Investigation of the Effect of Agarose Gel Concentration and Culture Period on Bio and Mechanical Properties of Chondrocyte Tissue Engineering

As a gel scaffold for chondrocyte tissue engineering, agarose concentration plays a significant role in the relationship between porosity and nutrition. In this work, the effect of concentration and period cultured on Glycosaminoglycan (GAG) and mechanical properties have been studied. A bovine chondrocytes have been isolated and seeded in different agarose gel scoffed concentrations, about 4% and 6%, for different period cultured, 0 and 7 days. The MTS machine and Spectrophotometric with calibration curve method were used to measure mechanical properties, and GAG concentration of the prepared samples, respectively. The results of mechanical tests and GAG contents shown that there are a wide range of dispersion in the most of the samples, which attribute to different factors. For mechanical properties, these factors could be attributed to anisotropic of the produced chondrocyte with agarose scaffolds, insufficient cells' dispersion within the gel scaffold during seeding and cultured time, and some test procedure condition, such as EBSS hydration. While for GAG results, those factors could be the differences of the cell growth environment between in-vitro and in vivo media.

Improvement in Ridge Coefficient Optimization Criterion for Ridge Estimation-Based Dynamic System Response Curve Method in Flood Forecasting

The ridge estimation-based dynamic system response curve (DSRC-R) method, which is an improvement of the dynamic system response curve (DSRC) method via the ridge estimation method, has illustrated its good robustness. However, the optimization criterion for the ridge coefficient in the DSRC-R method still needs further study. In view of this, a new optimization criterion called the balance and random degree criterion considering the sum of squares of flow errors (BSR) is proposed in this paper according to the properties of model-simulated residuals. In this criterion, two indexes, namely, the random degree of simulated residuals and the balance degree of simulated residuals, are introduced to describe the independence and the zero mean property of simulated residuals, respectively. Therefore, the BSR criterion is constructed by combining the sum of squares of flow errors with the two indexes. The BSR criterion, L-curve criterion and the minimum sum of squares of flow errors (MSSFE) criterion are tested on both synthetic cases and real-data cases. The results show that the BSR criterion is better than the L-curve criterion in minimizing the sum of squares of flow residuals and increasing the ridge coefficient optimization speed. Moreover, the BSR criterion has an advantage over the MSSFE criterion in making the estimated rainfall error more stable.

Penetapan Kadar Tanin pada Teh Hitam Kering Produksi Pekalongan dengan Metode Spektrofotometri UV-Vis

Tea plants have benefits as antioxidants and help protect body cells from the bad effects of free radicals. The content in dried black tea leaves has tannin compounds that have a good effect on the body. The purpose of this study was to determine the difference in tannin levels in dry tea produced by Pekalongan with UV-Vis Spectrophotometry and to find out that all samples of tea brands met the requirements for consumption limits in tea. The data obtained were the average tannin content of black tea leaf extract from various samples with concentrations used of 8, 16, 24, 32, and 40 g/ml. Data analysis to determine the tannin content using the standard curve method, linear regression y = a + bx. The results obtained from the TLC qualitative test contained sample and comparison spots at UV 254 nm, namely Rf T1 of 0.84 cm, T2, T4, T5, T8, T9 of 0.85 cm, on samples T3, T7, T10, T11 obtained an Rf value of 0.86 cm which has the same Rf value as the comparison of catechins. and the sample T6 obtained an Rf value of 0.81 cm. As for the quantitative test, the highest levels were obtained in samples T1, T3, T6, T8, T10 as much as 0.004 ± 0 g/g while the lowest levels were obtained in samples T2, T4, T5, T7, T9, T11 as much as 0.003 ± 0 g/g It can be concluded that the circulating tannins produced by Pekalongan meet the consumption limit requirements.Keywords: Content; Tea; Tannins; UV-Vis Spectrophotometry AbstrakTanaman teh memiliki manfaat sebagai antioksidan dan membantu melindungi sel-sel tubuh dari efek buruk radikal bebas. Kandungan pada daun teh hitam kering mempunyai senyawa tanin yang memberikan efek baik bagi tubuh. Tujuan penelitian ini mengetahui adanya perbedaan kadar tanin pada teh kering produksi Pekalongan dengan metode Spektrofotometri UV-Vis dan mengetahui semua sampel merk teh memenuhi persyaratan batas konsumsi dalam teh. Data yang didapatkan adalah data rata-rata kadar tanin dari ekstrak daun teh hitam dari berbagai sampel dengan konsentrasi yang digunakan 8, 16,24, 32,dan40µg/ml. Analisis data untuk mengetahui kadar tanin dengan menggunakan metode kurva standar, regresi linier y = a + bx. Hasil yang diperoleh dari uji kualitatif KLT terdapat bercak noda sampel dan pembanding pada UV 254 nm, yaitu Rf T1 sebesar 0,84 cm , T2,T4,T5,T8, T9 sebesar 0,85 cm, pada sampel T3,T7,T10,T11 diperoleh nilai Rf sebesar 0,86 cm yang nilai Rf nya sama dengan pembanding katekin. dan pada sampel T6 diperoleh nilai Rf sebesar 0,81 cm. Adapun untuk uji kuantitatif nya diperoleh kadar tertinggi pada sampel T1, T3, T6, T8, T10 sebanyak 0,004 ± 0 g/g sedangkan kadar terendah diperoleh sampel T2, T4, T5, T7, T9, T11 sebanyak 0,003 ± 0 g/g, Hal ini dapat disimpulkan bahwa tanin yang beredar produksi Pekalongan memenuhi syarat batas konsumsi.Kata kunci: Kadar; Teh; Tanin; Spektrofometri UV-Vis

Distortion-Induced Fatigue Reassessment of a Welded Bridge Detail Based on Structural Stress Methods

Typically, bridge structural systems are affected by random loads that can cause significant damage. One challenging problem in this field is the high-stress amplitude associated with distortion-induced fatigue. In this study, the hot-spot method and the master S-N curve method were validated for the evaluation of fatigue resistance induced by distortion in welded joints of steel bridges. Validation of the master S-N curve method in this research was a necessary prior step for application of the method in real case studies of road bridges, which will be subject to loads of variable amplitudes in the near future, ensuring the basis for the application. The method of validation was based on an important available full-scale fatigue test database, which was generated decades ago to serve as the foundation for the assessment of distortion-induced fatigue. Modelling was carried out based on the finite element method with the aid of ANSYS software, considering the shell and solid elements and equivalent structural stresses. The experimental results were compared with the numerical ones obtained with the two methodologies, and the difference, in terms of global and local tension, was less than 1%.

Regulation of Hydrogen Peroxide Dosage in a Heterogeneous Photo-Fenton Process

In this work, a classical linear control approach for the peroxide (H2O2) dosage in a photo-Fenton process is presented as a suitable solution for improving the efficiency in the treatment of recalcitrant organic compounds that cannot be degraded by classical wastewater treatment processes like anaerobic digestion. Experiments were carried out to degrade Lignin, Melanoidin, and Gallic acid, which are typical recalcitrant organic compounds present in some kinds of effluents such as vinasses from the Tequila and Cachaça industries. Experiments were carried in Open-Loop mode for obtaining the degradation model for the three compounds in the form of a Transfer Function, and in Closed-Loop mode for controlling the concentration of each compound. First-order Transfer Functions were obtained using the reaction curve method, and then, based on these models, the parameters of Proportional Integral controllers were calculated using the direct synthesis method. In the Closed-Loop experiments, the Total Organic Carbon removal was 39% for lignin, 7% for melanoidin, and 29% for Gallic acid, which were greater than those obtained in the Open-Loop experiments.

Outflow adjustment coefficient for the design of storage facilities using the rain envelope method applied to Brazilian state capitals

Detention devices are often used as alternative measures for stormwater control. The Envelope Curve Method is widely used in Brazil to estimate detention device volumes. This method estimates the storage volume based on inlet and outlet balance, where the inlet is obtained by the Rational Method and the outlet by orifice bottom discharge. Usually, the outlet flow is adopted as a constant and equivalent to the maximum allowed, and this procedure can cause reservoir undersizing. This paper evaluates detention control measures’ hydraulic behavior for the Envelope Curve Method and proposes the inclusion of an outflow adjustment coefficient (Cout), seeking to compensate for the adoption of constant outlet flow simplification. Values for this coefficient were estimated for several Brazilian state capitals, ranging from 0.62 up to 0.65. The undersizing hypothesis due to the adoption of constant outlet flow was confirmed, as the simulations showed the need for an increase between 8.4% to 16.8% in the device size. This undersizing may be compensated for by applying the outflow adjustment coefficient (Cout). Keywords: adjustment coefficient, detention facilities, envelope curve, hydrologic design outflow adjustment coefficient.

A cucurbit[7]uril-based supramolecular fluorescent probe for the detection of metronidazole with high sensitivity and strong anti-interference capacity

We propose a new method for the selective detection of the antibiotic metronidazole (MNZ) using CB[7]-JAT (cucurbit[7]uril = CB[7] and JAT = jatrorrhizine) as a fluorescent probe, which is based on the competitive reaction between MNZ and JAT for the occupancy of the CB[7] cavity. The proposed method gives a good calibration curve in the concentration range of 0.38–60 μM, and the limit of detection for MNZ is 65 ng mL−1 with those obtained by the standard curve method. Moreover, the proposed method was successfully applied for the determination of MNZ in liquid milk. Most importantly, due to the high binding affinity between CB[7] and MNZ, the proposed method shows great anti-interference capacity to accurately detect MNZ in the presence of other antibiotics.

Gender assignment: Monolingual constraints contribute to a bilingual outcome

Aims and objectives: This study explores the well-researched topic of gender assignment to English nouns in Spanish discourse through a usage-based framework. The goal is to elucidate the relative impact of both previously studied and novel constraints on the variable application of feminine determiners. Methodology: A variationist analysis of English nouns surrounded by Spanish discourse in the spontaneous speech of bilinguals. Data and analysis: Data come from the New Mexico Spanish–English Bilingual Corpus. Tokens ( N = 707) were coded for independent variables and submitted to a logistic regression. The goodness of fit was determined via the area under the receiver operating characteristic (ROC) curve method. Findings: All independent variables were selected as significant by the logistic regression model. Based on factor weight ranges, the hierarchy of constraints is the following, from the most to the least impactful: Analogical Gender, Phonological Shape, Syntactic Role, and Determiner Definiteness. These results suggest that bilinguals utilize a variety of constraints in gender assignment, as opposed to a single default strategy. Originality: While previous studies have tested and found similar results for constraints such as analogical gender and phonological shape, none have offered a unified analysis explaining findings from a usage-based approach. The originality and utility of this approach is most apparent in the discussions of prototypicality and schematicity. Significance/implications: A corpus-based approach and usage-based theory is shown to bring new insight to a topic of interest in many other linguistic sub-fields. The discussion reinterprets previous conclusions about gender assignment using a framework not proposed in previous research, despite similar overall results.