1,059 research outputs found
UTHM water quality classification based on sub index
River or stream at their source is unpolluted, but as water flow downstream, the river or lake is receiving point and non-point pollutant source. Ammoniacal nitrogen (NH3- N) and suspended solids (SS) strongly influences the dynamics of the dissolved oxygen in the water. Studies on monitoring this parameter were conducted for a river or lake but limited to the small man-made lake. This study is initiate to determine the changes in water quality of UTHM watershed as the water flows from upstream to downstream. The monitoring of NH3-N and TSS were monitored at two sampling schemes, 1) at the two-week interval and, 2) at a daily basis followed by the determination of the water quality sub-index particularly SIAN and SISS. The results showed that the two lakes in UTHM watershed were classified as polluted. In conclusion, the remedial action should be implemented to improve the water quality to meet the requirements at least to meet the recreational purpose
An analytical solution for reliability assessment of pseudo-static stability of rock slopes using jointly distributed random variables method
PublishedReliability analysis of rock slope stability has received considerable attention in the
literature. It has been used as an effective tool to evaluate uncertainty so prevalent in variables. In
this research the application of the jointly distributed random variables method for probabilistic
analysis and reliability assessment of rock slope stability with plane sliding is investigated. In a
recently published paper, the authors showed the dependency of the numerator and denominator of
the safety factor relationship and argued that, as a result of this dependency, the method could not
assess the reliability correctly. In the current research the authors present a new approach to solve
this problem. In this approach, using the basic relations in this method, the safety factor
relationship is obtained directly without separation of its numerator and denominator. Furthermore,
in addition to friction angle of sliding surface, apparent cohesion, depth of water in tension crack,
and earthquake acceleration ratio, in the present work the unit weight of rock is also considered as
a stochastic parameter. The results are compared with the Monte Carlo simulation. Comparison of
the results indicates good performance of the proposed approach for assessment of reliability. The
new results of parametric analysis using the jointly distributed random variables method show that
the friction angle of sliding surface is the most effective parameter in rock slope stability with
plane sliding
Influence of hybridization on tensile behaviors of non-absorbable braided polymeric sutures
This paper aims to investigate the effects of fiber hybridization technique on the mechanical behaviors of non-absorbable braided composite sutures. Fifteen types of hybrid braided sutures (HBSs) made of polyester (PET), polypropylene (PP), and polyamide 6 (PA6) are produced and tested to measure ultimate tensile strength (UTS), maximum strain, elastic modulus, and breaking toughness. Based on the results, it is observed that the suture material plays a significant role in the tensile and mechanical performance of HBSs, and they can be tailored through the different combinations of yarns according to the required mechanical properties. Experiments exhibit occurrence positive hybrid effect in both maximum strain and elastic modulus, and negative hybrid effect in UTS. The optimal tensile performance is associated with the hybrid structure comprising 75% PA6-12.5% PET-12.5% PP. This means the ternary structure with higher PA6 content along with PP and PET, demonstrates a synergistic effect. Thus, such a ternary composite structure is very promising for the design of novel non-absorbable sutures. Due to the absence of similar results in the specialized literature, this paper is likely to advance the state-of-the-art composite non-absorbable sutures and contribute to a better understanding of the hybridization concept for optimizing composite material systems
Minimal model for beta relaxation in viscous liquids
Contrasts between beta relaxation in equilibrium viscous liquids and glasses
are rationalized in terms of a double-well potential model with
structure-dependent asymmetry, assuming structure is described by a single
order parameter. The model is tested for tripropylene glycol where it accounts
for the hysteresis of the dielectric beta loss peak frequency and magnitude
during cooling and reheating through the glass transition.Comment: Phys. Rev. Lett. (in press
Toxicity comparison of colloidal silver nanoparticles in various life stages of rainbow trout (Oncorhynchus mykiss)
Recognizing the significance of the life stage of fish for nano-eco-toxicological studies, the acute toxicity of colloidal silver nanoparticles (AgNPs) was tested in three different life stages of rainbow trout. Fishes were exposed to colloidal AgNPs at nominal concentrations of 100, 32, 10, 3.2, 1, 0.32, 0.1, and 0.032 mg/L. The estimated 96 hr LC50 values were 0.25, 0.71, and 2.16 mg/L for the eleutheroembryos, larvae and juveniles, respectively, revealing a higher sensitivity for the early life stages. In addition, a dose-dependent blood plasma reduction of chloride and potassium, also increase of cortisol and cholinesterase were observed in the juveniles to exposed AgNPs when compared to the controls. Thus, colloidal AgNPs should be classified as ‘very toxic’ and ‘toxic’ to the eleutheroembryo-larva and juvenile stages, respectively, meaning that the release of nanosilver into the aquatic environment or its direct application as an antimicrobial agent in aquaculture should no longer be allowed
Consolidation parameters of reconstituted peat soil: oedometer testing
This paper presents the consolidation parameters of reconstituted peat soils with different
peat soil particle sizes. The reconstituted peat sample was used to determine the consolidation
parameters since the undisturbed samples were difficult to collect. The selected sizes of soil
particles passing given sieve sizes have been collected and formed the reconstituted peat samples by
preloading with a given pressure. The testing involve was one-dimensional oedometer consolidation
test with the load increment method (5 – 320kPa). It is important to gather the information about a
soil profile, especially on consolidation properties which were important in predicting the
settlement of soil. Based on the results, compression index (Cc) and swell index (Cs), the values
were increased with the increasing peat particles siz
Comparison of digestive enzyme activity in the stomach, pyloric caeca and intestine in diploid and triploid female of rainbow trout (Oncorhynchus mykiss)
The effects of chromosome manipulation on the digestive enzyme activity in the rainbow trout were studied. The enzymes included Pepsin, Trypsin, Chymotrypsin, cileimylase, Lipase and Alkaline Phosphatase which were assessed in diploid and triploid female of rainbow trout. Pepsin activity in the stomach of the assessed fish showed no significant difference between the diploid and triploid fish (P>0.05). The measurement of Trypsin and Chymotrypsin activity in the intestine and pyloric caeca revealed no significant difference in the treated and untreated fish (P>0.05). The activity of a-Amylase, Lipase and Alkaline Phosphatase showed no significant difference in the intestine and pyloric caeca of the diploid and triploid fish (P>0.05).The results indicated that chromosome manipulation in rainbow trout had no effects on digestive enzyme activity
Anomaly Detection and Localization in NFV Systems: an Unsupervised Learning Approach
Due to the scarcity of labeled faulty data, Unsupervised Learning (UL) methods have gained great traction for anomaly detection and localization in Network Functions Virtualization (NFV) systems. In a UL approach, training is performed on only normal data for learning normal data patterns, and deviation from the norm is considered as an anomaly. However, it has been shown that even small percentages of anomalous samples in the training data (referred to as contamination) can significantly degrade the performance of UL methods. To address this issue, we propose an anomaly-detection approach based on the Noisy-Student technique, which was originally introduced for leveraging unlabeled datasets in computer-vision classification problems. Our approach not only provides robustness against training-data contamination, but also can leverage this contamination to improve anomaly-detection accuracy. Moreover, after an anomaly is detected, localization of the anomalous virtualized network functions in an unsupervised manner is a challenging task in the absence of labeled data. For anomaly localization in NFV systems, we propose to exploit existing local AI-explainability methods to achieve a high localization performance and propose our own novel AI-explainability method, specifically designed for the anomaly-localization problem in NFV, to improve the performance further. We perform a comprehensive experimental analysis on two datasets collected on different NFV testbeds and show that our proposed solutions outperform the existing methods by up to 22% in anomaly detection and up to 19% in anomaly localization in terms of F1-score
Influence of sulfate and chloride on the mechanical properties of fired clay masonry wall
This paper presents the influence of aggressive environment on the mechanical properties of masonry systems. The investigation involved the measurement of strength and modulus of elasticity of single leaf brick masonry wall which were built from fired clay bricks in conjunction with designation (iii) mortar with proportions of 1: 1: 6 (OPC: lime: sand). After being constructed, the specimens were cured under polythene sheet for 14 days in a controlled environment room with 80 ± 5% relative humidity and temperature of 25 ± 2ºC. The specimens were then exposed to the solution containing sodium sulfate and sodium chloride. The strength and modulus of elasticity of the brickworks were determined at the ages of 28, 56 and 180 days. The strength and modulus of elasticity of the brickworks, unbonded bricks, and mortar prisms were determined at the ages of 28, 56 and 180 days to quantify the contribution of bricks and mortar on the deformation of the masonry walls. As a result, fired clay brickwork is not durable and deteriorate in the environment containing sodium sulfate but durable in sodium chloride. The deterioration of the brickwork clearly influenced by the deterioration of mortar joint. The present of sodium chloride also retarding the attack of sodium sulphate
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