fresh standards. Currently in the Marcellus shale play, some companies are reusing almost all of their flowback water with minimal treatment.

Separation and identification of porphyrin biomarkers from a heavy crude oil Zaap-1 offshore well, Sonda de Campeche, México

The task to isolate metalloporphyrin compounds from crude oils is difficult, especially from reservoirs; the existence of well-known complexes homologous series type etioporphyrin (E), deoxophyloerythroetioporphyrin (DPEP), tetrahydrobenzodeoxoerythroetioporpyrin (THBD), benzoetio- porphyrin(BE) and benzodeoxoerythroetioporphyrin (BD) of vanadyl and nickel porphyrins, compounds found in crude oils around the world makes it hard. This includes natural porphyrins found in Mexican crude oils such as Ixtal-101, Zaap-1 and Ceh-1 from Sonda de Campeche, México, were the vanadyl porphyrins mixtures of the main series Etio and DPEP have also been reported elsewhere [14]. The objective of this investigation was to isolate porphyrins isomers from a single heavy crude oil from the Sonda de Campeche area, in México, and is based on the modified reversed-phase high-performance liquid chromatography method (RP-HPLC) [9, 11, 12]. Forty vanadyl porphyrin isomers, such as nickel porphyrin complexes were successfully isolated for the first time from heavy crude oil Zaap-1, through an exhaustive work which included a process of demetallization of vanadyl porphyrins to transmetallization to nickel porphyrins, in agreement with other methods [9, 11, 12, 14]. Further purification was achieved by thin-layer chromatography (TLC) with small glass chromatographic columns, packed with silica gel; then the purified isomers were analyzed and identified by electron impact mass spectrometry (EI-MS), providing the following results: from the Etio series seven isomers C 27 E , C 28 E , C 29 E , C 30 E , C 31 E , C 32 E , C 33 E were identified. From DPEP series six isomers C 29 D , C 30 D , C 31 D , C 32 D , C 33 D , C 34 D were identified; from the BD series it was identified only 1 isomer of vanadyl from BD.

The dynamic characteristics of a rotor supported on ball bearings with different floating ring squeeze film dampers

Two different floating ring squeeze film dampers (FSFD) were studied, one has a single oil film, which is referred as FSFDS, and the other has a double layer oil film, which is referred to as FSFDD. To investigate the dynamic characteristics of FSFDS and FSFDD, two rotor dynamic models are established. In the model, the coupling effect between rotor, ball bearing and FSFDS/FSFDD is considered. Then an efficient numerical integration approach has been employed to conduct the investigation into the rotor system. Numerical results show that the performances of FSFDS and FSFDD are better than the traditional SFD, but worse than FSFD that has a double layer oil film and does not contain the elastic support of a floating ring, in preventing bistable, non-synchronous and the transient amplitude of the sudden unbalance response. They have better performance than FSFD in controlling the transient process of the sudden unbalance response by increasing the support stiffness of the floating ring. But it may lead to the bistable response.

Study on Capacity of Vertical Lathe for Heavy Hydrostatic Bearing

For DVT500 vertical lathe of the carrying capacity of heavy hydrostatic bearing problem, Through the simplification of the geometric model of a single oil pad to derive the effective bearing area of a single oil pad, then establish its mathematical model, for the following to prepare for the simulation of heavy hydrostatic bearing, and through the simulation of heavy hydrostatic bearing, get the input under the condition of unchanged, with the constant improvement of the speed, the change of heavy hydrostatic bearing pressure field. Results show that the feed quantity under the condition of unchanged, with the constant improvement of the speed, start from the center of the biggest oil cavity pressure peak around gradually diminishing, isobar and high oil and shape of cavity shape basically the same. Numerical calculation results reflect the inside of the bearing pressure distribution, the simulation results for the engineering practice the bearing oil cavity structure optimization design provides a theoretical basis.

Desarrollo embrionario-larval y tiempo de metamorfosis del pez tropical <i>Xenomelaniris brasiliensis</i> (Pisces: Atherinidae)

Embryonic-larval development, and metamorphosis larval time, were studied in the tropical fish Xenomelaniris brasiliensis. Twenty nine sexually mature specimens were used, 16 females (10.86+/-1.01 cm and 7.63+/-2.62 g) and 13 males (10.43+/-0.57 cm and 6.54+/-1.44 g) which produced gametes through abdominal massage. Fertilized eggs were spherical (1.18 +/-0.44 mm diameter), greenish, transparent, benthonic and vitelus-rich; rugose striated chorion with numerous external filaments randomly distributed and abundant oil globules (0.11 + 0.07 mm diameter). The embryonic development was finished at 26.36+/-2.03 degrees C, 39.67+/-0.58 PSU and pH 8.30+/-0.10. Larvae (4.56+/-0.97 mm total length) hatched at 143 hours and 19 minutes. with vitteline sac vestiges and a single oil globule. The larvae were fed on Brachionus plicatilis and Isochrysis galbana. After the second week .4rtemia nauplii were added and I. galbana maintained. Flexion started 13 days after larvae hatched (6.10+/-1.54 mm total length) and was completed 32 days later (11.25+/-1.87 mm total length) with the hipural complex completely developed. In conclusion, X brasiliensis showed direct larval development and started larval metamorphosis (13.08+/-2.07 mm total length) to juvenile 40 days after hatching.

Study of Rheological Properties of Industrial Lubricants

The most important rheological parameter for lubricants is viscosity as it also affects the tribological properties like friction between interacting surfaces and wear. This research intends to study the relationship between viscosity and temperature at different shear rates for multiple grades of three different categories of lubricants used for different applications viz. L1: MG20W50 (engine oil), L2: SAE20W50 (engine oil), L3: MC20W50 (mineral engine oil), L4: EP90 (gear oil), and L5: DXTIII (steering fluid). Constant high dynamic viscosity, shear stress, and low compressibility at different temperatures in multigrade as well as single grade industrial oil will help to maintain the surface film over the period of time and hence the reduction in wear. The dynamic viscosity of these chosen samples has been measured experimentally in temperature range of 20 to 50°C. The measurements have been extended to observe the dependence of shear rate, time, and temperature on the dynamic viscosity. All the samples are observed to behave like Newtonian fluids in the entire temperature range of study. Further, all samples seem to obey the Arrhenius relationship with temperature. Shear stress shows linear variation with shear rate exhibiting uniform viscosity which is substantiated by almost no variation in dynamic viscosity with shear rate for value above 5 per second.

Depositional environment of oil shale within the Eocene Jijuntun Formation in the Fushun Basin (NE China)

The non-marine Fushun Basin in NE China is a fault-controlled basin filled with Eocene sediments. It hosts the largest opencast coal and oil shale mine in Asia. A single thick oil shale layer overlying sub-bituminous coal occurs within the Middle Eocene Jijuntun Formation. Based on mineralogy, inorganic and organic geochemistry, organic petrography, stable isotope geochemistry, and vitrinite reflectance measurements, the depositional environment and the oil shale potential of the oil shale-bearing succession were investigated. The Jijuntun Formation is subdivided into a lower and an upper unit characterized by a low and high quality oil shale, respectively. The thick oil shale layer of the Jijuntun Formation developed under long-lasting stable conditions in a deep freshwater lake, after drowning of a swamp. The organic matter in the lower unit is characterized by landplant-derived macerals. The sediments containing a type II kerogen (HI: ∼400 mgHC/gTOC) were deposited during warm and humid conditions. Lacustrine organisms predominant in the upper unit are forming kerogen type I (HI: ∼700 mgHC/gTOC). High bioproductivity and excellent preservation conditions resulted in high TOC contents up to 23.6 wt.% in the upper unit. The organic matter preservation was controlled by photic zone anoxia originating in a temperature stratified water column in the deep lake, without significant changes in bottom water salinity. Mid-Eocene cooling during deposition of the upper unit of the Jijuntun Formation is reflected by clay mineral composition. A hot and arid climate favoring brackish conditions in a shallow lake prevailed during accumulation of the overlying carbonate-rich Xilutian Formation. Individual geochemical parameters in the Fushun Basin have to be used with caution, e.g. the maturity proxy Tmax is affected by kerogen type, the redox proxy Pr/Ph ratio is probably biased by different sources of isoprenoids. This demonstrates the importance of multi-proxy studies.

Development of an oil spill hazard scenarios database for risk assessment

den Boer, S., Azevedo, A., Vaz, L., Costa, R., Fortunato, A.B., Oliveira, A., Tomas, L.M., Dias, J.M., Rodrigues, M., 2014. Development of an oil spill hazard scenarios database for risk assessment. In: Green, A.N. and Cooper, J.A.G. (eds.), Proceedings 13 th International Coastal Symposium (Durban, South Africa), Journal of Coastal Research, Special Issue No. 70, pp. 539-544, ISSN 0749-0208. The occurrence of oil spills in coastal regions may have catastrophic consequences on the environment and severe socio-economic impacts. This work presents a new methodology to evaluate the risk associated with oil spills in coastal zones and estuaries, and illustrates its application in a coastal lagoon (Ria de Aveiro, Portugal). A ranked list of the hydrodynamic scenarios under which oil spills are most likely generated through the analysis of 33 years of wave and wind data, retrieved from the ERA-INTERIM project database, and from the analysis of oil spills that occurred in the Atlantic Iberian shelf. Considering six spill locations and a single oil type spill inside the Aveiro harbor, the database resulted in approximately 3500 simulations. Hydrodynamic simulations were made with the MORSYS2D modeling system, a soft coupling of the hydrodynamic model ELCIRC and the wave model SWAN. The high-accuracy, unstructured grid, oil fate model VOILS was used in 2D mode to simulate the transport and the oil weathering processes at the surface and in the intertidal areas. The hazard assessment analysis included the determination of the trajectory of the plumes, the shoreline retention areas affected by the oil and their oil exposure time. Time evolution of the oil properties, such as the oil evaporation rate and emulsification processes of the mixture, are provided to support clean-up operations, as well as robustness controls such as oil mass balance.

Size Dependence of Shape and Stiffness of Single Sessile Oil Nanodroplets As Measured by Atomic Force Microscopy

This article presents results and guidelines on the quantitative analysis of size, shape, and stiffness of single sessile oil droplets in air and in water. Atomic force microscopy (AFM) facilitates the analysis of micro- and nanoscale droplets which are of growing importance for agrochemicals, cosmetics, or foodstuffs containing emulsions with nanoscale compartments or droplets. Measurement of droplet shape and stiffness provides information on the contact angle with the support surface as well as the interfacial tension of the liquid-liquid interface. In this study, micro- and nanoscale droplets were imaged both in amplitude modulation (AM) and force mapping modes. The effects of the AM mode set point ratio on the measured droplet shape are discussed, and a modified spherical cap model is suggested to extract the droplet-substrate contact angle. This model was applied to a population of different sized oil droplets imaged in water and led to the finding that the contact angle with the solid support varies with the droplet size. Force mapping was undertaken to measure the droplet stiffness as a function of the droplet size. Smaller droplets were found to be stiffer, in reasonable agreement with the Attard-Miklavcic model [Langmuir 2001, 17, 8217-8223] which describes the deformation of a sessile droplet in the nonwetting regime, i.e., by partial wrapping of the droplet around the probe surface. The model limitations are discussed in terms of the diverging droplet stiffness predicted for droplet radii similar to the probe radius as well as the error propagation associated with the droplet shape function.

Edward Hopper’s Drawings

Edward Hopper’s Drawings Carter E. Foster (bio) Those who confront the awkwardness, illogic, and irrationality common in the figures and spaces of Edward Hopper’s paintings sometimes read such qualities as evidence of a lack of skill. Though praising him, critic Clement Greenberg famously called him a “bad painter,” a moniker that his reputation has never fully shaken, even among some who admire his art. But the evidence of Hopper’s drawings, which are relatively little-known, argues differently (as does close attention to his actual painting technique). On paper, his abundant skill is directly apparent, particularly in his virtuoso ability to tease subtle tonal effects from chalk and charcoal. The groups of related drawn studies that exist for many of his painted compositions reflect the long gestation period typical for a single oil—the drawings a partial record of a thought process, much of which also occurred intangibly in Hopper’s mind. The subtle anxiety and the narrative and social tensions that are hallmarks of Hopper’s achievement are qualities he worked out carefully in drawing; he arrived at formal disjunctions, strange torsions, and artificial spaces to underscore and enhance his taut psychological confrontations and atmospheres of disquietude. One need only look at the evolution of his subjects in drawing to see how aware Hopper was of what he was doing. It is far more useful to consider the precise nature of Hopper’s subtle expressionistic distortion, deployed with keen and precise control. It is astonishing how much of Hopper’s full artistic personality is here in this very early sheet (Figure 1), drawn at the New York Academy of Art when he was barely out of adolescence. He makes [End Page 206] life class more than that, setting up tension and voyeuristic frisson by aligning the spectator’s view with that of a classmate’s, the female nude model in between. Hopper’s supreme ability to create mood and atmosphere with light is fully evolved already, his manipulation of charcoal and exploitation of paper texture a means for extraordinarily subtle tonal effects. Hopper’s first trip to Paris over the winter-spring of 1906–7 yielded at least two sketchbooks, filled with rapid, fluid pen and ink observations of cafe and street life (Figure 2). The intermingling of accurate observation and caricature shows the artist’s interest in nineteenth century graphic art. His sharp, quick capturing of essences is appropriate to this medium—pen and ink resists less than chalk or charcoal and requires more certainty, as it cannot be changed. Hopper would never use pen and ink extensively as he got older, favoring black chalk and charcoal almost exclusively. Between 1920 and 1925, Hopper regularly attended life class at the Whitney Studio Club, focusing on the posed nude model and producing hundreds of drawings in the genre (Figure 3). He never again returned to studying the nude human figure with such consistent attention. Perhaps this self-imposed, concentrated self-pedagogy in the human form solidified a comfortable mastery in how to best deploy nuance of pose and gesture, a skill he mined for the rest of his career. Hopper made a clear conceptual distinction between working from direct observation—“from the fact,” and creating imagined scenes—”improvising.” His watercolors were always in the former category, directly executed outdoors from scenes Hopper carefully chose, and a group of finished chalk and charcoal drawings form a striking, monochromatic parallel in drawing. With its classical balance of verticals and diagonals and industrial subject, in this sheet (Figure 4) Hopper comes as close as he ever would to the American movement known as Precisionism; this drawing strikingly anticipates aspects of Charles Sheeler’s definitive industrial-themed canvases from the early 1930s. [End Page 207] Though seemingly slight, Hopper’s fire hydrant deftly records nuance of light and texture through the careful balance of blended, blurred chalk marks pushed into the paper support underneath crisply applied, sharper strokes (Figure 5). The artist adapted the hydrant into a symbolic protagonist in the painted masterpiece with which this is associated, a work devoid of people but rich with anthropomorphic allusion. In these three studies for New York Movie (Figure 6, 7, 8) we...

Scope of state involvement in the management of oil and gas complex

Based on the geological-economic analysis, it is shown that there is no single (averaged or global) oil and gas complex development scheme, however, no country completely entrusts this process to the power of market relations. The article substantiates a position which specifies that the key point is to take into account macroeconomic determinants, reflecting the fact that the more the state is dependent on the resource base, the more attention it has to pay to it. This approach ensures the raw material and, on the whole, economic and, consequently, strategic security of Russia. A co nclusion is made that the main elements of economic policy in the field of oil and gas field development are tax and price policy, monitoring and control over the processes of field exploration and development, which ultimately defines transition to active development of oil and gas complex. The analysis of the structure of consumption of fuel and energy resources in Russia supports the conclusion that by the year 2025 the «oil era» will have to be replaced by the «gas energy structure», which shows a steady increase in the share of gas in the national energy balance. To implement active gas field development in strategic perspective it is suggested to create investment mechanisms that would make it possible to invite additional investment resources and fully achieve the goals established. This will make it possible to involve out-of-action license areas in the development, increase investment volumes by inflow of free capital from other sectors of the economy. The desire to stabilize supplies stimulates state-legal regulation in order to improve scientific and technical level of the national oil and gas complex. The oil and gas complex is one of the most innovative and knowledge-based sectors of the economy. Only such a complex is able to develop hydrocarbon deposits within the offshore area, especially in the High Arctic latitudes. It is obvious that the state policy concerning the oil and gas complex can by no means proceed from the need to reduce the influence of the structure on the development of the whole economy of the country. On the contrary, the influence of the oil and gas complex should be strengthened, but only providing that its overall scientific and technological level is taken into account.