Search results for: biomethane production

Authors: Bijit Kalita, R. Jayaganthan

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Additive manufacturing (AM) is a novel manufacturing method which provides more freedom in design, manufacturing near-net-shaped parts as per demand, lower cost of production, and expedition in delivery time to market. Among various metals, AM techniques, Laser Powder Bed Fusion (L-PBF) is the most prominent one that provides higher accuracy and powder proficiency in comparison to other methods. Particularly, 17-4 PH alloy is martensitic precipitation hardened (PH) stainless steel characterized by resistance to corrosion up to 300°C and tailorable strengthening by copper precipitates. Additively manufactured 17-4 PH stainless steel exhibited a dendritic/cellular solidification microstructure in the as-built condition. It is widely used as a structural material in marine environments, power plants, aerospace, and chemical industries. The excellent weldability of 17-4 PH stainless steel and its ability to be heat treated to improve mechanical properties make it a good material choice for L-PBF. In this study, the microstructures of martensitic stainless steels in the as-built state, as well as the effects of process parameters, building atmosphere, and heat treatments on the microstructures, are reviewed. Mechanical properties of fabricated parts are studied through micro-hardness and tensile tests. Tensile tests are carried out under different strain rates at room temperature. In addition, the effect of process parameters and heat treatment conditions on mechanical properties is critically reviewed. These studies revealed the performance of L-PBF fabricated 17–4 PH stainless-steel parts under cyclic loading, and the results indicated that fatigue properties were more sensitive to the defects generated by L-PBF (e.g., porosity, microcracks), leading to the low fracture strains and stresses under cyclic loading. Rapid melting, solidification, and re-melting of powders during the process and different combinations of processing parameters result in a complex thermal history and heterogeneous microstructure and are necessary to better control the microstructures and properties of L-PBF PH stainless steels through high-efficiency and low-cost heat treatments.

Keywords: 17–4 PH stainless steel, laser powder bed fusion, selective laser melting, microstructure, additive manufacturing

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Authors: Anurak Khrueakham, Tassanee Chanphuthin

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Indigo is a well-known natural blue dye that is used hither to even though synthetic ones are commercially available. The removal of indigo from effluents is difficult due to its resistance towards biodegradation which causes an aquatic environment effect. Fenton process is a reaction between hydrogen peroxide H2O2 and Fe2+ to generate •OH (highly reactive oxidant (E◦= 2.8 V)). Additionally, •OH is non-selective oxidant which is capable of destroying wide range of organic pollutants in water and wastewater. The aims of this research were to investigate the effect of H2O2, Fe2+ and pH on indigo wastewater oxidation by Fenton process. A liter reactor was operated in all experiments. The batch reactor was prepared by filling 1 liter of indigo wastewater. The pH was adjusted to the desired value; then, FeSO4 at predetermined amount was added. Finally, H2O2 was immediately added to start the Fenton’s reaction. The Fenton oxidation of indigo wastewater was operated for 60 minutes. Residual H2O2 was analyzed using titanium oxalate method. The Fe2+ concentration was determined by phenanthroline method. COD was determined using closed-reflux titrimetric method to indicate the removal efficiency. The results showed that at pH 2 increasing the initial ferrous concentration from 0.1 mM to 1 mM enhanced the indigo removal from 36% to 59%. Fenton reaction was rapidly due to the high generation rate of •OH. The degradation of indigo increased with increasing pH up to pH 3. This can be explained that the scavenging effect of the •OH by H+ in the condition of low pH is severe to form an oxonium ion, resulting in decrease the production of •OH and lower the decolorization efficiency of indigo. Increasing the initial H2O2 concentration from 5 mM to 20 mM could enhance the decolorization. The COD removal was increased from 35% to 65% with increasing H2O2 concentration from 5 mM to 20 mM. The generations of •OH were promoted by the increase of initial H2O2 concentration. However, the higher concentration of H2O2 resulted in the reduction of COD removal efficiency. The initial ferrous concentrations were studied in the range of 0.05-15.0 mM. The results found that the COD removals increased with increasing ferrous concentrations. The COD removals were increased from 32% to 65% when increase the ferrous concentration from 0.5 mM to 10.0 mM. However, the COD removal did not significantly change at higher 10.0 mM. This is because •OH yielding was lower level of oxidation, therefore, the COD removals were not improved. According to the studies, the Fenton’s reagents were important factors for COD removal by Fenton process. The optimum condition for COD removal of indigo dye wastewater was 10.0 mM of ferrous, 20 mM of H2O2 and at pH 3.

Keywords: indigo dye, fenton oxidation, wastewater treatment, advanced oxidation processes

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Authors: Edgar Gasafi, Robert Pardemann, Linus Perander

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For the production of lithium carbonate or hydroxide out of lithium bearing ores, a thermal activation (calcination/decrepitation) is required for the phase transition in the mineral to enable an acid respectively soda leaching in the downstream hydrometallurgical section. In this paper, traditional processing in Lithium industry is reviewed, and opportunities to reduce energy consumption and improve product quality and recovery rate will be discussed. The conventional process approach is still based on rotary kiln calcination, a technology in use since the early days of lithium ore processing, albeit not significantly further developed since. A new technology, at least for the Lithium industry, is fluidized bed calcination. Decrepitation of lithium ore was investigated at Outotec’s Frankfurt Research Centre. Focusing on fluidized bed technology, a study of major process parameters (temperature and residence time) was performed at laboratory and larger bench scale aiming for optimal product quality for subsequent processing. The technical feasibility was confirmed for optimal process conditions on pilot scale (400 kg/h feed input) providing the basis for industrial process design. Based on experimental results, a comprehensive Aspen Plus flow sheet simulation was developed to quantify mass and energy flow for the rotary kiln and fluidized bed system. Results show a significant reduction in energy consumption and improved process performance in terms of temperature profile, product quality and plant footprint. The major conclusion is that a substantial reduction of energy consumption can be achieved in processing Lithium bearing ores by using fluidized bed based systems. At the same time and different from rotary kiln process, an accurate temperature and residence time control is ensured in fluidized-bed systems leading to a homogenous temperature profile in the reactor which prevents overheating and sintering of the solids and results in uniform product quality.

Keywords: calcination, decrepitation, fluidized bed, lithium, spodumene

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Authors: Yili Liu, Honghao Ren, Mariko Kondo

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In the field of second language (L2) speech learning, it is well-known that that learner’s first language (L1) phonetic and phonological characteristics will be transferred into their L2 production and perception, which lead to foreign accent. For L1 Mandarin learners of Japanese, the confusion of /u/ and /o/ in /CjV/ sequences has been observed in their utterance frequently. L1 transfer is considered to be the cause of this issue, however, other factors which influence the identification of /Cju/ and /Cjo/ sequences still under investigation. This study investigates the perception of Japanese /Cju/ and /Cjo/ units by L1 Mandarin learners of Japanese. It further examined whether learners’ proficiency, syllable position, phonetic features of preceding consonants and background noise affect learners’ performance in perception. Fifty-two Mandarin-speaking learners of Japanese and nine native Japanese speakers were recruited to participate in an identification task. Learners were divided into beginner, intermediate and advanced level according to their Japanese proficiency. The average correct rate was used to evaluate learners’ perceptual performance. Furthermore, the comparison of the correct rate between learners’ groups and the control group was conducted as well to examine learners’ nativelikeness. Results showed that background noise tends to pose an adverse effect on distinguishing /u/ and /o/ in /CjV/ sequences. Secondly, Japanese proficiency has no influence on learners’ perceptual performance in the quiet and in background noise. Then all learners did not reach a native-like level without the distraction of noise. Beginner level learners performed less native-like, although higher level learners appeared to have achieved nativelikeness in the multi-talker babble noise. Finally, syllable position tends to affect distinguishing /Cju/ and /Cjo/ only under the noisy condition. Phonetic features of preceding consonants did not impact learners’ perception in any listening conditions. Findings in this study can give an insight into a further understanding of Japanese vowel acquisition by L1 Mandarin learners of Japanese. In addition, this study indicates that L1 transfer is not the only explanation for the confusion of /u/ and /o/ in /CjV/ sequences, factors such as listening condition and syllable position are also needed to take into consideration in future research. It also suggests the importance of perceiving speech in a noisy environment, which is close to the actual conversation required more attention to pedagogy.

Keywords: background noise, Chinese learners of Japanese, /Cju/ and /Cjo/ sequences, second language perception

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Authors: Katie Emerson, Sara Perez-Ojalvo, Jim Komorowski, Danielle Greenberg

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The purpose of this study was to evaluate arginase activity levels in response to combinations of an inositol-stabilized arginine silicate (ASI; Nitrosigine®), L-arginine, and Inositol. Arginine acts as a vasodilator that promotes increased blood flow resulting in enhanced delivery of oxygen and nutrients to the brain and other tissues. ASI alone has been shown to improve performance on cognitive tasks. Arginase, found in human serum, catalyzes the conversion of arginine to ornithine and urea, completing the last step in the urea cycle. Decreasing arginase levels maintains arginine and results in increased nitric oxide production. This study aimed to determine the most effective combination of ASI, L-arginine and inositol for minimizing arginase levels and therefore maximize ASI’s effect on cognition. Serum was taken from untreated healthy donors by separation from clotted factors. Arginase activity of serum in the presence or absence of test products was determined (QuantiChrom™, DARG-100, Bioassay Systems, Hayward CA). The remaining ultra-filtrated serum units were harvested and used as the source for the arginase enzyme. ASI alone or combined with varied levels of Inositol were tested as follows: ASI + inositol at 0.25 g, 0.5 g, 0.75 g, or 1.00 g. L-arginine was also tested as a positive control. All tests elicited changes in arginase activity demonstrating the efficacy of the method used. Adding L-arginine to serum from untreated subjects, with or without inositol only had a mild effect. Adding inositol at all levels reduced arginase activity. Adding 0.5 g to the standardized amount of ASI led to the lowest amount of arginase activity as compared to the 0.25g 0.75g or 1.00g doses of inositol or to L-arginine alone. The outcome of this study demonstrates an interaction of the pairing of inositol with ASI on the activity of the enzyme arginase. We found that neither the maximum nor minimum amount of inositol tested in this study led to maximal arginase inhibition. Since the inhibition of arginase activity is desirable for product formulations looking to maintain arginine levels, the most effective amount of inositol was deemed preferred. Subsequent studies suggest this moderate level of inositol in combination with ASI leads to cognitive improvements including reaction time, executive function, and concentration.

Keywords: arginine, inositol, arginase, cognitive benefits

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Authors: Keethadath Arshad, Kappalli Sudha

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Mud crab, Scylla Serrata, a commercially important shellfish with high global demand appears to be the rich source of dietary fatty acids. Its increased production through aquaculture and highly perishable nature would necessitate improved techniques for their proper preservation. Optimized irradiation has been identified as an effective method to facilitate safety and extended shelf life for a broad range of the perishable food items including finfishes and shellfishes. The present study analyzed the effects of dose-dependent gamma irradiation on the fatty acid profile of the muscle derived from the candidate species (S. serrata) at both qualitative and quantitative levels. Wild grown, average sized, intermolt male S. Serrata were gamma irradiated (^60C, 3.8kGy/ hour) at the dosage of 0.5kGy, 1.0kGy and 2.0kGy using gamma chamber. Total lipid extracted by Folch method, after methylation, were analyzed for the presence fatty acids adopting Gas Chromatograph equipped with flame ionization detector by comparing with the authentic FAME reference standards. The tissue from non-irradiated S. serrata showed the presence of 12 SFA, 6 MUFA, 8PUFA and 2 TF; PUFA includes medicinally important ω-3 FA such as C18:3, C20:5 and C22:6 and ω-6 FA such as γ- C18:3 and C20:2. Dose-dependent gamma irradiation reduced the number of detectable fatty acids (10, 8 and 8 SFA, 6, 6 and 5MUFA, 7, 7, and 6 PUFA and 1, 1, and 0 TF in 0.5kGy, 1.0kGy and 2kGy irradiated samples respectively). Major fatty acids detected in both irradiated and non-irradiated samples were as follows: SFA- C16:0, C18:0, C22:0 and C14:0; MUFA - C18:1 and C16:1and PUFA- C18:2, C20:5, C20:2 and C22:6. Irradiation doses ranging from 1-2kGy substantially reduced the ω-6 C18:3 and ω-3 C18:3. However, the omega fatty acids such as C20:5, C22:6 and C20:2 could survive even after 2kGy irradiation. Significantly, trans fat like C18:2T and C18:1T were completely disappeared upon 2kGy irradiation. From the overall observations made from the present study, it is suggested that irradiation dose up to 1kGy is optimum to maintain the fatty acid profile and eradicate the trans fat of the muscle derived from S. serrata.

Keywords: fatty acid profile, food preservation, gamma irradiation, scylla serrata

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Authors: Daniel Alfonso Reséndiz-García, Luis Antonio García-Villanueva

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As a result of the high industrial activity, which arises from the search to satisfy the needs of products and services for society, several chemical accidents have occurred, causing serious damage to different sectors: human, economic, infrastructure and environmental losses. Historically, with the study of this chemical accidents, it has been determined that the causes are mainly due to human errors (inexperienced personnel, negligence, lack of maintenance and deficient risk analysis). The industries have the aim to increase production and reduce costs. However, it should be kept in mind that the costs involved in risk studies, implementation of barriers and safety systems is much cheaper than paying for the possible damages that could occur in the event of an accident, without forgetting that there are things that cannot be replaced, such as human lives.Therefore, it is of utmost importance to implement risk studies in all industries, which provide information for prevention and planning. The aim of this study is to compare risk methodologies by identifying the consequences of accidents related to the storage of flammable, dangerous goods for decision making and emergency response.The methodologies considered in this study are qualitative and quantitative risk analysis and consequence analysis. The latter, by means of modeling software, which provides radius of affectation and the possible scope and magnitude of damages.By using risk analysis, possible scenarios of occurrence of chemical accidents in the storage of flammable substances are identified. Once the possible risk scenarios have been identified, the characteristics of the substances, their storage and atmospheric conditions are entered into the software.The results provide information that allows the implementation of prevention, detection, control, and combat elements for emergency response, thus having the necessary tools to avoid the occurrence of accidents and, if they do occur, to significantly reduce the magnitude of the damage.This study highlights the importance of risk studies applying tools that best suited to each case study. It also proves the importance of knowing the risk exposure of industrial activities for a better prevention, planning and emergency response.

Keywords: chemical accidents, emergency response, flammable substances, risk analysis, modeling

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Authors: Uliana N. Tumanova, Viacheslav M. Lyapin, Vladimir G. Bychenko, Alexandr I. Shchegolev, Gennady T. Sukhikh

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It is well known that the gas formed as a result of postmortem decomposition of tissues can be detected already 24-48 hours after death. In addition, the conditions of keeping and storage of the corpse (temperature and humidity of the environment) significantly determine the rate of occurrence and development of posthumous changes. The presence of sepsis is accompanied by faster postmortem decomposition and decay of the organs and tissues of the body. The presence of gas in the vessels and cavities can be revealed fully at postmortem CT. Radiologists must certainly report on the detection of intraorganic or intravascular gas, wich was detected at postmortem CT, to forensic experts or pathologists before the autopsy. This gas can not be detected during autopsy, but it can be very important for establishing a diagnosis. To explore the possibility of postmortem CT for the evaluation of gas accumulations in the newborns' vessels, who died from congenital sepsis. Researched of 44 newborns bodies (25 male and 19 female sex, at the age from 6 hours to 27 days) after 6 - 12 hours of death. The bodies were stored in the refrigerator at a temperature of +4°C in the supine position. Grouped 12 bodies of newborns that died from congenital sepsis. The control group consisted of 32 bodies of newborns that died without signs of sepsis. Postmortem CT examination was performed at the GEMINI TF TOF16 device, before the autopsy. The localizations of gas accumulations in the vessels were determined on the CT tomograms. The sepsis diagnosis was on the basis of clinical and laboratory data and autopsy results. Gases in the vessels were detected in 33.3% of cases in the group with sepsis, and in the control group - in 34.4%. A group with sepsis most often the gas localized in the heart and liver vessels - 50% each, of observations number with the detected gas in the vessels. In the heart cavities, aorta and mesenteric vessels - 25% each. In control most often gas was detected in the liver (63.6%) and abdominal cavity (54.5%) vessels. In 45.5% the gas localized in the cavities, and in 36.4% in the vessels of the heart. In the cerebral vessels and in the aorta gas was detected in 27.3% and 9.1%, respectively. Postmortem CT has high diagnostic capabilities to detect free gas in vessels. Postmortem changes in newborns that died from sepsis do not affect intravascular gas production within 6-12 hours. Radiation methods should be used as a supplement to the autopsy, including as a kind of ‘guide’, with the indication to the forensic medical expert of certain changes identified during CT studies, for better definition of pathological processes during the autopsy. Postmortem CT can be recommend as a first stage of autopsy.

Keywords: congenital sepsis, gas, newborn, postmortem CT

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Authors: Mohammed Alnuwairan, Mahmoud Abdelrahman

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Based on the sustainability concept, this paper explores the current situation of construction and demolition waste (C&D) in the Kingdom of Saudi Arabia (KSA) from the source of production to final destinations. The issues that hindered the investment of recycling C&D in the context will be studied in order to identify the challenges and opportunities to improve this sector and put forward a strategic framework to reduce, reuse, recycle and minimize the disposal of this type of waste. The research, which is exploratory in nature, identified four types of organizations that were appropriate case studies. These organizations were drawn from the municipalities, city council, recyclers and manufacturers. Secondary data collection, direct observation, and elite interviewing methods were used in the case studies to facilitate comparisons with existing literature to explore opportunities to improve sustainability practices in the buildings sector. Implementation of C&D waste management and recycling in KSA is in the early stages. Resistance of virgin building material manufacturers, free usage of landfill, culture, surpluses of natural raw material, availability of land and the cost of recycling this material compared with virgin material hinders the adoption of recycled buildings martial. Although the metal material is collected and recycled but it has the lowest percentage of C&D waste in Saudi. The findings indicate that government and industry need to collaborate more closely in order to successfully implement best practices. Economic and environmental benefits can be achieved, particularly through improvements to infrastructure and legislation. Feasible solution framework and recommendations for managing C&D waste under current situation are provided. The findings can be used to extend this framework and to enable it to be applicable in other context with emerging economies similar to that found in KSA. No study of this type has been previously carried out in KSA. The findings should prove useful in creating a future research agenda for C&D waste in KSA and, possibly, other emerging countries within a similar context.

Keywords: construction and demolition waste, recycling, reuse, sustainability

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Authors: Mohamed Ghoz, Hala Alsabeh

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Context: Macroscopic Nose Macroneedling (MNM) is a new non-surgical procedure for lifting and tightening the nose. It is a tissue-non-invasive technique that uses a needle to create micro-injuries in the skin. These injuries stimulate the production of collagen and elastin, which results in the tightening and lifting of the skin. Research Aim: The research aim of this study was to investigate the efficacy and safety of MNM for the treatment of nasal deformities. Methodology A total of 100 patients with nasal deformities were included in this study. The patients were randomly assigned to either the MNM group or the control group. The MNM group received a single treatment of MNM, while the control group received no treatment. The patients were evaluated at baseline, 6 months, and 12 months after treatment. Findings: The results of this study showed that MNM was effective in improving the appearance of the nose in patients with nasal deformities. At 6 months after treatment, the patients in the MNM group had significantly improved nasal tip projection, nasal bridge height, and nasal width compared to the patients in the control group. The improvements in nasal appearance were maintained at 12 months after treatment. Theoretical Importance: The findings of this study provide support for the use of MNM as a safe and effective treatment for nasal deformities. MNM is a non-surgical procedure that is associated with minimal downtime and no risk of scarring. This makes it an attractive option for patients who are looking for a minimally invasive treatment for their nasal deformities. Data Collection: Data was collected from the patients using a variety of methods, including clinical assessments, photographic assessments, and patient-reported outcome measures. Analysis Procedures: The data was analyzed using a variety of statistical methods, including descriptive statistics, inferential statistics, and meta-analysis. Question Addressed: The research question addressed in this study was whether MNM is an effective and safe treatment for nasal deformities. Conclusion: The findings of this study suggest that MNM is an effective and safe treatment for nasal deformities. MNM is a non-surgical procedure that is associated with minimal downtime and no risk of scarring. This makes it an attractive option for patients who are looking for a minimally invasive treatment for their nasal deformities.

Keywords: nose, surgery, tie, suture

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Authors: Farangiz Davranbekova

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Subject: The study explores the impact of Over-the-Top services in the sports rights market, focusing on football games. This impact is analysed in the big five European football markets. The research entails how the pay-TV market is combating the disruptors' entry, how the fans are adjusting to these changes and how leagues and football clubs are orienting in the transitional period of more choice. Aims and methods: The research aims to offer a general overview of the impact of OTT players in the football rights market. A theoretical framework of Jenkins’ five layers of convergence is implemented to analyse the transition the sports rights market is witnessing from various angles. The empirical analysis consists of secondary research data as and seven expert interviews from three different clusters. The findings are bound by the combination of the two methods offering general statements. Findings: The combined secondary data as well as expert interviews, conducted on five layers of convergence found: 1. Technological convergence presents that football content is accessible through various devices with innovative digital features, unlike the traditional TV set box. 2. Social convergence demonstrates that football fans multitask using various devices on social media when watching the games. These activities are complementary to traditional TV viewing. 3. Cultural convergence points that football fans have a new layer of fan engagement with leagues, clubs and other fans using social media. Additionally, production and consumption lines are blurred. 4. Economic convergence finds that content distribution is diversifying and/or eroding. Consumers now have more choices, albeit this can be harmful to them. Entry barriers are decreased, and bigger clubs feel more powerful. 5. Global convergence shows that football fans are engaging with not only local fans but with fans around the world that social media sites enable. Recommendation: A study on smaller markets such as Belgium or the Netherlands would benefit the study on the impact of OTT. Additionally, examination of other sports will shed light on this matter. Lastly, once the direct-to-consumer model is fully taken off in Europe, it will be of importance to examine the impact of such transformation in the market.

Keywords: sports rights, OTT, pay TV, football

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Authors: Joel Bonales, Venecia Solorzano, Carlos Garcia

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A great percentage of the wastewater generated in developing countries don’t receive any treatment, which leads to numerous environmental impacts. In response to this, a paradigm change in the current wastewater treatment model based on large scale plants towards a small and medium scale based model has been proposed. Nevertheless, small scale wastewater treatment (SS-WTTP) with novel technologies such as anaerobic digesters, as well as the utilization of derivative co-products such as biogas, still presents diverse environmental impacts which must be assessed. This study consisted in a Life Cycle Assessment (LCA) performed to a SS-WWTP which treats wastewater from a small commercial block in the city of Morelia, Mexico. The treatment performed in the SS-WWTP consists in anaerobic and aerobic digesters with a daily capacity of 5,040 L. Two different scenarios were analyzed: the current plant conditions and a hypothetical energy use of biogas obtained in situ. Furthermore, two different allocation criteria were applied: full impact allocation to the system’s main product (treated water) and substitution credits for replacing Mexican grid electricity (biogas) and clean water pumping (treated water). The results showed that the analyzed plant had bigger impacts than what has been reported in the bibliography in the basis of wastewater volume treated, which may imply that this plant is currently operating inefficiently. The evaluated impacts appeared to be focused in the aerobic digestion and electric generation phases due to the plant’s particular configuration. Additional findings prove that the allocation criteria applied is crucial for the interpretation of impacts and that that the energy use of the biogas obtained in this plant can help mitigate associated climate change impacts. It is concluded that SS-WTTP is a environmentally sound alternative for wastewater treatment from a systemic perspective. However, this type of studies must be careful in the selection of the allocation criteria and replaced products, since these factors have a great influence in the results of the assessment.

Keywords: biogas, life cycle assessment, small scale treatment, wastewater treatment

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Authors: Ahilya Singh, Brad Carte, Ramesh Subramani, William Aalbersberg

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A total of 37 actinomycete strains were purified from 25 Solomon Islands marine sediments using four different types of isolation media. Among them, 54% of the strains had obligate requirement of seawater for growth. The ethyl acetate extract of 100 ml fermentation product of each strain was screened for antimicrobial activity against multidrug resistant human pathogens and cytotoxic activity against brine shrimps. A total of 67% of the ethyl acetate extracts showed antimicrobial and/or cytotoxic activities. A strain F-1915 was selected for isolation and evaluation of bioactive compound(s) based on its bioactive properties and chemical profile analysis using the LC-MS. The strain F-1915 was identified to have 96% sequence similarity to Streptomyces violaceusniger on the basis of 16S rDNA sequences using BLAST analysis. The 16S rDNA revealed that the strain F-1915 is a new member of MAR4 clade of actinomycetes. The MAR4 clade is an interesting clade of actinomycetes known for the production of pharmaceutically important hybrid isoprenoid compounds. The ethyl acetate extract of the fermentation product of this strain was purified by silica gel column chromatography and afforded the isolation of one bioactive pure compound. Based on the 1D and 2D NMR spectral data of compound 1 it was identified as a new mono-brominated phenazinone, Marinophenazimycin A, a structure which has already been studied by external collaborators at Scripps Institution of Oceanography but is yet to be published. Compound 1 displayed significant antimicrobial activity against drug resistant human pathogens. The minimum inhibitory concentration (MIC) of compound 1 was against Methicillin Resistant Staphylococcus aureus (MRSA) was about 1.9 μg/ml and MIC recorded against Amphotericin Resistant Candida albicans (ARCA) was about 0.24 μg/ml. The bioactivity of compound 1 against ARCA was found to be better than the standard antifungal agent amphotericin B. Compound 1 however did not show any cytotoxic activity against brine shrimps.

Keywords: actinomycetes, antimicrobial activity, brominated phenazine, MAR4 clade, marine natural products, multidrug resistent, 1D and 2D NMR

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Authors: Elena Carcano, James Ball, Betty Tiko

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Carrying capacity refers to the maximum population that a given level of resources can sustain over a specific period. In undisturbed environments, the maximum population is determined by the availability and distribution of resources, as well as the competition for their utilization. This information is typically obtained through long-term data collection. In regulated environments, where resources are artificially modified, populations must adapt to changing conditions, which can lead to additional challenges due to fluctuations in resource availability over time and throughout development. An example of this is observed in hydropower plants, which alter water flow and impact fish migration patterns and behaviors. To assess how fish species can adapt to these changes, specialized surveys are conducted, which provide valuable information on fish populations, sample sizes, and density before and after flow modifications. In such situations, it is highly recommended to conduct hydrological and biological monitoring to gain insight into how flow reductions affect species adaptability and to prevent unfavorable exploitation conditions. This analysis involves several planned steps that help design appropriate hydropower production while simultaneously addressing environmental needs. Consequently, the study aims to strike a balance between technical assessment, biological requirements, and societal expectations. Beginning with a small hydro project that requires restoration, this analysis focuses on the lower tail of the Flow Duration Curve (FDC), where both hydrological and environmental goals can be met. The proposed approach involves determining the threshold condition that is tolerable for the most vulnerable species sampled (Telestes Muticellus) by identifying a low flow value from the long-term FDC. The results establish a practical connection between hydrological and environmental information and simplify the process by establishing a single reference flow value that represents the minimum environmental flow that should be maintained.

Keywords: carrying capacity, fish bypass ladder, long-term streamflow duration curve, eta-beta method, environmental flow

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Authors: Sadeq Al Yaari, Muhammad Alkhunayn, Ayah Al Yaari, Ayman Al Yaari, Montaha Al Yaari, Adham Al Yaari, Sajedah Al Yaari, Fatehi Eissa

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Developmental co-ordination disorder (DCD) (also known as dyspraxia) causes a child to speak less well than expected in social conversations. We propose that the smart speaking technology could help improve sound production mechanism at both phonetic and phonological levels, which leads to better articulation of an utterance. The participants are twelve privately beginner pupils aged between 6-12 years old and diagnosed with DCD (apraxia) divided into two groups: Experimental group (n=6) and control group (called apraxic control group) (n=6). A total of fifty typically developing and achieving (TD) pupils participated as control group 2 in both groups and were preassigned into two groups (27 pupils with the treatment group and 23 with the apraxic control group). Weekly quizzes were given to all participants each week for four continuous months and results were analyzed by psychoneurolinguists and a statistician. Although being taught by the same speech-language therapist (SLT), treatment group along with TD groups were taught a full-time speaking course with sociolinguistic themes covering both phonetic and phonological properties. The course lasted for a whole semester whereby smart speaking aids have become dominant while apraxic control group and its TD group were not. Compared with apraxic control group and its TD subgroup, results show obvious changes in speaking behavioral mechanism of the DCD experimental group and its TD subgroup. Improvement could be taken from the scores where the zero marks disappeared in the fourth week (end of the first month of treatment). Good marks (5 +/10) were seen starting from the eighth week and culminating with full marks in the week number 15 of treatment where some participants scored full mark. This study concludes to support the primacy of the smart educational technology for speaking purposes and also shows that such aids can expand the range of academic performance differential categories. Further research is required to evaluate the current demonizing of smart educational aids and weighting more reasonably the relationship specificity that speaking aids can offer to other language skills, as well as their limitations.

Keywords: smart educational technology, speaking aids, pupils with SCD, apraxia

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Authors: H. Tavakoli, S. S. Mohtasebi, R. Alimardani, R. Gebbers

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Nitrogen (N) is one of the most important agricultural inputs affecting crop growth, yield and quality in rain-fed cereal production. N demand of crops varies spatially across fields due to spatial differences in soil conditions. In addition, the response of a crop to the fertilizer applications is heavily reliant on plant available water. Matching N supply to water availability is thus essential to achieve an optimal crop response. The objective of this study was to determine effect of drought stress on estimation of nitrogen status of winter wheat by some vegetation indices. During the 2012 growing season, a field experiment was conducted at the Bundessortenamt (German Plant Variety Office) Marquardt experimental station which is located in the village of Marquardt about 5 km northwest of Potsdam, Germany (52°27' N, 12°57' E). The experiment was designed as a randomized split block design with two replications. Treatments consisted of four N fertilization rates (0, 60, 120 and 240 kg N ha-1, in total) and two water regimes (irrigated (Irr) and non-irrigated (NIrr)) in total of 16 plots with dimension of 4.5 × 9.0 m. The indices were calculated using readings of a spectroradiometer made of tec5 components. The main parts were two “Zeiss MMS1 nir enh” diode-array sensors with a nominal rage of 300 to 1150 nm with less than 10 nm resolutions and an effective range of 400 to 1000 nm. The following vegetation indices were calculated: NDVI, GNDVI, SR, MSR, NDRE, RDVI, REIP, SAVI, OSAVI, MSAVI, and PRI. All the experiments were conducted during the growing season in different plant growth stages including: stem elongation (BBCH=32-41), booting stage (BBCH=43), inflorescence emergence, heading (BBCH=56-58), flowering (BBCH=65-69), and development of fruit (BBCH=71). According to the results obtained, among the indices, NDRE and REIP were less affected by drought stress and can provide reliable wheat nitrogen status information, regardless of water status of the plant. They also showed strong relations with nitrogen status of winter wheat.

Keywords: nitrogen status, drought stress, vegetation indices, precision agriculture

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Authors: Nadia Chougui, Nawal Makhloufi, Farouk Rezgui, Elias Benramdane, Carmen S. R. Freire, Carla Vilela, Armando J. D. Silvestre

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Native to Mexico, Opuntia ficus-indica was introduced in southern Spain, and thereafter, it was spread throughout the Mediterranean Basin by the Spanish conquerors in the 16th and 17th centuries. O. ficus-indica is a tropical and subtropical plant able to grow in arid and semi-arid regions, such as the Mediterranean and Central America regions. The culture of Opuntia covers about 200,000 ha in North Africa. This tree is used against soil erosion and desertification for fruit production and is encouraged to promote the livestock sector. It has recently received ever-increasing attention from researchers worldwide for the multivalent pharmaceutical and cosmetical potential of its different compartments (fruits, seeds, cladodes). The present study investigated the elaboration by casting method and characterization of new biodegradable films composed of cladodes powder (CP) of the plant raw material mentioned above, and a marine seaweed derivative, namely agar (A). The effect of glycerol concentration on the properties of the films was evaluated at four different contents (30, 40, 50 and 60 wt.%). The films present UV-blocking properties, thermal stability as well as moderate mechanical performance and water vapor transmission rate (WVTR). The results point to an increase in thickness, elongation at break, moisture content, water solubility, and WVTR with increasing glycerol content. On the contrary, Young’s modulus, tensile strength and contact angle decreased as glycerol concentration increased. The best combination is obtained for the film with 30% glycerol, based on an intermediate compromise between physical, mechanical, thermal and barrier properties. All these outcomes express the potentiality of the powder obtained from grinding the OFI cladodes as raw material to produce low-cost films for the development of sustainable packaging materials.

Keywords: Opuntia ficus-indica cladodes powder, agar, biobased films, effect of plasticizer, sustainable packaging

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Authors: David Maina Muthegethi

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For decades, archaeological work of Swahili Civilization has mainly concentrated on exploration of economic and political dynamics of City states. This paper moves further and explore how gender roles were formed, maintained, negotiated and re-negotiated through time and space in Gede City. Unlike other Swahili city states, Gede was located around two miles away from the shores of Indian Ocean. Nonetheless, the city was characterized by security walls, stone houses, mosques and tombs typical of Swahili City states such as Kilwa. The study employed several methods of data collection namely: archival research, survey, re-examination of collected materials and excavation of Gede archaeological site. Since, the study aimed to examine gender roles across different social class, a total of three houses were excavated based on their social hierarchy. Thus, the houses were roughly categorized as belonging to elites, middle class and lower class. The house were located in the inner wall, second inner wall and the outer wall of Gede City respectively. Key findings shows that gender roles differed considerably along classes in Gede archaeological site. For instance, the women of the elite and middle class were active participants in Gede international trade through production and consumption of imported goods. This participation corresponded with commercialization of Gede households especially in elite’ areas where they hosted international traders. On the other hand, the middle class houses, women concentrated on running of light industries aimed at supplying goods for the urban community. Thus, they were able to afford exotic goods as their elites counterparts. Lastly, the gender roles of lower class entailed subsistence gender roles with little participation in Gede formal commerce. Interestingly, gender roles in Gede were dynamic in nature and response to cultural diffusion, spread of Islam, intensification of trade, diversification of subsistence patterns and urbanization. Therefore, this findings, demonstrate centrality of gender in reconstruction of social lives of Swahili Civilization.

Keywords: gender roles, Islam, Swahili civilization, urbanization

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Authors: F. Murilo T. Luna, Vanessa F. Oliveira, Alysson Rocha, Expedito J. S. Parente, Andre V. Bueno, Matheus C. M. Farias, Celio L. Cavalcante Jr.

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Aviation jetfuel used in aircraft gas-turbine engines is customarily obtained from the kerosene distillation fraction of petroleum (150-275°C). Mineral jetfuel consists of a hydrocarbon mixture containing paraffins, naphthenes and aromatics, with low olefins content. In order to ensure their safety, several stringent requirements must be met by jetfuels, such as: high energy density, low risk of explosion, physicochemical stability and low pour point. In this context, aviation fuels eventually obtained from biofeedstocks (which have been coined as ‘biojetfuel’), must be used as ‘drop in’, since adaptations in aircraft engines are not desirable, to avoid problems with their operation reliability. Thus, potential aviation biofuels must present the same composition and physicochemical properties of conventional jetfuel. Among the potential feedtstocks for aviation biofuel, the babaçu oil, extracted from a palm tree extensively found in some regions of Brazil, contains expressive quantities of short chain saturated fatty acids and may be an interesting choice for biojetfuel production. In this study, biojetfuel was synthesized through homogeneous transesterification of babaçu oil using methanol and its properties were compared with petroleum-based jetfuel through measurements of oxidative stability, physicochemical properties and low temperature properties. The transesterification reactions were carried out using methanol and after decantation/wash procedures, the methyl esters were purified by molecular distillation under high vacuum at different temperatures. The results indicate significant improvement in oxidative stability and pour point of the products when compared to the fresh oil. After optimization of operational conditions, potential biojetfuel samples were obtained, consisting mainly of C8 esters, showing low pour point and high oxidative stability. Jet engine tests are being conducted in an automated test bed equipped with pollutant emissions analysers to study the operational performance of the biojetfuel that was obtained and compare with a mineral commercial jetfuel.

Keywords: biojetfuel, babaçu oil, oxidative stability, engine tests

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Authors: Iseoluwa Bukunmi Kolawole, Omowunmi Precious Isreal

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Social media has completely revolutionized the ways communication used to take place even a decade ago. It makes use of computer mediated technologies which helps in the creation of information and sharing. Social media may be defined as the production, consumption and exchange of information across platforms for social interaction. The social media has become a forum in which customer’s look for information about companies to do business with and request answers to questions about their products and services. Customer service may be termed as a process of ensuring customer’s satisfaction by meeting and exceeding their wants. In delivering excellent customer service, knowing customer’s expectations and where they are reaching out is important in meeting and exceeding customer’s want. Facebook is one of the most used social media platforms among others which also include Twitter, Instagram, Whatsapp and LinkedIn. This indicates customers are spending more time on social media platforms, therefore calls for improvement in customer service delivery over the social media pages. Millions of people channel their issues, complaints, complements and inquiries through social media. This study have being able to identify what social media customers want, their expectations and how they want to be responded to by brands and companies. However, the applied research methodology used in this paper was a mixed methods approach. The authors of d paper used qualitative method such as gathering critical views of experts on social media and customer relationship management to analyse the impacts of social media on customer's satisfaction through interviews. The authors also used quantitative such as online survey methods to address issues at different stages and to have insight about different aspects of the platforms i.e. customer’s and company’s perception about the effects of social media. Thereby exploring and gaining better understanding of how brands make use of social media as a customer relationship management tool. And an exploratory research approach strategy was applied analysing how companies need to create good customer support using social media in order to improve good customer service delivery, customer retention and referrals. Therefore many companies have preferred social media platform application as a medium of handling customer’s queries and ensuring their satisfaction, this is because social media tools are considered more transparent and effective in its operations when dealing with customer relationship management.

Keywords: brands, customer service, information, social media

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Authors: Violina Angelova, Galina Pevicharova

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A comparative research had been carried out to allow us to determine the quantities and the centers of accumulation of Pb, Cu, Zn and Cd in the vegetative and reproductive organs of the sweet potatoes and to ascertain the possibilities for growing them on soils, polluted with heavy metals. The experiments were performed on agricultural fields contaminated by the (1) Non-Ferrous-Metal Works near Plovdiv, (2) Lead and Zinc Complex near Kardjali and (3) a copper smelter near Pirdop, Bulgaria. The soils used in this experiment were characterized by acid, neutral and slightly alkaline reaction, loamy texture and a moderate content of organic matter. The total content of Zn, Pb, and Cd was high and exceeded the limit value in agriculture soils. Sweet potatoes were in a 2-year rotation scheme on three blocks in the experimental field. On reaching commercial ripeness the sweet potatoes were gathered and the contents of heavy metals in their different parts – root, tuber (peel and core), leaves and stems, were determined after microwave mineralization. The quantitative measurements were carried out with inductively coupled plasma atomic emission spectroscopy. The contamination of the sweet potatoes was due mainly to the presence of heavy metals in the soil, which entered the plants through their root system, as well as by diffusion through the peel. Pb, Cu, Zn, and Cd were selectively accumulated in the underground parts of the sweet potatoes, and most of all in the root system and the peel. Heavy metals have an impact on the development and productivity of the sweet potatoes. The high anthropogenic contamination leads to an increased assimilation of heavy metals which reduces the yield and the quality of the production of sweet potatoes, as well as leads to decrease of the absolute dry substance and the quantity of sugars in sweet potatoes. Sweet potatoes could be grown on soils, which are light to medium polluted with lead, zinc, and cadmium, as they do not accumulate these elements. On heavily polluted soils, however, (Pb – 1504 mg/kg, Zn – 3322 mg/kg, Cd – 47 mg/kg) the growing of sweet potatoes is not allowed, as the accumulation of Pb and Cd in the core of the potatoes exceeds the Maximum Acceptable Concentration. Acknowledgment: The authors gratefully acknowledge the financial support by the Bulgarian National Science Fund (Project DFNI DH04/9).

Keywords: heavy metals, polluted soils, sweet potatoes, uptake

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Authors: Sunbul Jassim Hamodi, Muna Khalid Khudayer, Firas Muzahem Hussein

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The experiment was conducted to study the effect of supplement sources of Phytase enzyme (bacterial, fungal, enzymes mixture) using levels (250, 500, 750) FTY/ kg feed to diets compared with control on the performance for one thousand fifty broiler chicks (Ross 308) from 1day old with initial weight 39.78 gm till 42 days. The study involved 10 treatments, three replicates per treatment (35 chicks/replicate). Treatments were as follows: T1: control diet (without any addition). T2: added bacterial phytase enzyme 250FTY/ kg feed. T3: added bacterial phytase enzyme 500FTY/ kg feed. T4: added bacterial phytase enzyme 750FTY/ kg feed. T5: added fungal phytase enzyme 250FTY/ kg feed. T6: added fungal phytase enzyme 500FTY/ kg feed. T7: added fungal phytase enzyme 750FTY/ kg feed. T8 added enzymes mixture 250U/ kg feed. T9: added enzymes mixture 500U/ kg feed. T10: added enzymes mixture 750U/ kg feed. The results revealed that supplementing 750 U from enzymes mixture to broiler diet increased significantly (p <0.05) body weight compared with (250 FTY bacterial phytase/Kgfeed), (750 FTY bacterial phytase/Kg feed), (750FTY fungal phytase/Kgfeed) at 6 weeks, also supplemented different sources and levels from phytase enzyme improved a cumulative weight gain for (500 FTY bacterial phytase/Kgfeed), (250FTY fungal phytase/Kgfeed), (500FTY fungal phytase/Kgfeed), (250 Uenzymes mixture/Kgfeed), (500 Uenzymes mixture/Kgfeed) and (750 U enzymes mixture/Kgfeed) treatments compared with (750 FTY fungal phytase/Kgfeed)treatment, about accumulative feed consumption (500 FTY fungal phytase/Kgfeed) and (250 Uenzymes mixture/Kgfeed) increased significantly compared with control group and (750FTY fungal phytase/Kgfeed) during 1-6 weeks. There were significantly improved in cumulative feed conversion for (500U enzymes mixture/Kgfeed) compared with the worse feed conversion ratio that recorded in (250 FTY bacterial phytase/Kgfeed). No significant differences between treatments in internal organs relative weights, carcass cuts, dressing percentage and production index. Mortality was increased in (750FTY fungal phytase/Kgfeed) compared with other treatments.

Keywords: phytase, phytic acid, broiler, productive performance

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Authors: Venkateswara R. Naira, Debasish Das, Soumen K. Maiti

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Achieving high cell densities of microalgae under obligatory light-limiting and high light conditions of diurnal (low-high-low variations of daylight intensity) sunlight are further limited by CO₂ supply and dissolved oxygen (DO) accumulation in large-scale photobioreactors. High DO levels cause low growth due to photoinhibition and/or photorespiration. Hence, scalable elevated CO₂ levels (% in air) and their effect on DO accumulation in a 10 L cylindrical membrane photobioreactor (a vertical tubular type) are studied in the present study. The CO₂ elevation strategies; biomass-based, pH control based (types II & I) and diurnal light based, were explored to study the growth of Chlorella sp. FC2 IITG under single-sided LED lighting in the laboratory, mimicking diurnal sunlight. All the experiments were conducted in fed-batch mode by maintaining N and P sources at least 50% of initial concentrations of the optimized BG-11 medium. It was observed that biomass-based (2% - 1st day, 2.5% - 2nd day and 3% - thereafter) and well-known pH control based, type-I (5.8 pH throughout) strategies were found lethal for FC2 growth. In both strategies, the highest peak DO accumulation of 150% air saturation was resulted due to high photosynthetic activity caused by higher CO₂ levels. In the pH control based type-I strategy, automatically resulted CO₂ levels for pH control were recorded so high (beyond the inhibition range, 5%). However, pH control based type-II strategy (5.8 – 2 days, 6.3 – 3 days, 6.7 – thereafter) showed final biomass titer up to 4.45 ± 0.05 g L⁻¹ with peak DO of 122% air saturation; high CO₂ levels beyond 5% (in air) were recorded thereafter. Thus, it became sustainable for obtaining high biomass. Finally, a diurnal light based (2% - low light, 2.5 % - medium light and 3% - high light) strategy was applied on the basis of increasing/decreasing photosynthesis due to increase/decrease in diurnal light intensity. It has resulted in maximum final biomass titer of 5.33 ± 0.12 g L⁻¹, with total biomass productivity of 0.59 ± 0.01 g L⁻¹ day⁻¹. The values are remarkably higher than constant 2% CO₂ level (final biomass titer: 4.26 ± 0.09 g L⁻¹; biomass productivity: 0.27 ± 0.005 g L⁻¹ day⁻¹). However, 135% air saturation of peak DO was observed. Thus, the diurnal light based elevation should be further improved by using CO₂ enriched N₂ instead of air. To the best of knowledge, the light-based CO₂ elevation strategy is not reported elsewhere.

Keywords: Chlorella sp., CO₂ elevation strategy, dissolved oxygen accumulation, diurnal light based CO₂ elevation, high cell density, microalgae, scale-up

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Authors: Anil Kumar, Diwakar Aggarwal, M. Sudhakara Reddy

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The wood of Eucalyptus, Populus and bamboos are some important species used as raw material for the manufacture of pulp. However, higher levels of lignin pose a problem during Kraft pulping and yield of pulp is also lower. In order to increase the yield of pulp per unit wood and reduce the use of chemicals during kraft pulping it is important to reduce the lignin content and/or increase cellulose content in wood. Cellulose biosynthesis in wood takes place by the coordinated action of many enzymes. The two important enzymes are KORRIGAN and SUCROSE SYNTHASE. KORRIGAN (Endo-1,4--glucanase) is implicated in the process of editing growing cellulose chains and improvement of the crystallinity of produced cellulose, whereas SUCROSE SYNTHASE is involved in providing substrate (UDP-glucose) for growing cellulose chains. The present study was aimed at the cloning, characterization and overexpression of these genes in Eucalyptus and Populus. An efficient shoot organogenesis protocol from leaf explants taken from micro shoots of the species has been developed. Agrobacterium mediated genetic transformation using Agrobacterium tumefaciens strain EHA105 and LBA4404 harboring binary vector pBI121 was achieved. Both the genes were cloned from cDNA library of Populus deltoides. These were subsequently characterized using various bioinformatics tools. The cloned genes were then inserted into pBI121 under the CaMV35S promotors replacing GUS gene. The constructs were then mobilized into above strains of Agrobacterium and used for the transformation work. Subsequently, genetic transformation of these clones with target genes following already developed protocol is in progress. Four transgenic lines of Eucalyptus tereticornis overexpressing Korrigan gene under the strong constitutive promoters CaMV35S have been developed, which are being further evaluated. Work on development of more transgenic lines overexpressing these genes in Populus and Eucalyptus is also in progress. This presentation will focus on important developments in this direction.

Keywords: Eucalyptus tereticornis, genetic transformation, Kraft pulping Populus deltoides

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Authors: David Sarpong, Waleed Khursheed, Ernest Danquah, Erin Murphy

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Shigella is a pathogenic bacterium responsible for shigellosis, a severe diarrheal disease that claims the lives of immunocompromised individuals worldwide. To develop therapeutics against this disease, an understanding of the molecular mechanisms underlying the pathogen’s physiology is crucial. Small non-coding RNAs (sRNAs) have emerged as important regulators of bacterial physiology, including as components of toxin-antitoxin systems. In this study, we investigated the role of RyfA in S. flexneri physiology and virulence. RyfA, originally identified as an sRNA in Escherichia coli, is conserved within the Enterobacteriaceae family, including Shigella. Whereas two copies of ryfA are present in S. dysenteriae, all other Shigella species contain only one copy of the gene. Additionally, we identified a putative open reading frame within the RyfA transcript, suggesting that it may be a dual-functioning gene encoding a small protein in addition to its sRNA function. To study ryfA in vitro, we cloned the gene into an inducible plasmid and observed the effect on bacterial growth. Here, we report that RyfA production inhibits the growth of S. flexneri, and this inhibition is dependent on the contained open reading frame. In-silico analyses have revealed the presence of two divergently transcribed sRNAs, RyfB1 and RyfB2, which share nucleotide complementarity with RyfA and thus are predicted to function as anti-toxins. Our data demonstrate that RyfB2 has a stronger antitoxin effect than RyfB1. This regulatory pattern suggests a novel form of a toxin-antitoxin system in which the activity of a single toxin is inhibited to varying degrees by two sRNA antitoxins. Studies are ongoing to investigate the regulatory mechanism(s) of the antitoxin genes, as well as the downstream targets and mechanism of growth inhibition by the RyfA toxin. This study offers distinct insights into the regulatory mechanisms underlying Shigella physiology and may inform the development of new anti-Shigella therapeutics.

Keywords: sRNA, shigella, toxin-antitoxin, Type 1 toxin antitoxin

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Authors: Yuvarani Naidu, Yasmeen Siddiqui, Mohd Yusof Rafii , Abu Seman Idris

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Sustainability of oil palm production in Southeast Asia, especially in Indonesia and Malaysia, is jeopardized by Ganoderma boninense, the fungus which causes basal stem rot (BSR) in oil palm. The root contact with unattended infected debris left in the plantations during replanting is known to be the primary source of inoculum. Abiding by the law, potentially effective technique of managing Ganoderma infected oil palm debris is deemed necessary because of the zero-burning policy in Malaysian oil palm plantations. White-rot hymenomycetes antagonistic to Ganoderma sp were selected to test their efficacy as log treatments in degrading Ganoderma infected oil palm logs and to minimize the survival of Ganoderma inoculum. Decay rate in terms of mass loss was significantly higher after the application of solid-state cultivation (SSC) of Trametes lactinea FBW (64% ±1.2), followed by Pycnoporus sanguineus FBR (55% ±1.7) in infected log block tissues, after 10 months of treatments. The degradation pattern was clearly distinguished between the treated and non-treated log blocks with the developed SSC formulations. The control infected log blocks showed the highest, whereas infected log blocks treated with either P. sanguineus FBR or T. lactinea FBW SSC formulations exhibited statistically lowest number of Ganoderma spp. recovery on Ganoderma Selective Medium (GSM), after 8 months of treatment. Out of that, the lowest recovery of Ganoderma spp. was reported in infected log blocks inoculated with the strain T. lactinea FBW (21% ± 0.9) followed by P. sanguineus FBR (33% ± 2.2), after 8 months, Further, no recovery of Ganoderma was noticeable, 10 months after treatment applications in log blocks treated with both of the formulations. This is the first nursery-base study to substantiate the initial colonization of white-rot hymenomycetes on oil palm log blocks previously infected with BSR pathogen, G. boninense. The present study has indicated that log blocks treatment with white-rot hymenomycetes significantly affected the mass loss of diseased and healthy log block tissues. This study provides a basis of biotechnological approaches inefficient degradation of oil palm-generated crop debris, under natural conditions with an ultimate aim of reducing the Ganoderma inoculum under heavy BSR infection pressure in eco-friendly manner.

Keywords: basal stem rot disease, ganoderma boninense, oil palm, white-rot fungi

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Authors: Mohd. Khaidir Abu Talib, Noriyuki Yasufuku, Ryohei Ishikura

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It is well recognized that peat can impede the proper hydration of cement because of high organic content, presence of humic acid and less solid particles. That means the large amount of cement is required in order to neutralize the acids or otherwise the process of the peat stabilization remains retarded. Nevertheless, adding a great quantity of cement into the peat is absolutely an unfriendly and uneconomical solution. Sugarcane production is world number one commodities and produced a lot of bagasse. Bagasse is burnt to generate power required for diverse activities in the factory and leave bagasse ash as a waste. Increasing concern of disposal of bagasse residual creates interest to explore the potential application of this material. The objective of this study is to develop alternative binders that are environment friendly and contribute towards sustainable management by utilizing sugarcane bagasse ash (SCBA) in the stabilization of peat soil. Alongside SCBA, Ordinary Portland Cement (OPC), calcium chloride (CaCl2) and silica sand (K7) were used as additives to stabilize the peat that sampled from Hokkaido, Japan. In obtaining the optimal mix design, specimens of stabilized peat were tested in unconfined compression. It was found that stabilized peat comprising 20% and 5% (PCB1-20 and PCB2-5) partial replacement of OPC with SCBA 1 and SCBA 2 attain the maximum unconfined compressive strength (UCS) and discovered greater than untreated soil (P) and UCS of peat-cement (PC) specimen. At the optimal mix design, the UCS of the stabilized peat specimens increased with increasing of curing time, preloading during curing, OPC dosage and K7 dosage. For PCB1-20 mixture, inclusion of a minimum OPC dosage of 300 kg/m3 and K7 dosage of 500 kg/m3 along with curing under 20kPa pressure is recommendable for the peat stabilization to be effective. However for PCB2-5 mixture, it suggested to use more OPC and K7 dosage or alternatively increase the preloading during curing to 40kPa in order to achieve minimum strength target. It can be concluded that SCBA 1 has better quality than SCBA 2 in peat stabilization especially the contribution made by its fine particle size.

Keywords: peat stabilization, sugarcane bagasse ash utilization, partial cement replacement, unconfined strength

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Authors: A. Elsayed, M. H. Dewaidar, M. Ghali, M. Elkemary

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The high production cost of the conventional solar cells requires the search for economic methods suitable for solar energy conversion. Cadmium Sulfide (CdS) is one of the most important semiconductors used in photovoltaics, especially in large area solar cells; and can be prepared in a thin film form by a wide variety of deposition techniques. The preparation techniques include vacuum evaporation, sputtering and molecular beam epitaxy. Other techniques, based on chemical solutions, are also used for depositing CdS films with dramatically low-cost compared to other vacuum-based methods. Although this technique is widely used during the last decades, due to simplicity and low-deposition temperature (~100°C), there is still a strong need for more information on the growth process and its relation with the quality of the deposited films. Here, we report on deposition of high-quality CdS thin films; with low-surface roughness ( < 3.0 nm) and sharp optical absorption edge; on low-temperature glass substrates (70°C) using a new method based on the room-temperature chemical solution. In this method, a mixture solution of cadmium acetate and thiourea at room temperature was used under special growth conditions for deposition of CdS films. X-ray diffraction (XRD) measurements were used to examine the crystal structure properties of the deposited CdS films. In addition, UV-VIS transmittance and low-temperature (4K) photoluminescence (PL) measurements were performed for quantifying optical properties of the deposited films. The deposited films show high optical quality as confirmed by observation of both, sharp edge in the transmittance spectra and strong PL intensity at room temperature. Furthermore, we found a strong effect of the growth conditions on the optical band gap of the deposited films; where remarkable red-shift in the absorption edge with temperature is clearly seen in both transmission and PL spectra. Such tuning of both optical band gap of the deposited CdS films can be utilized for tuning the electronic bands' alignments between CdS and other light-harvesting materials, like CuInGaSe or CdTe, for potential improvement in the efficiency of solar cells devices based on these heterostructures.

Keywords: chemical deposition, CdS, optical properties, surface, thin film

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Authors: Ebere Christian Ugochukwu, Okafor Josephine, Oyawoye Tomisin

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The occurrence of multidrug resistance patterns that have been developed by bacteria has made it difficult to properly treat infections using standard clinical medications. Hence, the use of herbs as an alternative source of therapy is considered cheap and easily accessible to locals. This research explored the antimicrobial effects of aqueous and ethanolic extracts obtained from Chrysophyllum albidum (commonly called ‘Agbalumo’ in southwest Nigeria and ‘Udara’ in the eastern and southern parts of Nigeria) plant parts (leaves, roots and seeds) against bacteria isolated from urinary catheter tips. The following isolates were obtained; Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Proteus mirabilis, and Klebsiella aerogenes. The agar well diffusion method was used. The average percentages of antimicrobial resistance of the isolates to gentamycin were 45.5% for P. aeruginosa, 42.1% for E. coli, 46.9% for K. aerogenes, and ˃90% for other isolates. Qualitative phytochemical screening of the plant parts extracts was done using chemical test for the screening and identification of bioactive chemical constituents. The ethanolic extract mixtures (leaf, root and seed) had the greatest effect on all the isolates, with inhibition zones (IZs) ranging from 8-26 mm and MICs ranging from <16-32 mg/ml. The Potencies of the C. albidum extracts based on the IZ and MIC values were greater in the extract mixtures, followed by those in the roots. Phytochemical screening revealed that all the extracts contained phenol except for the seeds while tannins were present in all the extracts except the leaves. The activity of the ethanolic extracts of each part at high and low concentrations was greater than that of the aqueous extracts at the same concentrations (p<0.05). The acute toxicity results showed that the LD50 of the extracts was ˃5000 mg/body weight, indicating no toxicity. The antibacterial activities of the extract mixtures and roots on the isolates confirmed the use of C. albidum in folk medicine for the treatment of CAUTIs, hence indicating its antibacterial potential for use in novel antibiotic production.

Keywords: antimicrobials, susceptibility, minimum inhibitory concentration, extracts

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Authors: Ana Miguel

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Purpose: Glaucoma is the second cause of worldwide blindness and the first cause of irreversible blindness. Trabeculectomy, the standard glaucoma surgery, has a success rate between 36.0% and 98.0% at three years and a high complication rate, leading to the development of different surgeries, micro-invasive glaucoma surgeries (MIGS). MIGS devices are diverse and have various indications, risks, and effectiveness. We intended to review MIGS’ surgical techniques, indications, contra-indications, and IOP effect. Methods: We performed a literature review of MIGS to differentiate the devices and their reported effectiveness compared to traditional surgery (tubes and blebs). We also conducted a video review of the last 1000 glaucoma surgeries of the author (including MIGS, but also trabeculectomy, deep sclerectomy, and tubes of Ahmed and Baerveldt) performed at glaucoma and advanced anterior segment fellowship in Canada and France, to describe preferred surgical techniques for each. Results: We present the videos with surgical techniques and pearls for each surgery. Glaucoma surgeries included: 1- bleb surgery (namely trabeculectomy, with releasable sutures or with slip knots, deep sclerectomy, Ahmed valve, Baerveldt tube), 2- MIGS with bleb, also known as MIBS (including XEN 45, XEN 63, and Preserflo), 3- MIGS increasing supra-choroidal flow (iStar), 4-MIGS increasing trabecular flow (iStent, gonioscopy-assisted transluminal trabeculotomy - GATT, goniotomy, excimer laser trabeculostomy -ELT), and 5-MIGS decreasing aqueous humor production (endocyclophotocoagulation, ECP). There was also needling (ab interno and ab externo) performed at the operating room and irido-zonulo-hyaloïdectomy (IZHV). Each technique had different indications and contra-indications. Conclusion: MIGS are valuable in glaucoma surgery, such as traditional surgery with trabeculectomy and tubes. All glaucoma surgery can be combined with phacoemulsification (there may be a synergistic effect on MIGS + cataract surgery). In addition, some MIGS may be combined for further intraocular pressure lowering effect (for example, iStents with goniotomy and ECP). A good surgical technique and postoperative management are fundamental to increasing success and good practice in all glaucoma surgery.

Keywords: glaucoma, migs, surgery, video, review

Procedia PDF Downloads 83