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The article compares the effectiveness of three washing methods in removing acid compounds from aged papers. The three washing methods include immersion washing, blotter washing and suction table washing with the aid of ultrasonic mist. In samples of thin and porous papers, it was found that immersion washing was the most effective followed by the suction table washing with the aid of ultrasonic mist. However, suction table washing was ineffective for the treatment of thick and dense papers while blotter washing showed the lowest effectiveness in removing organic acids particularly oxalic acid. It is noted that the suction table washing with ultrasonic mist uses the least amount of water.

Abstract: The influence of temperature on an ultrasound-assisted ink removal process has been investigated. White copy paper was evenly soaked in black writing ink. After drying the paper to constant weight at 75°C, ink removal was attempted under varying conditions. Results were assessed by monitoring the UV–vis absorbance of the aqueous phase and measuring the brightness of the paper. Sonication was observed to improve the brightness of the paper in the temperature range of 15–45°C with an optimum effect at 35°C. Monitoring UV–vis spectra of the aqueous phase provided evidence that modification of the chemical structure of the ink desorbed from the paper occured. Further investigation under the same conditions showed that ink, when not absorbed on paper, did not undergo the same chemical change. This supports the hypothesis that only the compound released from the ink absorbed onto the paper is sensitive to sonodegradation. One possible explanation is that the metal binding component of the ink stays absorbed on the paper, releasing the organic part, whose chemical structure can be altered by the effect of sonication. Inductively coupled plasma analysis was used to confirm that during the de-inking process of the paper, the metal binding component stays absorbed on the paper and only the organic part is released in the aqueous phase. [Copyright &y& Elsevier]

Abstract: Porous conducting carbon paper with its unique combination of properties acts as the backing material of electrode in a fuel cell. It not only assists in the flow of electrons and reactant gases but also acts as an effective support for the electrolyte and the catalyst layer. The electrically conducting porous carbon paper was prepared by adopting a modified process of preparation which involves molding together several carbon fiber preforms in the form of laminates rather than a single preform. The method was found to influence the characteristics of the paper significantly and resulted in improved performance of the unit fuel cell employing the laminated paper as electrode. The I–V performance of the fuel cell using carbon paper formed by molding single ply showed a peak power density of 573mW/cm2 as compared to that of 722mW/cm2 for three ply laminates, a value very close to that of achieved by using Toray (Japan) carbon paper (782mW/cm2) under identical operating conditions. [Copyright &y& Elsevier]

The editorial in the Journal of Mathematical Chemistry discusses the intersection of mathematics and chemistry, highlighting the importance of mathematical formalisms in predicting chemical properties. The recent surge in research in mathematical chemistry is attributed to advancements in molecular structure characterization, access to high-speed computers, and large databases of experimental data. The editorial also mentions the history and impact of the Indo-US Mathematical Chemistry Workshop series, which has become a significant forum for scientists in the field. The special issue of the journal includes 34 papers on original research, review articles, and studies on topics such as Density Functional Theory, graph theory, and Structure Activity Relationship. [Extracted from the article]

Microbial fuel cells (MFCs) can evolve in a viable technology if environmentally sound materials are developed and became available at low cost for these devices. This is especially important not only for the designing of large wastewater treatment systems, but also for the fabrication of low-cost, single-use devices. In this work we synthesized membranes by a simple procedure involving easily-biodegradable and economic materials such as poly (vinyl alcohol) (PVA), chitosan (CS) and the composite PVA:CS. Membranes were chemical and physically characterized and compared to Nafion®. Performance was studied using the membrane as separator in a typical H-Type MFCs showing that PVA:CS membrane outperform Nafion® 4 times (power production) while being 75 times more economic. We found that performance in MFC depends over interactions among several membrane characteristics such as oxygen permeability and ion conductivity. Moreover, we design a paper-based micro-scale MFC, which was used as a toxicity assay using 16 μL samples containing formaldehyde as a model toxicant. The PVA:CS membrane presented here can offer low environmental impact and become a very interesting option for point of need single-use analytical devices, especially in low-income countries where burning is used as disposal method, and toxic fluoride fumes (from Nafion®) can be released to the environment. [ABSTRACT FROM AUTHOR]

In this paper, Atomic Force Microscope (AFM) was used to observe the microscopic figure of aged insulation paper in order to analyze the microscopic ageing mechanism of power transformer insulation paper under electrical and thermal stresses. The results indicate that there are obvious concaves and convexes on the surface of aged insulation paper, and the paper samples are punctured because of chain scission and the flow of discharge current, which destroyed the compact cellulose chains structures and the diameter of punctures is about 0.5 nm. In addition, this paper analyzed the influence to the physical chemistry characteristics of insulation paper caused by partial discharge and paper ageing. [ABSTRACT FROM AUTHOR]

The low yield of indium tin oxide (ITO) thin-film deposition is an important factor in optoelectronic semiconductor production. An effective reclamation process was developed that uses ultrasonic electroetching and a designed bulge-form tool to remove the defective ITO nanostructure from the optical polyethyleneterephthalate (PET) surfaces of digital paper. In the current experiment, the assistance of ultrasonics was found to be more effective than pulsed current, requiring no increase in electric power. The large length of the bulge-form tool's cathode, with a small gap width between the cathode and the workpiece, requires less time to do the same amount of ITO etching. The small end radius of the cathode, combined with enough electric power, results in very fast etching. Additionally, electric power, when combined with a fast feed rate, provides highly effective etching. A higher rate of removal of the defective ITO nanostructure corresponds to high temperature, a large electrolyte flow rate, or a high rotational speed of the electrodes. Importantly, ultrasonic electroetching with the designed bulge-form tool requires only a short period of time to remove the ITO's thin-film coatings easily and cleanly. [ABSTRACT FROM AUTHOR]

Highlights: [•] Thermal analysis and kinetic data of microcrystalline cellulose are greatly affected by the concentration of the pulping reagent. [•] Concentration of the pulping medium also affects the physico-chemical properties of MCC. [•] At low concentration, higher yield of MCC was obtained from waste paper. [•] Morphology of the cellulose fibre was also affected by pulping concentration. [•] Moderate processing/isolation condition is vital for an improved grade of MCC to be obtained. [ABSTRACT FROM AUTHOR]

Paper–paraffin composites were prepared by an interfacial polymerisation reaction on the paper surface and its function of thermal energy storage was studied. Filter paper impregnated with O/W emulsion, which was composed of ethylenediamine, NaOH and paraffin microcapsules prepared by methyl methacrylate polymer (PMMA), was left in a beaker containing a cyclohexane solution of terephthaloyl chloride. The paraffin could fix on the treated paper surface and the encapsulation of the paraffin before the interfacial polymerisation reaction on the paper surface was effective in the preparation of paper with the function of heat storage. [ABSTRACT FROM AUTHOR]

This article describes a study to ascertain the reasons why certain old papers are still highly cited many years after their publication. Twenty-three old papers in the subject fields of physics and physical chemistry which are still highly cited were selected, and 978 of the papers that cited them in the period 1974-1975 were studied. A new typology of reasons for citing the papers was devised, and using this typology, it was found that about 40% of the citations were for historical reasons, but that in the remaining 60% of the cases, the old paper is still begin actively used. We discuss some discrepancies between our citation figures and citation figures quoted by Garfield. We also discuss a number of errors which were found, both in citing articles and in Science Citation Index. Finally, calculations indicate that there is a rule that each cited paper is referred to, on average, 1.05-1.15 times in every paper that cites it, and that this rule has general validity. [ABSTRACT FROM AUTHOR]

Loop-mediated isothermal amplification or LAMP has been identified to be an efficient technology for point-of-care diagnostics. Paper-based LAMP technique has tremendous potential in replacing the existing tube-based technology as the manufacturing cost of a paper-based device is comparatively lower and easy-to-use. LAMP-based paper diagnostic device for Mycobacterium tuberculosis (MTB) detection is of extreme importance as it will help in early and rapid diagnosis of the affected patients. The fabrication of these devices requires assessment of design parameters on the extent of LAMP amplification reaction. Hence, CFD studies would be extremely beneficial from the design perspective. The current work presents an insight into the CFD simulations for LAMP amplification reaction on a porous paper membrane (nitrocellulose membrane). The convection-diffusion-reaction model is solved on a COMSOL Multiphysics 5.0 platform. Studies on effect of pore size, aspect ratio and initial DNA concentration on the extent of DNA amplification reaction have been carried out. The current paper-based technique is effective in detecting a minimum of 5 copies of DNA contrasting the previous semi-quantitative technique which demonstrated the detection of minimum 98 copies. Overall, the simulation results displayed almost 96% enhancement in the DNA amplification rate on paper membrane. Graphical abstract Graphical abstract for the computational study of DNA amplification reaction via LAMP technique on a porous paper membrane. [ABSTRACT FROM AUTHOR]

Mg/Al-hydrotalcite (HDT)-dispersed paper-structured catalyst (PSC) was prepared by a simple paper-making process. The PSC exhibited excellent catalytic activity for the steam reforming of model biodiesel fuel (BDF), pure oleic acid methyl ester (oleic-FAME, C 19 H 36 O 2 ) which is a mono-unsaturated component of practical BDFs. The PSC exhibited fuel conversion comparable to a pelletized catalyst material, here, conventional Ni–zirconia cermet anode for solid oxide fuel cell (SOFC) with less than one-hundredth Ni weight. Performance of electrolyte-supported cell connected with the PSC was evaluated in the feed of oleic-FAME, and stable operation was achieved. After 60 h test, coking was not observed in both SOFC anode and PSC. [ABSTRACT FROM AUTHOR]

In 1964, Kenichi Fukui published a chapter in a book honoring the career of Robert S. Mulliken. While most of that chapter is a review of Fukui's previously published research dealing with frontier molecular orbital theory and organic reactions, one section provided a frontier molecular orbital explanation of the mechanism of the Diels‐Alder reaction. Fukui concluded that the "symmetry relation of wave functions of both dienes and dienophiles" control the course of this reaction. Thus, Fukui's paper was a precursor to Woodward and Hoffmann's 1965 papers that proposed orbital symmetry control of what would later be termed "pericyclic reactions." Fukui published numerous papers in the 1950s and 1960s, many of which were expositions of his research in theoretical chemistry. Eight of those Fukui papers were direct precursors to his breakthrough 1964 publication. This paper presents the intellectual and scientific path that Fukui took from the early 1950s to 1964 to his award‐winning publication. [ABSTRACT FROM AUTHOR]

Abstract: Since its invention, paper has become one of the main carriers of our cultural, scientific, political, economic and historical information. Given the importance of this material, its preservation is a matter of great interest. Paper can be deteriorated due to physical, chemical and biological agents. Within microorganisms, fungi are the major paper biodeteriogens. Throughout history, several methods have been used to prevent and stop fungal deterioration on paper based materials. In this work we present a review of the main chemical and physical methods used to avoid fungal paper biodeterioration until nowadays and also of some new approaches tested recently. The advantages and disadvantages of these methods are discussed as well as their health effects. Studies regarding antifungal compositions, methods of application, performance and effects on the treated materials are also presented with the aim of providing a clear set of conclusions on the topic. [Copyright &y& Elsevier]

This paper presents advantages and disadvantages of Raman spectroscopy when used for testing banknotes, i.e. in case study I, 1 and 5 dinars banknotes from a private collection dating from 1876 of numismatic value were analyzed, and in case study II, 1000 dinars banknote from circulation together with its counterfeit. In both cases banknotes were analyzed by using Raman spectrometer DXR Raman microscope at the Faculty of Physical Chemistry, with a laser of wave-length 780 nm at 12 mW of power. Specters were recorded under microscope using 50X lens in a range 1800-60 cm-1. Analyses from case study I on both specimens showed spectrum characteristic for fluorescence appearance, therefore intensive signal of fluorescence covered Raman signal. In case study II, it was established that Raman spectroscopy can reliably detect a counterfeit banknote. Research, comparisons and analyses regarding original and counterfeit 1000 dinars note were performed on red banknote surfaces. [ABSTRACT FROM AUTHOR]

Abstract: This paper deals with the calculation of various parameters such as dispersion, absorption and permittivity of synthetic insulation paper to see the effect of frequency and thermal aging to be used in various industrial applications. Firstly the calculations were made for a fresh sample and then for the samples, which were aged at three different times and temperatures. These calculations were done using the earlier reported data of capacitance and loss factor. The studies showed that with the increase in frequency the dispersion, absorption and permittivity of the samples decrease, however, with aging (increasing time and decreasing temperature) the values of dispersion, absorption and permittivity increase at any fixed frequency. [Copyright &y& Elsevier]

We report a novel surface enhanced Raman scattering (SERS) substrate platform based on a common filter paper adsorbed with plasmonic nanostructures that overcomes many of the challenges associated with existing SERS substrates. The paper-based design results in a substrate that combines all of the advantages of conventional rigid and planar SERS substrates in a dynamic flexible scaffolding format. In this paper, we discuss the fabrication, physical characterization, and SERS activity of our novel substrates using nonresonant analytes. The SERS substrate was found to be highly sensitive, robust, and amiable to several different environments and target analytes. It is also cost-efficient and demonstrates high sample collection efficiency and does not require complex fabrication methodologies. The paper substrate has high sensitivity (0.5nM trans-1,2-bis(4-pyridyl)ethene (BPE)) and excellent reproducibility (~15% relative standard deviation (RSD)). The paper substrates demonstrated here establish a novel platform for integrating SERS with already existing analytical techniques such as chromatography and microfluidics, imparting chemical specificity to these techniques. [ABSTRACT FROM AUTHOR]

Abstract: In this study, we developed a facile method for preparing a superhydrophobic paper surface using a multi-layer deposition of polydiallyldimethylammonium chloride (polyDADMAC) and silica particles, followed by a fluorination surface treatment with 1H,1H,2H,2H-perfluorooctyltriethoxysilane (POTS, CF3(CF2)5CH2CH2Si(OC2H5)3). The superhydrophobic wood fiber products prepared in this study have contact angles of water greater than 150° and sliding angles less than 5°. Besides their high water repelling property, the superhydrophobic paper products kept a high tensile strength at high relative humidity condition. The superhydrophobic paper products also showed high resistance to bacterial contamination. [Copyright &y& Elsevier]

Abstract: In this paper, we report the first observation of metal-enhanced fluorescence emission of fluorophores from paper substrates. The fluorescence intensity is ≈5- and ≈9-fold brighter from Rose Bengal (RB) and Pt(II) octaethylporphine (PtOEP), respectively, on silver colloid-deposited paper as compared to uncoated paper. In addition, a reduced lifetime of RB near to silver particles (0.77ns) was observed as compared to the non-silvered control sample (0.86ns). An equivalent photostability of RB on Ag colloid-deposited paper and uncoated paper was also observed. Our findings are potentially helpful in applications to high-throughput surface analysis and as the basis of an anti-counterfeiting technology. [Copyright &y& Elsevier]

Abstract: The role of bonding in the pre-failure tensile creep behavior of paper was analyzed using handsheets with a range of bonding levels produced through manipulation of relative bonded area and specific bond strength. This was done by varying the level of wet pressing (to change relative bonded area) and using debonding and bonding agents (to change specific bond strength). Once manufactured, sheets underwent an extensive battery of creep testing. Creep testing was conducted under constant humidity and cyclic humidity (accelerated creep) conditions. Microscopic analysis techniques were also employed to visually study bonded area loss from creep strain. Overall, the results from this study show that the role of bonding in tensile creep behavior (and accelerated creep behavior) is no different than its role in stress–strain behavior. The findings show that bonding influences tensile creep behavior by altering sheet efficiency and how effectively stress is distributed within the structure, bonded area loss is a strain-induced phenomenon and bonding is not the cause of accelerated creep behavior. [Copyright &y& Elsevier]

A study on oxygen-plasma treatment of ink-jet paper is presented. Paper was exposed to a weakly ionized, highly dissociated oxygen plasma with an electron temperature of 5?eV, a positive-ion density of 8 × 1015?m?3and a density of neutral oxygen atoms of 5 × 1021?m?3. Optical emission spectroscopy (OES) was applied as a method for detection of the reaction products during the plasma treatment of the paper. OES spectra between 250 and 1000?nm were measured continuously during the plasma treatment. The wettability of the samples before and after the plasma treatment was determined by measuring the contact angle of a water drop. The appearance of the surface-functional groups was determined by using high-resolution x-ray photoelectron spectroscopy (XPS), while changes in the surface morphology were monitored with scanning electron microscopy (SEM). Already after 1?s of the plasma treatment the surface, which was originally hydrophobic, changed to hydrophilic, as indicated by a high absorption rate of a water drop into the paper. The OES showed a rapid increase of the CO and OH bands for the first few seconds of the plasma treatment, followed by a slow decrease during the next 40?s. The intensity of the O atom line showed reversed behaviour. The XPS analyses showed a gradual increase of oxygen-rich functional groups on the surface, while SEM analyses did not show significant modification of the morphology during the first 10?s of the plasma treatment. The results were explained by degradation of the alkyl ketene dimer sizing agent during the first few seconds of the oxygen-plasma treatment. [ABSTRACT FROM AUTHOR]

Abstract: Dr. E. Storms has published a Letter [E. Storms, Comment on papers by K. Shanahan that propose to explain anomalous heat generated by cold fusion, Thermochim. Acta, 2006] in which he argues that in a sequence of recent papers, the apparent excess heat signal claimed by Dr. Shanahan to arise from a calibration constant shift is actually true excess heat. In particular he proposes that the mechanisms proposed that foster the proposed calibration constant shifts cannot occur as postulated for several reasons. As well, he proposes Shanahan has ignored the extant data proving this. Because this Letter may lend unwarranted support to acceptance of cold fusion claims, these erroneous arguments used by Storms need to be answered. [Copyright &y& Elsevier]

Abstract: Magnetic paper lumen via loading process was prepared from never-dried and dried kraft kenaf pulp. PEI was used as retention aid during the inter-stage treatment. The paper produced from the magnetic pulp showed an increase of magnetic properties as the loading increased. The physical properties of the paper such as tensile index, burst index, tear and folding endurance showed a reduction in the strength value as the loading capacity increased. The flocculation study shows that the magnetic colloid exists in multi particles aggregates form in water solution, which caused by magneto-dipole interaction. [Copyright &y& Elsevier]

In 1981, Kenichi Fukui shared the Nobel Prize in Chemistry with Roald Hoffmann "for their theories, developed independently, concerning the course of chemical reactions." In 1964, Fukui used his frontier molecular orbital theory to reveal the mechanism of the Diels‐Alder reaction, a prototypical pericyclic cycloaddition reaction. Fukui revealed this molecular orbital symmetry explanation a year before Woodward and Hoffmann's first publication on "the conservation of orbital symmetry." As detailed in this paper, during the 1960s and early 1960s, Fukui was involved in several major programs in synthesis and polymer chemistry as well as aspects of theoretical chemistry quite distant from his contributions to the orbital symmetry research that preceded Woodward and Hoffmann. In this paper, a detailed examination of Fukui's pre‐1965 research is discussed. This is Paper 4 – Part III of a trilogy that deals with Fukui's Nobel Prize research and is part of a 27‐paper series on the history of the development of the Woodward‐Hoffmann rules. [ABSTRACT FROM AUTHOR]

Abstract: This second paper in a series describes results of pilot-scale testing for mercury (Hg) removal from coal combustion flue gas using a scrubbing solution based on the Fenton reactions. The selected reagents contain hydrogen peroxide and iron salts. The mercury scrubbing was performed in a condensing heat exchanger (CHX) with flue gas generated by coal combustion in CANMET’s vertical combustor research facility (VCRF). Both the Ontario Hydro method and a Hg CEM were used for Hg sampling and speciation. The results, obtained with the combustion of three different pulverized coals – bituminous, sub-bituminous and lignite – showed that the CHX was very effective in removing oxidized mercury (Hg(II)). Concerning the performance of the scrubbing solutions, 30–40% of elemental mercury (Hg(0)) oxidation was achieved for the lignite coal, with the solution being preferably composed of FeCl3 and H2O2 and with pH value between 1 and 3. Results also showed that better Hg removal results were achieved by combining sulphur removal and Hg removal in the same stage of the CHX. An additional test done on the pilot-scale research boiler with a conventional wet scrubber showed that the Hg removal capability using the Fenton reactions was not dependent on the configuration of the wet scrubber. Although the Hg(0) oxidation ratio was not particularly high compared to the achievements from bench-scale tests, considering the economic and non-toxic nature of the scrubbing solution and the readily available equipment, the current results are encouraging and deserve further work to develop a better understanding of the chemistry in order to determine if the method can be further optimized. [Copyright &y& Elsevier]

Abstract: A number of discussion points are raised concerning the nonequilibrium melting and crystallization as described in the paper by Sommer and Reiter.1 [Copyright &y& Elsevier]

Comments on Eric Scerri’s research paper on quantum mechanics and if it explains the periodic table. Ab initio quantum chemistry; Analysis of pertinent topics and relevant issues; Implications on studies of chemistry.

This exercise is designed to teach students about the different types of electron orbitals (specifically s, p, and d orbitals). Electron density and nodes are simulated for each type of orbital by dropping a marble onto a piece of white paper that has been stacked on top of a sheet of carbon paper. The white paper is folded according to specific templates for s, p, or d orbitals. By folding the paper in this manner, certain areas will not be in contact with the carbon paper. These areas remain unmarked as the marble is dropped and illustrate the concept of "nodes" around the "nucleus" of the atom at the center of the paper. [ABSTRACT FROM AUTHOR]

Resonance Raman spectroscopy was applied for investigating the malaria pigment hemozoin, which is an important target structure of antimalarial drugs. Morphology-sensitive low wavenumber modes of hemozoin were selectively enhanced with help of excitation wavelengths at λ= 633 nm and λ= 647 nm. The assignment of the most prominent bands in the Raman spectra at 343 cm−1and 368 cm−1was assisted by DFT calculations of the hemozoin dimer. The mode at 343 cm−1in the Raman spectrum of hemozoin is strongly enhanced with λexc.= 647 nm and is represented by a combined, symmetric doming mode of the two hematin units in the hemozoin dimer. The enhancement of this vibration is stronger in the resonance Raman spectrum of hemozoin compared with less crystalline β-hematin. The selective resonance enhancement of the morphology-sensitive Raman modes of hemozoin is caused by absorption bands in the UV-VIS-NIR spectrum. This absorption spectrum of the crystalline malaria pigment hemozoin shows a strong band at 655 nm. Another broad absorption band at 870 nm is the reason for the strong relative resonance enhancement of the mode at 1372 cm−1in the Raman spectrum of crystalline hemozoin with λexc.= 830 nm. In conclusion, resonance Raman micro-spectroscopy with λexc.= 647 nm was shown to have great potential as an analytical tool to probe the morphology of hematin samples. [ABSTRACT FROM AUTHOR]

4-Fluorinated levoglucosans were synthesised to test if OH⋅⋅⋅F H-bonds are feasible even when the O⋅⋅⋅F distance is increased. The fluorinated 1,6-anhydro-β-D-glucopyranoses were synthesised from 1,6 : 3,4-dianhydro-β-D-galactopyranose (8). Treatment of 8 with KHF2 and KF gave 43% of 4-deoxy-4-fluorolevoglucosan (9), which was transformed into the 3-O-protected derivatives 13 by silylation and 15 by silylation, acetylation, and desilylation. 4-Deoxy-4-methyllevoglucosan (19) and 4-deoxylevoglucosan (21) were prepared as reference compounds that can only form a bivalent H-bond from HO—C(2) to O—C(5). They were synthesised from the iPr3Si-protected derivative of 8. Intramolecular bifurcated H-bonds from HO—C(2) to F—C(4) and O—C(5) of the 4-fluorinated levoglucosans in CDCl3 solution are evidenced by the 1H-NMR scalar couplings h1J(F,OH) and 3J(H,OH). The OH⋅⋅⋅F H-bond over an O⋅⋅⋅F distance of ca. 3.0 4;Å is thus formed in apolar solvents, at least when favoured by the simultaneous formation of an OH⋅⋅⋅O H-bond. [ABSTRACT FROM AUTHOR]

Comments on a study regarding the dewetting morphologies of polystyrene films. Types of rupture process described in the study; Information on the transition of the processes; Interpretation of the morphologies.

Deals with a study which described the kinetic equation of cadmium mobility. Experimental details; Analysis of cadmium kinetics in various temperatures; Results and discussion.

The dissociation of methane is not only an important reaction step in catalytic processes, but also of fundamental interest. Dynamical effects during the dissociative chemisorption of methane on metal surfaces cause significant differences in computed reaction rates, compared to what is predicted by typical transition state theory (TST) models. It is clear that for a good understanding of the catalytic activation of methane dynamical simulations are required. In this paper, a general blueprint is provided for performing dynamical simulations of the dissociative chemisorption of methane on metal surfaces, by employing either the quasi-classical trajectory or ring polymer molecular dynamics approach. If the computational setup is constructed with great care-since results can be affected considerably by the setup - chemically accurate predictions are achievable. Although this paper concerns methane dissociation, the provided blueprint is, so far, applicable to the dissociative chemisorption of most molecules. [ABSTRACT FROM AUTHOR]

It is a reasonable question to ask, why, as of 1965 when the five Woodward‐Hoffmann communication appeared, did no other physical chemist or chemical physicist or theoretical chemist discover the orbital symmetry rules for all pericyclic reactions? Two theoretical chemists – Luitzen Oosterhoff (in 1961) and Kenichi Fukui (in 1964) had discovered portions of the orbital symmetry rules; their stories appear in the papers immediately preceding this paper which is Paper 5 in a 27‐paper series on the history of Woodward‐Hoffmann rules. Concise yet telling stories of 19 other chemists who could have, might have, perhaps even should have discovered the Woodward‐Hoffmann rules are presented with explanations as to why they did not do so. Social, political, and scientific explanations will summarize the analyses. [ABSTRACT FROM AUTHOR]

The publication activity of Russian scientists in various fields in chemistry is analyzed. Data on the indexing of articles of Russian Empire chemists in Chemisches Zentralblatt and Chemical Abstracts indicate active development of Russian science at the end of the 19th century and its rapid recovery and competitive ability after the First and Second World Wars. The collapse of the USSR dealt a severe blow to the scientific potential of the country, which was among the top five in all areas of chemical science before 1990. Currently, Russian scientists hold the strongest positions in the field of organic, inorganic, and physical chemistry. The number of publications of Russian scientists in foreign journals exceeds 50% of the total number of papers, and one third of the research is carried out with international cooperation. [ABSTRACT FROM AUTHOR]

Process waters in deinking mills often feature a strong coloration, due to dyes and pigments released from the recovered paper. This can usually be remediated by pulp bleaching treatment with appropriate chemicals. However, the red shade (from rhodamine dye) is resistant to conventional bleaching treatments. This largely limits the use of deinked pulp in white paper grades. In this review, the available technologies for process water decolorization are discussed (chemical methods, physicochemical methods and biological treatments). Ozonation of the process water appears to be the most promising technique for decolorization of process water in deinking mills. Other emerging technologies such as photo-catalytic treatment or mineralization by white-rot fungi (after adsorption on low-cost agricultural residues) should be considered as well. [ABSTRACT FROM AUTHOR]

This document discusses the importance of understanding the physicochemical properties of aerosol particles in order to comprehend aerosol dynamics and transformations. It highlights the need for new laboratory, theoretical, and modeling studies to address barriers in our understanding of aerosol physical chemistry. The document mentions two conferences that focused on aerosol physical chemistry and microphysics, which provided a platform for interdisciplinary discussions and the exchange of ideas. The document also introduces a special issue that collects papers on topics such as particle surfaces, particle phase, and particle acidity, which address complex aspects of aerosol physical chemistry. Several papers in the special issue explore how different physical properties of aerosols can influence heterogeneous reaction rates involving atmospheric organics. Other papers examine the limitations of experimental techniques and propose improvements, while some highlight the applications of aerosol microphysics in areas such as ice nucleation, cloud activation, and bioaerosols. The document concludes by expressing gratitude to the authors and hopes that the collection stimulates further discussion on these important topics. [Extracted from the article]

The article reports that this issue of the journal introduces a revised list of sections and subsections, designed in close collaboration with the whole editorial board. The aim of these modifications is to reflect more faithfully the wide diversity of activities covered by the journal. A new section has been introduced as "Atomic and Molecular Collisions", it covers a large range of activities, from atom/atom or atom/molecules collisions including the very active field of ultra-cold collisions in laser-cooled atomic or molecular gases, to electron scattering and molecular reactivity.

The present comment concerns some doubtful results included in the above papers. [ABSTRACT FROM AUTHOR]

Copyright of University Chemistry is the property of Peking University, College of Chemistry & Molecular Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Peter Politzer (1937–2022) grew up with no doubt in his mind that he would pursue a career in chemistry. His research interests ranged from theoretical concepts such as electronegativity and chemical hardness to applications of electrostatic potentials and average local ionization energies to molecular interactive behavior and bonding, as well as to the study of chemical reactions and the reaction force in a variety of disciplines, including energetic materials. He will be remembered as a world-renowned leader in halogen bonding and other σ-hole bonding interactions and other areas of theoretical and computational chemistry, with over 520 research publications in scientific journals and books, leaving quite a legacy, with a marked tendency toward simplicity. [ABSTRACT FROM AUTHOR]

Understanding the correlation between chemical and microstructural properties is critical for unraveling the fundamental relationship between materials chemistry and physical structures that can benefit materials science and engineering. Here, we demonstrate novel in situ correlative imaging of the X‐ray Compton scattering computed tomography (XCS‐CT) technique for studying this fundamental relationship. XCS‐CT can image light elements that do not usually exhibit strong signals using other X‐ray characterization techniques. This paper describes the XCS‐CT setup and data analysis method for calculating the valence electron momentum density and lithium‐ion concentration, and provides two examples of spatially and temporally resolved chemical properties inside batteries in 3D. XCS‐CT was applied to study two types of rechargeable lithium batteries in standard coin cell casings: (1) a lithium‐ion battery containing a cathode of bespoke microstructure and liquid electrolyte, and (2) a solid‐state battery containing a solid‐polymer electrolyte. The XCS‐CT technique is beneficial to a wide variety of materials and systems to map chemical composition changes in 3D structures. [ABSTRACT FROM AUTHOR]

Jiang and co-workers use high resolution STM to investigate the reaction and self-assembly of (3,6-dibromo-9,10-phenanthrenequinone, or DBPQ) molecules on Ag (100) and Ag (110) surfaces in order to understand the mechanism of bottom-up assembly on surfaces.[31] They show that, through the inclusion of multiple functional groups within a precursor molecule, it becomes possible to fabricate new low-dimensional materials with unique chemical, physical, and electronic properties. Herbst and Fransson consider the core-valence separation approximation that is often used in the calculation of core-level spectra.[5] They show how to quantify the errors in this approximation, thereby opening the door to error-quantified predictions relevant to x-ray spectroscopy. 153(16), 164108 (2020).10.1063/5.0019557 5 M. F. Herbst and T. Fransson, "Quantifying the error of the core-valence separation approximation", J. Chem. Phys. Zhu and co-workers tackle this problem for a model system containing a 2D semiconductor heterojunction and show convincingly the efficient hot electron transfer from photoexcited MoTe SB 2 sb to WS SB 2 sb .[30] This finding provides important insight into the competition between hot electron cooling and transfer at 2D semiconductor interfaces and suggests an intriguing possibility for the exploration of hot electron devices. [Extracted from the article]

Crystallization of salts is recognized to be a major factor of the degradation of porous materials such as stone and concrete. On the theoretical side, there is now general acceptance about the thermodynamic origin of this phenomenon. However, on the experimental side, there are only scarce quantitative data. In this respect, the reference work par excellence is that of Correns (Discuss Faraday Soc 5:267–271, ) who shows a good correlation between calculated and measured crystallization pressures. However, concerns about both the thermodynamic derivation and the experimental conditions raise the question about why Correns could have obtained such a good correlation. This issue is discussed extensively in this paper which is organized as a commented translation of a former paper by Correns, co-authored by Steinborn, and that is much richer in experimental details. [ABSTRACT FROM AUTHOR]