Caracterização mecânica das argamassas de assentamento para alvenaria estrutural – previsão e modo de ruptura

Este trabalho pretende avaliar o comportamento mecânico das argamassas de assentamento para o uso estrutural, por meio das propriedades de resistência à compressão, tração na flexão e módulo de elasticidade, sob estados de tensões uniaxial e multiaxial. Portanto, estabelecer correlações entre os resultados mecânicos de diferentes traços de argamassas, relações água/cimento e geometria da amostra associada ao modo de ruptura. As principais conclusões obtidas, entre outras, são: existe uma relação potencial entre a resistência a compressão da amostra de geometria cúbica, cilíndrica e a resistência à flexão (amostra de geometria prismática) em função da relação água/cimento; a função linear é a que melhor ajusta os valores médios do módulo de elasticidade em função da resistência à compressão; a envoltória de ruptura da argamassa confinada lateralmente pode ser representada como uma relação linear de Mohr-Coulomb; observou-se, por meio de ensaios de microscopia eletrônica de varredura a existência de fissuras de retração na interface pasta-agregado e poros isolados, devido ao fluxo ascendente de água causado pela exsudação

First order piecewise collocation solution of Fredholm integral equation second kind by using gauss-seidel iteration

We determine the approximation solution of first-order piecewise via polynomial collocation with first-order Quadrature scheme on Fredholm integral equations of second kind. This discretization has derived the formation for solving piecewise approximation equation in which constructing the linear system. In order to get the approximation solutions, the Gauss-Seidel method has been stated as a linear solver in which its formulation has been constructed and implemented in this study. The combination of the iterative method of GS with the first-order piecewise polynomial via collocation with first-order Quadrature scheme has shown that performance of GS method is excel than Jacobi method in the matter of iterations number and completion time

Mechanical and Morphological Properties of Polypropylene/Epoxidized Natural Rubber Blends at Various Mixing Ratio

This research is to investigate the effect of mixing ratio on the properties of polypropylene (PP) incorporated with epoxidized natural rubber (ENR). The blends of PP/ENR were prepared by melt compounding using an internal mixer and vulcanized through sulfur curing. Mechanical testing such as tensile test, hardness test and impact test were performed to characterize the properties of PP/ENR blends. It was clearly observed that the increase of the ENR percentage increases the toughness and flexibility of the PP/ENR blends. In comparison to the pure PP, the 40/60 PP/ENR blend showed an improvement of elongation at break and impact strength, up to 68% and 56%, respectively. In contrary, the tensile strength and hardness decreases as the amount of PP decreases. The changes were associated to the properties imparted by the elastic chains of cross-linked ENR. The obtained properties showed good correlation with fracture surfaces observed in microscopy analysis performed by Field Emission Scanning Electron Microscope at a magnification of 500 and 5000-x

Water quality assessment at Royal Belum State Park, Perak, Malaysia

This study demonstrated water quality study at the Royal Belum State Park, Perak. The Royal Belum State Park is one the major reservoir for water resource in Perak and under National Heritage Site UNESCO. The lake is surrounded by the reserved forest and rich with flora and fauna. The Royal Belum State Park is considered as one of the oldest, protected, undisturbed and pristine land mass in Peninsular Malaysia of more that 130 million years old. This lake provides biodiversity education, research, and ecotourism to the public. One of the major attractions is the houseboat. There are more than ten (10) houseboats operated every day due to the high demand from the local and international tourists. Due to this activity, water quality of the lake has been deteriorated and required short and long-term mitigation measures. Water quality study (ex-situ and in-situ measurements) was conducted at selected six (6) sampling locations (e.g., Royal Belum registration point, Sungai Tiang, Kg. Orang Asli, houseboat docking area, Kem Sg. Tiang and houseboat parking area). The water quality index (WQI) measurement of all sampling points is in the range of 60-80, indicating that the WQI value is under class II and III. The WQI values are significantly deteriorated by the concentrations of dissolved oxygen (DO), biological oxygen demand (BOD), and chemical oxygen demand (COD). The water quality at Kg.Orang Asli, Sg. Tiang and houseboat parking area slightly deteriorated compared to other sampling points. This is probably due the leakage of petrol from the houseboat, stagnant water at certain area of the lake (e.g., Kem. Sg. Tiang), discharge of wastewater and sullage water from the houseboat and unknown non-point source nearby the lake. Therefore, the Perak State Government, State Parks Corporation, and other relevant authority (e.g., NGOs) should play an important role to preserve and sustain the water quality at the Royal Belum State Park, Perak because this lake is one of significant source of clean water supply in Perak

Measurement of dijet photoproduction for events with a leading neutron at HERA

Differential cross sections for dijet photoproduction and this process in association with a leading neutron, e+ + p -> e+ + jet + jet + X (+ n), have been measured with the ZEUS detector at HERA using an integrated luminosity of 40 pb-1. The fraction of dijet events with a leading neutron was studied as a function of different jet and event variables. Single- and double-differential cross sections are presented as a function of the longitudinal fraction of the proton momentum carried by the leading neutron, xL, and of its transverse momentum squared, pT^2. The dijet data are compared to inclusive DIS and photoproduction results; they are all consistent with a simple pion-exchange model. The neutron yield as a function of xL was found to depend only on the fraction of the proton beam energy going into the forward region, independent of the hard process. No firm conclusion can be drawn on the presence of rescattering effects.Comment: 40 pages, 18 figure

Analysis of fuzzy power system stabilizer using various defuzzification interface for takagi-sugeno fuzzy logic

Power System Stabilizer (PSS) is well known to provide damping in low-frequency oscillation and improve power system stability. This paper discussed the use of Takagi-Sugeno (TS) fuzzy logic to design the PSS controller and the performance is tested on single machine infinite bus (SMIB) system. The generator represented by the standard K-coefficients as second order system. The mechanism to determine the rule is describe and the performance is being investigated for both conventional PSS and proposed TS fuzzy PSS (FPSS) with different type of defuzzification for changes in mechanical input in the system. The angular speed deviation and its acceleration are being taken as the input parameters and the stabilize voltage signal as output. The system is simulated in MATLAB/SIMULINK environment. The superior response for FPSS proved the ability of Takagi-Sugeno fuzzy controller to enhance the stability of the system in comparison of the conventional one

Screening Drug, Alcohol and Substance Abuse the Psychometric Measures

Urinalysis was used in previous studies among higher institution students (n=16252) in Malaysia to answer the question of whether university students are involved in drug abuse. However, the use of urinalysis had faced some problems. The problems were related to human rights issues and the cost to perform the urinalysis was expensive and quite impossible to be implemented to a large population of university students. To overcome this problem, this study was conducted to examine the effectiveness of psychometric measures in screening drug, alcohol and substance abuse. The Substance Abuse Subtle Screening Inventory A2 (SASSI-A2) was used for this purpose. SASSI-A2 is a brief screening tool designed to identify individuals who have a high probability of having a substance use disorder, including both substance abuse and substance dependence. SASSI-A2 comprises of 72 items that are rated on a two point scale with response; true and false. SASSI-A2 was translated into Malay language and it was refined through a back-translation technique and focus group approach. Psychometric testing was undertaken on a sample of 750 university students from five public universities in Malaysia. All participants were aged between 19 and 20 years. Internal consistency coefficients were calculated for the total scale and its subscales. Chronbach's alpha obtained for SASSI-A2 was 0.72. This relatively high level of Chronbach's alpha showed relatively high level of reliability. The results demonstrated that the whole SASSI-A2 meets the fundamental measurement properties and can discriminate groups of higher institution students from high to low on the substance dependency variable. The accuracy of the test has been found to be unaffected by gender, ethnicity, age and years of education. Although more rigorous validation studies are needed, it is recommended that SASSI-A2 be considered for usage to higher institution students populations when a brief, objective, and accurate screening tool for chemical dependency is needed

Screening Drug, Alcohol and Substance Abuse the Psychometric Measures

Urinalysis was used in previous studies among higher institution students (n=16252) in Malaysia to answer the question of whether university students are involved in drug abuse. However, the use of urinalysis had faced some problems. The problems were related to human rights issues and the cost to perform the urinalysis was expensive and quite impossible to be implemented to a large population of university students. To overcome this problem, this study was conducted to examine the effectiveness of psychometric measures in screening drug, alcohol and substance abuse. The Substance Abuse Subtle Screening Inventory A2 (SASSI-A2) was used for this purpose. SASSI-A2 is a brief screening tool designed to identify individuals who have a high probability of having a substance use disorder, including both substance abuse and substance dependence. SASSI-A2 comprises of 72 items that are rated on a two point scale with response; true and false. SASSI-A2 was translated into Malay language and it was refined through a back-translation technique and focus group approach. Psychometric testing was undertaken on a sample of 750 university students from five public universities in Malaysia. All participants were aged between 19 and 20 years. Internal consistency coefficients were calculated for the total scale and its subscales. Chronbach's alpha obtained for SASSI-A2 was 0.72. This relatively high level of Chronbach's alpha showed relatively high level of reliability. The results demonstrated that the whole SASSI-A2 meets the fundamental measurement properties and can discriminate groups of higher institution students from high to low on the substance dependency variable. The accuracy of the test has been found to be unaffected by gender, ethnicity, age and years of education. Although more rigorous validation studies are needed, it is recommended that SASSI-A2 be considered for usage to higher institution students populations when a brief, objective, and accurate screening tool for chemical dependency is needed

Retracted: Flood Victims Quality of Life Index 2017 (FVQoL-Index’17: scale development and validation

This article was withdrawn and retracted by the Journal of Fundamental and Applied Sciences and has been removed from AJOL at the request of the journal Editor in Chief and the organisers of the conference at which the articles were presented (www.iccmit.net). Please address any queries to [email protected]