209 research outputs found
EFFECTS OF KORTTA FIBRES AND MICROSILICA ON THE MECHANICAL PROPERTIES OF LIGHTWEIGHT CONCRETE IN OIL PRODUCT ENVIRONMENTS
Crude oil and its products are strategic and vital goods for most countries in the world. It is necessary to store these products in the production and transfer chain and send them to refineries, ports, and airports for military and national purposes. Lightweight concrete is propounded as a useful replacement for normal concrete due to its low specific weight and acceptable resistance property; however, compared to normal concrete, it is considered to be more permeable, less durable, and less resistant. Therefore, in this study, the reliability of this synthetic material in oil conditions has been investigated. In this regard, two groups of samples were investigated under normal and oil environmental conditions, polymer Kortta fibres with percentages of 0, 0.5, 1, 1.5, and 2% and microsilica with percentages of 0 and 15% by cement weight were incorporated alone and combined. Subsequently, tests were performed on the specimens after 90 days. The results showed that the combination of microsilica and Kortta fibres causes a significant increase in lightweight concrete strength and impermeability
UTJECAJ PROGRAMA KRUŽNOG TRENINGA NA MIŠIĆNU SNAGU, SLIKU O SAMOM SEBI TE ANKSIOZNOST STUDENATA NISKOG STUPNJA UHRANJENOSTI
The purpose of this study was to compare the effects
of 8-week circuit-strength training on muscle strength,
body image and anxiety of anxious underweight male
college students. Hence, forty underweight male college
students anxious were divided into 2 groups: a strength
training group (N=20) and a control group (N=20).
Subjects in strength training group trained an 8-week, 3
days per week full body progressive circuit-strength
training, whereas control subjects did not participate in
any training activity. The anthropometrical, body
composition, body image (Multidimensional Body Self-
Relations Questionnaire), anxiety (Spielberger state-trait
Anxiety Inventory), muscle endurance and one repetition
maximum in six exercises were measured before and after
an eight-week training period. The results showed that 8-
week strength training elicited significant (P<0.05)
increase in upper- and lower body strength as measured by
1RM as well as legs\u27 and arms\u27 muscle hypertrophy. In
addition, strength training group had a significantly
greater improved increase in body image (BI) and reduced
social physique anxiety (SPA) then control group. This
study provides support for the use of weight training to
improve body image and anxiety, these may be derive
from considerable physical changes results from
resistance training such as significant increase in muscle
endurance, strength and muscle mass.Svrha ovog istraživanja bila je usporediti učinke
osmotjednog kružnog trening jakosti na snagu mišića,
sliku o samom sebi te na tjeskobu studenata niskog
stupnja uhranjenosti muškog spola. Četrdeset studenata
niskog stupnja uhranjenosti koji su bili anksiozni oko toga
su podijeljeni u 2 skupine: skupina treninga jakosti (N =
20) i kontrolna skupine (N = 20). Eksperimentalna
skupina je trenirala 8 tjedana, 3 dana tjedno , kružnim
treningom snage koji je uključivao sve mišićne skupine.
dok kontrolni ispitanici nisu sudjelovali u nikakvom
tjelesnom vježbanju. Izmjerene su antropometrijske
karakteristike, sastav tijela, slika o svome tijelu
(Multidimensional Body Self-Relations Questionnaire),
anksioznost (Spielberger state-trait Anxiety Inventory),
mišića izdržljivosti i jedno maksimalno ponavljanje (u
šest vježbi mjereni) su prije i nakon osam tjedana.
Rezultati su pokazali da je trening snage od 8 tjedana
izazvao značajno povećanje (P <0,05) u snazi gornjeg i
donjeg dijela tijela mjereno s 1RM. Osim toga, skupina u
treningu jakosti je imala značajno poboljšanje u doživljaju
slike tijela (BI-body image) i smanjenje socijalnog
stupnja anksioznosti (SPA) od kontrolne skupine. Ova
studija pruža dokaze u korist korištenja treninga s utezima
za poboljšanje slike tijela i smanjenje tjeskobe što
vjerojatno proizlazi iz osjećaja bolje tjelesne
pripremljenosti i tjelesnog izgleda zbog značajnog porasta
mišićne izdržljivosti, snage i mišićne mase
A chaotic jerk system with different types of equilibria and its application in communication system
In this paper, a new jerk system is designed. This system can display different characters of equilibrium points according to the value of its parameters. The proposed nonlinear oscillator can have both self-excited and hidden attractors. Dynamical properties of this system are investigated with the help of eigenvalues of equilibria, Lyapunov exponents' spectrum, and bifurcation diagrams. Also, an electronic circuit implementation is carried out to show the feasibility of this system. As an engineering application of this new chaotic jerk system, a chaotic communication system is realized by correlation delay shift keying. When the results of the communication system are examined, the transmitted information signal is successfully obtained in the receiving unit, and its performance efficiency is investigated in the presence of additive white Gaussian noise
Chimera states in a multi-weighted neuronal network
There are multiple types of interactions among neurons, each of which has a remarkable effect on the neurons' behavior. Due to the significance of chimeras in neural processes, in this paper, we study the impact of different electrical, chemical, and ephaptic couplings on the emergence of chimera. Consequently, a multi-weighted small-world network of neurons is considered. The simultaneous effects of two and three couplings are explored on the chimera and complete synchronization. The results represent that the synchronization is achieved in very small coupling strengths in the absence of chemical synapses. In contrast, without electrical synapses, the neurons only exhibit chimera behavior. In the three-weighted network, the synchronization is enhanced for special chemical coupling strengths. The network with directed links is also examined. The general behaviors of the directed and undirected networks are the same; however, the directed links lead to lower synchronization error
Economic Evaluation of the Drugs Used In Treating Patients with Myocardial Infarction: A Systematic Review
Introduction: Myocardial infarctions (MI), as one of the outcomes of cardiovascular diseases, are responsible for 20% of deaths, so that every 30 seconds, one person suffers from MI. Various drugs are used to treat myocardial infarction, and we need to have precise information of the cost-effectiveness of these drugs. The aim of this study was to examine economic evaluation of the drugs used for treatment of patients with MI.
Methods: In the present systematic review study, published articles related to economic evaluation of the drugs used for treatment of patients with MI within the time interval between 2000 and 2017 were searched, using electronic databases such as Tufts Medical Center Cost-Effectiveness Analysis Registry ,Cochrane library, NHS Economic Evaluations Database Medline, PubMed, Google scholar, web of science using the following keywords: Cost- effectiveness* OR cost- utility* OR economic evaluation * AND (myocardial infarction*) AND (angiotensin- converting enzyme inhibitor (lisinopril) OR thrombolytic agents (streptokinase, anistreplase or anisoylated plasminogen streptokinase activator complex OR
beta blockers (metoprolol, propranolol, atenolol, acebutolol, bisoprolol). Due to heterogeneity in the outcome, we were not able to use meta-analysis. Methodological quality of the structure
e of tarticles was examined by Drummond’s standard checklist.
Results: Based on the inclusion criteria, the search of databases resulted in 12 articles that fully covered economic evaluation of the drugs used in treating patients with MI. The results of the present study indicated that a streptokinase and t-PA drug for treatment of patients with myocardial infarction was cost-effective. The results showed that most of the studies clearly stated the time horizon of the study and included direct medical costs in their analysis.
In addition, the majority of the studies were used the Markov model. The quality-adjusted life years (QALYs) were the main outcome used for measuring the effectiveness.
Conclusion: The results of the present study showed that a thrombolytic agent for treatment of patients with myocardial infarction was cost-effective. The results were relatively varied due
to the differences in time horizon and variables used in the models such as efficacy and drug prices. Furthermore, these studies were designed and conducted in high-income countries; thus, the application of these results in low- and middle-income countries will be limited
Dynamic system with no equilibrium and its chaos anti-synchronization
Recently, systems with chaos and the absence of equilibria have received a great deal of attention. In our work, a simple five-term system and its anti-synchronization are presented. It is special that the system has a hyperbolic sine nonlinearity and no equilibrium. Such a system generates chaotic behaviours, which are verified by phase portraits, positive Lyapunov exponent as well as an electronic circuit. Moreover, the system displays multistable characteristic when changing its initial conditions. By constructing an adaptive control, chaos anti-synchronization of the system
with no equilibrium is obtained and illustrated via a numerical example
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