Solution/ammonolysis syntheses of unsupported and silica-supported copper(I) nitride nanostructures from oxidic precursors

Herein we describe an alternative strategy to achieve the preparation of nanoscale Cu3N. Copper(II) oxide/hydroxide nanopowder precursors were successfully fabricated by solution methods. Ammonolysis of the oxidic precursors can be achieved essentially pseudomorphically to produce either unsupported or supported nanoparticles of the nitride. Hence, Cu3N particles with diverse morphologies were synthesized from oxygen-containing precursors in two-step processes combining solvothermal and solid−gas ammonolysis stages. The single-phase hydroxochloride precursor, Cu2(OH)3Cl was prepared by solution-state synthesis from CuCl2·2H2O and urea, crystallising with the atacamite structure. Alternative precursors, CuO and Cu(OH)2, were obtained after subsequent treatment of Cu2(OH)3Cl with NaOH solution. Cu3N, in the form of micro- and nanorods, was the sole product formed from ammonolysis using either CuO or Cu(OH)2. Conversely, the ammonolysis of dicopper trihydroxide chloride resulted in two-phase mixtures of Cu3N and the monoamine, Cu(NH3)Cl under similar experimental conditions. Importantly, this pathway is applicable to afford composite materials by incorporating substrates or matrices that are resistant to ammoniation at relatively low temperatures (ca. 300 °C). We present preliminary evidence that Cu3N/SiO2 nanocomposites (up to ca. 5 wt.% Cu3N supported on SiO2) could be prepared from CuCl2·2H2O and urea starting materials following similar reaction steps. Evidence suggests that in this case Cu3N nanoparticles are confined within the porous SiO2 matrix

Ultra-rapid synthesis of the MgCu2 and Mg2Cu Laves phases and their facile conversion to nanostructured copper with controllable porosity; an energy-efficient, reversible process

Phase-pure MgCu2 and high-purity Mg2Cu have been synthesised within 1 min from elemental powders via the microwave-induced metal plasma (MIMP) approach for the first time. Subsequent room temperature, acidic de-alloying led to 3-dimensional nanoporous (NP) Cu within minutes. Each distinctive metallic matrix exhibited a large surface area with a porosity of either 37.47% (from MgCu2) or 56.25% (from Mg2Cu). Both NP Cu powders are composed of crystalline grains (“ligaments”) measuring tens of nanometers across, which exhibit rich point- and extended defects. The selection of Laves precursor dictates the form of ligament obtained, which directs the ensuing NP structure. As an example application, a working electrode of NP Cu from Mg2Cu presented linear non-enzymatic sensing properties over glucose concentrations of 0.5 - 4.5 and 4.5 - 10.0 mM with high confidence levels (> 99 %). This study provides a facile, rapid and energy-efficient route to functional NP Cu with eclectic structures, which should be equally applicable to other metals

Facile preparation of copper nitride powders and nanostructured films

The simple fluorinated precursor, copper(II) trifluoroacetate, Cu(CF3COO)2 can be effectively utilised in the synthesis of Copper(I) nitride, Cu3N, powders and films by combinations of wet processing and gas-solid (ammonolysis) techniques. The resulting materials were characterized by powder X-ray diffraction (PXD), scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), diffuse reflectance UV-visible spectroscopy (DRUV-Vis), Raman spectroscopy, infrared spectroscopy (IR), thermogravimetric-differential thermal analysis-mass spectrometry (TG-DTA-MS) and nitrogen adsorption (BET) analysis. Moreover, variable temperature IR (VT-IR) studies of the solid phase were performed in situ during ammonolysis. Single-phase Cu3N powders composed of sub-micron scale platelets can be produced over relatively short reaction times. Materials prepared in this way are stoichiometric narrow band gap semiconductors. The same trifluoroacetate precursor was used to prepare nanostructured nitride films by dip coating. The surface microstructure was investigated and evaluated relative to films deposited by spin coating and nebulisation using soluble carboxylate precursors

Training influence over competence development of employees in automotive industry

Celem niniejszej pracy jest analiza efektywności szkoleń przeprowadzanych wśród pracowników branży motoryzacyjnej w zakresie rozwoju ich kompetencji zawodowych, wiedzy technicznej i innych umiejętności. Omówione zostało pojęcie kompetencji pracowniczych, jako element skutecznego zarządzania zasobami ludzkimi. Dzięki temu wykazano, że ich rozwój poprzez szkolenia, istotnie wpływa na sytuację przedsiębiorstwa. Zdefiniowano pojęcie szkolenia, określając przy tym cel i rolę szkoleń dla rozwoju organizacji. Następnie przedstawiono proces identyfikacji potrzeb szkoleniowych, scharakteryzowano metody szkoleniowe i omówiono sposób oceny ich efektywności. Przedstawiono charakterystykę branży motoryzacyjnej, z uwzględnieniem obszarów zatrudnienia i potencjalnych potrzeb szkoleniowych. Za pomocą kwestionariusza zbadano wpływ szkoleń na rozwój kompetencji pracowniczych. Obiektem badawczym w przedstawionej pracy są pracownicy branży motoryzacyjnej, pracujący w obszarze sprzedaży i obsługi klienta. Podsumowanie badań stanowi ocenę, czy szkolenia wpływają na rozwój kompetencji pracowników branży motoryzacyjnej.This thesis is to analyse training effectiveness among automotive industry employees within the scope of their professional competence development, technical knowledge and other skills. Employee’s competence development has been analysed as a method of effective human resources management. It has been proved here, that development through training has significant influence over company’s performance. Training concept focuses on purpose and meaning of the training for development of an organisation. Process of training needs identification was described, as well as training methods and assessment of their effectiveness. Afterwards, I have introduced automotive industry, taking into consideration employment groups and potential training needs. By means of a questionnaire, influence of the training over competence development has been researched. The research is focused on automotive employees, working in sales and customer service areas. The summary presents evaluation, whether trainings have influence on competence development of automotive industry employees

Next eukaryotic genome revealed with cooperation of the Polish laboratories. Potato genome sequenced

W połowie lipca 2011, w Nature ukazał się artykuł "Sekwencja genomu ziemniaka i jej analiza" autorstwa Konsorcjum Sekwencjonowania Genomu Ziemniaka (PGSC). W skład tego Konsorcjum wchodziły 32 zespoły z 14 krajów - znaczących producentów ziemniaków. Współautorami ze strony polskiej, tej wielo autorskiej pracy (94 badaczy, 25 zespołów wiodących) byli członkowie zespołu z Instytutu Biochemii i Biofizyki PAN. Prace Konsorcjum, rozpoczęte w 2007 roku, wspierane były przez rządy państw uczestniczących w programie, w tym Polskiego Ministerstwa Nauki i Szkolnictwa Wyższego, (projekt 47/PGS/2006/01). To trzeci wielki genom (po S. cerevisiae i P. caudatum) w którego poznaniu uczestniczyli pracownicy IBB PAN. Konsorcjum zsekwencjonowało dwa szczepy ziemniaka DM1-3 516 R44 and RH 89-039-16. Szczep DM zsekwencjonowano metodą "shotgun" wykorzystując m. in. platformę sekwencjonowań genomowych IBB PAN (sekwenator Roche GS FLX Titanium 454). Metodami ab initio określono zasób genów kodowanych przez otrzymane sekwencje. Wyniki zweryfikowano analizami transkryptomu objawiającego się w różnych tkankach, czy stadiach rozwojowych oraz w wyniku kontrolowanego stresu. Sumarycznie zidentyfikowano w otrzymanej sekwencji 39031 genów kodujących białka. 25,3% tych genów koduje transkrypty mogące podlegać alternatywnemu składaniu, a więc kontrolujące średnio 2-3 odmienne białka. Wydaje się więc, że w genomie ziemniaka zakodowana jest informacja na temat syntezy ok. 100,000 różnych białek. Porównanie sekwencji DM and RH dowodzi, że ziemniak to roślina wysoce heterozygotyczna. Mutacje punktowe (SNP) występują średnio co 40 nukleotydów, a insercje lub delecje co 394 pary zasad. Wskazuje to wyraźnie, że genom ziemniaka jest niestabilny, co zapewne znajduje swoje odbicie w łatwej degeneracji odmian uprawnych.In mid-July 2011 Nature published the paper "Genome sequence and analysis of the tuber crop potato" by the Potato Genome Sequencing Consortium - PGSC. This international consortium consisted of 32 teams from 14 countries that are significant potato producers are active in potato breeding programs. The Polish team, representing the PAS Institute of Biochemistry and Biophysics, co-authored the paper, which was signed by 94 consortium members from 25 leading institutions. The work, begun in 2007, was funded by the participating countries' governments - including Poland's Ministry of Science and Higher Education - within the 47/PGS/2006/01. After the yeast and paramecium genomes this is the third large genome sequencing in which IBB teams have participated. Consortium sequenced two strains of potato DM1-3 516 R44 and RH 89-039-16. The DM strain was sequenced by the consortium using the "Shotgun method" on genome sequencing platforms, one of which was created in Warsaw (Roche GS FLX Titanium 454 sequencer).The second strain sequenced was a laboratory S. tuberosum heterodiploid RH 89-039-16. Ab initio predictions of genes and their functions were verified by RNA transcriptome analysis done for various tissues, development stages and under stress. This allowed for the identification of 39031 gene-coding proteins. 25,3% of these genes produce RNA that undergoes splicing, coding for an average of 2-3 different proteins. It therefore seems that the potato genome codes for approximately 100 000 different proteins. Comparisons of the DM and RH sequences show that the potato exhibits high heterozygosity. Single-nucleotiste polymorphisms (SNP) are encountered on average every 40 nucleotides, while insertions or deletions (so-called indel) of an average length of 12.8 nucleotides are encountered on average every 394 base pairs. This data clearly shows that gene damage in the potato genome is a frequent occurrence, which accounts for the easy degeneration of industrial strains

Shaping the Microstructure of High-Aluminum Cast Iron in Terms of the Phenomenon of Spontaneous Decomposition Generated by the Presence of Aluminum Carbide

A suitable aluminum additive in cast iron makes it resistant to heat in a variety of environments and increases the abrasion resistance of the cast iron. It should be noted that high-aluminum cast iron has the potential to become an important eco-material. The basic elements from which it is made—iron, aluminum and a small amount of carbon—are inexpensive components. This material can be made from contaminated aluminum scrap, which is increasingly found in metallurgical scrap. The idea is to produce iron castings with the highest possible proportion of aluminum. Such castings are heat-resistant and have good abrasive properties. The only problem to be solved is to prevent the activation of the phenomenon of spontaneous decomposition. This phenomenon is related to the Al4C3 hygroscopic aluminum carbide present in the structure of cast iron. Previous attempts to determine the causes of spontaneous disintegration by various researchers do not describe them comprehensively. In this article, the mechanism of the spontaneous disintegration of high-aluminum cast iron castings is defined. The main factor is the large relative geometric dimensions of Al4C3 carbide. In addition, methods for counteracting the phenomenon of spontaneous decay are developed, which is the main goal of the research. It is found that a reduction in the size of the Al4C3 carbide or its removal lead to the disappearance of the self-disintegration effect of high-aluminum cast iron. For this purpose, an increased cooling rate of the casting is used, as well as the addition of elements (Ti, B and Bi) to cast iron, supported in some cases by heat treatment. The tests are conducted on the cast iron with the addition of 34–36% mass aluminum. The molten metal is superheated to 1540 °C and then the cast iron samples are cast at 1420 °C. A molding sand with bentonite is used to produce casting molds

Impact of Methanol Concentration on Properties of Ultra-Nanocrystalline Diamond Films Grown by Hot-Filament Chemical Vapour Deposition

Diamond is a very interesting material with a wide range of properties, making it highly applicable, for example, in power electronics, chemo- and biosensors, tools’ coatings, and heaters. Due to the high demand for this innovative material based on the properties it is already expected to have, it is important to obtain homogeneous diamond layers for specific applications. Doping is often chosen to modify the properties of layers. However, there is an alternative way to achieve this goal and it is shown in this publication. The presented research results reveal that the change in methanol content during the Hot Filament Chemical Vapour Deposition (HF CVD) process is a sufficient factor to tune the properties of deposited layers. This was confirmed by analysing the properties of the obtained layers, which were determined using Raman spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and an atomic force microscope (AFM), and the results were correlated with those of X-ray photoelectron spectroscopy (XPS). The results showed that the increasing of the concentration of methanol resulted in a slight decrease in the sp3 phase content. At the same time, the concentration of the -H, -OH, and =O groups increased with the increasing of the methanol concentration. This affirmed that by changing the content of methanol, it is possible to obtain layers with different properties

Multiple roles of unconventional heteroatom dopants in chalcogenide thermoelectrics: the influence of Nb on transport and defects in Bi2Te3

Improvements in the thermoelectric performance of n-type Bi2Te3 materials to more closely match their p-type counterparts are critical to promote the continued development of bismuth telluride thermoelectric devices. Here the unconventional heteroatom dopant, niobium, has been employed as a donor in Bi2Te3. Nb substitutes for Bi in the rhombohedral Bi2Te3 structure and exhibits multiple roles in its modulation of electrical transport and defect-induced phonon scattering. The carrier concentration is significantly increased as electrons are afforded by aliovalent doping and formation of vacancies on the Te sites. In addition, incorporation of Nb in the pseudoternary Bi2–xNbxTe3−δ system increases the effective mass, m*, which is consistent with cases of “conventional” elemental doping in Bi2Te3. Lastly, inclusion of Nb induces both point and extended defects (tellurium vacancies and dislocations, respectively), enhancing phonon scattering and reducing the thermal conductivity. As a result, an optimum zT of 0.94 was achieved in n-type Bi0.92Nb0.08Te3 at 505 K, which is dramatically higher than an equivalent undoped Bi2Te3 sample. This study suggests not only that is Nb an exciting and novel electron dopant for the Bi2Te3 system but also that unconventional dopants might be utilized with similar effects in other chalcogenide thermoelectrics

Multimodal detection and analysis of a new type of advanced Heinz body-like aggregates (AHBA) and cytoskeleton deformations in human RBCs

A new type of aggregates, formed in human red blood cells (RBCs) in response to glutaraldehyde treatment, were discovered and analyzed with the classical and advanced biomolecular imaging techniques. Advanced Heinz body-like aggregates (AHBA) formed in a single human RBC are characterized by higher level of hemoglobin (Hb) degradation compared to typical Heinz bodies, which are consist of hemichromes. The complete destruction of porphyrin structure of Hb and the aggregation of the degraded proteins with the presence of Fe3+ ions are observed. The presence of such aggregated, highly degraded proteins inside RBC, without cell membrane destruction, has been never reported before. For the first time the spatial differentiation of two kinds of protein mixtures inside the single RBC, with different phenylalanine (Phe) conformations, is visualized. The non-resonant Raman spectra of altered RBCs with AHBA are characterized by presence of a strong band located at 1037 cm-1, which confirms that glutaraldehyde interacts strongly with Phe. The shape-shifting of RBC from the biconcave disk to spherical structure as well as sinking of AHBA to the bottom of the cell are observed. Results reveal that presence of AHBA should be considered when fixing RBCs and indicate the analytical potential of Raman spectroscopy, atomic force microscopy and scanning near-filed optical microscopy in AHBA detection and analysis