Abstract: Environmental awareness and depletion of the wood resources are among vital factors that motivate various researchers to explore the potential of agro-based crops as an alternative source of fiber material in paper industries such as writing, printing, wrapping, and packaging. Fibers from agro-based crops are available in abundance, low cost, and most importantly its biodegradability features, which sometimes referred as “ecofriendly” materials. This paper reports the effects of mercerization (NaOH treatment) on the properties of pineapple leaf fiber (PALF) pulp and paper. The individual fibers were characterized having good tensile properties at 15% NaOH treatment and favourable structural properties as characterized by Fourier transform infra-red (FTIR) spectroscopy and X-ray diffractometer (XRD). It was also shown that the PALF paper achieved desirable tear index value and uniform morphological observations at 15% NaOH concentration. This type of chemical treatment is useful to obtain PALF based paper products.

Abstract: In this study, the theoretical analysis was conducted the three-dimensional turbulent recirculating for air distribution within enclosed cooling space. A modified version of a three-dimensional computer program (fluent 6.3.26) was to simulate the complex flow inside the room by using the Realizable k-e and SST k-? models. The study depended on design conditions for Iraq and relying on the Iraqi Code of cooling. The results of numerical model were validate with experimental predications of previous researchers. The airflow in a room ventilated by displacement diffuser, slot diffuser, square diffuser, and grille diffuser is calculated by the simplified system, respectively. Comparing calculated results to measured data and these comparisons show a good agreement, it is clear that the simplified methodology can predict indoor airflow and temperature gradient with satisfactory results for engineering applications

Abstract: Failure criteria from six theories were applied to estimate shear strength of the adhesive line in terms of grain slope when under loaded compressive stress. The shear stresses of the adhesive line as a function of the angle of the wood grain were determined by means of experimental tests. Specimens were obtained from a sample of 12 Eucalyptus saligna wood beams. They were prepared with varying angles of the grain (0o, 15º, 30º, 45º, 60º, 75º, 90º) in relation to load application, following the requirements of the Brazilian standard. From the results of the six failure criteria and experimental results, robust statistical analysis was carried out and thus it was possible to adapt the models to determine shear strength of the adhesive line as a function of the angle of the wood grain. Of the six mathematical models evaluated, those of Hankinson, DIN 1052, Tsai-Hill and Hyperbolic do not show statistical significance in their original format. With the modifications made in the models, they all showed significance, and those with the best fit were, in order of significance: DIN 1052, Keylwerth, Hankinson, Karlsen, Hyperbolic and Tsai-Hill. Through ease of application, the most recommended models for estimating shear strength of the adhesive line under compressive load as a function of wood grain angle are the DIN 1052 and Hankinson formulas.

Abstract: This study involves the photocatalytic degradation of Aniline blue(AB) dye, employing heterogeneous photocatalytic process. Photocatalytic activity of different semiconductors such as zinc oxide (ZnO) ,zinc sulfide (ZnS) and Tin dioxide (SnO2) has been investigated. An attempt has been made to study the effect of process parameters through amount of catalyst, concentration of dye, pH of dye solution and temperature on photocatalytic degradation of AB solution. The experiments were carried out by varying pH (2-12), amount of catalyst (0.05–1.5 g), initial concentration of dye (25–100ppm ) and temperature range(293-323)K. The optimum catalyst dose was found to be( 0.1 ,0.5 g and 1) g\L by using ZnO ,ZnS and SnO2, respectively. In the case of ZnO and SnO2 , maximum rate of photoreaction of AB solution was observed in acidic medium at pH 4, whereas the degradation of AB reached maximum at pH 5 when using ZnS catalyst . The performance of photocatalytic system employing ZnO/UV light was observed to be better than ZnS /UV and SnO2/UV system. The complete degradation of AB was observed after 12 min with ZnO, whereas with ZnS, only 75% dye degraded and 24.5% with SnO2in 12 min. Photocatalytic degradation was found to increase with increasing temperature. Arrhenius plot shows that the activation energy is equal to 20.94 kJ mol-1 with ZnO, 17.97 kJ mol-1 with ZnS and 14.1 mol-1 with SnO2 catalyst. The thermodynamic parameters of the photodegradation of AB, like energy of activation, enthalpy of activation, entropy of activation and free energy of activation revealed the efficiency of the process.

Abstract: In this work, the effect of aromatic rings number on the photooxidation rate was studied by comparison photocatalytic degradation of an aqueous Sunset yellow, and Amaranth dyes by the suspension of ZnO catalyst. The effect of some parameters, such as mass of catalyst, initial dye concentration, initial pH of aqueous dye solution, and temperature were studied. The results indicate that the photo catalytic reactions are a pseudo first order reactions according to the Langmuir-Hinshelwood .Thermodynamic parameters such as: Ea, H#, S# and G# were calculated .The activation energy has been found equal to, 5.493±1 and 5.088±1 kJ.mol-1 for Sunset yellow and Amaranth respectively. the results indicate that at low concentrations of dyes the number of aromatic rings has no effect on photooxidation rate but at higher concentrations we show the inversely relationship.

Abstract: The power spectral density of an incoherent scatter radar signal contains information on several ionospheric plasma parameters. There is a close relationship between the plasma conditions in ionosphere and the shape of power spectral density. The sensitivity of the shape, in the ion part of the spectra, roughly depends on the plasma parameter fluctuations. Here we will study and analyze the relationship between electron temperature to ion temperature ratio (Te/Ti) and the corresponding shape of the spectra considering Maxwellian plasma conditions. In addition, the relationship of ion mass (mi) and the respective shape of ion line for hydrogen (H+), helium (He+), oxygen (O+), diatomic oxygen (O2+), nitrogen (N+), diatomic nitrogen (N2+) and nitrogen monoxide (NO+) is discussed.

Abstract: Inverse Square Law in Environmental Acoustic Theory has always been recognized as a Grand Theory of Acoustic Environmental science. Since its inception by scientists including Diendrik Hendrik Buys Ballot in 1892, this theory has been much enhanced by the acoustic environment experts. This theory states that the greater the distance the less the intensity of the sound and the smaller the distance, the greater the intensity of the sound. Variables contained in these theories are the distance and intensity of sound. By the development of science and technology, it appears the angle of orientation variable. On understanding the theory, and in relation to aspects of the sound source within the building, the housing in the airport area will have an effective distance to the sound source and it will be varies depend on the direction of the orientation and configuration of the building blocks toward the runway which has a significance sound source of the airplane. This article will discuss the evolution of the new variable of orientation angle (a) into the formula of Grand theory, Inverse Square Law. To clarify the discussion, the housing close to Achmad Yani International Airport in Semarang, Indonesia has been choosen as a case of study.

Abstract: Recent studies on the surface modification by alkali and heat treatments in Titanium metal are reviewed. Previous laboratory studies investigated the effects of different alkali and heat treatments on properties of Ti implant material. It seems hopeful that this type of treatments is a suitable technique for dental implants. In the present study, heat treatments applied above700c? that may seem hopeful to apply change in the limit of temperature range that all previous researches decide. Apply physical studies to correlate with other properties for development of high bioactive materials.

Abstract: In this study, the method of drill resistance was applied to wood to estimate the Janka hardness rating and the shear strength of tropical woods. For validation of the nondestructive tests, destructive tests were performed of apparent density, shear strength and Janka hardness in the three orthotropic directions of wood - longitudinal, tangential and radial. All the destructive tests were adjusted for moisture content of 12%. To obtain correlations between nondestructive and destructive tests, seven types of wood were used: angelim pedra (Hymenolobium petraeum), angelim vermelho (Dinizia excelsa), castanheira (Bertholletia excelsa), garapa (Apuleia leiocarpa), muiracatiara (Astronium lecointei), pequi (Caryocar villosum) and roxinho (Peltogyne discolor). The density interval was from 650 to 1150 kg/m³. For estimation of Janka hardness, the method of drill resistance in wood exhibited good correlations, with R² greater than 85%. For shear strength, positive results were also found, however, with intermediate R² values, ranging from 59% to 75%. This nondestructive method proved to be an efficient and practical alternative for estimation of wood mechanical properties.