Vertical profile of polycyclic aromatic hydrocarbons in the core sediment found in Langkawi, Kedah

Aim: To determine the concentration of PAHs by layers in each core sediment around one of Malaysia's tourism-oriented areas and to distinguish and classify the origin of PAHs in core sediments using index of molecular ratios. Methodology: The individual compounds and sources of polycyclic aromatic hydrocarbon (PAHs) were studied in 72 cm and 54 cm long sediment core, each that were taken in the Kuah Jetty and a rural area between Tanjung Ayer and Tanjung Batu Kulat of Langkawi Island. A total of 12 PAHs were determined and quantified by gas chromatography coupled with mass spectrometry (GC-MS). Results: Kuah Jetty, Langkawi's total PAH concentrations of sediment core layers ranged from 45.82 ng g-1 to 252.43 ng g-1. Furthermore, the total PAH concentrations of the sediment core layers from the rural area between Tanjung Ayer and Tanjung Batu Kulat ranged between 28.97 ng g-1 to 312.20 ng g-1. Interpretation: The potential application of a combination of molecular ratios and individual concentrations of PAH in determining the origin and source of pollution in sediments resulted in the determination of low to moderate pollution and indicated mixed sources of PAHs in the study area.

Synthesis of superabsorbent hydrogel based on starch copolymers and methods for their preparation

The aim of this work is to synthesize and study a superabsorbent hydrogel based on starch copolymers. The optimal synthesis conditions have been determined and studies have been carried out on the effect of the molar ratios of the starting materials on the water absorption of the synthesized hydrogel. In the course of research, the optimum copolymerization temperature was 60 °C, and the reaction time was 3 hours. As a result of the study, a hydrogel was synthesized with a starch: acrylamide: bentonite ratio of 10 : 9 : 0.8, respectively. The resulting hydrogel was investigated by IR spectroscopy and differential thermal analysis. The influence of the molecular ratios of starch and acrylamide, as well as the concentration of the initiator, binder and bentonite, affecting the degree of swelling of the synthesized hydrogel, has been studied

Copper Flash Smelting Process Balance Modeling

Process control in flash smelting is based on mass and energy balance from which the operational parameters (oxygen coefficient, oxygen enrichment, and flux demand) are obtained to achieve matte and slag with defined compositions and at defined temperatures. Mineral compositions of copper concentrates, and their blends, have been used in order to optimize the heat process balance. The classical balance methodology has been improved by using equations for molecular ratios and distribution coefficients that have been calculated using FactSage™. This paper describes the development of balance equations and compares their theoretical (equilibrium) results with industrial data logs of the smelting process.

Specifics of bulk chemical composition of virgin forest cambisols within the Ukrainian Carpathians

Material composition is one of the most vital components of soil analysis and it which allows to determine the bulk or elemental composition, to get an insight into the total content of chemical elements per the genetic horizons of a soil profile against the soilforming rock, and to identify the direction of soil formation processes, that is, to establish the genesis of soils. The study objective supposed both the identification of bulk chemical composition (BCC) specifics peculiar to cambisols (acc. the WRB) located beneath different virgin forest ecosystems and the change caused by the composition of soil-forming rock, specifics of mountainous terrain and climatic conditions. The study subject is cambisol of virgin (beech and coniferous) ecosystems formed at the eluvium-deluvium flysch with prevailing sandstones, argillites and siltstones. The study scope is bulk chemical composition of beech and coniferous forest cambisols within the Ukrainian Carpathians and its transformation. Comparative-geographical, comparative-profile, analytical and statistical methods have been used accounting for the above objective. The bulk chemical composition has been determined under the method devised by E.V. Arinushkina. Recalculations and ratios have been used to analyse data on the bulk chemical composition of soils. Our article provides the results of the study of bulk chemical composition of cambisols located beneath beech and the coniferous virgin forests. Changes occurred in this, one of the most conservative, soil substance, under the influence of phytocenotic diversity of virgin forest ecosystems and soil species, are analysed, the nature and direction of changes as well as their main regularities are identified. Molecular ratios for the genetic soil horizons are calculated since they testify the removal of elements outside the soil profile boundaries and are the main factor used to assess the direction of cambisols soil-forming process. The article considers the content of constitutional water and the ratio of change in the siliceous soil part. Results obtained allow suggesting intrinsic weathering in the soils under study. Major reasons of changes in the bulk chemical composition of virgin forest cambisols are caused by the character of vegetation, its aggressiveness with respect to the soil mineral content, by climatic features that affect processes of soil formation in mountainous areas depending on the vertical zonality, and by the composition of soil-forming rocks being the substrate for the studied soils. SiO2, Al2O3, Fe2O3 oxides form the predominant bulk chemical composition of virgin forest cambisols in the Ukrainian Carpathians. Their total content ranges from 65.59 to 87.56 %. The mineral base of virgin forest cambisols is SiO2 and its content in virgin forest cambisols amounts up to 63.46 - 75.03 %, Al2O3 sesquioxide content is 13.16 - 17.14 %, Fe2O3 content is 4.25 - 6.83 %. Molecular ratios in cambisols located beneath the beech virgin forests postulate the removal of sesquioxides out from a soil profile. For instance, the ratios of SiO2/Fe2O3 in beech virgin forests cambisols are 42.8 - 44.61 and they decrease sharply at the soil profile bottom to 26.35, i.e. the removal of Fe2O3 sesquioxide out from a soil profile is observed. The molar ratio of SiO2/R2O3 in cambisols located beneath coniferous virgin forests is narrower than in beech virgin forest cambisols and amounts up to 5.64 - 5.81, which is due to the lower content of SiO2 oxide and higher number of Fe2O3 and Al2O3 sesquioxides. The analysis of leach factor indices shows that leaching of Calcium and Magnesium oxides is observed in these soils. However, leaching in cambisols located beneath the beech virgin forests is less intense than in cambisols located beneath the coniferous virgin forests. Leaching of Sodium and Potassium oxides in cambisols located beneath the beech virgin forests is minor, and in cambisols located beneath the coniferous virgin forests is weakly expressed.

Il calcolo urinario. Proposta di un nuovo metodo di determinazione: dati preliminari

Introduzione: La visualizzazione soggettiva delle reazioni utilizzate per l’identificazione e la quantificazione delle sostanze presenti nel calcolo urinario presentano notevoli problemi. Metodi: Viene descritta una nuova procedura per la determinazione del calcolo urinario. La rilevazione dei carbonati e le concentrazioni di calcio, fosforo, magnesio, ammonio, acido urico (dosaggi quantitativi su analizzatore COBAS 6000 ditta Roche) ed ossalato e cistina (determinazioni adattate su Viva E ditta Siemens) si inseriscono in un foglio Excel per ottenere i possibili principali calcoli urinari (calcio ossalato, acido urico, urato di ammonio, cistina, struvite, brushite, apatite, carbonato apatite) e più in generale “calcio fosfato”. Le determinazioni di chimica clinica sono simili a quelle utilizzate effettuate per lo studio metabolico sulle urine delle 24h in cui il dosaggio fotometrico della cistina all’acido fosfotungstico, non essendo commercializzato, è stato costruito ed adattato su analizzatore Viva E. Particolarmente utile risulta l’uso del rapido metodo quantitativo al ferro-solfosalicilico, non commercializzato e costruito nel nostro laboratorio, per la determinazione dell’ossalato nel calcolo. Risultati: Il software proposto converte le concentrazioni degli analiti in mmoli/dL e, partendo dalla struvite, definisce successivamente l’eventuale presenza di calcio ossalato, urato di ammonio ed i diversi calcio fosfato, determinati a seconda del rapporto Ca/P. La conversione finale in concentrazione delle diverse componenti presenti nel calcolo, assieme ad un eventuale residuo inorganico, da la presentazione dei dati in percentuale. Conclusioni: I dati ottenuti, specie se riferiti a concrezioni formate da più componenti, evidenziano buoni risultati se confrontati con la tecnica di riferimento FTIR suggerendo una metodica di laboratorio pratica, rapida ed affidabile. A new laboratory procedure is described for the determination of urinary calculus. The detection of carbonates (production of carbon dioxide with the use of concentrated sulfuric acid) and the concentrations of calcium, phosphorus, magnesium, ammonium, uric acid (quantitative dosages carried out on COBAS 6000 analyzer of the Roche company) and oxalate and cystine (determinations adapted by us on the Siemens Viva E instrument) they are inserted in an Excel sheet created by us in order to obtain the main possible urinary calculations (calcium oxalate, uric acid, ammonium urate, cystine, struvite, brushite, apatite, carbonate apatite and more generally "calcium phosphate." The clinical chemistry determinations are similar to those used for the metabolic study carried out on the urine of 24 hours in which the photometric dosage of cystine with phosphotungstic acid, not being marketed, was built by us and adapted on Viva E analyzer. The use of the rapid quantitative method, with non-commercial sulfosalicylic acid, is particularly useful zato and then built in our laboratory, for the determination of oxalate in the calculation. The software proposed by us converts all the concentrations of the above mentioned analytes to mmoles / dL and, starting from struvite (molecular ratios: 1P - 1Mg - 1NH4), the possible presence of calcium oxalate is subsequently defined (molecular ratios: 1Ca - 1Ox ), that of ammonium urate and the different calcium phosphate (brushite, apatite / carbonate apatite and "calcium phosphate"), the latter determined according to the Ca / P ratio (brushite: <1.155; 1.155≥ "calcium phosphate" <1 , 45; apatite ≥1.45). The final conversion into concentration of the various components present in the calculation, together with any inorganic residue, determines the presentation of the data as a percentage. The data obtained, especially if referring to concretions formed by several components, show good results when compared with the FTIR reference technique.

The formation mechanism of hollow spherulites and molecular conformation of curcumin and solvate

In this study, curcumin 1,4-dioxane solvates (CUR–DIO) were obtained in two molecular ratios of 1 : 1.5 (CUR–DIO-1.5) and 1 : 1 (CUR–DIO-1) at different temperatures.

Astrochemistry in external galaxies: how to use molecules as probes of their physical conditions

It is now well established that chemistry in external galaxies is rich and complex. In this review I will explore whether one can use molecular emissions to determine their physical conditions. There are several considerations to bear in mind when using molecular emission, and in particular molecular ratios, to determine the densities, temperatures and energetics of a galaxy, which I will briefly summarise here. I will then present an example of a study that uses multiple chemical and radiative transfer analyses in order to tackle the too often neglected ‘degeneracies’ implicit in the interpretation of molecular ratios and show that only via such analyses combined with multi-species and multi-lines high spatial resolution data one can truly make molecules into powerful diagnostics of the evolution and distribution of molecular gas.