Coupling-Strength Criteria for Sequential Implicit Formulations

Sequential Fully Implicit (SFI) schemes have been proposed as an alternative to the Fully Implicit Method (FIM). A significant advantage of SFI is that one can employ scalable strategies to the flow and transport problems. However, the primary disadvantage of using SFI compared with FIM is the fact that the splitting errors induced by the decoupling operator, which separates the pressure from the saturation(s), can lead to serious convergence difficulties of the overall nonlinear problem. Thus, it is important to quantify the coupling strength in an adaptive manner in both space and time. We present criteria that localize the computational cells where the pressure and saturation solutions are tightly coupled. The approach is using terms in the FIM Jacobian matrix, we quantify the sensitivity of the mass and volume-balance equations to changes in the pressure and the saturations. We identify three criteria that provide a measure of the coupling strength across the equations and variables. The standard CFL stability criteria, which are based entirely on the saturation equations, are a subset of the new criteria. Here, the pressure equation is solved using Algebraic MultiGrid (AMG), or a multiscale solver, such as the Multiscale Restricted-Smooth Basis (MsRSB) approach. The transport equations are then solved using a fixed total-velocity. These ‘coupling strength’ criteria are used to identify the cells where the pressure-saturation coupling is strong. The applicability of the derived coupling-strength criteria is tested using several test cases. The first test is using a gravitational immiscible dead-oil lock-exchange under a unit mobility ratio and large differences in density. For this case, the SFI algorithm fails to converge to the fully coupled solution due to the large splitting errors. Introducing a fully coupled solution stage on the local subdomains as an additional correction step restores nonlinear convergence. Detailed analysis of the ‘coupling strength’ criteria indicates that the criteria related to the sensitivity of the mass balance to changes in the pressure and the sensitivity of the volume balance to changes in the saturations are the most important ones to satisfy. Other test cases include an alternate gas-water-gas injection in a top layer of the SPE 10 test case and an injection-production scenario in a three-dimensional reservoir with layered lognormally distributed permeability. We propose novel criteria to estimate the strength of coupling between pressure and saturation. These CFL-like numbers are used to identify the cells that require fully implicit treatment in the nonlinear solution strategy. These criteria can also be used to improve the nonlinear convergence rates of Adaptive Implicit Methods (AIM).

Development of a three-zone combustion model for stratified-charge spark-ignition engine

A thermodynamic model for calculating the operating process in the cylinder of a spark-ignition engine with internal mixture formation and stratified air-fuel charge based on the volume balance method was developed. The model takes into account the change in the working fluid volume during the piston movement in the cylinder. The equation of volume balance of internal mixture formation processes during direct fuel injection into the engine cylinder was compiled. The equation takes into account the adiabatic change in the volume of the stratified air-fuel charge, consisting of fuel-air mixture volume and air volume. From the heat balance equation, the change in the fuel-air mixture volume during gasoline evaporation in the fuel stream and from the surface of the fuel film due to external heat transfer was determined. Basic equations of combustion-expansion processes of the stratified air-fuel charge were derived, taking into account three zones corresponding to combustion products, fuel-air mixture and air volumes. The equation takes into account the change in the working fluid volume due to heat transfer and heat exchange between the zones and the walls of the above-piston volume. Dependences for determining the temperature in the three considered zones and pressure in the cylinder were obtained. Graphs of changes in the volumes of the combustion products, fuel-air mixture and air zones with the change of the above-piston volume in partial load modes (n=3,000 rpm) were plotted. With increasing load from bmep=0.144 MPa to bmep=0.322 MPa, at the moment of fuel ignition, the volume of the fuel-air mixture increases from 70 % to 92 % of the above-piston volume. At the same time, the air volume decreases from 30 % to 8 %. Analysis of theoretical and experimental indicator diagrams showed that discrepancies in the maximum combustion pressure do not exceed 5 %

Role of landslides on the volume balance of the Nepal 2015 earthquake sequence

The 7.8 Mw earthquake that struck Nepal on April 25th, 2015 triggered over 21,000 landslides over an area of more than 25,000 km2. These landslides contributed to mass wasting, partially compensating the tectonic uplift by the earthquake. In this paper we quantify the volume balance resulting from the 2015 earthquake uplift (or subsidence) and landslide erosion. Starting from a new complete earthquake-induced landslide inventory, we calculated landslide volume by adopting different strategies for low-mobility and high-mobility landslides, considering also the potential supply of sediments to the drainage network. The results show that the contribution of earthquake-induced landslides to erosion is about one order of magnitude smaller than the vertical coseismic displacement. We found landslide volume values, due to the 2015 Nepal earthquake, ranging between 251 (− 15/ + 16) Mm3 up to 1503 (− 183/ + 210) Mm3 based on the adopted method, and a volume due to coseismic vertical displacement of 2134 (± 1269) Mm3 for the whole area. The volume balance of the 2015 Nepal earthquake is strongly dominated by tectonic displacement. We show that these estimates depend on several uncertainties. We identified and quantified uncertainties related to: (1) the choice of empirical volume-area scaling relationships and their parameters; (2) the completeness and quality of landslide inventory through comparison with available inventories; (3) the approach adopted for the assessment of elongated landslide volume; (4) the InSAR displacement data.

Analisis pendapatan pedagang pulsa dan paket data di Kabupaten Tanjung Jabung Barat (Studi Kasus Kecamatan Tungkal Ilir)

This research aims to find out and analyze the socio-economic characteristics of pulse kiosks and data packages and to find out and analyze the effect of capital. Product prices sold several credits, and sales volume on pulse and data package traders in Tungkal Ilir District, Tanjung Jabung Barat Regency. The data used in this study is primary data. The analytical tool used is multiple linear regression. The results showed that the variables of capital, the price of products sold, the number of credit balances, and the volume of sales of data packages had a significant effect on the income variable of pulse traders and data packages. In contrast, partially, the variables of working capital and sales volume of data packages had a considerable effect. In comparison, the price of products sold and the number of credit balances do not significantly affect the income variable of pulse traders and package data in Tungkal Ilir District, Tanjung Jabung Barat Regency. Keywords: Traders, Capital, Volume, Balance

Abstract P079: Lymphatic Contraction Was Enhanced In Spontaneously Hypertensive Rats

Because lymph capillary network regulates interstitial electrolyte and volume balance, this system may function as regulating blood pressure (BP). Thus, changes in lymphatic activity can be expected to alter systemic BP. We recently reported that increasing BP caused lymphatic endothelial dysfunction via oxidative stress in hypertension. In this study, we examined lymphatic contractile function in thoracic duct from 10-14-week-old Wister-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR). No distinct morphological difference was observed in thoracic duct isolated from WKY and SHR (n=4). Thoracic duct from SHR exhibited enhanced contractile response to serotonin (5-HT) or endothelin-1 (ET-1) compared to age-matched WKY (5-HT: 127.8±19.7% vs 53.6±10.3% of KCl-induced maximum contraction, p<0.05, n=5). The augmented contraction in SHR was diminished by fasudil, ROCK inhibitor (p<0.05, n=4-5). Consistent with this, increased phosphorylation of myosin phosphatase targeting protein (MYPT) was observed in SHR thoracic duct. Expression of ROCK1 or ROCK2 was not changed in SHR thoracic duct. Next we examined lymphatic contractile function in 4-week-old SHR showing normal BP. Contractile response to 5-HT or ET-1 was not enhanced in young SHR compared to age-matched WKY (n=4). To examine if lymphatic dysfunction was associated with increased BP, we treated 4-week-old SHR with antihypertensive drugs (hydrochlorothiazide and hydralazine) for 6 weeks. This treatment completely blocked elevation of systolic BP (SBP) in SHR (p<0.05, n=5), but did not prevent the augmentation of lymphatic contraction (5-HT: 99.0±7.2% vs 98.1±14.5%, n=5). Interestingly, treatment of young SHR with losartan (Angiotensin II type 1 receptor [AT1R] blocker) for 6 weeks ameliorated the augmented contraction (5-HT: 137.4±12.7% vs 77.9±8.8%, p<0.05, n=5), while this treatment scarcely diminished the increase in SBP (152.0±8.7 mmHg vs. 177.2±10.9 mmHg, p<0.05, n=5). We conclude that lymphatic contractile function was significantly enhanced in adult hypertensive SHR, which is mediated by RhoA/ROCK pathway thorough activation of AT1R. The increase in lymphatic constriction may be involved in increased BP in hypertension through decreased lymphatic compliance.

Analisis Dinamika Molekuler Pengaruh Suhu Tubuh Terhadap Keseimbangan Volume Human Serum Albumin (HSA) Menggunakan Model Potensial Lennard-Jones

Research on molecular dynamics analysis of the influence of body temperature on HSA fluid volume balance using the Lennard-Jones potential model with temperature variations of 35 ℃, 37 ℃, and 40 ℃ in the form of cubic systems in GROMACS applications. The results show that the denaturation of HSA that is affected by body temperature causes changes in osmotic pressure in the body with changes in the balance of HSA fluid volume. At temperatures of 35 ℃ denaturations occurs Thr566 to Gln580 with a distance of 20.9 A, Lys444 to Met446 with a distance of 5.76 A, Asn61 to Cys62 with a distance of 3.9 A, Glu570 to Ser579 with a distance of 18.09 A, and Gly431 to Cys438 with a distance of 11.43 A. At a temperature of 37 ℃ denaturations occurs Ile513 to Cys514 has a distance of 3.75 A, Pro303 to Glu311 has a distance of 12.78 A, Asn267 to Ser270 has a distance of 4.65 A, Leu275 to Cys279 has a distance of 7 A At a temperature of 40 ℃ denaturations occurs Ser304 to Glu311 with a distance of 11.38 A, Asn267 to Ile271 with a distance of 7.75 A, Asn61 to Cys62 with a distance of 3.9 A, and Ala511 to Cys514 with a distance of 4.86 A. RMSD results shows that stable structural changes occur in HSA with values of 2.6–9.0 nm. And the Lennard-Jones average energy yield shows that the interaction behavior between HSA atoms is dynamic. At a temperature of 35 ℃ of 7.97E + 05 kJ/mol, a temperature of 37 ℃ of 6.78 kJ/mol, and a temperature of 40 ℃ of 7.89E + 05 kJ/mol.

Evaluasi Kualitas dan Kuantitas Lumpur Alum dari Instalasi Pengolahan Air Minum Citayam

ABSTRACTWater treatment plants (WTPs) produces residues in the form of alum sludge during the treatment process. In Indonesia, due to various techno-economic constraints, some WTPs are not equipped by sludge treatment systems, so the generated alum sludge is discharged directly into water bodies without appropriate treatment. This condition may pollute water bodies because alum sludge contains various contaminants such as solid particles, organic compounds, inorganic metals, aluminum, and pathogenic microorganisms. This study aims to evaluate the characteristics of alum sludge from aspects of quality and quantity, which is indispensable for the design of sludge treatment facilities. Citayam WTP (capacity of 120 L/s) in Depok City was chosen as a case study. The study was conducted in several stages as follows: (i) survey and sampling; (ii) quality analysis of alum sludge; (iii) estimation of sludge generation; and (iv) mass and volume balance analysis. Results of comparative analysis of alum sludge quality against the Regulation of Minister of Environment of Indonesia 5/2014 shows alum sludge from flocculation units meets quality standards. In contrast, alum sludge from sedimentation and filter units were exceeded for TSS, COD, and Total Coliform parameters. Quantity-wise, the estimation of sludge generation by theoretical and empirical methods was found to be 1,898 kg/day and 4,854 kg/day. Analysis of mass and volume balance using STAN software indicates that the theoretical approach is quite representative, while the empirical method tends to be over-estimated.Keywords: alum sludge, sludge quality, sludge generation, water treatment plant, case studyABSTRAKInstalasi pengolahan air (IPA) dalam proses pengolahannya akan menghasilkan residu berupa lumpur alum. Di Indonesia, akibat berbagai kendala tekno-ekonomis, masih terdapat IPA yang belum memiliki sistem pengolahan lumpur alum sehingga langsung dibuang ke badan air tanpa pengolahan. Kondisi ini berpotensi mencemari badan air karena lumpur alum mengandung berbagai kontaminan seperti partikel padat, senyawa organik, inorganik, logam aluminium serta mikroorganisme patogen. Penelitian ini bertujuan untuk mengevaluasi karakteristik lumpur alum dari aspek kualitas dan kuantitas yang merupakan informasi penting dalam perancangan sistem pengolahan lumpur. IPA Citayam (Kapasitas 120 L/detik) di Kota Depok dipilih sebagai objek studi. Penelitian dilakukan dalam beberapa tahapan yakni survei dan sampling, analisis kualitas lumpur alum, estimasi timbulan lumpur, dan analisis neraca massa dan volume. Hasil perbandingan analisis kualitas lumpur alum terhadap PermenLH 5/2014 menunjukan lumpur alum dari unit flokulasi memenuhi baku mutu sedangkan lumpur alum dari unit sedimentasi dan filter melebihi baku mutu lingkungan untuk parameter TSS, COD dan Total Koliform. Dari aspek kuantitas, estimasi timbulan lumpur yang dilakukan dengan metode teoritik dan empirik berturut-turut sebesar 1.898 kg/hari dan 4.854 kg/hari. Analisis neraca massa dan volume menggunakan software STAN mengindikasikan bahwa metode teoritik cukup representatif, sedangkan perhitungan dengan metode empirik cenderung menjadi over-estimasi.Kata kunci: lumpur alum, kualitas lumpur, timbulan lumpur, instalasi pengolahan air, studi kasus