An Artificial Neutral Network (ANN) model for predicting biodiesel kinetic viscosity as a function of temperature and chemical compositions

An Artificial Neural Network (ANN) is a computational modeling tool which has found extensive acceptance in many disciplines for modeling complex real world problems. An ANN can model problems through learning by example, rather than by fully understanding the detailed characteristics and physics of the system. In the present study, the accuracy and predictive power of an ANN was evaluated in predicting kinetic viscosity of biodiesels over a wide range of temperatures typically encountered in diesel engine operation. In this model, temperature and chemical composition of biodiesel were used as input variables. In order to obtain the necessary data for model development, the chemical composition and temperature dependent fuel properties of ten different types of biodiesels were measured experimentally using laboratory standard testing equipments following internationally recognized testing procedures. The Neural Networks Toolbox of MatLab R2012a software was used to train, validate and simulate the ANN model on a personal computer. The network architecture was optimised following a trial and error method to obtain the best prediction of the kinematic viscosity. The predictive performance of the model was determined by calculating the absolute fraction of variance (R2), root mean squared (RMS) and maximum average error percentage (MAEP) between predicted and experimental results. This study found that ANN is highly accurate in predicting the viscosity of biodiesel and demonstrates the ability of the ANN model to find a meaningful relationship between biodiesel chemical composition and fuel properties at different temperature levels. Therefore the model developed in this study can be a useful tool in accurately predict biodiesel fuel properties instead of undertaking costly and time consuming experimental tests.

Axial elongation associated with biomechanical factors during near work

Purpose: To investigate the changes occurring in the axial length, choroidal thickness and anterior biometrics of the eye during a 10 minute near task performed in downward gaze. Methods: Twenty young adult subjects (10 emmetropes and 10 myopes) participated in this study. To measure ocular biometrics in downward gaze, an optical biometer was inclined on a custom built, height and tilt adjustable table. Baseline measures were collected after each subject performed a distance primary gaze control task for 10 mins, to provide wash-out period for prior visual tasks before each of three different accommodation/gaze conditions. These other three conditions included a near task (2.5 D) in primary gaze, and a near (2.5 D) and a far (0 D) accommodative task in downward gaze (25°), all for 10 mins duration. Immediately after, and then 5 and 10 mins from the commencement of each trial, measurements of ocular biometrics (e.g. anterior biometrics, axial length, choroidal thickness and retinal thickness) were obtained. Results: Axial length increased with accommodation and was significantly greater for downward gaze with accommodation (mean change ± SD 23 ± 13 µm at 10 mins) compared to primary gaze with accommodation (mean change 8 ± 15 µm at 10 mins) (p < 0.05). A small amount of choroidal thinning was also found during accommodation that was statistically significant in downward gaze (13 ± 14 µm at 10 mins, p < 0.05). Accommodation in downward gaze also caused greater changes in anterior chamber depth and lens thickness compared to accommodation in primary gaze. Conclusion: Axial length, choroidal thickness and anterior eye biometrics change significantly during accommodation in downward gaze as a function of time. These changes appear to be due to the combined influence of biomechanical factors (i.e. extraocular muscle forces, ciliary muscle contraction) associated with near tasks in downward gaze.

Expression, regulation and putative nutrient-sensing function of taste GPCRs in the heart

G protein-coupled receptors (GPCRs) are critical for cardiovascular physiology. Cardiac cells express >100 nonchemosensory GPCRs, indicating that important physiological and potential therapeutic targets remain to be discovered. Moreover, there is a growing appreciation that members of the large, distinct taste and odorant GPCR families have specific functions in tissues beyond the oronasal cavity, including in the brain, gastrointestinal tract and respiratory system. To date, these chemosensory GPCRs have not been systematically studied in the heart. We performed RT-qPCR taste receptor screens in rodent and human heart tissues that revealed discrete subsets of type 2 taste receptors (TAS2/Tas2) as well as Tas1r1 and Tas1r3 (comprising the umami receptor) are expressed. These taste GPCRs are present in cultured cardiac myocytes and fibroblasts, and are enriched in myocytes, which we corroborated using in situ hybridization. Tas1r1 gene-targeted mice (Tas1r1Cre/Rosa26tdRFP) strikingly recapitulated these data. In vivo taste receptor expression levels were developmentally regulated in the postnatal period. Intriguingly, several Tas2rs were upregulated in cultured rat myocytes and in mouse heart in vivo following starvation. The discovery of taste GPCRs in the heart opens an exciting new field of cardiac research. We predict that these taste receptors may function as nutrient sensors in the heart.

Measurement of the first neutron diffraction peak of D2O flowing in a 2 mm diameter aluminium tube as a function of temperature

A pilot experiment was performed using the WOMBAT powder diffraction instrument at ANSTO in which the first neutron diffraction peak (Q0) was measured for D2O flowing in a 2 mm internal diameter aluminium tube. Measurements of Q0 were made at -9, 4.3, 6.9, 12, 18.2 and 21.5 °C. The D2O was circulated using a siphon with water in the lower reservoir returned to the upper reservoir using a small pump. This enabled stable flow to be maintained for several hours. For example, if the pump flow increased slightly, the upper reservoir level rose, increasing the siphon flow until it matched the return flow. A neutron wavelength of 2.4 Å was used and data integrated over 60 minutes for each temperature. A jet of nitrogen from a liquid N2 Dewar was directed over the aluminium tube to vary water temperature. After collection of the data, the d spacing of the aluminium peaks was used to calculate the temperature of the aluminium within the neutron beam and therefore was considered to be an accurate measure of water temperature within the beam. Sigmaplot version 12.3 was used to fit a Weibull five parameter peak fit to the first neutron diffraction peak. The values of Q0 obtained in this experiment showed an increase with temperature consistent with data in the literature [1] but were consistently higher than published values for bulk D20. For example at 21.5 °C we obtained a value of 2.008 Å-1 for Q0 compared to a literature value of 1.988 Å-1 for bulk D2O at 20 °C, a difference of 1%. Further experiments are required to see if this difference is real or artifactual.

The first x-ray diffraction peak of water as a function of temperature in the range 4 – 63 °C

X-ray diffraction structure functions for water flowing in a 1.5 mm diameter siphon in the temperature range 4 – 63 °C were obtained using a 20 keV beam at the Australian Synchrotron. These functions were compared with structure functions obtained at the Advanced Light Source for a 0.5 mm thick sample of water in the temperature range 1 – 77 °C irradiated with an 11 keV beam. The two sets of structure functions are similar, but there are subtle differences in the shape and relative position of the two functions suggesting a possible differences between the structure of bulk and siphon water. In addition, the first structural peak (Q0) for water in a siphon, showed evidence of a step-wise increase in Q0 with increasing temperature rather than a smoothly varying increase. More experiments are required to investigate this apparent difference.

Cryptanalysis of RC4-based hash function

RC4-Based Hash Function is a new proposed hash function based on RC4 stream cipher for ultra low power devices. In this paper, we analyse the security of the function against collision attack. It is shown that the attacker can find collision and multi-collision messages with complexity only 6 compress function operations and negligible memory with time complexity 2 13. In addition, we show the hashing algorithm can be distinguishable from a truly random sequence with probability close to one.

A critical look at cryptographic hash function literature

The cryptographic hash function literature has numerous hash function definitions and hash function requirements, and many of them disagree. This survey talks about the various definitions, and takes steps towards cleaning up the literature by explaining how the field has evolved and accurately depicting the research aims people have today.

Source code watermarking based on function dependency oriented sequencing

In the current market, extensive software development is taking place and the software industry is thriving. Major software giants have stated source code theft as a major threat to revenues. By inserting an identity-establishing watermark in the source code, a company can prove it's ownership over the source code. In this paper, we propose a watermarking scheme for C/C++ source codes by exploiting the language restrictions. If a function calls another function, the latter needs to be defined in the code before the former, unless one uses function pre-declarations. We embed the watermark in the code by imposing an ordering on the mutually independent functions by introducing bogus dependency. Removal of dependency by the attacker to erase the watermark requires extensive manual intervention thereby making the attack infeasible. The scheme is also secure against subtractive and additive attacks. Using our watermarking scheme, an n-bit watermark can be embedded in a program having n independent functions. The scheme is implemented on several sample codes and performance changes are analyzed.

Evaluation of BMP-2 gene-activated muscle grafts for cranial defect repair

Large, osseous, segmental defects heal poorly. Muscle has a propensity to form bone when exposed to an osteogenic stimulus such as that provided by transfer and expression of cDNA encoding bone morphogenetic protein-2 (BMP-2). The present study evaluated the ability of genetically modified, autologous muscle to heal large cranial defects in rats. Autologous grafts (8 mm � 2 mm) were punched from the biceps femoris muscle and transduced intraoperatively with recombinant adenovirus vector containing human BMP-2 or green fluorescent protein cDNA. While the muscle biopsies were incubating with the vector, a central parietal 8 mm defect was surgically created in the calvarium of the same animal. The gene-activated muscle graft was then implanted into the cranial defect. After 8 weeks, crania were examined radiographically, histologically, and by micro-computed tomography and dual energy X-ray absorptiometry. Although none of the defects were completely healed in this time, muscle grafts expressing BMP-2 deposited more than twice as much new bone as controls. Histology confirmed the anatomical integrity of the newly formed bone, which was comparable in thickness and mineral density to the original cranial bone. This study confirms the in vivo osteogenic properties of genetically modified muscle and suggests novel strategies for healing bone. � 2011 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1095–1102, 2012

Use of genetically modified muscle and fat grafts to repair defects in bone and cartilage

We report a novel technology for the rapid healing of large osseous and chondral defects, based upon the genetic modification of autologous skeletal muscle and fat grafts. These tissues were selected because they not only possess mesenchymal progenitor cells and scaffolding properties, but also can be biopsied, genetically modified and returned to the patient in a single operative session. First generation adenovirus vector carrying cDNA encoding human bone morphogenetic protein-2 (Ad.BMP-2) was used for gene transfer to biopsies of muscle and fat. To assess bone healing, the genetically modified (“gene activated”) tissues were implanted into 5mm-long critical size, mid-diaphyseal, stabilized defects in the femora of Fischer rats. Unlike control defects, those receiving gene-activated muscle underwent rapid healing, with evidence of radiologic bridging as early as 10 days after implantation and restoration of full mechanical strength by 8 weeks. Histologic analysis suggests that the grafts rapidly differentiated into cartilage, followed by efficient endochondral ossification. Fluorescence in situ hybridization detection of Y-chromosomes following the transfer of male donor muscle into female rats demonstrated that at least some of the osteoblasts of the healed bone were derived from donor muscle. Gene activated fat also healed critical sized defects, but less quickly than muscle and with more variability. Anti-adenovirus antibodies were not detected. Pilot studies in a rabbit osteochondral defect model demonstrated the promise of this technology for healing cartilage defects. Further development of these methods should provide ways to heal bone and cartilage more expeditiously, and at lower cost, than is presently possible.

Key derivation function based on stream ciphers

A key derivation function (KDF) is a function that transforms secret non-uniformly random source material together with some public strings into one or more cryptographic keys. These cryptographic keys are used with a cryptographic algorithm for protecting electronic data during both transmission over insecure channels and storage. In this thesis, we propose a new method for constructing a generic stream cipher based key derivation function. We show that our proposed key derivation function based on stream ciphers is secure if the under-lying stream cipher is secure. We simulate instances of this stream cipher based key derivation function using three eStream nalist: Trivium, Sosemanuk and Rabbit. The simulation results show these stream cipher based key derivation functions offer efficiency advantages over the more commonly used key derivation functions based on block ciphers and hash functions.

The effect of exercise on the skeletal muscle phospholipidome of rats fed a high-fat diet

The aim of this study was to examine the effect of endurance training on skeletal muscle phospholipid molecular species from high-fat fed rats. Twelve female Sprague-Dawley rats were fed a high-fat diet (78.1% energy). The rats were randomly divided into two groups, a sedentary control group and a trained group (125 min of treadmill running at 8 m/min, 4 days/wk for 4 weeks). Forty-eight hours after their last training bout phospholipids were extracted from the red and white vastus lateralis and analyzed by electrospray-ionization mass spectrometry. Exercise training was associated with significant alterations in the relative abundance of a number of phospholipid molecular species. These changes were more prominent in red vastus lateralis than white vastus lateralis. The largest observed change was an increase of similar to 30% in the abundance of 1-palmitoyl-2-linoleoyl phosphatidylcholine ions in oxidative fibers. Reductions in the relative abundance of a number of phospholipids containing long-chain n-3 polyunsaturated fatty acids were also observed. These data suggest a possible reduction in phospholipid remodeling in the trained animals. This results in a decrease in the phospholipid n-3 to n-6 ratio that may in turn influence endurance capacity.

Exercise alters the profile of phospholipid molecular species in rat skeletal muscle

We have determined the effect of two exercise-training intensities on the phospholipid profile of both glycolytic and oxidative muscle fibers of female Sprague-Dawley rats using electrospray-ionization mass spectrometry. Animals were randomly divided into three training groups: control, which performed no exercise training; low-intensity (8 m/min) treadmill running; or high-intensity (28 m/min) treadmill running. All exercise-trained rats ran 1,000 m/session for 4 days/wk for 4 wk and were killed 48 h after the last training bout. Exercise training was found to produce no novel phospholipid species but was associated with significant alterations in the relative abundance of a number of phospholipid molecular species. These changes were more prominent in glycolytic (white vastus lateralis) than in oxidative (red vastus lateralis) muscle fibers. The largest observed change was a decrease of ∼20% in the abundance of 1-stearoyl-2-docosahexaenoyl-phosphatidylethanolamine [PE(18:0/22:6); P < 0.001] ions in both the low- and high-intensity training regimes in glycolytic fibers. Increases in the abundance of 1-oleoyl-2-linoleoyl phopshatidic acid [PA(18:1/18:2); P < 0.001] and 1-alkenylpalmitoyl-2-linoleoyl phosphatidylethanolamine [plasmenyl PE (16:0/18:2); P < 0.005] ions were also observed for both training regimes in glycolytic fibers. We conclude that exercise training results in a remodeling of phospholipids in rat skeletal muscle. Even though little is known about the physiological or pathophysiological role of specific phospholipid molecular species in skeletal muscle, it is likely that this remodeling will have an impact on a range of cellular functions.

Phospholipid composition of the rat lens is independent of diet

Dietary fatty acids are known to influence the phospholipid composition of many tissues in the body, with lipid turnover occurring rapidly. The aim of this study was to investigate whether changes in the fatty acid composition of the diet can affect the phospholipid composition of the lens. Male Sprague-Dawley rats were fed three diets with distinct profiles in both essential and non-essential fatty acids. After 8 weeks, lenses and skeletal muscle were removed, and the lenses sectioned into nuclear and cortical regions. In these experiments, the lens cortex was synthesised during the course of the variable lipid diet. Phospholipids were then identified by electrospray ionisation tandem mass spectrometry, and quantified via the use of internal standards. The phospholipid compositions of the nuclear and cortical regions of the lens differed slightly between the two regions, but comparison of the equivalent regions across the diet groups showed remarkable similarity. In contrast, the phospholipid composition of skeletal muscle (medial gastrocnemius) in these rats varied significantly. This study provides the first direct evidence to show that the phospholipid composition of the lens is tightly regulated and thus appears to be independent of diet. As phospholipids determine membrane fluidity and influence the activity and function of integral membrane proteins, regulation of their composition may be important for the function of the lens. Crown Copyright (C) 2008 Published by Elsevier Ltd. All rights reserved.

Alterations in cervical muscle activity in functional and stressful tasks in female office workers with neck pain

This study determined differences between computer workers with varying levels of neck pain in terms of work stressors, employee strain, electromyography (EMG) amplitude and heart rate response to various tasks. Participants included 85 workers (33, no pain; 38, mild pain; 14, moderate pain) and 22 non-working controls. Work stressors evaluated were job demands, decision authority, and social support. Heart rate was recorded during three tasks: copy-typing, typing with superimposed stress and a colour word task. Measures included electromyography signals from the sternocleidomastoid (SCM), anterior scalene (AS), cervical extensor (CE) and upper trapezius (UT) muscles bilaterally. Results showed no difference between groups in work stressors or employee strain measures. Workers with and without pain had higher measured levels of EMG amplitude in SCM, AS and CE muscles during the tasks than controls (all P < 0.02). In workers with neck pain, the UT had difficulty in switching off on completion of tasks compared with controls and workers without pain. There was an increase in heart rate, perceived tension and pain and decrease in accuracy for all groups during the stressful tasks with symptomatic workers producing more typing errors than controls and workers without pain. These findings suggest an altered muscle recruitment pattern in the neck flexor and extensor muscles. Whether this is a consequence or source of the musculoskeletal disorder cannot be determined from this study. It is possible that workers currently without symptoms may be at risk of developing a musculoskeletal disorder.