The Physicomechanical Deterioration Characteristics and Mesoscopic Damage Analysis of Sandstone under Acidic Environment

The physicomechanical deterioration characteristics of sandstone subjected to H2SO4, HCl, and H2O solutions of different pH values are studied by the method of long-term accelerated immersion. The quantitative relationships between the damage variables based on CT (computer tomographic identification technology) numbers and the immersion time, the uniaxial compressive strength, the peak point strain, and the elastic modulus of rock samples are analyzed. The test results indicate that the pH value of immersion solutions, the dissolution rate of Ca2+ and Na+, and the quality change of rock samples show visible stage characteristics under acidic environment. With the soaking time extended, the pH value of solutions increases gradually, and the quality change of rock samples decreases gradually. The smaller the pH value of immersion solutions is, the higher the dissolution rate of Ca2+ and Na+ is. However, the cation dissolution rate under a weak acid environment with a high pH value has little difference with that under the distilled water (pH = 7). With the increase of the soaking time and the acidity, the compaction stage of rock samples becomes longer, the elastic stage becomes shorter, the deterioration degree of mechanical parameters becomes more extensive, and the destruction of sandstone samples shows ductility characteristics increasingly. The corrosion degree of corroded sandstone samples is quantitatively represented by microscopic damage variables based on CT numbers. The regression analysis results show that damage variables of acid-corroded sandstone samples have a power function relationship with soaking time and an exponential function relationship with peak strength, peak point strain, and elastic modulus.

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STUDY ON TIME-CONSTANT MODELS OF SnO2pH SENSOR

Biomedical Engineering Applications Basis and Communications ◽

10.4015/s1016237209001623 ◽

2009 ◽

Vol 21 (06) ◽

pp. 449-452

Author(s):

Chi-Wei Chen ◽

Jung-Chuan Chou ◽

Tai-Ping Sun ◽

Shen-Kan Hsiung

Keyword(s):

Time Constant ◽

Electrochemical Impedance ◽

Ph Value ◽

Ph Sensor ◽

Membrane Resistance ◽

Hysteresis Effect ◽

Equivalent Model ◽

Resistance Change ◽

Ph Buffer ◽

Function Relationship

The aim of this study was to discuss the hysteresis effect of SnO2 pH sensor based on separative extended gate field effect transistor (SEGFET). Based on the theorem of three time-constants model, hysteresis model is linked with drift effect. Function relationship of pH value and time constant is also derived from the drift effects with difference pH value. Besides, electrochemical impedance spectroscopy (EIS) is utilized to interpret the mechanism of hysteresis effect. Experiments of EIS are carried out in different pH buffer solutions. An equivalent model of sensing membrane is obtained by theorem of EIS. The experimental results indicate that the equivalent circuit elements, such as membrane capacitance and membrane resistance, change with pH. This phenomenon is compared with other literatures and discussed on hysteresis effect.

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Influence of Humidity on the Elastic Modulus and Axis Compressive Strength of Concrete in a Water Environment

Materials ◽

10.3390/ma13245696 ◽

2020 ◽

Vol 13 (24) ◽

pp. 5696

Author(s):

Guohui Zhang ◽

Changbing Li ◽

Hai Wei ◽

Mingming Wang ◽

Zhendong Yang ◽

...

Keyword(s):

Compressive Strength ◽

Elastic Modulus ◽

Water Saturation ◽

Water Environment ◽

Systematic Research ◽

Saturation State ◽

Soaking Time ◽

Axial Compressive Strength ◽

Saturated Concrete ◽

Compressive Strength Of Concrete

Concrete structures are often in different humidity conditions that have a significant impact on the elastic modulus of concrete, therefore, systematic research on the evolution of the law of concrete elastic modulus under different humidity conditions is needed. In this study, the variation laws of the water saturation of concrete specimens with strength grades C15, C20, and C30 were obtained, and then the influence laws of the water saturation on the concrete axial compressive strength were carried out, and the prediction model of elastic modulus of concrete with respect to water saturation was constructed. The results showed that the water saturation of concrete with strength grades C15, C20, and C30 increased with an extension of immersion time, and the water saturation showed an approximately linear rapid growth within three soaking hours, reaching 47.56%, 71.63%, and 47.29%, respectively. Note, the concrete reached saturation state when the soaking time was 240 h. The axial compressive strength with strength grades C15, C20, and C30 decreased with increased water saturation, and the axial compressive strength of saturated concrete decreased by 27.25%, 21.14%, and 20.76%, respectively, as compared with the dry state concrete. The elastic modulus of concrete with strength grades C15, C20, and C30 increased with increased water saturation, and the elastic modulus of saturated concrete was 1.18, 1.19, and 1.24 times higher than those of dry concrete, respectively.

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Development of Bioactive Ti-15Mo-5Zr-3Al Alloy by Incorporation of Apatite Nuclei

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.758.75 ◽

2017 ◽

Vol 758 ◽

pp. 75-80 ◽

Cited By ~ 1

Author(s):

Takeshi Yabutsuka ◽

Yasutaka Kidokoro ◽

Shigeomi Takai ◽

Takeshi Yao

Keyword(s):

Elastic Modulus ◽

Simulated Body Fluid ◽

Adhesive Strength ◽

Body Fluid ◽

Ph Value ◽

Apatite Layer

Ti-15Mo-5Zr-3Al alloy, with lower elastic modulus in comparison with Ti-6Al-4V alloy, was treated with H2SO4 solution to form pores on its surface. In order to provide apatite-forming ability to the alloy, apatite nuclei were precipitated in the pores using simulated body fluid with higher pH value in comparison with the conventional one. By this treatment, a bioactive Ti-15Mo-5Zr-3Al alloy was obtained. The apatite-forming ability of the bioactive Ti-15Mo-5Zr-3Al alloy was evaluated by soaking in SBF. In addition, adhesive strength of the bone-like apatite layer formed in the SBF was measured.

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Effect of Sodium Caseinates Addition on the Rheological Properties of Kefir during Gel Formation

Journal of Food Research ◽

10.5539/jfr.v5n1p114 ◽

2016 ◽

Vol 5 (1) ◽

pp. 114

Author(s):

Kleio D. Antoniou ◽

Stylianos Exarhopoulos ◽

Stylianos N. Raphaelides ◽

Georgia Dimitreli ◽

Apostolos S. Thomareis

Keyword(s):

Elastic Modulus ◽

Loss Tangent ◽

Protein Interactions ◽

Ph Value ◽

Bovine Milk ◽

Three Dimensional ◽

Fermented Milk ◽

Elastic Behavior ◽

Gel Formation ◽

Fermentation Time

The effect of Sodium Caseinates (SCN) addition on the rheological behavior of kefir during gel formation was monitored by means of a dynamic rheometer of novel design (U-tube Rheometer). Kefir samples were prepared from homogenized and pasteurized full fat (3.5% w/w) bovine milk with or without the addition of SCN at varying concentrations (1%, 2% or 3% w/w). A fermented milk inoculum derived from kefir grains was inoculated into the heat-treated milk and incubated at 25°C until the pH dropped to 4.6. According to the results, the fermentation time required for the onset of gelation, as well as for the pH value to reach 4.6 increased with increasing SCN concentration. The beginning of cross-linking of proteins towards aggregates that leads to the formation of a three-dimensional protein matrix, took place at higher pH values with increasing SCN concentration. The values of elastic modulus and loss tangent that correspond to this point decreased with increasing SCN content. The increase in SCN concentration caused the values of elastic modulus during gel formation to increase and those of loss tangent to decrease. The addition of caseins into the milk increased the number and the strength of the protein-protein interactions causing the elastic behavior of the samples to increase. The presence of SCN into the system of kefir greatly affected the formation of the kefir gel.

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Pemanfaatan Hasil Samping Fermentasi Belimbing Wuluh (Asam Sunti) dalam Pengolahan Ikan

Jurnal Ilmiah Mahasiswa Pertanian ◽

10.17969/jimfp.v3i2.2915 ◽

2018 ◽

Vol 3 (2) ◽

pp. 351-356

Author(s):

Weny Weny ◽

Rasdiansyah Rasdiansyah ◽

Novia Mehra Erfiza

Keyword(s):

Soluble Protein ◽

Room Temperature ◽

Storage Time ◽

Ph Value ◽

Block Design ◽

Total Acid ◽

Soaking Time ◽

Ph Values ◽

Randomized Block Design ◽

And Storage

Abstrak. Sampai saat ini belum ada penelitian lebih lanjut mengenai pemanfaatan hasil samping dari produk asam sunti. Tujuan penelitian ini untuk melihat pengaruh perendaman ikan di dalam air asam sunti dan penyimpanannya pada suhu ruang terhadap karakteristik ikan. Penelitian ini menggunakan Rancangan Acak Kelompok Faktorial dengan 2 faktor yaitu faktor waktu perendaman (W), yang terdiri dari 3 taraf (W1 : 30 detik, W2 : 5 menit, W3 : 10 menit) dan lama penyimpanan (S), yang terdiri dari 2 taraf (S1 : 0 jam, S2 : 2 jam). Hasil penelitian menunjukkan bahwa karakteristik air asam sunti pada uji pH memiliki rataan yaitu 1,27, total asam 49% dan total bakteri asam laktat 5,1×104 CFU/gram. Nilai pH ikan setelah direndam air asam sunti 5,22-5,65 dengan rataan 5,43 dan nilai protein terlarut berkisar antara 18,42-18,74% dengan rataan 18,74%.Dari penelitian didapatkan bahwa waktu perendaman (W) berpengaruh nyata (P≤0,05) terhadap nilai protein terlarut dari ikan namun berpengaruh tidak nyata (P0,05) terhadap nilai pH ikan, uji deskriptif aroma dan tekstur ikan. Lama penyimpanan (S) berpengaruh sangat nyata (P≤0,01) terhadap nilai pH ikan setelah perendaman namun berpengaruh tidak nyata (P0,05) terhadap uji deskriptif aroma dan tekstur ikan. Interaksi waktu perendaman dengan lama penyimpanan berpengaruh nyata (P≤0,05) terhadap nilai pH ikan namun berpengaruh tidak nyata terhadap uji deskriptif aroma dan tekstur ikan.Waktu perendaman ikan di dalam air asam sunti selama 10 menit dapat menghambat kenaikan pH ikan selama penyimpanan sampai 2 jam. Semakin lama perendaman ikan di dalam air asam sunti maka semakin tinggi protein terlarut dari ikan. Abstrack. Therefore, this study was conducted to see the effect of soaking the fish in asam sunti water and its storage at room temperature on the characteristics of the fish. This study uses a randomized block design factorial with 2 factors: soaking time (W), consisting of 3 levels (W1: 30 seconds, W2: 5 minutes, W3: 10 minutes) and storage time (S), consisting of 2 levels ( S1: 0 hours, S2: 2 hours). The results showed pHof asam sunti water is 1.27, total acid is 49% and lactic acid bacteria has of 5.1 × 104 CFU / gram and the soaked fish has pH values ranged from 5.22 to 5.65 with the average of 5.43 and soluble protein values ranged from 18.42 to 18.74% with the average 18.74%.The results indicated that the soaking time (W) has effect significantly to the value of soluble protein (P≤0,05) of fish but iteffect not significantly (P 0.05) on pH value of fish, descriptive test the of aroma and texture of the fish. Storage time (S) effect significantly (P≤0,01) to pH value of fish after soaking but it effectnot significantly (P 0.05) to the descriptive test of aroma and texture of the fish. Interaction withsoaking time and storage (WxS) effect significantly (P≤0,05) to pH value of fish but it effect to not significantly the descriptive test of aroma and texture of the fish.Soaking time the fish in water for 10 minutes sunti can inhibit increasing in the pH of the fish during storage up to 2 hours. The longer soaking time of the fish in the asam sunti water, the higher sunti acid soluble proteins from value.

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Suizhong 36-1 Oil Field Acid Rock Dissolution Rate Studies

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.490-491.146 ◽

2014 ◽

Vol 490-491 ◽

pp. 146-149

Author(s):

Qing Wang Liu ◽

Ning Ning Zhan ◽

Zhen Zhong Fan ◽

Hao Tian

Keyword(s):

Dissolution Rate ◽

Oil Field ◽

Acid System ◽

Acid Rock ◽

Rock Samples

Through the Suizhong 36-1 oilfield core acidification experiments, we studied the different acid systems on the dissolution rate of rock samples and determine the preferred suitable for different circumstances Suizhong 36-1 oilfield cuttings acid system[1].

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Formulation and Investigation of Lacidipine as a Nanoemulsions

Iraqi Journal of Pharmaceutical Sciences ( P-ISSN 1683 - 3597 E-ISSN 2521 - 3512) ◽

10.31351/vol29iss1pp41-54 ◽

2020 ◽

Vol 29 (1) ◽

pp. 41-54

Author(s):

Rajaa A. Dahash ◽

Nawal A. Rajab

Keyword(s):

Particle Size ◽

Zeta Potential ◽

Dissolution Rate ◽

Thermodynamic Stability ◽

Water Solubility ◽

Ph Value ◽

Pharmaceutical Preparations ◽

Light Transmittance ◽

Drug Content

Many pharmaceutical molecules have solubility problems that until yet consist a hurdle that restricts their use in the pharmaceutical preparations. Lacidipine (LCDP) is a calcium-channel blocker with low aqueous solubility and bioavailability. Lipid dosage forms are attractive delivery systems for such hydrophobic drug molecules. Nanoemulsion (NE) is one of the popular methods that has been used to solve the solubility problems of many drugs. LCDP was formulated as a NE utilizing triacetin as an oil phase, tween 80 and tween 60 as a surfactant and ethanol as a co-surfactant. Nine formulas were prepared, and different tests performed to ensure the stability of the NEs, such as thermodynamic stability, particle size, Polydispersity index, zeta potential, dye solubility test, dilution test, drug content test and in-vitro drug release. Results of characterization showed that LCDP NE (F-5) with (oil: Smix (3:1):DDW (10:60:30)) ratio was selected as a best formula, since it have excellent thermodynamic stability with a particle size of 13.42, low PDI 0.234 , zeta potential (-14.5mV), efficient electrical conductivity 0.241ms/cm , good pH value (5.9), good percent of light transmittance (99.10%) , with acceptable viscosity , higher percent of drug content (99.14%) and complete release of the drug after (30 min.) with significantly higher (P<0.05) dissolution rate in comparison with pure drug powder. From the results obtained NE was found to be an efficient method to enhance the solubility and dissolution rate of drugs that have poor water solubility (lipophilic drugs).

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PENGARUH KONSENTRASI ASAP CAIR DAN LAMA PERENDAMAN TERHADAP MUTU ORGANOLEPTIK IKAN KAYU (KATSUO-BUSHI)

MEDIA TEKNOLOGI HASIL PERIKANAN ◽

10.35800/mthp.5.1.2017.14877 ◽

2017 ◽

Vol 5 (1) ◽

pp. 1

Author(s):

Yisia Katiandagho ◽

Siegfried Berhimpon ◽

Albert Royke Reo

Keyword(s):

Polycyclic Aromatic Hydrocarbon ◽

Moisture Content ◽

Aromatic Hydrocarbon ◽

Sensory Quality ◽

Ph Value ◽

Soaking Time ◽

Smoked Fish ◽

Liquid Smoke ◽

Polycyclic Aromatic

Dried smoked skipjack or better known as Katsuo-bushi is a popular type of smoked fish in Japan. It has a distinctive flavor and widely used in traditional Japanese cuisine. The weakness of commercial Katsuo-bushi nowadays is the high content of Polycyclic Aromatic Hydrocarbon (PAH) (may exceed 10 ppb). Recent study examined the low PAH Katsuo-bushi product made with liquid smoke. However, the sensory acceptance of this product has not been determined yet. The purpose of this study was to determine the effect of liquid smoke concentration (1%, 2% and 3%) and soaking time (10, 20 and 30 min) on the sensory quality of Katsuo-bushi. Duo-trio method was used for sensory evaluation. Additional chemical analysis such as moisture content and pH were performed. Significant differences were found among liquid smoke Katsuo-bushi product compare to traditional Katsuo-bushi (P<0.1). Also, it is suggested that the longer the soaking time, the higher the moisture content and pH value. Keyword: Katsuo-bushi, liquid smoke, Duo trio method. Ikan kayu atau lebih dikenal dengan Katsuo-bushi adalah sejenis ikan asap yang telah lama dikenal dan memiliki flavor yang khas yang biasanya digunakan pada masakan tradisional di Jepang. Kelemahan ikan kayu yang ada di dunia dewasa ini adalah tingginya kandungan Polycyclic Aromatic Hydrocarbon (PAH) yang melebihi 10 ppb. Penelitian terkini (Berhimpon, dkk 2016) meneliti ikan kayu asap cair yang rendah PAH, tetapi belum diteliti tingkat kesukaan secara organoleptik. Penelitian ini adalah untuk mendapatkan ikan kayu asap cair yang rendah PAH tetapi disukai oleh konsumen. Tujuan penelitian ini ialah untuk mengetahui pengaruh konsentrasi asap cair dan lama perendaman terhadap mutu organoleptik ikan kayu asap cair yang dibuat dengan berbagai konsentrasi dan lama perendaman, dan dibandingkan dengan ikan kayu konvensional. Parameter pengamatan ialah analisa organoleptik dengan metode duo trio (Berhimpon, dkk. 2005), analisa kadar air dan pH (AOAC, 2005). Hasil penelitian ini menunjukkan bahwa ikan kayu yang direndam dalam asap cair dengan konsentrasi 2% dan 3% masing-masing selama 30 dan 10 menit berbeda sangat nyata (P<0,1) dengan ikan kayu konvensional. Sedangkan perlakuan yang lain sama dengan ikan kayu konvensional. Untuk analisa kadar air dan pH menunjukkan bahwa lama perendaman memberikan pengaruh yang nyata terhadap nilai kadar air dan pH dari ikan kayu asap cair, dimana semakin lama waktu perendaman dalam larutan asap cair maka semakin tinggi kadar air dan pH dari ikan kayu tersebut. Kata Kunci: Ikan kayu (Katsuo-bushi), asap cair, metode duo trio.

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Evaluation Approach of Rock Brittleness Index for Fracturing Acidizing Based on Energy Evolution Theory and Damage Constitutive Relation

Lithosphere ◽

10.2113/2021/2864940 ◽

2021 ◽

Vol 2021 (Special 4) ◽

Author(s):

Shaobo Jin ◽

Xin Wang ◽

Zhen Wang ◽

Shaoyuan Mo ◽

Fengshou Zhang ◽

...

Keyword(s):

Constitutive Relation ◽

Ph Value ◽

Acid Corrosion ◽

Strain Curve ◽

Brittleness Index ◽

Evaluation Methodology ◽

Evolution Theory ◽

Energy Evolution ◽

Soaking Time ◽

The Impact

Abstract Acidizing, as an essential approach for well stimulation of sandstone or carbonate reservoirs, greatly affects the brittleness of the rock mass. Therefore, it is of great significance to develop a scientific brittleness evaluation methodology for the acid-corroded rock. In this paper, firstly, a damage constitutive model considering the compression hardening process of the acid-corroded sandstone under uniaxial loading is established and verified. Then, the evolution formulae of the relevant mechanical and fitting parameters are derived, and the stress-strain curve of the sandstone subjected to acid corrosion with soaking time is predicted. Finally, a theoretical model for evaluating the brittleness index (BI) of the acid-corroded sandstone based on energy evolution theory and damage constitutive relation is proposed. Based on this model, the BI of the sandstone subjected to acid corrosion is calculated and analyzed, and the BI of the acid-corroded sandstone with the soaking time is predicted. Results show that the BI of the sandstone is negatively correlated with the soaking time, and the rate of descent of the BI decreases with the increment of the soaking time. In addition, the decline degree of the BI has a negative correlation with the pH value. On the other hand, the temperature (25°C, 50°C, and 75°C) has greater weakening effects on the BI compared with the impact of the pressure (5 MPa, 10 MPa, and 15 MPa). Besides, days 50 and 120 are two turning points where the decreasing rates of the BI change from rapid to slow and slow to almost constant, respectively. Furthermore, a coefficient (θ) is proposed to quantify the effect of the acid corrosion, and some suggestions are provided for the application of the acidizing treatment.

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Bioactivity and Bone Cell Formation with Poly-ε-Caprolactone/Bioceramic 3D Porous Scaffolds

Polymers ◽

10.3390/polym13162718 ◽

2021 ◽

Vol 13 (16) ◽

pp. 2718

Author(s):

Po-Kai Juan ◽

Fang-Yu Fan ◽

Wei-Chun Lin ◽

Pei-Bang Liao ◽

Chiung-Fang Huang ◽

...

Keyword(s):

Elastic Modulus ◽

Cell Attachment ◽

Ph Value ◽

Ceramic Powder ◽

High Ratio ◽

Porous Scaffolds ◽

Alp Activity ◽

Mg63 Cells ◽

Human Cancellous Bone

This study applied poly-ε-caprolactone (PCL), a biomedical ceramic powder as an additive (nano-hydroxyapatite (nHA) or β-tricalcium diphosphate (β-TCP)), and sodium chloride (NaCl) and ammonium bicarbonate ((NH4)HCO3) as porogens; these stuffs were used as scaffold materials. An improved solvent-casting/particulate-leaching method was utilized to fabricate 3D porous scaffolds. In this study we examined the physical properties (elastic modulus, porosity, and contact angle) and degradation properties (weight loss and pH value) of the 3D porous scaffolds. Both nHA and β-TCP improved the mechanical properties (elastic modulus) of the 3D porous scaffolds. The elastic modulus (0.15~1.865 GPa) of the various composite scaffolds matched that of human cancellous bone (0.1~4.5 GPa). Osteoblast-like (MG63) cells were cultured, a microculture tetrazolium test (MTT) was conducted and alkaline phosphatase (ALP) activity of the 3D porous scaffolds was determined. Experimental results indicated that both nHA and β-TCP powder improved the hydrophilic properties of the scaffolds. The degradation rate of the scaffolds was accelerated by adding nHA or β-TCP. The MTT and ALP activity tests indicated that the scaffolds with a high ratio of nHA or β-TCP had excellent properties of in vitro biocompatibility (cell attachment and proliferation).

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