Thermo-mechanical description of material diffusion during an ultrasonic wire bonding process

The volume diffusion during an ultrasonic wire bonding process leads to a material transport between the wire and the material of the substrate and thus creates an intermetallic phase between them. In order to investigate this process, the thermal and mechanical mechanisms occurring during wire bonding should be studied. For this purpose, finite element simulations based on coupled thermo-mechanical equations are performed to study the temperature and stress distribution in and around the interface. The final objective of the model is to develop a growth law for the intermetallic phases by considering the mechanical work applied to the wire in addition to the temperature increase at the interface. (© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Extension of VIKOR method for decision making problem with interval numbers

The VIKOR method was developed for multi-criteria optimization of complex systems. It determines the compromise ranking list and the compromise solution obtained with the initial (given) weights. This method focuses on ranking and selecting from a set of alternatives in the presence of conflicting criteria. It introduces the multi-criteria ranking index based on the particular measure of “closeness” to the “ideal” solution. The aim of this paper is to extend the VIKOR method for decision making problems with interval number. The extended VIKOR method’s ranking is obtained through comparison of interval numbers and for doing the comparisons between intervals, we introduce α as optimism level of decision maker. Finally, a numerical example illustrates and clarifies the main results developed in this paper.     

Environmental Degradation of Microbial Polyhydroxyalkanoates and Oil Palm-Based Composites

This paper investigates the degradation of polyhydroxyalkanoates and its biofiber composites in both soil and lake environment. Time-dependent changes in the weight loss of films were monitored. The rate of degradation of poly(3-hydroxybutyrate) [P(3HB)], poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-23?mol% 4HB)] and poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-4-hydroxybutyrate) [P(3HB-co-9?mol% 3HV-co-19?mol% 4HB)] were investigated. The rate of degradation in the lake is higher compared to that in the soil. The highest rate of degradation in lake environment (15.6?% w/w week^?1) was observed with P(3HB-co-3HV-co-4HB) terpolymer. Additionally, the rate of degradation of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-38?mol% 3HV)] was compared to PHBV biofiber composites containing compatibilizers and empty fruit bunch (EFB). Here, composites with 30?% EFB displayed the highest rate of degradation both in the lake (25.6?% w/w week^?1) and soil (15.6?% w/w week^?1) environment.     

Cycloisomerization of dienes and enynes catalysed by a modified ruthenium carbene species

Cycloisomerization is a totally atom economic procedure which converts dienes and enynes into cyclic molecules. Modification of Grubbs' 2nd generation catalysts by reaction with dimethylformamide provides a new species able to catalyse this transformation. Selection of suitable conditions allowed high yields and selectivity. Studies performed in order to identify the catalytic species point to a non-carbenic ruthenium complex that has lost the phosphine. No hydride signals appeared. In addition, the reaction works with enynes and the new species catalyses efficiently crossed cyclotrimerizations of alkynes with diynes.     

Electrochemical properties of gold nanoparticles assembly at polarised liquid|liquid interfaces

Capacitance measurements of a polarised liquid|liquid interface show that the capacitance of the interface increases in the presence of an adsorbed monolayer of citrate-coated gold nanoparticles. This unusual observation can be explained by an increase of the interfacial charge density or by an increase of the interfacial corrugation. This study shows that capacitance measurements provide a method to monitor metallic film formation at ITIES.     

Combined radiolytic and catalytic oxidizing method to remove toluene in gas phase

We enhanced the decomposition and the removal of toluene in gas phase using a combined method that consists of electron beam (EB) irradiation and catalytic oxidation. The catalytic oxidation system comprises oxidizing particles of 0.1 wt% Pt or 0.1 wt% Pd deposited to supporting materials, which were also used as adsorbents. These adsorbents—supporting materials are Cordierite, Y-zeolite, and γ-alumina. We demonstrated that 100% removal of toluene can be achieved using approximately 9 kGy of dose level in the presence of Pt or Pd deposited to 12 wt%. The G (-toluene) values were determined to be 0.498 and 0.829 μmol/J in the absence and presence of these catalysts with adsorbents, respectively. We have also demonstrated that the presence of the oxidation-catalyst prevents the toluene from undergoing radiolytic polymerization.     

On the carrier generation and HD signal transmission using the millimeter-wave radio over fiber system

The dual sideband optical carrier suppression (DSB-OCS) technique is employed in the optical carrier generation for 40 GHz radio over fiber (ROF) system. A dual electrode Mach-Zehnder modulator (DE-MZM) with the minimum transmission bias (MiTB) technique is employed to build the system. The results show that, a 40 GHz carrier is successfully generated with the amplitude up to −29 dBm and signal to noise ratio (SNR) of 35 dB and a high definition (HD) signal is successfully transmitted using the system. Finally, the bit error rate (BER) measurement is carried out for the system with 1.25 Gbps OOK signal showing an error free 40 GHz ROF system with almost no penalty between the back to back and 20 km fiber for a BER of 10⁻⁹.     

An entropic economic order quantity (EnEOQ) for items with imperfect quality

This paper presents an entropic version of an EOQ model with imperfect quality items. The approach adopted herein models the commodity flow (demand rate) as a heat flow in a thermodynamic system. As a result, an entropy cost term is added to the classical inventory cost to form an entropic total inventory cost function. This provides an estimation of the hidden or difficult to estimate cost inventory systems that usually are the result of disorder (or entropy). A mathematical model is developed with numerical results presented and discussed.     

Pulp Enhancement of Oil Palm Empty Fruit Bunches (OPEFBs) via Biobleaching by Using Xylano-Pectinolytic Enzymes of Bacillus amyloliquefaciens ADI2

The present work reports the biobleaching effect on OPEFB pulp upon utilisation of extracellular xylano-pectinolytic enzymes simultaneously yielded from Bacillus amyloliquefaciens ADI2. The impacts of different doses, retention times, pH, and temperatures required for the pulp biobleaching process were delineated accordingly. Here, the OPEFB pulp was subjected to pre-treatment with xylano-pectinolytic enzymes generated from the same alkalo-thermotolerant isolate that yielded those of higher quality. Remarkable enhanced outcomes were observed across varying pulp attributes: for example, enzyme-treated pulp treated to chemical bleaching sequence generated improved brightness of 11.25%. This resulted in 11.25% of less chlorine or chemical consumption required for obtaining pulp with optical attributes identical to those generated via typical chemical bleaching processes. Ultimately, the reduced consumption of chlorine would minimise the organochlorine compounds found in an effluent, resulting in a lowered environmental effect of paper-making processes overall as a consequence. This will undoubtedly facilitate such environmentally-friendly technology incorporation in the paper pulp industry of today.