1,632 research outputs found
Preparation of Waste Paper Fibrous Cement and Studying of Some Physical Properties
Waste paper is available in environment from different sources, such as office, newspaper and markets. Waste papers are the abundant source of cellulose and may be used as landfill. Using of these wastes in building materials has two benefits, the first one has reduced the environmental pollution and the second improves the physical properties of concrete and building bricks (or blocks). Addition of waste paper cellulose to concrete at certain percentage improve its thermal insulation properties and affect its density to produce lightweight and insulating building materials. The material which produces by using waste paper is called papercrete. It is a mixture of waste paper pulp, sand, cement and water by replacing the cement by waste paper pulp at a certain percentage. Also fibrous cement could be produced by mixing of waste paper pulp with cement and water. In the current work the waste paper was processed to obtain the raw materials of papercrete and fibrous cement. The processing method includes a sequence of processes which are shredding, soaking, mixing, dewatering and drying. In the dewatering process, a wet pulp was obtained and it can be used as it is in the mixtures of papercrete or fibrous cement. A dry pulp also could be used. It is observed that one kilogram of office paper and that of newspaper produces 3.24 kg and 3.26 kg of wet paper pulp respectively. The dry pulp, which is produced during the drying process is 0.954 kg and 0.949 kg for 1 kg of office paper and newspaper respectively. Design of mix proportion, test of water absorption, apparent porosity and drying curve of samples with different percentage of paper pulp were investigated in the present work. Keywords: wastepaper, papercrete, fibrous cement, porosity, water absorption, bulk densit
Dynamic Analysis Of A Novel Manpowered Transportation Vehicle With High Mechanical Efficiency
This paper evaluates the dynamics of a novel manpowered
transportation vehicle. The vehicle has a novel mechanism that
maximizes the mechanical input work and utilizes the weight of the
rider for propulsion. The rider applies reciprocating stepping linear
forces to drive chain and ratchet mechanism. The later transfer the
reciprocating motion into a unidirectional rotational motion at the rear
wheel to propel the vehicle. We analyzed the dynamics of the driving
and transmission mechanism and derived the equations of motion, at
first. Then, we evaluated the performance of the vehicle. Results show
significant advantages of the novel driving mechanism
Protective effect of propolis on manganese chloride neurotoxicity of olfactory bulb in adult male albino rat
Background: Manganese (Mn) is widely used for industrial purposes and exposure to high levels of Mn may cause an irreversible brain disease. Propolis is a natural plant product; it acts as a powerful reactive oxygen species scavenger and improves the neurodegeneration process. Materials and methods: In this study 40 adult male albino rats were divided randomly into four groups 10 rats each: group I (control group), group II manganese chloride (MnCl2) received 10 mg/kg/day/orally for 4 weeks by intra-gastric tube, group III (propolis group) received 50 mg/kg/day/orally for 4 weeks by intra-gastric tube, and group IV (MnCl2 + propolis group) received the same doses with the same duration and route as in groups II and III. Rats were sacrificed after 24 h of last dose. The olfactory bulbs removed, the right bulb cut to be processed for haematoxylin and eosin, immunohistochemical staining and the left cut for electron microscopic studies. Results: Results revealed that rat olfactory bulb from MnCl2 group showed darkly stained mitral cells with dark pyknotic nuclei, some show pericellular spaces and vacuolation, dark apoptotic cells in granular cells, neuropil vacuolation and pyknotic astrocyte. Electron microscopic examination showed abnormal granular cell with irregular damaged nuclear membrane, rupture of myelin fibre. Mitral nerve cell with destructed nucleus, many cytoplasmic vacuoles, swollen rough endoplasmic reticulum, vacuolated mitochondria and neuropil were observed. Manganese chloride + propolis group showed improvement compared to MnCl2 group. Conclusions: It was concluded that propolis can ameliorate the toxic changes of manganese chloride on rat olfactory bulb
Kalman Filter of Dynamic Hierarchical Model
In a specific way, the dynamic hierarchical model has been presented alongside with the derivation of the final formula of the Kalman filter. The filtering coefficient used along with the equations necessary for the filtering process has also been determined. Most of the related works were studied which gave rise to the problem statement of filtering problems placed under the case of st = . Most of the basic concepts of the dynamic hierarchical linear model were also displayed based on some previous works. A mathematical formula was also formulated and derived to calculate the dynamic hierarchical Kalman filter model, which results in a repetitive measure to estimate the model parameters. The proposed derived formula reduces the error associated with the model and achieves a successful optimal estimation of the parameters. This proves that the Kalman coefficient is the best filtering for any normal probability distribution and provides the least variance among the estimates. This study also provides an illustrative example of the model with the filtering process concerned. It was further illustrated that the findings can be used in practical applications, which reveals the fields that can be investigated in this area
Process Simulation Modeling of the Linear Low-Density Polyethylene Catalytic Pyrolysis in a Fluidized Bed Reactor
In this work, a comprehensive process simulation was developed to study and predict the pyrolysis of linear low-density polyethylene (LLDPE) in a fluidized bed reactor (FBR). The comprehensive simulation operated at 600 and 700 °C to investigate the pyrolytic oil and wax yields. These products were chosen as they mimic fuel range products available as a renewable fuel and energy source. The results showed that the oil yield decreased from 600 to 700 °C. This is because of an increase in the polyolefin polymer matrix’s vibration leading to an increase in temperature and absorbed thermal energy. In addition, there is a higher gas yield produced and negligible wax formation at 700 °C, which is beneficial in controlling accrued plastic waste (PW), of which polyethylene (PE) represents a vast proportion of via thermo-chemical conversion (TCC) technologies. The detailed process simulation was compared with experimental data under the same technology and operating conditions, and it was found that less than 10% discrepancy was observed between the two sets of data, suggesting a good validation between the two studies. Further studies showed that the diesel fuel lumped hydrocarbon (HC) range (C10-C19) was between 40 and 63% in the pyrolysis oil yield obtained. Moreover, the temperature profiles and fluidized bed distributor parameters were compared and investigated. The current simulation has proven that it can successfully predict the pyrolysis of LLDPE in an FBR
Role of Nigella sativa seed oil on corneal injury induced by formaldehyde in adult male albino rats
Formaldehyde is frequently used in occupational environments, its toxicity concerns to all who work closely with it such as anatomists. Nigella sativa is an amazing herb with a rich historical and religious background; its seeds are the source of its active ingredients. The purpose of the present study was to evaluate the role of Nigella sativa oil on corneal injury induced by formaldehyde in adult male albino rats. Forty adult male albino rats were divided randomly to four groups 10 rats each: I — Control group, II — Formaldehyde exposed group, III — Nigella sativa oil group (40 mg/kg/day) via intragastric tube daily for 2 weeks and IV — Formaldehyde and Nigella sativa group. Rats were sacrificed with ether, the corneas were extracted, one processed for haematoxylin and eosin stain and the other was used for transmission electron microscopic examination. Our results in group II revealed marked disorganisation, erosion, vacuolation and necrosis of epithelial cells with loss of parts of epithelial layer. Large congested invasion of blood vessels with separation and disorganisation of stromal fibrils. The corneas of group IV showed intact layers of epithelial cells with appearance close to control group. Star shaped cells (limbal stem cells) were obviously noticed in basal and intermediate layer with intact Bowman’s membrane. Stroma showed regular parallel collagen, limbal stem cells were also noticed in group III. We concluded that Nigella sativa oil can ameliorate the toxic changes of formaldehyde on rat corneas.
Variation in gas chromatography (GC) analysis in setting up laboratory protocols for waste to energy novel fixed bed reactor setups
Gas Chromatography coupled with Mass Spectrometry (GC/MS) has been applied in various analytical chemistry works. However, to fine tune a system that can serve the purposes of pyrolysis oil identification has proven to be a laborious effort, especially when considering the fact that no standard protocol exists for such analysis. In addition, obtained products were yielded from a newly commissioned unit with a unique and novel design. In this study, a US patent office claimed reactor [SULTAN-1, Pyrolysis Reactor System for the Conversion and Analysis of Organic Solid Waste, Patent application number: 15,487,351] that degrades polyolefinc virgin and waste materials to obtain petroleum refinery and petrochemical feedstock, has been commissioned. The reactor produces three distinct physical states of matter products accumulated as testing specimens, i.e. solids, gaseous and oil. The samples analysed in this work were of the gas and oil produced by pyrolysis of end of life tyre (ELTs) shavings that required to have a special recipe to work with in the laboratory. Various MS cords were utilised and experimental setups to fine tune the process, and special emphasis was given on the gas samples variation in this communication. To reach the desired analysis results with high repeatability, a plethora of experiences of lab personnel and laboratory-based experimental work was accumulated. Laboratory protocols were also setup for this work. These will be detailed along the process execution which yielded a standard laboratory best practice analytical method as part of the State of Kuwait newly initiated Government Initiative project
Portulaca oleracea Linn seed extract ameliorates hydrogen peroxide-induced cell death in human liver cells by inhibiting reactive oxygen species generation and oxidative stress
Purpose: To investigate the protective effects of Portulaca oleracea seed extract (POA) against cytotoxicity, oxidative stress and reactive oxygen species (ROS) generation induced by hydrogen peroxide (H2O2) in human liver cells (HepG2).Methods: The extract (POA) was obtained by ethanol extraction of P. oleracea seeds. Cytotoxicity in HepG2 cells was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, neutral red uptake (NRU) assay and morphological changes. The cells were pre-exposed to noncytotoxic concentrations (5 - 25 μg/mL) of POA for 24 h, and then cytotoxic (0.25 mM) concentration of H2O2. After 24 h of exposure, MTT and NRU assays were used to evaluate cell viability, while morphological changes were assessed using phase contrast inverted microscopy. The effect of POA on reduced glutathione (GSH) level, lipid peroxidation (LPO), and ROS generation induced by H2O2 was also studied.Results: The results showed that pre-exposure to POA (25 μg/mL) significantly (p <0.01) attenuated the loss of cell viability by up to 38 % against H2O2-induced oxidative stress and ROS generation. In addition, POA (25 μg/mL) significantly (p <0.01) increased GSH level (31 %), but decreased the levels of LPO (37 %) and ROS generation (49 %).Conclusion: This study demonstrates that POA has the capacity to protect HepG2 cells against H2O2- induced cell death by inhibiting oxidative stress and ROS generation.Keywords: Portulaca oleracea, HepG2 cells, Cytotoxicity, Oxidative stress, Reactive oxygen specie
Comparative assessment of ambient air quality in two urban areas adjacent to petroleum downstream/upstream facilities in Kuwait
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