INTENTION TO USE FINGERPRINT SYSTEM IN ELECTRONICS INDUSTRY

Purpose: The aim of this study is to assist the Malaysian electronics companies in reducing the non-value added practices and in return, will minimize the cost and improves productivity with the use of the fingerprint system. Methodology: This study uses a quantitative research approach and data were sampled from 137 front-line employees using simple random sampling technique. Result: The empirical findings of the study confirm that perceived usefulness and perceived ease of use significantly affect the intention to use the fingerprint system. However, there was not enough evidence that relative advantage has any effect on the intention to use the system.  Implications: The study results affirmed that business organizations, especially electronic companies should transform their use of conventional attendance system to fingerprint system in improving efficiencies and effectiveness within the human resource practices

Turnover intention among manufacturing industry employees in Malaysia: an analysis using structural equation modeling (SEM)

This research paper explores the turnover intention among manufacturing industry employees in Malaysia. Four variables were studied: role overload, role ambiguity, role conflict, and work-family conflict. The survey results collected from 153 employees from manufacturing companies in Malaysia. The analysis been obtained via SEM-PLS. Total four hyphotheses were tested. Positive results obtained for role overloaded towards turnover intention. Negative results obtained for role ambiguity, role conflict, and work-family conflict. Based on the findings all the manufacturing recognize importance of staff retention for superior value for an organization

Experiential quality among coffee lovers: an empirical study in the Malaysian coffee outlets industry

Experiential Quality has become extremely important for coffee outlets industry due to the highly competitive environment. The main objective of this study is to analyze the quality of the coffee outlets to win more customers in Malaysia. This study specifically design to investigate the existing literature on experiential quality comprising Interaction quality, Physical environment quality, Outcome quality and Affective quality. Researcher used a self-administrated questionnaire survey with a sample size of 200 respondents from various coffee outlets in Selangor, Malaysia (One of the state with high population in Malaysia). The Findings shows that Interaction quality, Physical environment quality, and Outcome quality have direct effect on experimental quality among coffee lovers. Affective quality shows an negative effect on experiential quality. Coffee is one of the global product. Coffee sold at branded coffee outlets are niche market product. Coffee outlets industry is a classified destination of consumers with intrinsic value of coffee. Coffee outlets offer typical coffer qualities in attractive environment to withhold coffee lovers. This special product is consumed by middle income and higher income social class consumers. The findings further implied coffee outlets focused at managing coffee lovers’ service quality expectation to create and enlarge greater coffee loyalist for sustainable competitive advantage

Mono- und multivalente Wechselwirkungen zwischen Thiol- und Amin-Liganden mit Edelmetallnanopartikeln

In this thesis, the interactions between mono- and multivalent thiol and amine ligands and noble metal nanoparticles are investigated. The multivalent interactions are characterized by the simultaneous binding of multivalent ligands on one entity to multivalent receptors on another one. The binding affinities of multivalent ligands are stronger than that of monovalent ones. So far, multivalent interactions with nanoparticles are not fully explored. Therefore, different physico-chemical techniques are used to investigate the interactions between mono- and multivalent ligands with nanoparticles. The results gathered in this work are divided into four parts. In first part, the effect of the ligand’s multivalency and the nanoparticles size on the binding kinetics of thiol ligands on gold nanoparticles is evaluated by exchanging monovalently bound pyrene thiol ligands bound to gold nanoparticles against flexible mono- and multivalent thiol ligands. For this, gold nanoparticles with diameters of 2.2±0.4 nm, 3.2±0.7 nm, and 4.4±0.9 nm are used as substrates. The pyrene thiol is used as a fluorescent probe as well as a stabilizer of the gold nanoparticles before the ligand exchange reaction takes place. The effects of the ligand’s multivalency and the particles size are evaluated by comparing the rate constants of the ligand exchange reactions. To evaluate these effects, the experimental data have been fitted by using various models. The results from kinetics studies are well fitted by a bi- exponential function as well as by a second order Langmuir diffusion models. However, only a bi-exponential fit function can reasonably explain the processes occurring with the ligand exchange process. Systematic investigations reveal a significant enhancement of the reaction rates of di- and trivalent ligands compared to the monovalent ones. This is attributed to a distinct multivalency effect. In contrast, the exchange rates of the trivalent ligands are similar or even lower than those of the divalent ones. This is explained by steric hindrance of bulky trivalent ligands. In addition, it is also observed that the rate constants increase with the particle size. The results are used to derive structural information on the binding of the mono- and multivalent ligands to the nanoparticles surface. Furthermore, it turns out, that gold particles larger than 4 nm in diameter aggregate during the ligand exchange reaction, likely because the non-bulky incoming alkyl thiol ligands do not provide sufficient steric stabilization. In the second part of this work, the binding of rigid aromatic thiols on gold nanoparticles of 2.2±0.4 nm, 3.2±0.7 nm, and 4.4±0.9 nm is investigated. The pyrene thiol bound on gold nanoparticles is exchanged by 4-toluenethiol or 3,4-toluenedithiol. During the exchange reaction, the particles aggregate immediately after the addition of the aromatic rigid thiol ligands. This clearly shows that flexible alkyl thiol ligands provide sufficient steric stabilization for the gold nanoparticles than the rigid aromatic thiol ligands. In the third part, the binding of mono- and multivalent alkyl thiol ligands on silver nanoparticles with 4.6±2.0 nm diameter is studied, wherein the same alkyl thiol ligands which are also used in the experiments on gold nanoparticles are used. Silver particles stabilized by pyrene thiol ligands are synthesized and the thiol ligands are exchanged by the mono- and multivalent alkyl thiol ligands. During the exchange process partial precipitation of the particles occurs as a consequence of severe aggregation. The results on the silver nanoparticles are compared to those obtained from gold nanoparticles of a similar size (4.4±0.9 nm) during the exchange of pyrene thiol against mono- and multivalent alkyl thiol ligands. The exchange rates of pyrene thiol with di- and trivalent ligands are similar for silver and gold nanoparticles. In case of the monovalent ligands, initially, the exchange rate on silver nanoparticles seems to be faster than on gold nanoparticles. In last part of this work, the influence of the presence of mono-, di-, and trivalent alkyl amine ligands on the nucleation and growth of platinum and silver nanoparticles is investigated. Here, for the first time mono- and multivalent amine ligands are used to control the formation of platinum and silver nanoparticles using platinum (II) acetylacetonate and silver (II) acetylacetonate as precursors, respectively. Platinum and silver nanoparticles are prepared by one-step processes at 200 °C and 120 °C, respectively, in order to investigate the influence of the amine ligands on the formation of nanoparticles. Additionally, procedures are applied, where the reaction temperature is stepwise increased between 160 and 200 °C in the case of platinum and between 80 and 120 °C for silver. The multivalency effects of the ligands on the formation of platinum particles are investigated by using TEM measurements. The platinum particles prepared at 200 °C in the presence of monovalent ligands are rather polydisperse and have a non-spherical shape, whereas the di- and trivalent ligands cause the growth of monodisperse and spherical particles. In contrast, platinum particles prepared by stepwise increasing the temperature have a spherical shape independent on the ligand multivalency and the reaction temperature. The influence of the ligand’s multivalency on the formation, growth, and stability of silver particles is investigated by TEM and UV-Vis measurements. The size distributions of the silver particles prepared by a one-step process are wider than those of the particles prepared by a stepwise process. This is because faster nucleation and growth processes take place and as a consequence, nucleation and growth are not well separated if the particles are prepared by a one-step process at high temperature instead of a stepwise process at lower temperatures.In dieser Arbeit werden die Wechselwirkungen zwischen mono- und multivalenten Thiol- und Amin-Liganden und Edelmetall-Nanopartikeln untersucht. Charakteristisch für die multivalenten Wechselwirkungen ist die zeitgleiche Bindung multivalenter Liganden einer Spezies an multivalente Rezeptoren einer anderen Spezies. Dabei ist die Bindungsenergie der multivalenten Bindung größer, als die Summe der einzelnen, monovalenten Bindungen. Die Untersuchung des Multivalenzeffektes erfolgt mittels verschiedener physikalisch-chemischer Techniken mit dem Ziel, das grundlegende Verständnis der Wechselwirkungen zwischen multivalenten Liganden und Nanopartikeln zu verbessern. Die Ergebnisse dieser Arbeiten sind in vier Teilen zusammengefasst. Im ersten Teil werden der Einfluss der Multivalenz der Liganden sowie der Größe der Nanopartikel auf die Bindungskinetik von Thiol-Liganden auf Goldnanopartikel anhand des Austausches von monovalent gebundenen Pyren-Thiol-Liganden gegen flexible mono- und multivalente Alkyl-Thiol-Liganden untersucht. Dazu werden Gold-Nanopartikel mit einem Druchmesser von 2.2±0.4 nm, 3.2±0.7 nm und 4.4±0.9 nm als Substrat verwendet. Die Pyren-Thiol-Liganden dienen als fluoreszierende Sonden und zur Stabilisierung der Goldnanopartikel vor dem Ligandenaustausch. Die Auswirkungen der Multivalenz der Liganden und der Partikelgröße werden durch den Vergleich der Geschwindigkeitskonstanten der Liganden-Austausch- Reaktionen ermittelt. Um diese besser beurteilen zu können, wurden die erhaltenen Ergebnisse mit verschiedenen Modellen angepasst. Es stellte sich heraus, dass sich die Daten aus den Kinetik-Versuchen mit einer biexponentiellen Funktion und einem Langmuir-Diffusions-Modell zweiter Ordnung grundsätzlich annähnern lassen. Zur Anwendung kam jedoch ausschließlich das biexponentielle Modell, da dieses die ablaufenden Prozesse korrekt beschreibt. Systematische Untersuchungen zeigen eine deutliche Erhöhung der Reaktionsgeschwindigkeit di- und trivalenter Liganden im Vergleich zu den monovalenten Liganden. Dies ist auf einen deutlichen Multivalenzeffekt zurückzuführen. Im Gegensatz dazu ist die Austauschgeschwindigkeit der trivalenten Liganden ähnlich oder gar niedriger als die der divalenten Liganden. Dies wird durch die sterische Hinderung der sterisch anspruchsvollen trivalenten Liganden erklärt. Darüber hinaus wird beobachtet, dass die Geschwindigkeitskonstanten mit zunehmender Teilchengröße steigen. Die erhaltenen Resultate werden dazu genutzt, Informationen über die Struktur der Bindung der mono- und multivalenten Liganden an die Nanopartikel-Oberfläche abzuleiten. Darüber hinaus hat sich gezeigt, dass Gold-Partikel mit einem Durchmesser von mehr als 4 nm während des Ligandenaustausches aggregieren. Dies ist wahrscheinlich auf die unzureichende sterische Stabilisierung durch die Alkyl-Thiol-Liganden zurückzuführen. Im zweiten Teil wird die Bindung von starren, aromatischen Thiolen an Goldnanopartikel mit einem Durchmesser von 2.2±0.4 nm, 3.2±0.7 nm und 4.4±0.9 nm untersucht. Die an die Partikel gebundenen Pyren-Thiol-Liganden werden gegen 4-Toluolthiol und 3,4-Toluoldithiol substituiert. Während des Ligandenaustausches aggregieren die Teilchen unmittelbar nach der Zugabe der aromatischen Thiole. Dies ist möglicherweis auf eine unzulängliche sterische Stabilisierung der Goldpartikel durch die starren, aromatischen Thiol-Liganden zurückzuführen. Es wird deutlich, dass die flexiblen Alkyl-Thiol-Liganden im Vergleich zu den starren, aromatischen Thiolen eine stärkere Stabilisierung der Goldnanopartikel gewährleisten. Im dritten Abschnitt wird die Bindung von mono- und multivalenten Alkyl-Thiol-Liganden an Silber-Nanopartikel mit 4.6±2.0 nm Durchmesser untersucht, wobei die gleichen Liganden, die auch in den Versuchen mit den Gold-Nanopartikeln genutzt wurden, zum Einsatz kommen. Durch Pyren- Thiol-Liganden stabilisierte Silberpartikel werden synthetisiert und anschließend die Pyren-Liganden gegen mono- und multivalente Alkyl-Thiol- Liganden substituiert. Im Zuge dieses Austauschprozesses fallen die Partikel teilweise aus, was eine Folge ausgeprägter Aggregationsprozesse ist. Die erhaltenen Ergebnisse zu Silber-Nanopartikeln werden mit den Ergebnissen zum Ligandenaustausch von Pyren-Thiol-Liganden gegen mono- und multivalente Alkyl- Thiol-Liganden an Gold-Nanopartikel gleicher Größe verglichen. Die Austauschgeschwindigkeit von Pyren-Thiolen gegen di- und trivalente Liganden liegen im Fall von Gold- wie Silber-Nanopartikeln in derselben Größenordnung. Im Fall der monovalenten Liganden scheint die Austauschgeschwindigkeit der Liganden, die an Silberpartikel gebunden sind, höher zu sein als für Goldnanopartikel. Im letzten Teil dieser Arbeit wird der Einfluss von mono-, di- und trivalenten Alkyl-Amin-Liganden auf die Nukleation und das Wachstum von Platin- und Silber-Nanopartikel untersucht. Zum ersten Mal wurden mono- und multivalente Amin-Liganden verwendet, um die Bildung der Platin- und Silber-Nanopartikel aus den Vorstufen Platin(II)acetylacetonat bzw. Silber(II)acetylacetonat zu steuern. Um den Einfluss der Amin-Liganden auf die Partikelbildung zu untersuchen, werden Platin- und Silber-Nanopartikel zum einen durch ein einstufiges Verfahren bei 200 °C für Platin beziehungsweise 120 °C für Silber dargestellt. Zum anderen erfolgt die Synthese der Partikel durch ein Verfahren, bei dem die Reaktionstemperatur schrittweise zwischen 160 und 200 °C im Fall von Platin bzw. 80 und 120 °C im Fall von Silber erhöht wird. Die Auswirkungen des Multivalenz-Effektes der Liganden auf die Bildung von Platinpartikel wird vor allem durch TEM-Experimente untersucht. Die bei 200 °C in Gegenwart monovalenter Liganden dargestellten Platin-Nanopartikel weisen eine nicht-sphärische Form auf, wohingegen die mittels di- und trivalenten Liganden synthetisierten Partikel sphärisch sind. Im Gegensatz dazu führt die Synthesemethode mit einem schrittweisen Anstieg der Temperatur zu sphärischen Partikeln, unabhängig von der Wahl des Liganden. Der Einfluss der Valenz der Liganden auf die Bildung, das Wachstum und die Stabilität der Silber-Partikel wird mittels dem TEM- und UV-Vis-Messungen untersucht. Die Größenverteilung der Silberpartikel aus dem einstufigen Syntheseprozess ist breiter als die der Teilchen, die durch ein stufenweises Verfahren hergestellt worden sind. Der Grund hierfür liegt in den schnelleren Nukleations- und Wachstumsprozessen im Fall des einstufigen Prozesses bei hohen Temperaturen, die keine deutliche Trennung von Nukleation und Wachstum zulassen

Polymer Nanoparticles: Synthesis and Applications

Polymer nanoparticles (PNPs) are generally formed by the spontaneous self-assembly of polymers that vary size from 1 to 1000 nm [...

Controlled Synthesis of Platinum and Silver Nanoparticles Using Multivalent Ligands

Here, the controlled formation of platinum nanoparticles (PtNPs) and silver nanoparticles (AgNPs) using amine-functionalized multivalent ligands are reported. The effects of reaction temperature and ligand multivalency on the growth kinetics, size, and shape of PtNPs and AgNPs were systematically studied by performing a stepwise and a one-step process. PtNPs and AgNPs were prepared in the presence of amine ligands using platinum (II) acetylacetonate and silver (I) acetylacetonate, respectively. The effects of ligands and temperature on the formation of PtNPs were studied using a transmission electron microscope (TEM). For the characterization of AgNPs, additionally, ultraviolet-visible (UV-Vis) absorption was employed. The TEM measurements revealed that PtNPs prepared at different temperatures (160–200 °C, in a stepwise process) are monodispersed and of spherical shape regardless of the ligand multivalency or reaction temperature. In the preparation of PtNPs by the one-step process, ligands affect the shape of the PtNPs, which can be explained by the affinity of the ligands. The TEM and UV-Vis absorption studies on the formation of AgNPs with mono-, di-, and trivalent ligands showed narrower size distributions, while increasing the temperature from 80 °C to 120 °C and with a trivalent ligand in a one-step process

Novel cyclic tetraselenides of mannose: synthesis and mechanistic studies

In this Letter, we disclose the synthesis of novel cyclic tetraselenides starting from mannose which are very unusual and rare and have been synthesised for the first time. The structures are confirmed by X-ray analysis. The reactivity of the reagent tetraethylammonium tetraselenotungstate, $(Et_4N)_2WSe_4$ has been compared with the well-known selenium transfer reagents $Li_2Se_2$ and $Na_2Se_2$. A tentative reaction mechanism has been proposed

Synthesis of Water-Dispersed Sulfobetaine Methacrylate–Iron Oxide Nanoparticle-Coated Graphene Composite by Free Radical Polymerization

Research on the synthesis of water-soluble polymers has accelerated in recent years, as they are employed in many bio-applications. Herein, the synthesis of poly[2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (PSB) by free radical polymerization in a sonication bath is described. PSB and iron oxide nanoparticles (IONPs) were simultaneously stabilized on the graphene surface. Graphene surfaces with PSB (GPSB) and graphene surfaces with PSB and IONPs (GPSBI) were prepared. Since PSB is a water-soluble polymer, the hydrophobic nature of graphene surfaces converts to hydrophilic nature. Subsequently, the prepared graphene composites, GPSB and GPSBI, were well-dispersed in water. The preparation of GPSB and GPSBI was confirmed by X-ray diffraction, Raman spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. The impacts of PSB and IONPs on the graphene surfaces were studied systematically

Amphiphilic Fluorinated Block Copolymer Synthesized by RAFT Polymerization for Graphene Dispersions

Despite the superior properties of graphene, the strong π–π interactions among pristine graphenes yielding massive aggregation impede industrial applications. For non-covalent functionalization of highly-ordered pyrolytic graphite (HOPG), poly(2,2,2-trifluoroethyl methacrylate)-block-poly(4-vinyl pyridine) (PTFEMA-b-PVP) block copolymers were prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization and used as polymeric dispersants in liquid phase exfoliation assisted by ultrasonication. The HOPG graphene concentrations were found to be 0.260–0.385 mg/mL in methanolic graphene dispersions stabilized with 10 wt % (relative to HOPG) PTFEMA-b-PVP block copolymers after one week. Raman and atomic force microscopy (AFM) analyses revealed that HOPG could not be completely exfoliated during the sonication. However, on-line turbidity results confirmed that the dispersion stability of HOPG in the presence of the block copolymer lasted for one week and that longer PTFEMA and PVP blocks led to better graphene dispersibility. Force–distance (F–d) analyses of AFM showed that PVP block is a good graphene-philic block while PTFEMA is methanol-philic

Controlled Synthesis of Platinum and Silver Nanoparticles Using Multivalent Ligands

Here, the controlled formation of platinum nanoparticles (PtNPs) and silver nanoparticles (AgNPs) using amine-functionalized multivalent ligands are reported. The effects of reaction temperature and ligand multivalency on the growth kinetics, size, and shape of PtNPs and AgNPs were systematically studied by performing a stepwise and a one-step process. PtNPs and AgNPs were prepared in the presence of amine ligands using platinum (II) acetylacetonate and silver (I) acetylacetonate, respectively. The effects of ligands and temperature on the formation of PtNPs were studied using a transmission electron microscope (TEM). For the characterization of AgNPs, additionally, ultraviolet-visible (UV-Vis) absorption was employed. The TEM measurements revealed that PtNPs prepared at different temperatures (160–200 °C, in a stepwise process) are monodispersed and of spherical shape regardless of the ligand multivalency or reaction temperature. In the preparation of PtNPs by the one-step process, ligands affect the shape of the PtNPs, which can be explained by the affinity of the ligands. The TEM and UV-Vis absorption studies on the formation of AgNPs with mono-, di-, and trivalent ligands showed narrower size distributions, while increasing the temperature from 80 °C to 120 °C and with a trivalent ligand in a one-step process