Assessment of brittleness using rock strength and density with punch penetration test

Brittleness fracturing of rock is one of the most popular research areas in rock engineering, since some rocks show brittle fractures under loads. Direct standard testing method for measuring rock brittleness have not available yet. Therefore, rock brittleness is indirectly obtained as a function of rock strength. The aim of this study is not only to introduce direct method to measure rock brittleness as an index via punch penetration test, but also to investigate the relationship between intact rock properties (uniaxial compressive strength, Brazilian tensile strength, and density of rock) and the brittleness measured from the test. To obtain these objectives, rock cores were gathered from 48 tunnel projects throughout the world. Followings the sampling, the samples were prepared and relevant rock tests were carried out to establishment of dataset at the Earth Mechanics Institute of Colorado School of Mines in the USA. Consequently, using generated dataset, new brittleness index (BI_m) and rock brittleness classification was introduced base on type, strength and density of rock together with result of punch penetration test. Further, the rock brittleness index was predicted as a function of the uniaxial compressive strength, Brazilian tensile strength and density of rock with correlation coefficient of 0.94.     

Application of several optimization techniques for estimating TBM advance rate in granitic rocks

This study aims to develop several optimization techniques for predicting advance rate of tunnel boring machine(TBM)in different weathered zones of granite.For this purpose,extensive field and laboratory studies have been conducted along the 12,649 m of the Pahang-Selangor raw water transfer tunnel in Malaysia.Rock properties consisting of uniaxial compressive strength(UCS),Brazilian tensile strength(BTS),rock mass rating(RMR),rock quality designation(RQD),quartz content(q)and weathered zone as well as machine specifications including thrust force and revolution per minute(RPM)were measured to establish comprehensive datasets for optimization.Accordingly,to estimate the advance rate of TBM,two new hybrid optimization techniques,i.e.an artificial neural network(ANN)combined with both imperialist competitive algorithm(ICA)and particle swarm optimization(PSO),were developed for mechanical tunneling in granitic rocks.Further,the new hybrid optimization techniques were compared and the best one was chosen among them to be used for practice.To evaluate the accuracy of the proposed models for both testing and training datasets,various statistical indices including coefficient of determination(R~2),root mean square error(RMSE)and variance account for(VAF)were utilized herein.The values of R~2,RMSE,and VAF ranged in 0.939-0.961,0.022-0.036,and 93.899-96.145,respectively,with the PSO-ANN hybrid technique demonstrating the best performance.It is concluded that both the optimization techniques,i.e.PSO-ANN and ICA-ANN,could be utilized for predicting the advance rate of TBMs;however,the PSO-ANN technique is superior.     

Comparison of Minolta colorimeter and machine vision system in measuring colour of irradiated Atlantic salmon

BACKGROUND: Minolta and machine vision are two different instrumental techniques used for measuring the colour of muscle food products. Between these two techniques, machine vision has many advantages, such as its ability to determine L*, a*, b* values for each pixel of a sample's image and to analyse the entire surface of a food regardless of surface uniformity and colour variation. The objective of this study was to measure the colour of irradiated Atlantic salmon fillets using a hand‐held Minolta colorimeter and a machine vision system and to compare their performance. RESULTS: The L*, a*, b* values of Atlantic salmon fillets subjected to different electron beam doses (0, 1, 1.5, 2 and 3 kGy) were measured using a Minolta CR‐200 Chroma Meter and a machine vision system. For both Minolta and machine vision the L* value increased and the a* and b* values decreased with increasing irradiation dose. However, the machine vision system showed significantly higher readings for L*, a*, b* values than the Minolta colorimeter. Because of this difference, colours that were actually measured by the two instruments were illustrated for visual comparison. Minolta readings resulted in a purplish colour based on average L*, a*, b* values, while machine vision readings resulted in an orange colour, which was expected for Atlantic salmon fillets. CONCLUSION: The Minolta colorimeter and the machine vision system were very close in reading the standard red plate with known L*, a*, b* values. Hence some caution is recommended in reporting colour values measured by Minolta, even when the ‘reference’ tiles are measured correctly. The reason for this discrepancy in colour readings for salmon is not known and needs further investigation. Copyright © 2009 Society of Chemical Industry     

Static,Kinetic, and Isotherm Adsorption Performances of Macroporous Adsorbent Resins for Recovery and Enrichment of Bioactive Procyanidins from Cranberry Pomace

This study examined the ability of five Amberlite resins coupled with ultrasound‐assisted water extraction for the recovery and enrichment of bioactive procyanidins and total phenolics from cranberry pomace. Static adsorption showed that XAD‐7HP had the highest adsorption capacity for procyanidins (52.2 mg/g resin) and total phenolics (99.1 mg/g resin) whereas XAD‐761 had the lowest. Adsorption of procyanidins fitted better to pseudo‐second‐order kinetics than pseudo‐first‐order kinetics. Isotherm adsorption on XAD‐7HP suggested that Langmuir isotherm was a better model to describe the adsorption of procyanidins while Kemkin–Pyzhev equation was better for total phenolics based on higher coefficient of determinations (R²). Dynamic tests on XAD‐7HP suggested that the flow rate of 7 and 8 mL/min were the optimum conditions for adsorption and desorption of procyanidins, respectively. Measurements using HPLC revealed that adsorption increased the contents of procyanidins and total phenolics by 4.57‐ and 4.73‐folds, respectively, compared to the initial extracts. This research showed that Amberlite XAD‐7HP resin adsorption coupled with ultrasound‐assisted water extraction is an efficient method to separate and concentrate procyanidins from cranberry pomace.     

Effect of high pressure processing and cooking treatment on the quality of Atlantic salmon

The effect of high pressure treatment (HPP) (150 MPa and 300 MPa for 15 min) and cooking on quality of Atlantic salmon based on microbial activity, lipid oxidation, fatty acid profile, colour and texture during 6 days of storage was studied. High pressure and cooking significantly (p < 0.05) reduced microbial growth. The 300 MPa treatment and cooking showed higher L∗ and b∗ values but lower a∗ values for dark muscle compared to control and samples treated at 150 MPa. An increase in pressure resulted in an increase in hardness, gumminess and chewiness parameters, and a decrease in adhesiveness compared to control and cooked samples. Whereas cooking and 150 MPa led to similar oxidation development as control in dark muscle, the 300 MPa treatment effectively reduced the samples susceptibility to oxidation. Fatty acid profile of cooked Atlantic salmon dark muscle showed significantly (p < 0.05) lower amounts of total saturated, n−3 Polyunsaturated fatty acids (PUFA) and n−6 PUFA and significantly (p < 0.05) higher amounts of monoenes than HPP treated samples during the entire storage period. However, the most important finding of this study was that there was no significant (p > 0.05) difference between control and HPP treated samples in terms of total saturated, monoenes, n−3 PUFA and n−6 PUFA fatty acid profile. This demonstrates that HPP is a very mild process in terms of its effect on fatty acids.     

Optimized Inhibitors of MDM2 via an Attempted Protein-Templated Reductive Amination

Innovative and efficient hit-identification techniques are required to accelerate drug discovery. Protein-templated fragment ligations represent a promising strategy in early drug discovery, enabling the target to assemble and select its binders from a pool of building blocks. Development of new protein-templated reactions to access a larger structural diversity and expansion of the variety of targets to demonstrate the scope of the technique are of prime interest for medicinal chemists. Herein, we present our attempts to use a protein-templated reductive amination to target protein-protein interactions (PPIs), a challenging class of drug targets. We address a flexible pocket, which is difficult to achieve by structure-based drug design. After careful analysis we did not find one of the possible products in the kinetic target-guided synthesis (KTGS) approach, however subsequent synthesis and biochemical evaluation of each library member demonstrated that all the obtained molecules inhibit MDM2. The most potent library member (K_i=0.095 μm ) identified is almost as active as Nutlin-3, a potent inhibitor of the p53-MDM2 PPI.     

Phytochemicals from berries and grapes inhibited the formation of advanced glycation end‐products by scavenging reactive carbonyls

Phenolic phytochemicals were extracted from blueberries, blackberries, strawberries, raspberries, cranberries, and Noble muscadine grapes. These extracts were purified to remove free sugars. Blueberry extract was separated into five fractions using a Sephadex LH‐20 column. Berry extracts and fractions significantly inhibited AGEs generation in (bovine serum albumin) BSA‐fructose, BSA‐methylglyoxal, and arginine‐methylglyoxal models, respectively. Their capacity to scavenge methylglyoxal suggested carbonyl scavenging as a major mechanism of protein glycation inhibition. Procyanidins were detected in all berry extracts and blueberry subfractions and were deduced to be one class of active compounds. (+)‐Catechin, constituent unit of procyanidins, was used as a model compound to react with glyoxal and methylglyoxal. Five catechin‐carbonyl adducts were detected and their structures were tentatively identified using HPLC‐ESI‐MSⁿ. Results in this study suggested that sugar‐free phytochemicals extracted from berries were effective carbonyl scavengers and protein glycation inhibitors. These phytochemicals could be beneficial to prevent AGE‐related chronic diseases.     

Relationship between the standard penetration test and the pressuremeter test on sandy silty clays: a case study from Denizli

The standard penetration test (SPT) is the in situ test most commonly used to investigate the properties of silt, clay, sand and fine gravel. The Menard pressuremeter test (PMT) can be utilized to obtain the strength and deformation properties of any soil or weak rock. The study investigated the relationship between the corrected SPT blow count (N _cor) and the PMT parameters of elastic modulus (E _m) and limit pressure (p _L). It is concluded that for the soils tested, E _m and p _L can be estimated as a function of N _cor values, with r = 0.91 and 0.97, respectively.