Major challenges in platform design for the Russian continental shelf

There are fascinating economical and technical challenges facing field developers in the Russian continental shelf. As far as production platforms and offshore terminal structures are concerned one has to find out how to build them so that attractive investment economics can be achieved. Controlling project risks and reducing key uncertainties are found to have significance in this respect. Different ice resistant offshore structures and their construction methods are illustrated in this paper. The cost structure and technical features of the production platform types are also discussed with special attention given to the Russian construction facilities and equipment. Extreme ice loads and ice induced vibrations still remain areas of some uncertainty in offshore platforms. An approach to solve complicated interaction cases involving extreme first year ridges and hummock fields is outlined. Means to control ice loads and vibrations are discussed.     

Steady-state vibrations of offshore structures

Offshore structures subjected to the action of drifting ice floes may experience several kinds of interactions with the ice feature. This paper addresses the structural response to forces that arise when the ice floe fractures against a vertical structure. Special attention is paid to the steady-state vibrations which may arise at medium ice velocities. The paper describes a straightforward design procedure for the dynamic response of narrow structures. The applicability of simple design concepts is discussed in connection with the design problems of wide offshore structures. Reference is made to recent experimental findings to show that numerical models of dynamic ice-structure interaction provide a promising design tool for both quasi-static and dynamic response of wide offshore structures.Published in Gidrotekhnicheskoe Stroitel'stvo, No. 8, pp. 24–27, August, 1994.     

The effect of dietary forage to concentrate ratio and forage type on milk fatty acid composition and milk fat globule size of lactating cows

We examined the effects of 2 grass silage-based diets differing in forage:concentrate (FC) ratio and those of a red clover silage-based diet on intake, milk production, ruminal fatty acid (FA) biohydrogenation, milk FA composition, and milk fat globule (MFG) size distribution. Ten multiparous Nordic Red cows received the following treatments: grass silage-based diets containing high (70:30, HG) or low (30:70, LG) FC ratio or a red clover silage-based diet with an FC ratio of 50:50 (RC) on a dry matter basis. Determinations of MFG were performed from fresh milk samples without addition of EDTA so the results of fat globules >1 µm in diameter are emphasized instead of the entire globule population. Lower FC ratio in grass silage-based diets increased milk production with no effect on daily fat yield, leading to 13% lower milk fat concentration. The effect of FC ratio on MFG size was moderate. It did not affect the volume-weighted diameter in grass silage-based diets, although LG lowered the volume-surface diameter of MFG in the size class >1 µm compared with HG. Compared with HG, feeding LG moderately decreased the biohydrogenation of 18:2n-6, leading to a higher level of polyunsaturated fatty acids in milk fat. Feeding RC lowered milk fat concentration and daily milk fat yield compared with grass silage-based diets. The volume-weighted diameter of MFG in the size class >1 µm was smaller in RC milk compared with grass silage-based diets. Feeding RC increased the flow of 18:3n-3 at the omasum by 2.4-fold and decreased the apparent ruminal 18:3n-3 biohydrogenation compared with grass silage-based diets despite similar intake of 18:3n-3. It also resulted in the lowest amount of saturated FA and the highest amounts of cis-9 18:1, 18:3n-3, and polyunsaturated FA in milk. In conclusion, LG decreased milk fat content and induced minor changes in MFG size distribution compared with HG, whereas RC lowered milk fat production, altered milk FA composition to nutritionally more beneficial direction, and led to smaller MFG compared with grass silage-based diets.     

Modeling the effects and uncertainties of contaminated sediment remediation scenarios in a Norwegian fjord by Markov chain Monte Carlo simulation

Multimedia environmental fate models are useful tools to investigate the long-term impacts of remediation measures designed to alleviate potential ecological and human health concerns in contaminated areas. Estimating and communicating the uncertainties associated with the model simulations is a critical task for demonstrating the transparency and reliability of the results. The Extended Fourier Amplitude Sensitivity Test(Extended FAST) method for sensitivity analysis and Bayesian Markov chain Monte Carlo (MCMC) method for uncertainty analysis and model calibration have several advantages over methods typically applied for multimedia environmental fate models. Most importantly, the simulation results and their uncertainties can be anchored to the available observations and their uncertainties. We apply these techniques for simulating the historical fate of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the Grenland fjords, Norway, and for predicting the effects of different contaminated sediment remediation (capping) scenarios on the future levels of PCDD/Fs in cod and crab therein. The remediation scenario simulations show that a significant remediation effect can first be seen when significant portions of the contaminated sediment areas are cleaned up, and that increase in capping area leads to both earlier achievement of good fjord status and narrower uncertainty in the predicted timing for this.     

Acceleration of the PDHGM on Partially Strongly Convex Functions

We propose several variants of the primal–dual method due to Chambolle and Pock. Without requiring full strong convexity of the objective functions, our methods are accelerated on subspaces with strong convexity. This yields mixed rates, \(O(1{/}N^2)\) with respect to initialisation and O(1 / N) with respect to the dual sequence, and the residual part of the primal sequence. We demonstrate the efficacy of the proposed methods on image processing problems lacking strong convexity, such as total generalised variation denoising and total variation deblurring.     

Identification and Optimization of 4‐Anilinoquinolines as Inhibitors of Cyclin G Associated Kinase

4‐Anilinoquinolines were identified as potent and narrow‐spectrum inhibitors of the cyclin G associated kinase (GAK), an important regulator of viral and bacterial entry into host cells. Optimization of the 4‐anilino group and the 6,7‐quinoline substituents produced GAK inhibitors with nanomolar activity, over 50 000‐fold selectivity relative to other members of the numb‐associated kinase (NAK) subfamily, and a compound (6,7‐dimethoxy‐N‐(3,4,5‐trimethoxyphenyl)quinolin‐4‐amine; 49 ) with a narrow‐spectrum kinome profile. These compounds may be useful tools to explore the therapeutic potential of GAK in prevention of a broad range of infectious and systemic diseases.     

Noncholesterol Sterols as Surrogate Markers in Patients with Severe Alcoholic Hepatitis

Severe alcoholic hepatitis (AH) is a life‐threatening condition lacking good serologic markers to tailor treatment and predict recovery. We examined the cholesterol metabolism in severe AH to explore prognostic markers and evaluate the profile of cholesterol precursors, cholestanol and phytosterols, in this context. We assessed serum cholesterol, cholesterol precursors, cholestanol, phytosterols, and biochemical markers in 24 patients with severe AH treated with prednisolone and randomized to ciprofloxacin in the ratio 1:1. Response to prednisolone was assessed with the Lille model. Evaluations were made between responders and nonresponders to corticosteroid treatment and during follow‐up for 180 days. The findings were compared with those from patients with primary sclerosing cholangitis (PSC) (n = 156) and healthy individuals (n = 124). Responders to prednisolone had ~56–60% higher (p‐value 0.032–0.044) serum ratios to cholesterol of phytosterols, while the lathosterol/campesterol ratio was ~76% (p = 0.031) lower compared to nonresponders. Stigmasterol/cholesterol predicted response to corticosteroid therapy. Surrogate markers of cholesterol synthesis (lathosterol and desmosterol) inversely reflected those of absorption (cholestanol and phytosterols) in PSC and controls (r‐range ?0.247 to ?0.559, p < 0.01 for all), contrary to AH patients, among whom this reciprocal regulation was partially recovered on day 90 (lathosterol: r‐range ?0.733 to ?0.952, p < 0.05 for all). AH patients had ~26% lower lathosterol/cholesterol, but 1.13–3.87‐fold higher cholestanol/cholesterol and sitosterol/cholesterol compared to control groups (p < 0.05 for all). Median ferritin concentration at baseline was ~37% lower (p = 0.011) among the responders. Cholesterol precursors and phytosterols have a disease‐specific profile in AH. Phytosterols and ferritin may serve as surrogate markers for short‐term response.     

Effect of Camelina sativa expeller cake on performance and meat quality of broilers

The experiment was conducted to measure the effects of Camelina sativa expeller on the performance of broiler chickens and on the sensory quality and fatty acid composition of broiler meat. One‐day‐old broiler chickens were randomly allocated to the three dietary treatments which lasted 37 days. Experimental diets contained 0, 5 or 10% C. sativa expeller. Feed and water were offered ad libitum. The birds were weighed at the beginning, at 14 days and at the end of the trial at 37 days. Feed intake was recorded between weighings. C. sativa expeller reduced the growth of the birds linearly (P < 0.001). It also depressed their feed intake and feed conversion ratio during the starter phase (1–14 days). C. sativa did not cause any significant enlargement of the thyroid gland, nor were any liver lesions observed. Feeding of C. sativa significantly (P < 0.001) increased the omega‐3 fatty acid level in broiler meat. This was mainly due to an increase in α‐linolenic acid (18:3, n‐3). Feeding did not seem to have any adverse effect on the sensory quality of broiler meat. Meat from female broilers produced by feeding 5% C. sativa in the diet was significantly (P = 0.02) more tender than meat produced by feeding 10% C. sativa. Copyright © 2007 Society of Chemical Industry     

An application of the GLUE methodology for estimating the parameters of the INCA-N model

The conceptual and parameter uncertainty of the semi-distributed INCA-N (Integrated Nutrients in Catchments-Nitrogen) model was studied using the GLUE (Generalized Likelihood Uncertainty Estimation) methodology combined with quantitative experimental knowledge, the concept known as 'soft data'. Cumulative inorganic N leaching, annual plant N uptake and annual mineralization proved to be useful soft data to constrain the parameter space. The INCA-N model was able to simulate the seasonal and inter-annual variations in the stream-water nitrate concentrations, although the lowest concentrations during the growing season were not reproduced. This suggested that there were some retention processes or losses either in peatland/wetland areas or in the river which were not included in the INCA-N model. The results of the study suggested that soft data was a way to reduce parameter equifinality, and that the calibration and testing of distributed hydrological and nutrient leaching models should be based both on runoff and/or nutrient concentration data and the qualitative knowledge of experimentalist.     

Acid hydrolysis of glycosidic bonds in oat β‐glucan and development of a structured kinetic model

Homogeneous acid‐catalyzed hydrolysis of oat β‐glucan, which contains β‐(1,4) and β‐(1,3) glycosidic bonds in a nonrandom order, was studied at 353 K using HCl and H₂SO₄. A new structured kinetic model was developed that takes into account the difference in the reactivity of β‐(1,4) and β‐(1,3) glycosidic bonds as well as their positions in the polysaccharide chain. To minimize the correlation of adjustable parameters in the new model, the reactivities of these bonds were studied independently (T = 313…363 K; c_H+ = 0.1…2 mol/L) using cellobiose and laminaribiose. The difference in kinetic parameters (e.g., T = 338 K: k_β‐(1,4) = 0.693 × 10^?3 L/mol/min, k_β‐(1,3) = 1.027 × 10^?3 L/mol/min) was found to be statistically significant (P < 0.0001), which emphasizes the need for the structured model for oat β‐glucan hydrolysis. The simulation of β‐glucan hydrolysis with the new model was in good agreement with the experimental data and shows improvement over existing nonstructured models. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2570–2580, 2018