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We report an efficient method to synthesize vertically aligned Co3O4 nanostructures on the surface of cobalt foils. This synthesis is accomplished by simply heating the cobalt foils in the presence of oxygen gas. The resultant morphologies of the nanostructures can be tailored to be either one-dimensional nanowires or two-dimensional nanowalls by controlling the reactivity and the diffusion rate of the oxygen species during the growth process. A possible growth mechanism governing the formation of such nanostructures is discussed. The field-emission properties of the as-synthesized nanostructures are investigated in detail. The turn-on field was determined to be 6.4 and 7.7 V μm–1 for nanowires and nanowalls, respectively. The nanowire samples show superior field-emission characteristics with a lower turn-on field and higher current density because of their sharp tip geometry and high aspect ratio.

Through their decomposing activities, earthworms produce rich organic fertilizers called vermicomposts contain- ing mineral nutrients and anecdotal evidence of biologically active phytohormones. Aqueous extracts of vermicomposts, namely vermicompost tea (VT), have positive effects on plant growth. It has been postulated that trace amounts of phyto- hormones in vermicomposts or its VTare beneficial for plant growth and development. We therefore screened for the dif- ferent classes of phytohormones (auxins, cytokinins, abscisic acid, and gibberellin) in VT using liquid chromatography- tandem mass spectrometry (LC-MS/MS) after solid-phase extraction. VT was produced by earthworms being fed with a mixture of water hyacinth (Eichhornia crassipes) and chicken manure at a ratio of 4:1 (w/w). This investigation is the first mass spectrometric evidence for the presence of cytokinins in VT: namely trans-Zeatin (tZ), N 6 -Isopentenyladenine (iP) and N 6 -Isopentenyladenosine (iPR), which were present at 0.06, 3.33, and 0.02 nmol L -1 , respectively. The successful detection and quantitation of cytokinins in VT provided direct evidence to explain the growth efficacy of applying VT in order to enhance plant growth and development. We postulated that they were microbially synthesized due to the abundance of microbial communities in the vermicompost.

Rapid change of technologies, coupled with increase in demand of quality and reliability, development speed is the top challenge to have market win for semiconductor industries. As semiconductor is moving towards copper wire bonding, failure associated with reliability is critical. While reliability results take time to wait for the cycles to complete in order to have next decision or improvement. In this paper, the study is initiated due to corrosion failure in Autoclave 96 hours. Corrosion associated with copper wire bonding is considered one of the challenges to solve in term of reliability risk which happened at very low ppm rate. The focus on this paper is on early detection for corrosion associate with Cu wire on Aluminum pad. Therefore, establishment of early detection method in detecting/checking corrosion would significantly shorten the development cycle as complete package with normal Autoclave 96 hours reliability stress. The development of Autoclave test on non-encapsulation samples was developed based on assumption that mould compound is not the source of chlorine contamination to aluminum metallization corrosion. Without mould compound encapsulation, corrosion rate between copper wire and Aluminum bondpad in moisture environment would expect to be accelerated. This hypothesis is then proven in the experiment of non-encapsulation stripes with Autoclave 1 hours, 2 hours, 4 hours and 6 hours. The study shows that Autoclave 1 hour is not enough to provoke the corrosion whereas Autoclave 2 hours onwards is found to be corresponding and tally with moulded AC96 hours result where we observed similar corrosion signs - corrosion with crack mechanism and exposed metal stack. From the EDX mapping analysis on the corroded pad, presence of Cl on the bondpad is still persistence as similar observation on Autoclave 96 hours corroded pad. By means of the failure replication in Autoclave 2 hours test is successful and the failure mechanism was successfully demonstrated. With the findings in hypothesis study, the Autoclave 2 hours was used as the stress test to investigate the corrosion and the failure rate from each category actually tally with the final finding in DOE and it shows significant reduction in corrosion rate during Autoclave short duration test for the dominant corrosion influencing factor. In the final of the experiment, a proper full DOE leg was run with the highly dominant contributor of corrosion and the encapsulation units was send for Autoclave 96 hours as per standard JEDEC requirement, the results show positive with no sign of corrosion, the root cause was then nailed. As a conclusion, result of Autoclave 2 hours on non-encapsulation stripes are compatible with conventional Autoclave 96 hours in revealing a sign of corrosion in this case study and it is proven to be a reliable result. This newly developed method not only save the reliability cycle time compared to the conventional Autoclave 96 hours, it also save in term of the product assembly from processing in End of Line which normally easily takes up to 7 days. If all round up together this new method actually save the overall cycle time of minimum 30 days however in actual only need 2 days to get the DOE results after Autoclave 2 hours implementation.

Changes in pasting and thermal properties of non-waxy rice flour and its isolated starch during storage at 25, 35 and 45°C were compared. Aging had no apparent effect on the pasting behaviour of the isolated starch, but markedly affected that of the flour. Peak viscosity (Vp) of rice flour pastes generally increased with both temperature and time of storage, but reached a plateau within 4 weeks of storage at 45°C. Fresh flour paste exhibited lower Vp, a slower rise in apparent viscosity, and much better stability than an isolated starch paste. The addition of isolated oryzenin to isolated rice starch resulted in pasting behaviour which more closely approximated that of an extensively aged flour. DSC scans of fresh flour at ∼13% moisture revealed a weak heat-irreversible endothermic event over the temperature range from 47 to 66°C which was attributed to the denaturation of oryzenin. This transition was shifted to higher temperatures with increasing storage temperature and time. It also became increasingly skewed and broadened until it was no longer detectable after the flour had been stored at 45°C for 8 weeks. Starch gelatinization characteristics of both flour and isolated starch, as determined by DSC, were apparently unaffected by aging. However, rice flour exhibited significantly higher onset temperature of gelatinization, but lower gelatinization enthalpy, than isolated rice starch. Similarly, pulsed NMR studies showed no apparent effect of aging on retrogradation behaviour of rice flour or starch gels. These results suggest that modification of the protein component, rather than starch, was primarily responsible for rheological changes associated with aging of rice flour.

Thermal characterization of gelatinized binary rice starch-water and ternary starch-sugar-water gels before and after aging was carried out using differential scanning calorimetry. The glass transition temperature of the maximally freeze-concentrated solution (T′g) in both fresh and aged gels was observed to decrease progressively with increasing sugar concentration. Aging of the gels generally shiftedT′g to higher temperatures, but had little or no effect on the ice melting peak temperature (Tm). The presence of various sugars could either accelerate or retard starch (amylopectin) recrystallization, depending on the type and concentration of sugar, as well as on starch/water ratio. A hypothesis based on the dual antiplasticizing-plasticizing effects of sugars was postulated to explain the observed effects. Of the sugars studied, xylose and fructose appeared to display exceptional retardative and accelerative effects, respectively, on retrogradation.

A study of the staling of corn starch gel, bread, and rice cup-cake showed that measurements by pulsed NMR (based on the increase in signal from the solid phase of a system on ageing) gave very highly significant correlations (P < 0.001) with firmness measurements using the Instron Food Testing Instrument. Experimental data from the two methods were fitted into the Avrami equation. Values for the Avrami exponent (n) and the rate constant (k) obtained by compression were in good agreement with the corresponding values derived from NMR measurements. The pulsed NMR method thus offers a rapid and non-destructive means of monitoring changes at the molecular level which manifest themselves at the macroscopic level as an increase in firmness during ageing of starch gels and starch-based products. Alterung von auf Starke basierenden Produkten: Eine vergleichende Untersuchung durch Festigkeit und pulsierende NMR-Messungen. Eine Studie uber die Alterung von Maisstarkegel, Brot und Topfkuchen aus Reis zeigte, das Messungen mittels pulsierender NMR (basierend auf der Vergroserung des Signals von der festen Phase eines Systems zur Alterung) sehr hoch signifikante Korrelationen (P < 0,001) mit den Festigkeitsmessungen des Instron Food Testing Instruments ergaben. Die experimentellen Daten aus den beiden Methoden wurden in die Avrami-Gleichung eingebracht. Die durch Kompression erhaltenen Werte fur den Awrami-Exponenten (n) und die Geschwindigkeitskonstante (k) erhaltenen Werte standen in guter Ubereinstimmung mit den entsprechenden Werten, die von den NMR-Messungen abgeleitet wurden. Somit bietet die pulsierende NMR-Methode eine schnelle und nicht-destruktive Methode zur Kontrolle von Veranderungen im molekularen Bereich, die sich selbst im makroskopischen Bereich manifestieren als eine Zunahme der Festigkeit wahrend der Alterung von Starkegelen und auf Starke basierenden Produkten.

The increase of gold price had pushed industrial to develop copper wire in order to stay competitive. However, copper is not precious material like gold, there are numerous challenges in bonding & reliability risk associated with stringent automotive reliability requirements. Corrosion associated with copper wire bonding is considered one of the hard to solve reliability risk as the occurrence is in very low ppm and there was no specific pattern observed on the corroded bondpad location. This paper is focusing on the copper wire interconnect with Aluminum pad corrosion in humidity test including autoclave and temperature humidity bias test.

The study was carried out to further elucidate the effects of annealing under different temperature, time and moisture conditions on the DSC thermal profiles of native granular rice starch-water mixtures, and thus provide a greater insight into the molecular changes responsible for the thermal events associated with starch gelatinisation

A rapid and non-destructive pulsed NMR method of monitoring starch retrogradation was developed based on the principle that the signals from protons in the “solid-like” and liquid components in a system decay at significantly different rates following a 90° radio-frequency pulse. As molecular association or recrystallization proceeds during aging of a starch gel, the proportion of the “solid-like” component in the system increases. The resulting decrease in segmental mobility of the starch chains causes a decrease in the signal from the liquid component, but a concomitant increase in the signal attributed to protons in the “solid-like” fraction. The method was applied to study the retrogradation tendency of starches from different botanical sources. Eine impulsgesteuerte NMR-Methode zur Untersuchung der Starke-Retrogradation. Eine rasche und nicht zerstorende, impulsgesteuerte NMR-Methode zur Untersuchung der Starke-Retrogradation wurde entwickelt basierend auf dem Prinzip, das die Signale von den Protonen in den feststoffahnlichen und flussigen Komponenten bei signifikant verschiedenen Geschwindigkeiten, wobei sie von einem 90°-Radiofrequenz-Impuls gefolgt werden. Da molekulare Assoziation oder Rekristallisation wahrend der Alterung eines Starkegels fortschreiten, nimmt der Anteil der feststoffahnlichen Komponente in dem System zu. Die resultierende Verringerung der abschnittsweisen Mobilitat der Starkeketten verursacht eine Verringerung des Signals der flussigen Komponente, jedoch eine gleichzeitige Vergroserung des den Protonen in der feststoffahnlichen Fraktion zuzuschreibenden Signals. Die Methode wurde zur Untersuchung der Retrogradationstendenz von Starken aus verschiedenen botanischen Herkunften angewendet.