Effectiveness of Bracing in High Rise Structure under Response Spectrum Analysis

Volume 7 Issue 7 (July 201

Hygrothermal performance of building envelopes in the tropics under operative conditions : condensation and mould growth risk appraisal

Poor indoor hygrothermal performance increases the risk of indoor moisture problems and deterioration due to mould growth, corrosion and damage to archival materials. Hence, proper control of indoor thermohygric intensity abates indoor moisture and its associated problems. This paper presents the results of envelopes hygrothermal performance assessments in a hot and humid climate building with varying operational profile between adjacent spaces. The case-studied building runs on 24hrs cooling mode in one part against natural and/or mechanical supply-exhaust fan means on the other. In-situ experiments were combined with hygrothermal analytical methods to assess the envelope thermal quality together with the operative conditions against condensation and mould growth risks. The results show that the building is overcooled leading to poor envelope hygrothermal performance with associated condensation and mould growth problems on non-airconditioned sides of the envelopes

Utility of Certain Nucleophilic Aromatic Substitution Reactions for the Assay of Ethamsylate in its Dosage forms and in Presence of its Degradation Product

The study represents the first report on the development of spectrophotometric methods for determination of ethamsylate (EST) in the presence of hydroquinone as an impurity and/or acidic degradation product. The proposed methods are based on the reaction of EST through it,s secondary amino group either with 1,2-naphthoquinone-4-sulphonate sodium (NQS) at pH 10.7 or 2,4-dinitrofluorobenzene (DNFB) at pH 9.3 to form orange and yellow colored reaction products peaking at 478 and 387 nm for methods (I) and (II), respectively. The different experimental parameters affecting the development and stability of the reaction products in methods (I) and (II) were carefully studied and optimized. The absorbance-concentration plots were rectilinear over the concentration ranges of 2-30 and 2-14 µg mL−1 for methods (I) and (II), respectively. The lower detection limits were 0.13 and 0.19 µg mL−1 and the lower quantitation limits were 0.44 and 0.63 µg mL−1 for methods (I) and (II), respectively. Both methods were successfully applied to commercial ampoules and tablets

Relación entre aprendizaje en línea, instrucción multimedia y aprendizaje individualizado

The quest for effective teaching-learning strategies and instructional approach in engineering communication skills has been a challenge to educators throughout the world. Students must be in the centre of learning in any effective approach to cater for each individual to achieve the predetermined objectives. This study aimed at designing, developing and implementing a new online individualized multimedia instruction framework for engineering communication skills. The questionnaire has three sections to assess individualized instruction, multimedia instruction and online learning. Overall reliability using the Alpha Cronbach test and the Rasch Model analysis together with expert reviews for the content validation of the questionnaire, suggested that the questionnaire is reliable and valid to measure the OIMI model. Data collected from 166 engineering learners were tested with confirmatory factor analysis using AMOS to obtain three best-fit measurement models from the three latent variables. Subsequently, the structural equation modeling was applied to test the hypotheses. The results showed a strong relationship between Online Learning and Multimedia Instruction, and a negative relationship between Individualized Instruction and Multimedia Instruction.La búsqueda de estrategias de aprendizaje de enseñanza efectivas y un enfoque de instrucción en habilidades de comunicación de ingeniería ha sido un desafío para los educadores de todo el mundo. Los estudiantes deben estar en el centro de aprendizaje en cualquier enfoque efectivo para atender a cada individuo para lograr los objetivos predeterminados. Este estudio tuvo como objetivo diseñar, desarrollar e implementar un nuevo marco de instrucción multimedia individualizado en línea para las habilidades de comunicación de ingeniería. El cuestionario tiene tres secciones para evaluar la instrucción individualizada, la instrucción multimedia y el aprendizaje en línea. La confiabilidad general usando la prueba de Alpha Cronbach y el análisis del Modelo Rasch junto con revisiones de expertos para la validación del contenido del cuestionario, sugirió que el cuestionario es confiable y válido para medir el modelo OIMI. Los datos recopilados de 166 estudiantes de ingeniería se probaron con análisis factorial confirmatorio utilizando AMOS para obtener tres modelos de medición de mejor ajuste de las tres variables latentes. Posteriormente, se aplicó el modelo de ecuaciones estructurales para probar las hipótesis. Los resultados mostraron una fuerte relación entre el aprendizaje en línea y la instrucción multimedia, y una relación negativa entre la instrucción individualizada y la instrucción multimedia

Treatment of wastewater using response surface methodology: a brief review

Response surface methodology (RSM) is widely applied to gathering knowledge on the interactions among parameters that require optimization during the treatment of wastewater. It can be used to optimize parameters during the process of treating wastewater, e.g., landfill leachate. The experimental design methods are useful to evaluate the parameters involved in a treatment with the minimum number of experiments. This will reduce the need for reagents and materials for experiments, which finally causes both time and expense to be increased. Anaerobic digestion of wastewater technologies escalated depending on the design configuration of the reactor. Several important parameters are taken into consideration in designing an anaerobic reactor such as operating conditions, seed sludge, wastewater composition and mixing. To construct a highly efficient degradation system, it is necessary to optimize such effective parameters. As a result, the advanced statistical design is used for process characterization, optimization and modelling. In this paper, the fundamentals of RSM and its application in the anaerobic treatment of wastewater was discussed in brief. The various works done in an anaerobic reactor using RSM for prediction and optimization are given

A mathematical approach for hidden node problem in cognitive radio networks

Cognitive radio (CR) technology has emerged as a realistic solution to the spectrum scarcity problem in present day wireless networks. A major challenge in CR radio networks is the hidden node problem, which is the inability of the CR nodes to detect the primary user. This paper proposes energy detector-based distributed sequential cooperative spectrum sensing over Nakagami-m fading, as a tool to solve the hidden node problem. The derivation of energy detection performance over Nakagami-m fading channel is presented. Since the observation represents a random variable, likelihood ratio test (LRT) is known to be optimal in this type of detection problem. The LRT is implemented using the Neyman-Pearson Criterion (maximizing the probability of detection but at a constraint of false alarm probability). The performance of the proposed method has been evaluated both by numerical analysis and simulations. The effect of cooperation among a group of CR nodes and system parameters such as SNR, detection threshold and number of samples per CR nodes is investigated. Results show improved detection performance by implementing the proposed model

Four-Wave Mixing Crosstalk Suppression Based on the Pairing Combinations of Differently Linear-Polarized Optical Signals

A new approach to suppressing the four-wave mixing (FWM) crosstalk by using the pairing combinations of differently linear-polarized optical signals was investigated. The simulation was conducted using a four-channel system, and the total data rate was 40 Gb/s. A comparative study on the suppression of FWM for existing and suggested techniques was conducted by varying the input power from 2 dBm to 14 dBm. The robustness of the proposed technique was examined with two types of optical fiber, namely, single-mode fiber (SMF) and dispersion-shifted fiber (DSF). The FWM power drastically reduced to less than −68 and −25 dBm at an input power of 14 dBm, when the polarization technique was conducted for SMF and DSF, respectively. With the conventional method, the FWM powers were, respectively, −56 and −20 dBm. The system performance greatly improved with the proposed polarization approach, where the bit error rates (BERs) at the first channel were 2.57×10-40 and 3.47×10-29 at received powers of −4.90 and −13.84 dBm for SMF and DSF, respectively