Journal articles on the topic 'Glass-making furnace'

Glass melting has changed very little in general principles since the earliest times, still being produced in fireclay pots or crucibles—even up to the present day. In Europe, experiments to melt glasses in tank furnaces began about 1700 A.D., but this became an important form of glass manufacture after Siemens introduced the regenerative furnace in 1870. This design was the basis for the development of modern furnaces and there is still a considerable similarity to the original.Until the late 1920s the glass contact refractories used in tank furnaces were based on fireclay or sandstone blocks. About this time important changes began when sillimanite and fusion-cast mullite refractories became available. However, because of the higher cost of fusion-cast refractories the introduction of these materials was delayed and they did not come into general use for lining the glass melting tank until the late 1940s.The high performance of tank furnaces today is related to a number of factors such as improved furnace design and regeneration, but the most significant has been an improved melting rate brought about by the use of higher temperatures. This has only been achievable as a result of the improved quality of fusion-cast and other refractory materials, such as those used in the furnace superstructure and regenerators. Garstang showed that there has been a steady increase in melting temperatures in the container glass industry. In data going back to 1920, there has been an increase from about 1300°C to some 1590°C. Bondarev showed that the increase in production achieved by using higher temperatures reduces the specific consumption of fuel.

The results of a complex of experimental studies of thermal and aerodynamic indicators of water-heating heat-recovery exchangers of dusty exhaust gases from glass-making furnaces are presented. The studies were carried out on an experimental installation located behind a glass-melting furnace, and in the process of start-up operations during the introduction into operation of modular-type water-heating heat exchangers (HWM) developed by IET NAS of Ukraine at various glass-producing enterprises. The studies were carried out using modern measuring equipment according to certified methods of the services of metrological adjustment of glass-making enterprises, with the participation of which the experiments were carried out. In the process of research, the heating capacity, average values of the heat transfer coefficients and aerodynamic resistance of heat exchange surfaces, which are assembled from of panel packages formed by pipes with membranes, under conditions of heat-recovery of dusty furnace gases, were determined. The dynamics of the formation of a layer of deposits of technological dust on the surface of the panels on the gas side and the contamination coefficient of surface were also subject to research. According to the data on the heat-recovery exchanger heating capacity, the rational period of its operation between cleaning the working surfaces was determined. The experimental parameters obtained were also compared with their calculated values, as well as with the data of other researchers. According to the results of the studies, it is shown that TVM heat exchangers when used in conditions of dusty furnace gases are characterized by high thermal efficiency due to the layout of the heat exchange surface from the packets of panels formed by pipes with membranes, and the possibility of cleaning these surfaces from deposits of technological dust with practical restoration of the initial indicators. Based on the data obtained, the duration of the cycles for cleaning membrane heating surfaces from dust deposits was determined: for furnaces for the production of glass packaging, this period was 10-14 days, and for furnaces for melting medical glass - 5-7 days.

The degree of the baddeleyite-corundum refractories erosion depending on the areas of their location in the glass-making furnace in the float glass production was established. With the use of petrographic analysis the influence of chemical and mineral composition and also temperature and gas environment on corrosion of bacor linings was studied. Due to obtained results the recommendations in relation to the increase of glass-attack resistance of the furnace and its service life length were formulated.

It was shown that fused-cast chrome-containing refractories are the most promising as the lining material of designed glass-making electric furnaces and smallsized melters of the next generation. To provide a long (up to 10 years) life of the furnace, its elements that are subject to intensive wear must be made of refractories of HPL-85 type with a high chromium content. The bakor furnace masonry of other elements can be replaced with fused-cast refractory material type HAC-26M with a low content of chromium oxide.Ill.2. Ref. 11. Tab. 5.

Using the industrial limestone, fly ash and pure chemical reagents as raw materials, the blast furnace slag was prepared in the simulation condition of the actual slag-making process. Using uniform design method, the influence of blast furnace slag composition factors such as quaternary alkalinity, ratio of CaO/MgO and ratio of SiO2/Al2O3 on the glass content of blast furnace slag were studied in the present in investigation, the relationship between glass content and the various factors has been obtained through regression analysis, and the main influence factors and the optimum blast furnace slag compositions been found out. The results showed that, the impact of various factors on the glass content of granulated blast furnace slag was quaternary alkalinity > ratio of SiO2/Al2O3 > ratio of CaO/MgO. According to the significance test of the regression equation and the verification experiment, it was concluded that the optimum compositions of granulated blast furnace slag were: the quaternary alkalinity was 0.85, the ratios of CaO/MgO and SiO2/Al2O3 were 11.5 and 6.5 respectively, and in this condition, the glass content of granulated blast furnace slag reached to 98.47%.

A systematic analysis of the technological process of glass melting as an object of automatic control and management has been carried out. As an object of automatic control with distributed parameters, the mathematical description of the glassmaking furnace operation has been developed (considering the main phenomenological features of the technological mode of glassmaking).In this paper, a mathematical description of charge melting process, additional heating by electric current, bubbling, thermal conductivity and heat fluxes during the processing of molten glass have been generated. Initial conditions and simplifying assumptions have been derived. The model is based on the equations of continuity, momentum and energy, as well as kinetic turbulent energy, dissipation of kinetic turbulent energy. An experiment has been conducted on the proposed in order to check for its adequacy to real glass-making processes.

Using the industrial limestone, fly ash and pure chemical reagents as raw materials, the blast furnace slag was prepared in the simulation condition of the actual slag-making process by three different cooling ways, including air cooling, water cooling and liquid nitrogen cooling. Combined with different test methods such as XRD, SEM, IR, the influence of cooling ways on the structure and hydraulic activity of blast furnace slag was studied in the present in investigation. The relationship between glass content, compressive strength and the phase compositions of blast furnace slag has been obtained. The results showed that, the glass content of water cooling slag or liquid nitrogen cooling slag was slightly higher than that of air cooling slag, there was obviously gehlenite crystal phase in air cooling slag. The 7d and 28d compressive strength of three slags did not present positive correlation with vitreous content, the sequence of 28d compressive strength of three slags was water cooling slag > air cooling slag > liquid nitrogen cooling slag. SEM observation found that crystallization phases in water cooling slag had a small grain and uniform distribution, this kind of structure was advantageous to the latter hydration reaction and strength development of blast furnace slag.

The research continues the direction of intensification of glass-making processes by completely replacing soda ash in the glass batch with sodium hydroxide to obtain a well-classified intermediate two-component raw material. A method for obtaining a modified synthetic raw material (SRMm) for producing sodium-calcium-silicate glass based on quartz-containing raw material and sodium hydroxide is considered. SRMm consists of two parts, the chemical composition of one of which corresponds to the low-melting eutectic on the Na2O-SiO2 diagram, in contrast to the prototype SRM, the chemical composition of which corresponds to the chemical composition of silicate glass. The products of the synthesis of parts of quartz sand and sodium hydroxide are mixed with the rest of the components of the glass batch of alkali-silicate glasses, followed by possible agglomeration by known methods. The results of a comparative X-ray phase analysis of experimental charges, as well as heat-treated pelletized samples, show more pronounced glass formation processes in a charge based on SRMm than using the prototype. The use of experimental charges can intensify the physicochemical reactions at the stage of melting in a glass-making furnace, reduce the maximum melting temperature of glass, reduce the carryover of dust-like components of the charge and the technogenic load on the environment.

A unique find of four clay molds for making glass vessels was found during archaeological researches of the site on the Naberezhno-Khreshchatitska str., 21 (Kyiv Podil) in 2007. The excavations both on the street itself and on the bordering areas revealed the existence here of a large handicraft quarter with economic and production objects dated to the 11th and 12th centuries. Location of the studied site near the waterway (Dnieper River) was convenient for placing here fire-hazardous productions, such as glass-making workshops. On the site, remains of the construction of the furnace in the form of large pieces of vitrified clay and fragments of plinth form bricks were fixed. Numerous pieces of glass were found, as well as fragments of glassware, mainly those of bracelets and vessels. Among another finds there were such glass ornaments as beads and rings, and one inset for the ring. Among the ceramic material from the investigated complex, there were four clay molds for forming glass vessels. The molds were of bowl-like form and had a ribbed inner surface, made by hand. It is worthy to note that among the products there were two fragments of glass bottoms with ribbed outer surfaces, which could be made in such molds. Vessels with ribbed walls appear on the territory of Ancient Rus’ from the second half of the 12th century. Chemical analyzes of glass mass taken from the complex showed that samples could be identified as lead-potassium Ancient Rus’ glass. Glassware, certain materials (molds for glass vessels, crucibles, pieces of lead), allow to connect the excavated complex with glass-making production.

Excavations in the Roman villa of Aiano yielded twenty glass beads, a pendant, and a glass-recycling furnace, originally interpreted as a bead workshop. This article re-assesses the evidence of bead making in light of new data obtained thanks to recent progress in archaeological glass studies. A detailed study of the typology, technology, and chemical composition of the beads clearly excludes local production. Instead, two different forming techniques, four different base glasses (Roman, HIMT, Foy 2.1 and Foy 2.1/HIMT), and numerous colouring and opacifying materials point to a well-established and extensive network of the Roman bead trade, in which Aiano evidently participated. The majority of the beads can be related to the monumentalization of the villa in the fourth to fifth century ad and represent a sample of the ornaments worn by its inhabitants.

Aged bricks of AZS and mixed α-β-alumina refractories have been sampled in superstructures of glass making furnaces. α- and β-alumina phases contained in these refractories have been investigated by optical absorption spectroscopy, electron paramagnetic resonance, and electron probe microanalysis. On the side of the brick exposed to the tank atmosphere, β-alumina is the only phase present. The primary corundum grains are transformed into secondary β-alumina under the influence of contaminants from raw materials and oil ashes. The temperature conditions existing in the furnace preclude the formation of β” alumina. The bright blue color of β-alumina originates from the presence of tetrahedral Ni2+ in Al(2) sites, with no evidence for nickel atoms located in the ionic conduction band. By considering the chemical composition of β-alumina, spectroscopic results are consistent with a mutual interaction between divalent and monovalent species during cation diffusion. Indeed, the small divalent cations such as Ni are located in the spinel block and the larger alkali cations play a charge compensation role in the conduction band. As other divalent cations of small ionic radius, nickel hence helps to stabilize β-alumina, which maintains the refractory performance during furnace operation. The spectroscopic evidence of trace amounts of nickel (<100 ppm) in secondary corundum crystals means that this phase formed at the expense of β-alumina inside the high-alumina refractory brick. By considering the diffusion coefficients of Ni2+ in α- and β-alumina, this indicates a fast contamination of the material at an early stage of the furnace history. The formation of a permanent deep layer of primary and secondary corundum has protected the inner part of the refractory brick from further contamination.

The recycling of millions of tons of glass bottle waste produced each year is far from optimal. In the present work, ground blast furnace slag (GBFS) was substituted in fly ash-based alkali-activated mortars (AAMs) for the purpose of preparing glass bottle waste nano-powder (BGWNP). The AAMs mixed with BGWNP were subsequently subjected to assessment in terms of their energy consumption, economic viability, and mechanical and chemical qualities. Besides affording AAMs better mechanical qualities and making them more durable, waste recycling was also observed to diminish the emissions of carbon dioxide. A more than 6% decrease in carbon dioxide emissions, an over 16% increase in compressive strength, better durability and lower water absorption were demonstrated by AAM consisting of 5% BGWNP as a GBFS substitute. By contrast, lower strength was exhibited by AAM comprising 10% BGWNP. The conclusion reached was that the AAMs produced with BGWNP attenuated the effects of global warming and thus were environmentally advantageous. This could mean that glass waste, inadequate for reuse in glass manufacturing, could be given a second life rather than being disposed of in landfills, which is significant as concrete remains the most commonplace synthetic material throughout the world.

Based on the analysis of the glass use evolution in architecture and construction, the need to improve or search for new types of glass as an element of the interior or exterior and ways to decorate them and the feasibility of using artistic painting was shown. The purpose of this work was its use in the manufacture of decorative elements for architectural and construction purposes with different surface textures and relief of polished float sheet glass while providing significant resource and energy savings with the use of refractory materials. The equipment and materials which were used included: Z. Bavelloni grinder; muffle furnace CGB-100.150.55-10- 380 for painting and annealing; sprayer type LVLP 1.3 mm INTERTOOL PT-0132 for spraying fine kaolin suspension; degreasing solution; panels from the polished float glass with the following chemical composition, wt. %: SiO2 — 73.0; Al2O3 — 1.0; Fe2O3 — 0.1; CaO — 8.6; MgO — 3.6; Na2O — 13.4; SO3 — 0.3 and 6 mm thick; refractory plates LYTX—264B and heat-resistant paper LYTX—236B from ceramic fibers. The coefficient of thermal linear expansion of glasses and refractories was determined using a quartz vertical dilatometer. As a result of the carried out researches the possibility of obtaining the set texture and three-dimensional relief of the surface of architectural and construction decorative products from polished float glass sheet by artistic painting with the use of refractory materials was shown. The factors that are decisive in the choice of such materials and their effectiveness were identified. Significant simplification and cheapening of the method of making decorative glass by artistic painting has been achieved due to the fact that to obtain each effect on the surface of the product it is enough to replace the refractory fragments of the composition and their arrangement instead of making new support plates. Further research of forming processes and phase generations in compositions based on applied and new refractory materials and their waste will contribute to a significant expansion of the range and areas of use the artistic and decorative glass products use.

A manufacture of pressed refractory products with a maximum apparent density largely depends on a choice of optimal technological parameters for their forming, first of all, mass moisture and specific pressing pressure. The study objective was to establish of optimal values of these parameters in order to further improve the technology of alumina­zirconium silicate refractories. Researches of mass moisture and specific pressing pressure influence on the apparent density of green samples and main properties of alumina­zirconium silicate refractories samples fired at temperature 1580 C for 8 hours were carried out. Optimal values of alumina­zirconium silicate mass moisture (3.5 %) and specific pressing pressure (100 N/mm2), which provide receipt refractories with high apparent density of formed greens (2.96 g/cm3) and dried greens (2.89 g/cm3) and properties after firing: apparent density 3.1 g/cm3, open porosity 21 %, cold crushing strength 75 N/mm2, thermal shock resistance by 950 C — water — more than 20 thermal cycles were established. Obtained results were used at making of alumina­zirconium silicate products for glass melting furnace of industrial lining for fiberglass production from E glass.

ABSTRACTGlassy materials for HLW immobilization were produced from HLW surrogate, quartz sand, datolite (CaBSiO4OH), and bentonite clay at a temperature of up to 1200 °C. Waste loading (WL) ranged between 20 and 40 wt.%. The glasses were characterized by X-ray diffraction, scanning electron microscopy and Fourier-Transform infrared spectroscopy. Glasses with waste loading of up to 35 wt.% obtained by melt pouring onto a metal plate were found to be rather homogeneous but contained minor noble metal oxides and britholite (at high waste loadings) while those annealed in turned-off furnace were partly devitrified. Average chemical composition of britholite corresponded to formula Na1.00Ca4.02Y0.33Ce0.05Nd3.64Gd0.17Si6.79O24.39. The glass network is built from SiO4 units with one or two bridging oxygens and complex borate groups with primarily ternary coordinated boron. Increase of waste loading resulted in shift of band’s maxima to lower wavenumbers exhibiting increasing the fraction of SiO4 unit with lower number of bridging oxygen ions and thus reduction of glass network connectedness. Glasses with up to 30 wt.% waste loading kept their high hydrolytic durability making them suitable for HLW immobilization.

Comparative researches of grain composition batch influence with electrofusion corundum aggregate with a maximum grain size 2.0 mm or 1.0 mm on properties of alumina-zirconium silicate KTSS brand and alumina-chromia-zirconium silicate KCHTSS-30 and KCHTSS-15 brands refractories were carried out. It was established that, from batches with maximum grain size 2.0 mm and fraction content < 0.5 mm 20 % it is possible to obtain refractories with properties that approximate to the properties of refractories from batches with maximum grain size 1.0 mm and fraction content < 0.5 mm 10 %. It was shown that, for the manufacture of alumina-chromia-zirconium silicate refractories from optimal grain composition batches it is advisable to use metallurgical and pigment chromic oxide in the ratio of 2 : 1 or complete replacement of chromic oxide with mud, forming during mechanical treatment of chrome oxide refractory products. The developed compositions of batches make possible to increase efficiency of using electrofusion corundum in the manufacture of alumina-zirconium silicate and alumina-chromia-zirconium silicate refractories. Obtained results are used at making of products for glass melting furnace of industrial lining for fiberglass production from E glass.

Over the past years the target for waste recovery/ recycling has significantly increased in Romania, in according with the EU Directives. Nowadays, the competitive contexts of the current market lead the manufacturers to obtain novel and custom-made products using new technologies and quality raw materials. Such resources can be consisting of low-cost waste/by-products and in the processes of converting them into value-added products. On the other hand, the necessity for recycling waste is important under the strict European legislation. Regarding glass, the key sources of waste are container/ packaging glass, flat glass, electric and electronic equipments, domestic glass, E-glass, etc. According with source, waste glass can be: pre-and post-consumer waste glass. Now many recycling processes have been studied, developed and applied in industry. The major challenge is represented by creating of innovative and sustainable technologies and making it suitable. But recycling of glass is technologically more complicated than other waste (for example: paper). In case of glass, the most sustainable route is to use it for re-melting processes and obtaining a new glass. Glass is 100% recyclable but not all waste/cullet can be used for the manufacturing of any type of glass, due different chemical composition and the prohibitive shipping costs from collection points to glass factory. In this study, authors paid attention to the recycling process of soda-lime glass (post-industrial flat glass) and proposed the thermal embossing technique of glass, using glass slumping process, in order to obtain decorative products with aesthetic impact and functional role. An input image is prepared by applying different enhancement techniques, adjusting contrast, transferring into grayscale image in 256 shades of gray. The result image is transferred in Computer Aided Manufacture (CAM) software to refine the surface geometries and to obtain with rapid tooling the mould for glass. The method used for tooling fabrication consists of machining a block of suitable material with a Computer Numerical Controlled (CNC) machine which is known as a subtractive method. The next stage consists in applying of the heat treatment, using an electrical furnace. The major advantages of the embossing method for converting waste glass in value-added products is represented in the fact of use reduced energy comparing with the classic route of re-melting, possibility of obtaining bespoke products, ready to use in architectural and decorative fields. In addition, environmental benefits that results from processing waste glass are the reducing the raw materials (virgin) and the CO2 emissions.

Paved surfaces must reliably bear heavy loads, often under challenging environmental and geotechnical conditions. These requirements are addressed through the use of high-quality, newly produced materials in pavement design. However, in remote locations, newly produced materials are often expensive or unavailable, making waste or alternative materials more attractive. Waste materials can be used in their natural condition but are more commonly stabilised or otherwise improved to meet performance targets. However, this practice can incorporate unwarranted risk into pavement design solutions. The decision to use waste materials in a pavement is a balance between technical risk, maintenance liability, available materials, environmental emissions and capital cost. This study reviews the use of waste materials in pavement design and construction. Reclaimed asphalt pavement (RAP) materials and processed waste plastic for pavement construction are considered. Additionally, blast furnace slag (BFS) and waste glass in pavement construction are evaluated. This review focuses on the effects of alternative materials on the properties of asphalt pavement. The results indicate that RAP is acceptable as an alternative material, while BFS, waste plastic and waste glass can be used under specific conditions. Also, the current and future challenges for the use of waste materials in the pavement industry are discussed.

Research of pigment chromic oxide addition influence on properties of alumina-chromia-zirconium silicate refractories simples with a mass part 30 and 15 % Cr2O3 got by the semidry pressing method is carried out. It is set, that in samples made from batch with 30 % Cr2O3 optimal quantity of pigment chromic oxide, which provide achieving close properties indexes compared to indexes of samples without this component should be considered 10 %, and in samples made from batch with 15 % Cr2O3 — 6 %. The properties indexes of samples with 30 % Cr2O3 containing 10 % pigment chromic oxide are: mass part of Al2O3 — 62.7 %, Cr2O3 — 30.3 %, ZrO2 — 5.8 %, open porosity 22.6 %, apparent density 3.27 g/cm3, cold crushing strength 123 N/mm2, thermal shock resistance on the mode 950 оC — water 4 thermal cycles, residual changes of sizes at a temperature 1650 оC, exposition 2 hours 0 %. The properties indexes of samples with 15 % Cr2O3 containing 6 % pigment chromic oxide are: mass part of Al2O3 — 76.4 %, Cr2O3 — 15.2 %, ZrO2 — 6.1 %, open porosity 22.4 %, apparent density 3.17 g/cm3, cold crushing strength 145 N/mm2, thermal shock resistance on the mode 950 оC — water 4 thermal cycles, residual changes of sizes at a temperature 1650 оC, exposition 2 hours 0 %. Obtained results are used at making of products for glass melting furnace of industrial lining for fiberglass production from E glass.

Steelmaking is accompanied with releasing a large quantity of solid particle in the form of dust. Electric arc furnace dust (EAFD) is known to have high pH number and traces of heavy metals. The objective of this work was to find a suitable procedure for converting the dust waste into inert and useful byproducts using thermodynamic calculations and experimental investigation. The physical, chemical and mineralogical characteristics of initial EAFD were analyzed using different techniques, such as: X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), grain size analysis and metallography. The pH measurement procedure was carried out in accordance with the standard test method for pH of soils “ASTM 4972-95a”. The results of XRD, SEM and EDS analysis were consistent and showed that Fe2O3, CaO, Al2O3, SiO2, MgO, ZnO and traces of other oxides are in the main composition of the EAFD batches with different relative amounts. Furthermore, the particle size measurements revealed that the EAFD particles are in the 0.1 to 394 μm size range. The pH number was ranging between 11.15 and 12.21 for all measurements. The experimental results were used as input data for thermodynamic calculations and accordingly SiO2 and Al2O3 were among the candidates for making ceramic materials through forming glass regions that surround and encapsulate the iron oxide particles. SiO2 modified samples exhibited better apparent structural properties than other compositions. Whereas Al2O3-modified samples showed variation in the product color. Thus, it is concluded from this work that a mixture of EAFD can be modified by 5-20 wt.% of SiO2 and then fired at 1100°C to make inert ceramic materials with reasonable mechanical properties.

Al-Zn doped SnO2 (Sn1-2xAlxZnxO2) film has been growth using the sol-gel dip coating technique. The basic materials used in this study were water, C2H5OH, SnCl2.2H2O, AlCl3 and ZnCl2 with 99% purity (merck) with doping concentration variation x = 0.000, 0.005, 0.025, and 0.050. Glass substrate with size 2.54 mm x 76.2 mm x 1 mm cleaned with detergent, soaked in 30% HCl solution For 1 day and dried at 100°C. The process of making a SnO2 sol is done by mixing the precursor with various concentrations with water and stirring using a magnetic stirrer for 30 minutes at a temperature of 80 ° C. The next step by adding ethanol, stirring at 80 ° C. for 2 hours to obtain 0.4 M sol solution The deposition of SnO2 film was carried out using a dip coater with a whitdrawl speed 12 cm/min and then heated for nucleation and grown using an electric furnace at 600 ° C for 30 minutes. This step is repeated as much as 5 repetitions to get the SnO2 film by doing Al-Zn.

This paper discusses the influence of fiber reinforcement on the properties of geopolymer concrete composites, based on fly ash, ground granulated blast furnace slag and metakaolin. Traditional concrete composites are brittle in nature due to low tensile strength. The inclusion of fibrous material alters brittle behavior of concrete along with a significant improvement in mechanical properties i.e., toughness, strain and flexural strength. Ordinary Portland cement (OPC) is mainly used as a binding agent in concrete composites. However, current environmental awareness promotes the use of alternative binders i.e., geopolymers, to replace OPC because in OPC production, significant quantity of CO2 is released that creates environmental pollution. Geopolymer concrete composites have been characterized using a wide range of analytical tools including scanning electron microscopy (SEM) and elemental detection X-ray spectroscopy (EDX). Insight into the physicochemical behavior of geopolymers, their constituents and reinforcement with natural polymeric fibers for the making of concrete composites has been gained. Focus has been given to the use of sisal, jute, basalt and glass fibers.

Learning by the actual experience of fabrication and evaluation of a p-n junction is a very effective way for students to obtain a deep meaningful understanding of the fundamentals of semiconductor physics. To achieve this requirement at a real-world classroom situation, a simplified fabrication process for making the silicon p-n junction as the educational application was studied. The process without using the lithography process, and in use of simple thermal diffusion furnace under the air environment for the impurity thermal diffusion process by using phosphorous silicate glass (PSG) thin film prepared by the Sol-Gel material as the phosphorus (P) diffusion source was proposed and tested. As the results, it was obtained that the impurity concentration and diffusion depth were controlled well by this method, and good rectification phenomenon of the p-n junction was successfully observed. The typical diode factor n of the p-n junction was approximately 2.3. The p-n junction also performed well as a solar cell. The FF is approximately 0.7. These results show that it is possible to use the p-n junction prepared by this simplified process as the educational device to help students’ understanding of the theory of the p-n junction.

Generally, alkali-activated materials (aka geopolymers) present good behaviour at high temperatures, but previous studies of geopolymers under elevated temperatures are, in most cases, focused on metakaolin or fly ash based geopolymers, making the information on geopolymers with mining waste mud almost inexistent. In this paper, were analysed geopolymers with different combinations of mining waste mud, waste glass powder, metakaolin and expanded cork in a total of 15 different mixtures using sodium hydroxide and sodium silicate as alkaline activators. Materials particle size used is under 500 μm for mining waste mud, waste glass powder. Some mixtures also included expanded granulated cork with particle size between 2 to 4 mm. Ten samples with 40 × 40 × 40 mm dimensions were used for the compression test, one sample for the TGA test, and one cube (100 × 100 × 60 mm) with a frustoconical hole (50 mm deep) and a 100 × 100 × 25 mm cover, for the cup test. All the mixtures were cured for 24h at a temperature of 60 °C before being demoulded, and left at room temperature until they reach 7 days to be tested. On the 7th day, of each mixture, samples were placed in a static furnace before the compression test submitted to a temperature of 800 °C during 2h. Then, the compression test was performed and the values before and after exposure to high temperatures were compared. Were recorded maximum gains of 724% and maximum losses of 100% in the compressive strength. This preliminary result shows the potentials of mining waste alkali-activated materials for elevated temperatures applications.

Abstract Titanium (Ti) is widely known for its good mechanical properties and corrosion resistance. However, it has poor biocompatibility. Hydroxyapatite (HA) is a biocompatible material but has poor mechanical properties. Making Ti-HA composite creates a promising choice of biomaterial in dental and medical applications. However, creating a Ti-HA composite requires sintering at high temperatures which leads to oxidation of Ti. The aim of this study was to reduce the sintering temperature of Ti-HA composite by incorporating 45S5 Bioactive Glass (BG) without compromising the chemical, physical and mechanical properties of the composite. In this study, a Ti-HA-BG composite with wt% of 45-45-10 respectively was produced via powder metallurgy. This was compared with the control composite consisting of 50 wt% Ti- 50 wt% HA. Powders according to the above-mentioned ratio were milled at 200 rpm for 5 hours by using a planetary ball milling machine. Samples were then compacted into cylindrical pellets via uniaxial pressing at 1500 psi and sintered in an atmospheric furnace at 1000 °C, 1100 °C and 1200 °C for 4 hours. Ti-HA and Ti-HA-BG sample characteristics were examined and compared by using Fourier Transformed Infrared Spectroscopy (FTIR), Energy Dispersive X-Ray (EDX) and X-Ray Diffraction (XRD). The density and volumetric expansion of the composites were also measured and compared. Results from XRD data indicate the reduction of oxidation of Ti and decomposition of HA in Ti-HA-BG composite at lower temperature in comparison to Ti-HA composite. The density of Ti-HA-BG composites are higher compared to Ti-HA composite while the volumetric expansion of Ti-HA-BG composites is lesser than Ti-HA composite. Therefore, BG is a low melting point additive that acts as a good sintering aid to effectively lower the sintering temperature while maintaining the desired properties of initial components.

There are significant changes observed in concrete materials, the properties of innovated concrete have also experiencing revolutionize through hi-tech encroachment. Instead of new changes in the materials used in concrete making, the adjustment in concrete is started from conventional concrete strength and slowly tracked by high-strength concrete and high-performance concrete. Recently, the exploitation of by-products waste in the self-compacting concrete (SCC) had achieved massive interest among researchers due to practicable and beneficial features. Most of the prior works focused on SCC combining with supplementary cementitious materials such as fly ash, coal bottom ash, silica fume, ground granulated glass blast-furnace slag and rice husk ash. Concrete with these cementitious materials have been used extensively throughout the world. These materials used as mineral admixtures in concrete and strengthen the durability and concrete properties. The concrete applications are increasing with the passage of time due to their superior structural performance, environmental friendliness and low impact on energy utilization. Through these understanding, this research points out the idea of cementitious materials in concrete, especially SCC possess with numerous positive features such as durability, flowability and overall performance of concrete. It can be seen that cementitious materials have high benefit and lead to curing potential. However, it is important to understand that these materials are relatively expensive. Thus, this is a main reason behind their less adoption compared to add as mixtures in Portland cement.

Nowadays, scientific community is looking for alternatives to reduce the problem of CO2emissions, making more sustainable binders and reusing wastes from other industries.In this line, the technology of geopolymers was born, in which, binders based on alkali-activation can be produced entirely or almost entirely from waste materials. In alkali-activation a source of aluminosilicate is dissolved by a highly alkaline solution previous to precipitation reactions that form a gel binder.The use of alumino-silicate minerals such as metakaolin, blast furnace slag and fly ash to produce alkali-activated cements has been extensively studied and it’s increasing the interest in investigating the suitability of using other materials. Different wastes containing silica and alumina, such as hydrated-carbonated cement, glass, fluid catalytic cracking catalyst residues (FCC) have been activated.The aim of this study is to verify if the use of geopolymers is compatible with the manufacturing technology of typical building elements, in this case roof tiles.Mechanical properties of mortars and roof tiles using as source of aluminosilicates FCC have been studied, with different mixtures and variating the proportions of NaOH and waterglass.Compressive strength development was evaluated in mortars cured at 20oC for 7 and 28 days and flexural strength, impermeability and impact resistance were evaluated in roof tiles. The results obtained demonstrated the feasibility on the use of geopolymers in the design of new products with less CO2emissions and then the contribution to the sustainability in the construction sector.

Noise pollution is a workplace hazard which causes loss of hearing, depending on the sound pressure level and duration of exposure. Because duration of exposure is usually uncontrollable, sound absorbers are used to reduce the value of sound pressure level. A common method to reduce noise is to use porous sound absorbers made out of mineral wools or glass fibres. However, these materials pose health risks and are non-recyclable. This project aimed to fabricate a sound absorber using recycled paper which is in the form of egg cartons as an alternative to the abovementioned fibres. Paper fibres posses high fibre porosity and can be manufactured in a manner which the properties can be easily controlled, making them ideal to be made into sound absorbers. Furthermore, they are biodegradable, do not pose health risks and can be manufactured into different shapes easily. Recycled paper was first turned into pulp, blended and poured into moulds. Different amounts of pulp was compressed until the sample size was approximately 20 mm thick and then dried in a furnace dryer at 600C for 12 hours. The samples were tested using a two-microphone, transfer function impedance tubes according to the ISO 10534-2 standard. Its porosity was determined using a modified wash basin method. The results indicate that the optimum panel has an average noise reduction coefficient, (NRC) of 0.50, which qualifies it to be used as a sound absorbing material. It also encounters its maximum value of 0.98 which occurred at the 1575-1675 Hz range. When compared to other materials, recycled paper has similar properties as coir fibre and is quite comparable to other commercial sound absorbers at the same thickness.

A comprehensive analysis of the quality parameters of fused-cast aluminum-zirconium-silicate (AZS) refractories for glass furnaces has been carried out. It is shown that the assessment of the quality of AZS refractories by the content of ZrO2 and density in them does not give an objective idea of their operational properties. Of fundamental importance are the chemical composition and behavior of the glass phase, which determine the volume and temperature of the onset of exudation. Among the most important conditions for obtaining high-quality AZS refractories, characterized by a melting volume of 2‒3 % of the glass phase and a melting start temperature above 1400 °C, include the oxidative melting technology and the content of impurities in the chemical composition of the refractory no more than 0,25‒0,30 %. The conditions for the service of AZS refractories in the melting basin and the working space of glass-melting furnaces are formulated. Their influence on the course of the exudation process, the corrosion resistance of refractories and the formation of defects in glass is shown. Ill. 2. Ref. 30. Tab. 4.

In JSC “URIR named after A. S. Berezhnoy” chromia refractories for the lining of pool and feeder of glass-making furnaces for the production of glass fiber from E glass, which are in contact with the glass melt, and alumina-chromia-zirconia-silica refractories with 30 % Cr2O3 for service in the topsides of these furnaces, in areas affected by components of the glass batch and glass melt, have been developed and manufactured. The main raw material for the chromia products manufacturing is metallurgical chromium oxide. In the manufacture of alumina-chromia-zirconia-silica products, metallurgical chromium oxide or a mixture of metallurgical and pigment chromium oxide in a ratio of 2 : 1 is used as the chromium oxide component of the batch. The testing of new materials, such as a new grade of chromium oxide, in the technologies of chromia and alumina-chromia-zirconia-silica refractories is relevant. The effect of a new grade of chromium oxide on the properties of chromia refractories has been investigated. It was found that samples of a new grade of chromium oxide, pressed at optimal values of moisture content of the mass and specific pressing pressure, are characterized by a low apparent density of the raw material in comparison with samples made of metallurgical chromium oxide. After firing, samples from chromium oxide of the new grade are not inferior to those of metallurgical chromium oxide in terms of properties, but they have large changes in linear dimensions during firing, which can lead to the formation of cracks, therefore, the issue of obtaining chromia products from mixtures with the replacement of metallurgical chromium oxide with chromium oxide of the new grade in order to increase the apparent density of products requires additional research. A study on the effect of new grade of chromium oxide on the properties of alumina-chromia-zirconia-silica refractories with a content of 30 % Cr2O3 has been carried out. It was established that, in the batch for the manufacture of these refractories, containing metallurgical and pigment chromium oxide, it is possible to completely replace the pigment chromium oxide with chromium oxide of the new grade or to increase the content in the batch of chromium oxide of the new grade instead of a part of metallurgical chromium oxide to the ratio of metallurgical chromium oxide and chromium oxide of the new grade 1 : 2.

The results of experimental research of perspective thermometric material Lu1-xZrxNiSbwhich can be used for the production of sensitive elements of thermoelectric and electroresistive thermometers are presented. Thermometric materials Lu1-xZrxNiSb, x=0.01–0.10, were made by fusing a charge of components in an electric arc furnace with a tungsten electrode (cathode) in an atmosphere of purified argon under a pressure of 0.1 kPa on a copper water-cooled hearth (anode). Heat treatment of alloys consisted of homogenizing annealing at a temperature of 1073 K. Annealing of samples was carried out for 720 h in vacuumed up to 1.0 Pa ampoules of quartz glass in muffle electric furnaces with temperature control with an accuracy of ±10 K. Diffraction arrays were obtained on a diffractometer DRON-4.0 (FeKα radiation), and the structural characteristics of Lu1-xZrxNiSbwere calculated using the Fullprof program. The chemical and phase compositions of the samples were monitored using a scanning electron microscope (Tescan Vega 3 LMU). The study of the temperature dependences of the resistivity ρ(T,x) and the thermopower coefficientα(T,x) Lu1-xZrxNiSb was performed in the temperature range of 80÷400 K on samples in the form of rectangular parallelepipeds measuring ~1.0×1.0×5.0 mm3 . Measurements of the values of the specific magnetic susceptibility χ(x) of Lu1-xZrxNiSb samples were performed by the relative Faraday method at a temperature of 273 K using a thermogravimetric installation with an electronic microbalance EM-5-ZMP in magnetic fields up to 10 kGs. Microprobe analysis of the concentration of atoms on the surface of Lu1-xZrxNiSb samples, x=0.01–0.10, established their correspondence to the initial compositions of the charge, and X-ray phase analysis showed no traces of extraneous phases on the sample diffractograms, except for the main phase. The nonmonotonic nature of the change in the values of the unit cell period of the thermometric material an (x) Lu1-xZrxNiSb, x=0.01–0.10, which differs from the results of modeling structural characteristics using software packages AkaiKKR and Elk. The nonmonotonic change in the values of the period of the unit cell a(x) Lu1-xZrxNiSband the presence of the extremum dependence suggests that the impurity Zr atoms introduced into the matrix of the LuNiSb basic semiconductor can simultaneously occupy partially different crystallographic positions in different ratios. The temperature resistivities ρ and the thermopower coefficientα of the LuNiSb base semiconductor contain high- and lowtemperature activation regions, which is characteristic of doped and compensated semiconductors. The introduction into the LuNiSb structure of the lowest concentration of impurity Zr atoms in the experiment (x=0.01) radically changes both the behavior of the temperature dependences of the resistivity ρ and the thermopower coefficientα and the type of the main electric current carriers. The values of the resistivity ρ(T,x) Lu1-xZrxNiSbonly increase with increasing temperature, which is characteristic of the metallic type of electrical conductivity and is due to the mechanisms of scattering of current carriers. This nature of the change in electrical resistance ρ(T,x) is evidence that the Fermi level εF has left the bandgap εg and is in the conduction band εC. This is indicated by the negative values of thermopower coefficientα(T,x) at all concentrations and temperatures. Studies of the magnetic susceptibility χ(x) showed that the samples as a basic semiconductor LuNiSb, as well as the thermometric material Lu1-xZrxNiSb, at all concentrations of impurities Zr, are Pauli paramagnetic. There is a synchronicity of the behavior of χ(x) with the dependences of the resistivity ρ(x, T) and the thermopower coefficient α(x, T), which is due to the change in the density of states at the Fermi level g(εF). The results of experimental studies of the Lu1-xZrxNiSbthermometric material completely coincide with the results of modeling its kinetic characteristics under the presence of vacancies in the crystallographic positions 4a and 4c of the Lu and Ni atoms, respectively. Such studies allow making adjustments in the structural studies of thermometric material with an accuracy that significantly exceeds the accuracy of X-ray research methods. The obtained results will allow us to clarify the spatial arrangement of atoms in the nodes of the unit cell, as well as to identify the mechanisms of electrical conductivity to determine the conditions for the synthesis of thermosensitive materials with maximum efficiency of thermal energy conversion into electricity.

The paper presents the results of optimization of the geometric parameters of the heat exchange surface of water and air-heating heat exchangers of glass-making furnaces and an analysis of their exergy efficiency. Ensuring the efficient operation of heat recovery units in various thermal circuits is an urgent problem of heat power engineering. The aim of the work is to establish the optimal areas of the geometric parameters of the heat exchange surface of heat recovery units of glass-melting furnaces and to analyze their exergy efficiency. The paper presents the results of solving the tasks necessary to achieve the goal: - using statistical methods for planning the experiment, determine the levels of variation of the parameters of the geometric surface of heat transfer for the heat recovery units under study and calculate the values of the criteria for evaluating the efficiency at the points of the central orthogonal compositional plan; - to obtain the regression equations for the investigated heat exchangers, to determine the optimal areas of change in the geometric parameters of the heat exchange surface and the corresponding exergy efficiency criteria. To determine the optimal areas of geometric parameters of the heat exchange surface, a complex methodology is used based on the methods of exergy analysis and statistical methods of the theory of experiment planning. It has been established that when designing heat recovery schemes for heating water in heat supply systems and for heating blast air, heat recovery units with the following values of the areas of variation of the geometric parameters of the heat exchange surface can be used: - the values of the area of variation of the distance between the panels for heat recovery units with a staggered and corridor arrangement of pipes in a bundle s1 = 58.0-62.0 mm. - the values of the areas of change in the diameter of pipes for a hot water heat exchanger with a corridor arrangement of pipes d = 41.0-43.0 mm and for an air heating heat exchanger with a staggered and corridor arrangement of pipes d = 29.0-31.0 mm. - the use of the values of the ranges of change of other parameters is carried out taking into account additional technological factors. It has been established that the exergy efficiency of hot water heat recovery units is in all cases higher than the exergy efficiency of air heating units. For hot water heat exchangers, the values of exergy criteria are lower than for air heating ones: k – 2.0 times, ε – by 7.5%, m0 – 1.9 times. The expediency of using the investigated heat recovery units in heat recovery circuits of glass melting furnaces has been established, taking into account the results obtained and in the presence of certain technological factors. The results obtained and further developments in the field of optimization of the operating parameters of heat recovery units for glass-melting furnaces will provide an increase in the efficiency of heat recovery equipment for power plants.

The study aims to determine the effect of fermentation time complete feed and silage of Tebon corn to changes in pH and nutrient content. This research was conducted in January to March 2015, in the Laboratory airy College of Agricultural Sciences (STIPER) Kendari and analysis of feed materials to be carried out at the Laboratory of Animal Nutrition and Feed Faculty of Animal Husbandry Haluoleo university. Materials used in this study were aged 60-70 days corn Tebon, pollard 20%; copra 20%; premix 30%; corn Empok 25%; salt 2.5%; minerals 2.5%, Aquadest, a buffer solution pH 7. The catalyst, concentrated H2SO4, distilled water, 0,1N H2SO4, NaOH 40%, indicatormix, 0,1N NaOH. Equipment used in this study include: chopper, plastic, rope scales, vacuum, freezer, Erlenmeyer, pH meter, analytical balance, pumpkin Kjeldhal, Erlenmeyer, glass beaker, destructor, distillation, titration tools, ovens and furnaces. The method used in this study is completely randomized design experiment Nested with 2 treatments, three long storage and 3 replicates (2x3x3) on each treatment. The treatment tested was: Concentrate + Tebon corn with different fermentation time, concentrate + corn silage Tebon with different fermentation time, then do Silage-making, mixing Silage, Silage Testing. The parameters in this study the degree of acidity (pH), nutrient content includes dry matter (DM), organic matter (OM) and crude protein (CP) before and after fermentation. Based on the results of complete feed nutrient content analysis showed that each - each fermentation time treatment effect (P<0,01) to change the content of DM, OM and CP when compared to the control with the average low enough pH ranged from 4.18 to 4, 38. Based on this research can be concluded that the fermentation time very real impact on the quality of corn silage Tebon. Fermentation feed concentrate and corn Tebon (KT) decreased nutrient content higher than the complete feed made from concentrates and corn Tebon silage (KS)

The article is devoted to the Golden Horde complexes associated with the processing of non-ferrous metals and the organization of handicraft production. Historiography has repeatedly voiced the significant role of the masters of the conquered territories in the formation of the metalworking production of the Golden Horde. In the article the characteristic features of the Golden Horde craft complexes are considered in comparison with similar complexes of Kievan Rus cities, as well as with some traditions of the organization of Central Asian craft. Data from workshops of Tsarevskoe, Uvekskoe, Bolgarskoe settlements, Staryy Orhey were brought in. The complexes are considered in terms of such parameters as location in the city planning system, type of structure, presence of smelting furnaces and hydraulic structures, set of production, range of products and coexistence with other industries. It is noted that in the cities of the Golden Horde there are various forms of organization of metalworking crafts, small workshops in craft districts and complex workshops functioning within household plots. The workshops location is not clearly defined; in general, they do not form specialized areas. The structures in which the workshops operate have no design features and may not contain heat engineering structures. Workshops for the processing of non-ferrous metals most often function in conjunction with bone carving and pottery production, less often in a composition with leather, glass making, and gemstone processing. This is significantly different from the situation in Kievan Rus cities, where the processing of non-ferrous metals is most often combined in various forms with the processing of ferrous metals. The handicraft complexes of the Golden Horde cities demonstrate a wide variety of forms, and most of them find their analogies in the materials of ancient Russian cities, therefore, it is difficult to single out specific features indicating possible genetic connections.

Biogas production considered the most encouraging sources of renewable energy in Sudan. Anaerobic process of digestion is considered as efficient techniques of producing biogas. The process also a trustworthy method for treatment of municipal wastes, and the digested discharge could be utilized as soil conditioner to improve the productivity. This research work states at the option of using domestic sludge of the wastewater treatment plant in Soba municipal station (south of Khartoum-Sudan) to produce biological gas (biogas). A laboratory investigation was carried out using five-liter bioreactor to generate biogas for 30 days. The total volume of gas made was 270.25 Nml with a yield of 20 Nml of biogas/mg of COD removed. Chemical oxygen demand, Biological oxygen demand, & total solids drop produced were 89, 91 & 88.23% respectively. Microbial activity was declined from 1.8x107 (before starting the process of digestion) to 1.1x105 germs/mL (after completion of 30 days of digestion). This study offered a significant energetic opportunity by estimated the power production to 35 KWh.Key word: Sludge, municipal plant, organic material, anaerobic process, breakdown, biological gas potentialNTRODUCTIONIncreasing of urban industries style in the world has given rise to the production of effluents in huge amounts with abundant organic materials, which if handled properly, be able to end in a substantial source of energy. Although of a fact that there is an undesirable environmental effect related with industrialization, the influence can be diminished and energy can be tapped by means of anaerobic digestion of the wastewater (Deshpande et al., 2012). Biological wastewater treatment plant (WWTP) is a station for removal of mainly organic pollution from wastewaters. Organic materials are partly transformed into sludge that, with the use of up-to-date technologies, represents an important energy source. Chemical biological, and physical technology applied throughout handling of wastewater produce sludge as a by-product. Recent day-to-day totals, dry solids range from 60–90 g per population equivalent, i.e. EU produces per year 10 million tons of dry sludge (Bodík et al., 2011). Sludge disposal (fertilizers use, incineration, and landfills) is often explored since of increasingly limiting environmental legislation (Fytili and Zabaniotou, 2008). The energy present in sludge is obviously consumed in anaerobic digestion. Anaerobic Process is considering the most appropriate choice for the handling of organic effluents of strong content. This process upgraded in the last few years significantly with the applications of differently configured high rate treatment processes, particularly for the dealing of industrial releases (Bolzonella et al., 2005). Anaerobic process leads to the creation of biological gas with high content of methane, which can be recovered, and used as an energy source, making it a great energy saver. The produced gas volume during the breakdown process can oscillate over a wide range varying from 0.5 – 0.9 m3 kg–1 VS degraded (for waste activated sludge) (Bolzonella et al., 2005). This range rest on the concentration of volatile solids in the sludge nourish and the biological action in the anaerobic breakdown process. The residue after digestion process is stable, odorless, and free from the main portion of the pathogenic microorganism and finally be able to use as an organic nourishment for different application in agriculture. Sludge significant coming out from breakdown which allows to yield a renewable energy, that was cheap, obtainable, & no polluting. Sustainable development considered the production of biogas as environmentally friendly and an economic key (Poh and Chong, 2009).OBJECTIVES Sudan have huge tones of sewage sludge from domestic sewage water is accumulated daily in lagoon of soba sewage treatment plant, so this work, we were carried for energy production and treatment of sludge, which constitutes a plentiful waste which ever know any sort of handling after few years from establishing the station.MATERIALS AND METHODSExperimental apparatus: Anaerobic breakdown was done in five liters fermenter. The fermenter was maintained at 35oC in a thermostatic bath and stirred regularly. U shaped glass tube was connected to the fermenter, allowing the measurement of produced biogas volume and pressure. Water displacement technique was used for determination of the volume of produced biological gas (biogas) at the beginning of each sampling. Testing of the biogas combustibility was determined by connecting one of ends of the tube to a gas collection and storage device (balloon), the other end to a Bunsen burner. In the process of reduction of carbon dioxide (CO2) to maximum dissolution in the tube the liquid must be a salty saturated acid solution (5% citric acid, 20% NaCl, pH ¼ 2) (Connaughton et al., 2006).Substrate: About 5L sludge containing culture medium were taken from the lowest part of the first settling tank in Soba station. The moisture content of initial substrate was 35%. The collected sample was preserved at 4oC prior to loading the biological reactor (Tomei et al., 2008). Table 1 showed the sludge features in the reactor with a loading rate of 16 g TS/L, (Connaughton et al., 2006; Tomei et al., 2008).Analytical Methods: The pH was controlled by using HANNA HI 8314 model as pH meter device. Assay was used for determination of Alkanility & Volatile fatty acids (Kalloum et al., 2011). The standard method of analysis was used for recognized the Chemical Oxygen Demand (COD) (Raposo et al., 2009). Titrimetric method was used for analyzing Volatile fatty acids (VFA). Alkalinity assay was used for determination of Total Alkalinity (TA). Oxitop assay was used for measuring the biological oxygen demand. Ignition method was used for measuring Volatile Solids (VS) by losing weight in dry sample at 550oC in the furnace, & Total solids were done to constant weight at 104oC (Monou et al., 2009). A method of water displacement was used for determination of the total volume of Biological gas produced (Moletta, 2005). Microbial species & analyses were determined by microbial standard assay. Sample analysis was done by explore of three replicates and the outcomes were the middling of these replicates. Startup of experiments continues until a bubble of gas was detected.RESULTS AND DISCUSSIONMeasurement of pH: Figure 2 exhibited pH trends during 30 days with a drop pattern from 7.0 to 6.0 during the first five days; this was mainly because of the breakdown of organic materials and the development of (VFA). Then later, an increasing pattern in pH was noticed to 6.98, for the next week, then Steadying around this pH level was continued till the completion of the breakdown period which taken 30 days. Those out comes were also reported by other researchers (Raposo et al., 2008)Measurement of VFA: Development of VFA throughout 30 days was depicted in figure 3, an increase in volatile fatty acids up to 1400 mill equivalents per liter (meq/L) in the first ten days. This criterion of making of volatile fatty acid is typical to the researcher’s report of identification of hydrolysis in acidogenesis stage (Parawira et al., 2006). The decline in volatile fatty acids after the tenth day was owing to intake by bacteria which would relate to the stage of acetogenesis.Total alkalinity (TA): During the ten days, we observed rise in volatile fatty acids content followed by a drop in a pH in the same time (figures 4 and 5). Encountered to these alterations, an increase in the total alkalinity in the medium for reestablishing situations of alkalinity to the outbreak of methanogens stage (figure 4). Through all the digestion period the ratio of VFA/TA which was equal and lower than 0.6±0.1 were described in figure 6. These ratios designated the achievability of the procedure despite the essential production of volatile fatty acid (Chen and Huang, 2006; Nordberg et al., 2007). The anaerobic digestion process may be hinder by the production of volatile fatty acid.Biogas production: Pressure measurement and biogas volume were used for controlling biogas production. Figure 7 explained the changing in biogas pressure throughout the digestion period. quality of Biogas was obtained with minimum methane of 40% (Bougrier et al., 2005; Lefebvre et al., 2006). Total volume of biological gas production was 270.25 Nml. The yield of biological gas was 20.25 Nml/mg COD removed, which is in range of the others researcher report (Tomei et al., 2008). Biogas production can be calculated from the following formula (Álvarez et al., 2006): Biogas production= (Total quantity of biogas produced)/(Total solid).The COD and BOD removal: Chemical oxygen Demand (COD) and Biological Oxygen Demand (BOD) showed a significant reduction of 89% and 91% respectively (figures 8 and 9). Consequently these reduction in contaminants proved that anaerobic process of digestion was an operational technique for removal of organic pollution. Some researchers reported the same results (Bolzonella et al., 2005; Álvarez et al., 2006; Wang et al., 2006). Another criterion for proving the removal of organic pollutants was reduction of total solids (TS), where the drop approached 88.23% (figure 10). Some researcher’s reports approached the same drop (Hutnan et al., 2006; Linke, 2006; Raposo et al., 2009). Therefore it was possible to conclude that anaerobic digestion necessary showed decrease or reduction of organic pollutants rates because of the transformation of organic substances into biogas and accordingly led to the drop of chemical oxygen demand (COD). This could be explained in figure 11 by the comparison of the two techniques during the anaerobic digestion process. That means the chemical oxygen demand (COD) drop should be tailed essentially by Total solids drop (TS).Microbial activity: Figure 11 showed the microbial variation during anaerobic digestion. The total micro flora (total germs) declined from 1.8x107 (before starting the process of digestion) to1.1x105 germs/mL (after completion of 30 days of digestion). Moreover figure 12 obviously explained what was running during the process of digestion in the reactor, microbial species vanishing after the 30 days such as streptococci and Escherichia coli. Some researchers reports explained that there was some sort of relationship between physicochemical and the biological parameters of micro flora with total solid (TS). figure 13 described obviously this relationship of the drop of micro flora which go along with total solids reduction. This intended that consumption and a declining in the mass residue of organic materials created at the termination of digestion was the outcome of the transformation of organic materials into biological gas and also the sum of microorganism reduction. This attained result proved that the process of anaerobic digestion was a good process for decontamination (Deng et al., 2006; Perez et al., 2006; Davidsson et al., 2007).CONCLUSIONSoba sludge’s municipal station carried in this research paper demonstrated operative for biological gas production (biogas). During the first five days, breakdown of organic materials and the formation of volatile acids were started. Volatile fatty acids increased up to 1400 mill equivalents per liter (meq/L) in the first ten days, then started to decline in after the tenth day this owing to intake by bacteria which would resemble to acetogenesis stage. The biogas production lasted until the 21th day then starting decreasing till the last day (30 day) this due to instability of the culture medium of fermentation which became completely poor. COD and BOD showed a significant reduction of 89% and 91% respectively. 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The glass bead making furnace of the Masaga Glass Guild in Bida, Niger State Nigeria was evaluated in comparison to those of Ghana (Krobo) and India (Firozabad); it was discovered that the Masaga furnace falls short of an efficient system for sustainable work that should facilitate appreciable productivity. Furthermore, the furnace is not built with refractory bricks, implying that it has a short life span; the furnace is operated by hand-worked traditional cloth bellows requiring sustained and strenuous efforts over a relatively long period of time; Following this assessment, efforts were directed at modifying the furnace by producing design drawings of the modified furnace, design and production of refractory bricks from the design drawing, constructing the modified furnace structure using the refractory bricks, producing suitable furniture for the furnace and subsequently, devising a suitable mechanical blower device as an alternative to the manually worked bellows for the supply of combustion air. Consequently, a furnace was developed which eliminates the strenuous manual working of the bellows as well as the bellow operator and ensures that a single individual can work unassisted at the furnace in the process of glassware production.

The global sourcing department at World Kitchen faces a make/buy decision that could result in closing a 90-year-old facility in Pennsylvania. Concerns about labor costs and capital investment both come to the fore owing to ongoing union negotiations and the upcoming need for a major refurbishment of the glass-making furnace. Although many potential suppliers offer lower labor costs, tariffs, transportation, and quality must be factored into the decision.

Indium thin oxide (ITO) films have been used in solar cell applications as top conducting layers for many years. These films possess very good transmission and a low sheet resistance thus making them ideal candidate material for top conducting layers in thin film and HIT solar cells. In the present work, ITO films have been deposited over soda lime glass substrates for use as defogger applications, and for use as front contact electrode in HIT type solar cells as well. ITO deposition is done using pulsed DC sputtering technique inside a vacuum chamber with large size ITO sputtering target of 15 inches by 5 inches. Silver bus bars are printed at the two edges of glass using thick film screen printing technique and the firing of thick film is done in a belt furnace. The deposited ITO thin film characterization is done by using XRD, SEM and 4 probe sheet resistance measurement techniques. The transmission spectra is analyzed for optical transmission properties.