bluuebunny/crossref_metadata_2025_split huggingface dataset:
Clima organizacional em escritórios de contabilidade de pequeno porte
Authors: Pellizzon Dirceu Aparecido , Kubo Edson Keyso de Miranda , Minciotti Silvio Augusto , Cohen Eric David 
Published: February 2024

O ambiente de trabalho nas organizações tende a influenciar as práticas gerenciais e o comportamento de seus membros. O objetivo deste artigo foi realizar um estudo exploratório em escritórios de contabilidade de pequeno porte, buscando identificar o clima organizacional e a sua influência sobre o comportamento dos empregados. Nesta pesquisa, foram efetuadas 37 entrevistas envolvendo empregados assim como com os empregadores desses pequenos escritórios de contabilidade na região do ABC em São Paulo. Esta pesquisa de campo foi realizada com base em quatro categorias de análise intitulados de resistência às mudanças, estresse, liderança e motivação. As entrevistas foram transcritas e esse material subsidiou a análise de conteúdo com o apoio do Iramuteq versão 0.7 alpha 2. Os resultados apresentaram implicações significativas oriundas da rotina diária de trabalho. De um lado, observaram-se empregados frustrados pela falta de perspectivas de crescimento profissional e de outro, constataram-se empregadores que não parecem vislumbrar um futuro promissor para seus respectivos negócios.
Risk Assessment and Distribution of Heavy Metals in Water and Sediments along Ibelebiri Axis of Kolo Creek, Ogbia Local Government Area, Niger Delta Region of Nigeria
Authors: Onwudiegwu Chinwe A. , Ezekwe Chimere , Uzoekwe Stephen A. 
Published: February 2024

Pollution arising from uncontrollable combustion processes, including artisanal refineries are common in communities through which Kolo Creek traverses. Previous studies have centered on the effect of oil and gas production on Kolo Creek at shell flow station at Imiringi. Therefore, the aim of this study is to investigate the risk and distribution of heavy metals (Zn, Ni, Cr, Cu, Pb, Co, and Cd) in water and sediments along Ibelebiri axis of Kolo creek in Ogbia L.G.A., Niger Delta region of Nigeria. Water and sediment samples were collected at locations upstream, within and downstream at Ibelebiri community, and also from a control site. Generally, heavy metal concentrations showed a decreasing trend of Cu˃Zn˃Pb˃Cr˃Cd˃Co˃Ni for water samples. The mean concentration of these metals: Ni, Cr, Zn and Cu recorded in this study was below international recommended limits. But, Pb, Cd levels in locations LC1, LC3 and LC4 are above the international recommended limits. The heavy metals in the sediments showed a decreasing trend of Zn˃Pb˃Cu˃Co˃Cr˃Ni˃Cd. The concentrations of these metals Cd, Pb, Ni, Cr, Cu and Zn are below the permissible limit set by Department of Petroleum Resources (DPR). However, Co values at locations LC3 and LC4 are slightly above the DPR target value of 20 mg/kg for sediments. Using the geoaccumulation index (Igeo) classification, the sediments across the four locations are uncontaminated with Cd, Cr, Cu, Zn, Co and Ni. But, the sediments in locations LC1, LC3 and LC4 are moderately contaminated with Pb. Similarly, the contamination factor (CF) classification, revealed low contamination of Cd, Cr, Cu, Zn, Ni and Co across the four locations; moderate contamination of Pb in the four locations. Finally, principal component analysis (PCA) identified two major factors.
Quality of Cold Chain Equipment, a Guarantee of Carbon Footprint Reduction from Food Waste to a Sustainable Environment
Authors: Eric Kasamba Ilunga , Mulaj Brigel Tshilombo Mwan A. 
Published: February 2024

The objective of this work was to evaluate the current status of commercial cold chain equipment primarily, and secondarily to determine elements associated with the management of cold chain equipment.
To achieve this, a cross-sectional descriptive study began on August 7 to September 23 of 2023, covering 84 commercial establishments including supermarkets, delicatessens and butchers, food, and butchers in the city of Lubumbashi. The data were collected by interview and direct cross-sectional observation on the evaluation of the conservation of frozen products (fish, meat, and cold meats) on the market in the city of Lubumbashi.
The results show us that the structures using cold chains are food stores, butchers, delicatessens, and supermarkets and sometimes in a certain combination. All these structures mainly use freezing and sometimes refrigeration and freezing to guarantee this Cold chain freezers, quick freezers, refrigerated cabinets and refrigerators and finally insulated boxes are all the equipment used for this purpose and using the supply of electric current throughout and often using generators and rarely solar panels in the event of an outage electric current. Thus, these structures operate in an environment rich in temperature fluctuations leading to rapid deterioration of food, waste, responsible for 4% of global greenhouse gas emissions GHG, the equivalent of the contribution of the entire African continent to climate change.
This work demonstrated the importance of the quality of cold chain equipment on food quality and its impact on the carbon footprint, a situation observable from the production, transport, storage, and elimination of food. the use of solar energy would be a solution in this process because it produces less greenhouse gases.
Kinetic Studies of Effects of Heat on PET Plastics: TGA, DTA, XRD and DSC Analysis
Authors: Nurudeen A. , Nwosu F. O. , Soliu M. 
Published: February 2024

In this work, the effects of heat on plastic waste (PET plastic bottles) were investigated. During thermogravimetric analysis, the kinetics of the PET pyrolysis was studied using a combination of model-fitting and model-free methods. About 12mg of the grinded PET sample was weighed into the ceramic crucible and then heated from temperature of 30 °C to 950 °C at two heating rates of 10°C/min and 20°C /min. Thermogravimetric analysis indicated that the decomposition of plastic waste in a Nitrogen atmosphere can be divided into three stages: the minor loss stage (100°C), the major loss stage (450–520°C) and the stable loss stage (500–900°C). The corresponding weight loss at two different heating rates of 10°C/min and 20°C /min were determined to of 70% and 77.7% respectively. Based on R2 (regression coefficient) values, heating rate of 20oC/min gave the values (0.9279) for the model free method employed (KAS model). When compared to the model fitting, 0.75th order of reaction gave the closest R2 value (0.9643) which also translated to a very close Activation energies of 264 KJ/mol and 255 KJ/mol respectively. All in all, it can be deduced that the activation energy of PET pyrolysis falls within 250 – 280 KJ/mol based on this study. Also, X-Ray Diffraction and Differential Scanning Calorimetry analysis were carried out. The narrow and high nature of the XRD peaks depicted that the sample is crystalline. And lastly, DSC analysis investigated the heat flowing in and out of the PET sample. The exodermal (where cold re-crystallization occurred) and endothermal (where melting occur) peaks were recorded as 165oC and 138oC respectively. It is recommended that other model-free and model-fitting methods should be invested in further research in order to generate a wide range of data for kinetics of PET.
Analytical Chemistry of the Transition ElementsBased in part on the article Analytical Chemistry of the Transition Elements by Harry M. N. H. Irving & Alan T. Hutton which appeared in theEncyclopedia of Inorganic Chemistry, First Edition.
Authors: Hutton Alan T. 
Published: March 2006

AbstractThis article is concerned with the determination of what transition elements are present in a sample and their concentration. After considering the general nature of the problems confronting the analyst, a historical overview is given describing the development of the analytical chemistry of the transition elements from biblical times through to the nascent technologies of the eighteenth and nineteenth centuries. After a brief consideration of the treatment required by materials to get them in a form suitable for analysis, for example, sampling and digestion, the classical methods of gravimetry and titrimetry are discussed, with special emphasis on the use of organic reagents and on complexometric determinations using ethylenediaminetetraacetic acid (EDTA). The role of organic reagents is also seen to be important in spectrophotometric analysis or absorptiometry. Consideration is next given to the various modern instrumental techniques available for analysis of the transition elements, starting with various forms of atomic emission spectroscopy but giving emphasis to the inductively coupled plasma (ICP) sources. The widely used technique of atomic absorption spectroscopy (AAS) is next described, along with its many applications for the determination of transition elements in many diverse materials, from body fluids to engine oils. The modern day importance of X‐ray fluorescence (XRF) is highlighted in a discussion of X‐ray methods, while the technique of neutron activation analysis dominates the section on activation methods, this approach being of particular importance where a nondestructive analysis is essential, for example, of a museum artifact. Finally, brief consideration is given to the importance of the platinum group metals (PGMs) and the special analytical problems that they present.
Asymmetric Synthesis by Homogeneous CatalysisBased in part on the article Asymmetric Synthesis by Homogeneous Catalysis by Brice Bosnich which appeared in the
Encyclopedia of Inorganic Chemistry, First Edition
.
Authors: Walsh Patrick J. 
Published: March 2006

Abstract

This section describes new approaches to asymmetric catalysis including screening mixtures of chiral ligands, applications of normally unresolvable ligands, chiral poisoning, asymmetric activation of racemic catalysts, asymmetric activation of enantioenriched catalysts, optimization of enantioselective catalysts using achiral and
meso
ligands, and combinatorial methods for catalyst generation.
Bismuth: Inorganic Chemistry
Authors: Whitmire Kenton H. 
Published: March 2006

AbstractSolid state and molecular compounds of bismuth have many interesting and useful properties. In addition to bismuth alloys, this article describes simple binary compounds such as the bismuthine, bismuth halides, carboxylates, alkoxides, thiolates, dithiocarbamates and oxides are described in addition to coordination compounds based upon them. Some of these compounds have antibacterial and/or antifungal properties. They have also been used to treat gastrointestinal diseases. Also described are reduced bismuth cluster compounds and transition metal cluster compounds incorporating.
Borides: Solid‐State Chemistry
Authors: Lundström Torsten 
Published: March 2006

AbstractBoron forms compounds with most other elements. In addition to numerous binary and ternary compounds with metals – the true borides – boron forms related compounds with carbon, silicon, nitrogen, phosphorus, arsenic, oxygen, sulfur, and selenium. These related compounds are formed by elements more electronegative than boron and cannot therefore be denoted as borides. They display, however, similar properties and structures as borides, and are, therefore, included in the present article.Borides are to some extent related to carbides and nitrides. All three groups of compounds are compounds between small nonmetal and larger metal atoms. They are occasionally denoted interstitial compounds, since the small nonmetal atoms often occupy the interstices between the metal atoms in metal‐rich compounds. In boron‐rich compounds, however, boron octahedra or icosahedra form a continuous three‐dimensional network. Most borides are characterized by high melting points, extreme hardness, brittleness, high chemical stability, and high inertness toward reactive metals.The borides are nonmolecular compounds and knowledge of the crystal structure is consequently of very high importance to characterize a boride phase. The structural principles of mainly the binary and ternary borides are described in the article. There are a total number of at least 950 binary and ternary borides known at present.The chemical bonding in borides has evident contributions from covalent, ionic as well as metallic bonding, which explains some of the unique properties of the borides. As a rule, phases containing a large proportion of boron are semiconductors, while those with a lower proportion of boron are metallic conductors. TiB2and MgB2are good metallic conductors while MeB6phases are either semiconductors or metallic conductors depending on the metal. Many theoretical calculations are available, in particular of diborides, including the recently discovered superconductor MgB2.The uses of borides and related compounds are mainly based on the their hardness, chemical inertness, and magnetic and electrical properties. A few examples may be mentioned. B4C and cubic BN are used as abrasives, B4C and hexaborides as surface coatings, and CaB6as deoxidation agent in some metallurgical processes. TiB2is used in the production of vaporization boats for aluminum. It is also used in the industrial production process for aluminum owing to its high electrical conductivity and inertness toward liquid aluminum. Nd2Fe14B is the strongest permanent magnetic material known. Large single crystals of YB66are used for monochromating synchrotron radiation.
Boron HydridesBased in part on the article Boron Hydrides by James T. Spencer which appeared in the
Encyclopedia of Inorganic Chemistry, First Edition
.
Authors: Hosmane Narayan S. , Maguire John A. 
Published: March 2006

Abstract
Boranes are hydrides of boron in which BH groups occupy the apices of electron‐deficient clusters. The term ‘electron deficient’ arises from the fact that boron has more valence orbitals than it does valence electrons. The consequence of this imbalance is that the clusters are stabilized by extensive multicentered bondings. The relationships between cage structures and the number of cage electrons are discussed for boranes and their extension to heteroboranes, where one or more BH units are replaced by isolobal main group or transition metal moieties. General synthetic methods and reactivities of the heteroboranes are also discussed.
Boron: Organoboranes
Authors: Jäkle Frieder 
Published: March 2006

Abstract
This chapter provides an overview of recent developments in the highly interdisciplinary field of organoboron chemistry. The most important routes for the synthesis of organoboranes via transmetallation, hydroboration and other boration reactions, as well as CH activation are outlined. The various classes of organoboranes thus accessible are presented according to the nature of the organic substituents. Special emphasis is given to applications of organoboranes. For example, the development of new chiral organoboranes that are commonly used in enantioselective synthesis is shown. Moreover, the importance of fluorinated arylboranes as highly efficient Lewis acid catalysts and cocatalysts for organic transformations and polymerization reactions is discussed. The use of triarylboranes and related compounds as electronic and optical materials for device applications, and as sensors for the recognition of anions and neutral Lewis bases is also described in detail.
Calcium‐Binding ProteinsBased in part on the article Calcium‐Binding Proteins by Natalie C. J. Strynadka & Michael N. G. James which appeared in theEncyclopedia of Inorganic Chemistry, First Edition.
Authors: Yang Jenny J. , Yang Wei 
Published: March 2006

AbstractCa2+is an important second messenger in the regulation of cell life cycle in addition to being an essential component in biomineralization. Ca2+mediates its action in regulation by binding to Ca2+receptors/proteins that in turn regulate signal transduction, enzymatic activity, and protein stability. During the past few years, owing to the fast progress in genomic information and structural biological studies, our understanding of calcium‐binding proteins has been greatly expanded. Since 1991, the structures of calcium‐binding proteins have been extended to more than 1000 today and calcium‐binding proteins are found in every cellular compartment. In this article, we will first summarize the current knowledge about the common properties of calcium‐binding proteins. We then will highlight recent developments in structural biology and biological functions of calcium‐binding proteins.
Carbonylation Processes by Homogeneous CatalysisBased in part on the article Carbonylation Processes by Homogeneous Catalysis by George G. Stanley which appeared in the
Encyclopedia of Inorganic Chemistry, First Edition
.
Authors: Parr M. L. 
Published: March 2006

Abstract

This article reviews homogeneously catalyzed carbonylation reactions with particular emphasis on catalytic hydroformylation using cobalt, rhodium, platinum, and palladium complexes. The carbonylation of methanol based on rhodium and iridium complexes (Monsanto and Cativa
™
processes, respectively) is also discussed. Examples of the utility of carbonylation in the synthesis of complex molecules are given.
Copper: Inorganic & Coordination ChemistryBased in part on the article Copper: Inorganic & Coordination Chemistry by Rebecca R. Conry & Kenneth D. Karlin which appeared in the
Encyclopedia of Inorganic Chemistry, First Edition
.
Authors: Conry Rebecca R. 
Published: March 2006

Abstract
Copper was one of the first metals used widely because the metal is fairly plentiful (among the 25 most abundant elements in the earth's crust) and can be found in its metallic state. In addition, the metal and its alloys have a number of beneficial qualities including ductility, malleability, strength, corrosion resistance, and high thermal and electrical conductivity, combined with an attractive appearance. Copper is also an essential trace nutrient for organisms ranging from bacteria to mammals.
Copper exhibits a rich coordination chemistry with complexes known in oxidation states ranging from 0 to +4, although the +2 (cupric) and the +1 (cuprous) oxidation states are by far the most common, with +2 predominating. Compounds of copper have found extensive practical usage, including as catalysts in both homogeneous and heterogeneous reactions, as fungicides, pesticides, and wood preservatives, as pigments for paints and glasses, and in the so‐called high‐temperature superconductors.

The coordination numbers and geometries of copper complexes vary with oxidation state. For the spherically symmetric d
10
Cu
I
ion, the common geometries are two‐coordinate linear, three‐coordinate trigonal planar, and four‐coordinate tetrahedral. Cu
I
compounds are diamagnetic and colorless, except where color results from charge‐transfer bands or a counterion; these complexes are often fairly readily oxidized to Cu
II
compounds. The d
9
Cu
II
ion is usually found in a tetragonal coordination environment, with four short equatorial bonds and another one or two longer axial bonds although complexes with other structures are known, including tetrahedral, square planar, and trigonal bipyramidal geometries. Most of the Cu
II
compounds are blue or green because of d–d absorptions in the 600 to 900‐nm region; exceptions generally also have charge‐transfer bands tailing into the visible, causing a red or brown appearance. Cu
III
complexes are typically square planar and diamagnetic.
Copper Proteins: Oxidases
Authors: Stoj Christopher S. , Kosman Daniel J. 
Published: March 2006

AbstractOxidases are enzymes that use dioxygen as the electron acceptor in oxido‐reduction reactions. Many members of this enzyme class (EC 1.) rely on the Cu1+/Cu2+redox cycle of copper prosthetic group(s) in their catalysis of the electron transfer from reducing substrate to O2. Those copper oxidases that catalyze the four‐electron reduction of O2to 2H2O are known as multicopper oxidases (MCO) because each member of this group contains at least four copper atoms of three distinct electronic and spectral types. These three types are: type 1 or ‘blue’ Cu(II), so‐called because of its distinguishing strong absorbance at ∼600 nm; type 2 Cu(II), comparable in electronic structure to that found in square‐planar copper complexes; and type 3 Cu(II), a Cu(II)Cu(II) pair bridged by O(H) and thus diamagnetic. With four 1e−metal redox sites, MCOs are the all‐copper equivalent of the copper‐heme respiratory terminal oxidases. However, MCOs are true oxidases in that all members can use as electron acceptors common (di)phenolic, and aromatic (di)amine substrates, for example, hydroquinone, ascorbic acid, and phenylenediamine. The laccases and ascorbate oxidase are examples of these MCOs (EC 1.10.3). Members of a separate MCO class (EC 1.16.3) also use lower valent metal ions as substrates, for example, Fe2+, Cu1+, and/or Mn2+. These are thereby designated metallo‐oxidases; the most widely studied activity of this class has been towards Fe2+giving rise to the common enzyme name, ferroxidase. The typical MCO structure consists of three ‘cuprodoxin’ domains, a Greek‐key beta‐fold that characterizes a family of mononuclear copper electron‐transfer factors. Among MCOs are both soluble and type 1 membrane proteins. Functionally, MCOs are known to play essential roles in biodegradation and transformation, cell redox balance, and metal metabolism. This article summarizes current knowledge of this class of copper oxidase enzymes.
Fluorides: Solid‐State Chemistry
Authors: Massa Werner 
Published: March 2006

AbstractInorganic solid fluorides and fluorometalates play a unique role in inorganic chemistry. The preparation, mostly using aqueous or anhydrous HF or even elemental F2, requires special conditions: no glass or silicate containing vessels can be used. Their structural chemistry is governed by the outsider role of the fluoride anion. It is the smallest and least polarizable anion and its mainly ionic compounds follow the rules of hard spheres packing better than any other class of substances. Nearly all metal ions except those with the largest ionic radii form fluoride structures with octahedral [Mn+F6](6−n)–units. If the metal:fluorine ratio is less than 6, these octahedra share common vertices or, in rare cases, edges or even faces to account for electroneutrality, the more the lower the oxidation state of the metal. In this way, a variety of 1D chain, 2D net, and 3D framework structures is formed that can be classified into a few large structure families. In binary fluorides, for example, VF5has an octahedral cis‐chain structure, VF4a layer structure based on a square net of corner‐connected octahedra, VF3has a ReO3‐related 3D structure with all corners of octahedra connected, and VF2has the rutile‐type structure with partial edge‐sharing of octahedra. In ternary or quaternary compounds, for example, alkali or alkaline earth fluorometalates, the same principles are valid for the anionic substructure while the counter cations fill interstices and stabilize at the same time the structure. The main structure families are grouped according to the basic principles of octahedral nets. These are the ReO3‐related trifluorides, the fluoride perovskites AMF3, their relatives elpasolites A2A′MF6, and cryolites A3MF6, as well as some layer structures with square nets. A second large family is based on mixed octahedral nets including triple units: it includes for example, the pyrochlores, the weberites, the hexagonal and tetragonal tungsten bronze structures, and some derivable layer structures. Recent developments deal with ‘tailoring’ of low‐dimensional or framework structures using ‘soft‐chemistry’ methods. The relatively simple structural chemistry of fluorides invoked their use as model systems, for instance, for the investigation of electronic effects like Jahn–Teller ordering, or for magnetic investigations. Besides the cryolite Na3AlF6used in Al production, some fluorides are of technical interest owing to their special optical properties (e.g. laser optics, fluoride glasses), their ability for fluoride ion conductivity, or their role as catalysts for fluorinations or halogene exchange in organic systems.