Fenton-Like Oxidation of 4−Chlorophenol: Homogeneous or Heterogeneous?

Heterogeneous Fenton-like catalysts have received considerable research attention because they could potentially be attractive for oxidative removal of organic contaminants from tertiary wastewater. However, process design is still hampered by insufficient understanding of the chemical pathways involved, and especially whether oxidation activity stems from heterogeneous surface chemistry or minute concentrations of dissolved metal ions in the homogeneous phase. Using inductively coupled plasma-optical emission spectroscopy (ICP-OES) in combination with pH monitoring and ultraviolet–visible spectroscopy (UV–vis) we have monitored the degradation of 4-chlorophenol (4-CP) over two Fenton-like heterogeneous systems, namely FeOx supported on TiO2 and CuFe2O4. We show conclusively that these systems proceed predominantly through a homogeneous route via dissolved metal ions from the solid phase catalysts. Control experiments with homogeneous Fe3+ or Cu2+ systems reveal that even minute concentrations (μM/subppm) of dissolved metal ions leached from the solid phases account for the observed 4-CP degradation rates in the heterogeneous systems. ICP-OES revealed that metal leaching was time-dependent and variable because of pH variations associated with changing acid release rates. Buffering solutions at pH 7.4 suppressed metal leaching (and hence 4-CP degradation) in the FeOx/TiO2 system, but not in others. For example, pH buffering did not entirely suppress metal leaching from CuFe2O4, for which 4-CP degradation was retained through small concentrations of Fe and Cu ions in solution. Our results highlight the importance of careful monitoring of metal content in the aqueous phase, certainly with analytical sensitivity below ppm concentrations of the dissolved metals, and also the crucial influence of time-dependent pH variations on the reaction process. Recyclability of catalysts, pH buffering of solutions or monitoring of metal content in the solid phase by less sensitive analytical methods, for example, chemical analysis, gravimetry, X-ray fluorescence, or energy dispersive X-ray analysis in electron microscopes, cannot exclude the homogeneous Fenton route in the presence of solid catalysts

Electrochemical Insight into the Brust-Schiffrin Synthesis of Au Nanoparticles

The mechanism of the Brust–Schiffrin gold nanoparticle synthesis has been investigated through the use of ion transfer voltammetry at the water/1,2-dichloroethane (DCE) solution interface, combined with X-ray absorption fine structure (XAFS) of the reaction between [AuCl4]− and thiol (RSH) in homogeneous toluene (TL) solution. Ion transfer calculations indicate the formation of [AuCl2]− at RSH/Au ratios from 0.2–2 with a time-dependent variation observed over several days. At RSH/Au ratios above 2 and after time periods greater than 24 h, the formation of Au(I)SR is also observed. The relative concentrations of reaction products observed at the liquid/liquid interface are in excellent agreement with those observed by XAFS for the corresponding reaction in a single homogeneous phase. BH4– ion transfer reactions between water and DCE indicate that the reduction of [AuCl4]− or [AuCl2]− to Au nanoparticles by BH4– proceeds in the bulk organic phase. On the other hand, BH4– was unable to reduce the insoluble [Au(I)SR]n species to Au nanoparticles. The number and size of the nanoparticles formed was dependent on the concentration ratio of RSH/Au, as well as the experimental duration because of the competing formation of the [Au(I)SR]n precipitate. Higher concentrations of nanoparticles, with diameters of 1.0–1.5 nm, were formed at RSH/Au ratios from 1 to 2

Redox and Ligand Exchange during the Reaction of Tetrachloroaurate with Hexacyanoferrate(II) at a Liquid-Liquid Interface: Voltammetry and X-ray Absorption Fine-Structure Studies

AbstractVoltammetry for charge (ion and electron) transfer at two immiscible electrolyte solutions (VCTIES) has been used to provide insight into the ligand exchange and redox processes taking place during the interfacial reaction of aqueous hexacyanoferrate(II) with tetrachloroaurate ([AuCl4]−) in 1,2-dichloroethane (DCE). VCTIES permitted the detection of the reactants, intermediates and products at the liquid/liquid interface. A model for the sequence of interfacial processes was established with the support of speciation analysis of the key elementary reactions by X-ray absorption spectroscopy (XAS). The potential-driven transfer of [AuCl4]− from the organic into the aqueous phase is followed by reduction and ligand exchange by the aqueous hexacyanoferrate(II) to form dicyanoaurate ([Au(CN)2]−). Inferences from the reactions point to the likely formation of [AuCl2]− during the reduction sequence. The reaction is influenced by ligand exchange equilibria between [AuCl4]−, [AuCl3(OH)]– and [AuCl2(OH)2]– which are shown to be dependent on the chloride ion concentration and pH of the solution. The difference between the Gibbs energy of transfer at the water | DCE interface (ΔGDCEW°)of AuCl4– and [AuCl3(OH)]–, and the difference between [AuCl3(OH)]– and [AuCl2(OH)2]– were found to change by a value close to the difference between ΔGDCEW° of Cl– and that of OH–. The intermediate Au(I) species, [AuCl2]−, was seen to decompose at neutral pH and in the absence of Cl– in water to form metallic Au, although it was stable in >10mM HCl for an hour. Time-dependent VCTIES and X-ray absorption fine structure (XAFS) speciation analysis of the homogeneous aqueous phase indicate that reaction between [AuCl4]− and hexacyanoferrate(II) is accompanied by the formation of an intermediate ionic species, formed when the concentration of [AuCl4]− is close to that of hexacyanoferrate(II). This species, whose identity was not precisely determined, was also generated by reaction between [AuCl2]− and hexacyanoferrate(III). The species is shown by VCTIES to be more hydrophilic than [Au(CN)2]−, [AuCl2]− and [AuCl4]−

Earnings management and stock market reaction : evidence from restating firms.

This paper examines the capital market consequences of the announcement of earnings restatement by US firms. The study involves firms who announced the restatement of their earnings from the period of 1996-2001

Preparing for the worst while hoping for the best: The relevance of hope in the heart failure illness trajectory

BACKGROUND: Patients with heart failure have higher mortality rates than those with most malignant diseases. The heart failure illness trajectory is one of gradual decline characterized by unpredictable events such as acute decompensation of heart failure or a sudden cardiac death. Health professionals have an obligation to give patients and their families concise and honest information concerning their prognosis. The challenge exists to give what ostensibly may seem a bleak prognosis within a context of hope and optimism. AIM: To explore the role of hope in heart disease and the potential utility of this construct in the development of nursing interventions. METHODS: The electronic databases CINAHL, MEDLINE, EmBASE, and PSYCHlit were searched from 1982 to August 2004 using the key words "hope," "hopelessness, " "heart disease," and "heart failure." Articles were subsequently sorted to meet the inclusion criteria of (1) a philosophical discussion of the construct of hope and/or (2) investigation of hope in heart disease. RESULTS: This search retrieved 768 articles, and 24 met the inclusion criteria. Key findings from the review indicate that "hope" and "hopelessness" are underdeveloped, yet important constructs and conceptually linked with depression and spirituality. Intriguing findings from descriptive, observational studies have demonstrated the positive impact of expression of hope on cardiovascular outcomes. These findings need to be validated in randomized controlled trials. CONCLUSIONS: This critical literature review has determined that "hope" is strongly associated with the individual's future orientation. Increased understanding of this concept may assist in refining patient-focused interventions and developing therapeutic strategies to enhance hope. © 2007 Lippincott Williams & Wilkins, Inc

Robust and Simple Non-Reflecting Boundary Conditions for the Euler Equations: A New Approach Based on the Space-Time CE/SE Method

This paper reports on a significant advance in the area of non-reflecting boundary conditions (NRBCs) for unsteady flow computations. As a part of the development of the space-time conservation element and solution element (CE/SE) method, sets of NRBCs for 1D Euler problems are developed without using any characteristics-based techniques. These conditions are much simpler than those commonly reported in the literature, yet so robust that they are applicable to subsonic, transonic and supersonic flows even in the presence of discontinuities. In addition, the straightforward multidimensional extensions of the present 1D NRBCs have been shown numerically to be equally simple and robust. The paper details the theoretical underpinning of these NRBCs, and explains their unique robustness and accuracy in terms of the conservation of space-time fluxes. Some numerical results for an extended Sod's shock-tube problem, illustrating the effectiveness of the present NRBCs are included, together with an associated simple Fortran computer program. As a preliminary to the present development, a review of the basic CE/SE schemes is also included

Potilasturvallisuuskulttuuri terveyskeskuksissa : Kaarina, Loimaa ja Pöytyä

Tämän opinnäytetyön aiheena on potilasturvallisuuskulttuuri. Hyvässä turvallisuuskulttuurissa on kysymys siitä, että organisaation jäsenten keskuudessa turvallisuudesta välitetään aidosti, toimintaan liittyviä vaaroja pyritään aktiivisesti ymmärtämään ja ennakoimaan sekä turvallisuus ymmärretään kokonaisvaltaisesti organisaation systeemiseksi ominaisuudeksi. Turvallisuuden kehittämisessä on tärkeää vaikutusmahdollisuuden ja vastuun kokeminen sekä perustyön hal-linta. Hyvä potilasturvallisuuskulttuuri edistää hoidon laatua. Opinnäytetyön tarkoituksena oli kuvata Kaarinan terveyskeskuksen, Loimaan sosiaali- ja terveyspalvelukeskuksen ja Pöytyän kansanterveystyön kuntayhtymän henkilökuntien asennetta ja suhtautumista potilasturvallisuuskulttuuriin sekä niihin yhteydessä olevia tekijöitä. Opinnäytetyö toteutettiin osana Potilasturvallisuudella laatua hanketta (Potu), joka oli Turun ammattikorkeakoulun Terveysala-tulosalueen sekä Kaarinan terveyskeskuksen, Loimaan sosiaali- ja terveyspalvelukeskuksen ja Pöytyän kansanterveystyön kuntayhtymän välinen yhteistyöhanke. Tavoitteena on lisätä terveyskeskusten henkilökunnan potilasturvallisuusosaamista sekä väestön tietoisuutta potilasturvallisuuteen liittyvistä asioista ja potilas-turvallisuuskulttuurin kehittäminen kyseisissä terveyskeskuksissa. Kyselyssä käytettiin VTT:n (Valtion tekninen tutkimuslaitos) TUKU mittaria, jota on kehitetty vuodesta 2008 lähtien. Mittarissa potilasturvallisuuskulttuuria tarkastellaan sekä organisatorisen että psykologisen ulottuvuuden avulla. Vastausprosentiksi muodostui 27 % (n=262). Tulosten analysointiin käytettiin tilastollisia menetelmiä. Tulosten perusteella Kaarinan, Loimaan ja Pöytyän henkilöstö suhtautuu yleisesti potilas-turvallisuuskulttuuriin positiivisesti. Tuloksissa korostuivat psykologisen ulottuvuuden osalta henkilökunnan turvallisuusmotivaatio ja vastuuntunto. Organisatorisen ulottuvuuden osalta osaamisen hallinta ja työn edellytysten hallinta arvioitiin positiivisimmin. Läheltäpiti/haittatapahtumat, potilaskontaktin luonne ja esimiesasema olivat merkitsevästi yhteydessä organisatoriseen ulottuvuuteen. Potilaskontaktin luonne ja läheltäpiti/haittatapahtumassa mukana olivat puolestaan yhteydessä psykologiseen ulottuvuuteen. Opinnäytetyön tuloksia voidaan hyödyntää potilasturvallisuuskulttuurin edistämisessä ja haittatapahtumien vähenemisessä. Organisatorisen ulottuvuuden osalta muutosten hallintaa tulisi tulevaisuudessa kehittää, ja psykologisen ulottuvuuden osalta henkilökunnan hallinnan tunnetta tulisi edistää.The subject of the thesis is patient safety culture. A good safety culture is a question that is related to fact that the members of the organization truly value the safety, to the hazards related to the activity will be actively understood and anticipated and that safety is understood as an overall systemic element of the organization. In the development of safety it is important to have a sense of being able to influence and to have responsibility and the management of basic work. Good patient safety culture promotes quality of care. The thesis intends to describe staff attitudes and approach towards patient safety culture and factors related to these at Kaarina, Loimaa and Pöytyä health centers. The thesis was carried out as part of the Quality with Patient Safety project (Potu), which is joint project of the Turku University of Applied Sciences (health sector financial unit) and the Health Center of Kaarina, the Social and Health Center of Loimaa and the Municipality Union of the Public Health Work of Pöytyä. The aim is to increase the skills of the health center staff related to patient safety, as well as the awareness of public about the patient safety culture and about the development of patient safety culture in the health centers in question. The query was implemented with the help of the TUKU measurement tool developed by the VTT (Technical Research Centre of Finland) since 2008. In this measurement tool the patient safety culture is reviewed both as an organizational and as a psychological indicator. The answer percentage was 27% (n = 262). The analysis of the results was based on statistical methods. In light of the results, the staff in Kaarina, Loimaa and Pöytyä takes a generally a positive attitude on patient safety culture. The results underlined the psychological dimension of the safety motivation and of the sense of responsibility. As regards the organizational dimension, the management of knowhow and the prerequisites of work were estimated most positively. Close-by/adverse events, nature of patient contact and managerial status were significantly associated with the organizational dimension. The nature of the patient contact and being involved in close-by/adverse events were in turn linked to the psychological dimension. The results of the thesis can be exploited in promoting patient safety culture and in the reduction of adverse events. With respect to the organizational dimension the management of changes should be developed in the future, and with respect of the psychological dimension a sense of management by the staff should be promote

High-Resolution Genuinely Multidimensional Solution of Conservation Laws by the Space-Time Conservation Element and Solution Element Method

In this overview paper, we review the basic principles of the method of space-time conservation element and solution element for solving the conservation laws in one and two spatial dimensions. The present method is developed on the basis of local and global flux conservation in a space-time domain, in which space and time are treated in a unified manner. In contrast to the modern upwind schemes, the approach here does not use the Riemann solver and the reconstruction procedure as the building blocks. The drawbacks of the upwind approach, such as the difficulty of rationally extending the 1D scalar approach to systems of equations and particularly to multiple dimensions is here contrasted with the uniformity and ease of generalization of the Conservation Element and Solution Element (CE/SE) 1D scalar schemes to systems of equations and to multiple spatial dimensions. The assured compatibility with the simplest type of unstructured meshes, and the uniquely simple nonreflecting boundary conditions of the present method are also discussed. The present approach has yielded high-resolution shocks, rarefaction waves, acoustic waves, vortices, ZND detonation waves, and shock/acoustic waves/vortices interactions. Moreover, since no directional splitting is employed, numerical resolution of two-dimensional calculations is comparable to that of the one-dimensional calculations. Some sample applications displaying the strengths and broad applicability of the CE/SE method are reviewed

Production Improvement of Yam Variety Tainung No. 2

山藥台農2號於1996年命名，隨即於1997年推廣至14鄉鎮地區，推廣頗為迅速之因，與其兼具高產、質優且特性之表現甚為穩定有關。雖然台農2號之產量甚高且穩定，由1989至1992年在七地區之平均公頃產量達26.9 t/ha，但不同種植方式、栽培介質、施肥種類、種植期、生長期及行株距等因素，對其生產表現都有或多或少之影響。其中不同施肥種類、種植方式與栽培介質三因素之影響頗大，利用如甘藷般之種植方式栽培，配合化學肥料及少量牛糞肥，台農2號之平均公頃產量可達32.7 t/ha；利用50cm長度之半圓形塑膠穴管栽培台農2號，管內介質為牛糞肥：砂：田土=1:1:1時，其平均公頃產量為27.6 t/ha；若於半圓形塑膠穴管內，先換填蔗渣：牛糞肥=2:1之特定介質，再栽培台農2號，則其平均公頃產量可達41.3t/ha；若於半圓形塑膠穴管內，除了先填滿蔗渣：牛糞肥=2:l之介質外，穴管外之栽培田區另混施10 t/ha之牛糞肥，之後再栽培台農2號，則其平均公頃產量高達63.2 t/ha。在促成豐產之外，台農2號塊莖利用涼溫（17士1.50C）網袋貯藏方式，可以貯藏26週，此將有效解決台農2號之貯藏問題，延長塊莖之利用期限，並增加塊莖利用之可行性。 The yam variety Tainung No. 2 was registered and released for commercial production in 1996. Based on its high and stable yielding potential and high quality of tuber, it has been accepted and extended to 14 county areas throughout Taiwan in 1997. Although the mean tuber yield of Tainung No. 2 was relatively high and stable, a mean tuber yield of 26.9 t/ha had been obtained from 1989 to 1992 ,many factors such as year, location, elevation, fertilizer, planting date, growth duration, cultivating method and cultivating media, etc. could play a more or less important effect on its tuber yield. Experimental results showed that the mean tuber yield of Tainung No. 2 was 32.7 t/ha under normal cultivating method like sweet potato, when compared with a yield of 27.6 t/ha under cultivating with half plastic pipe, which was 50cm in length and was filled with mixed media of soil, sand, and cattle manure with a ratio of 1:1:1. But a yield of 41.3 t/ha was recorded, when the media in the half plastic pipe were changed by sugar-cane waste and cattle manure with a ratio of 2:1. In contrast with the yield obtained from the former cultivating method with half plastic pipe and mixed media of sugar-cane waste and cattle manure, a yield of 63.2 t/ha could be reached, when the plot soil was mixed with 10 t/ha of cattle manure before planting of Tainung No. 2. Besides higher tuber production of Tainung No. 2 had been achieved, a lengthening period for 26 weeks was obtained by storing tubers of Tainung No. 2 at 17±1.5℃, which can be very useful for tuber further usage purpose