Search results for: internal rate of return

Authors: Nidhi Jindal, Ashok Chaudhury, Manisha Mangal

Abstract:

Andrographis paniculata, (Burm f.) Wallich ex. Nees (Family Acanthaceae) popularly known as King of Bitters, is an important medicinal herb. It has an astonishingly wide range of medicinal properties such as anti-inflammatory,antidiarrhoeal, antiviral, antimalarial, hepatoprotective, cardiovascular, anticancer, and immunostimulatory activities. It is widely cultivated in southern Asia. Though propagation of this herb generally occurs through seeds, it has many germination problems which intrigued scientists to work out on the alternative techniques for its mass production. The potential of tissue culture techniques as an alternative tool for AP multiplication was found to be promising. However, the high mortality rate of explants caused by phenolic browning of explants is one of the difficulties reported. Low multiplication rates were reported in the proliferation phase, as well as cultures decline characterized by leaf fall and loss of overall vigor. In view of above problems, a study was undertaken to overcome seed dormancy to improve germination potential and to investigate further on the possible means for successful proliferation of cultures via preventive approaches to overcome failures caused by phenolic browning. Experiments were conducted to improve germination potential and among all the chemical and mechanical trials, scarification of seeds with sand paper proved to be the best method to enhance the germination potential (82.44%) within 7 days. Similarly, several pretreatments and media combinations were tried to overcome browning of explants leading to the conclusion that addition of 0.1% citric acid and 0.2% of ascorbic acid in the media followed by rapid sub culturing of explants controlled browning and decline of explants by 67.45%.

Keywords: plant tissue culture, empirical measure, germination, tissue culture

Procedia PDF Downloads 396

Authors: Fangyuan Shao, Wei Liu, Deli Gao

Abstract:

With the increasing speed of oil and gas exploration, development and production at home and abroad, the demand for drilling speed up technology is becoming more and more critical to reduce the development cost. Highly efficient and personalized PDC bit is important equipment in the bottom hole assembly (BHA). Therefore, improving the rock-breaking efficiency of PDC bits will help reduce drilling time and drilling cost. Advances in PDC bit technology have resulted in a leapfrogging improvement in the rate of penetration (ROP) of PDC bits over roller cone bits in soft to medium-hard formations. Recently, with the development of PDC technology, the diameter of the PDC tooth can be further expanded. The maximum diameter of the PDC cutter used in this paper is 22 mm. According to the theoretical calculation, under the same depth of cut (DOC), the 22mm-PDC cutter increases the exposure of the cutter, and the increase of PDC cutter diameter helps to increase the cutting area of the PDC cutter. In order to evaluate the cutting performance of the 22 mm-PDC cutter and the existing commonly used cutters, the 16 mm, 19 mm and 22 mm PDC cutter was selected put on a vertical turret lathe (VTL) in the laboratory for cutting tests under different DOCs. The DOCs were 0.5mm, 1.0 mm, 1.5 mm and 2.0 mm, 2.5 mm and 3 mm, respectively. The rock sample used in the experiment was limestone. Results of laboratory tests have shown the new 22 mm-PDC cutter technology greatly improved cutting efficiency. On the one hand, as the DOC increases, the mechanical specific energy (MSE) of all cutters decreases, which means that the cutting efficiency increases. On the other hand, under the same DOC condition, the larger the cutter diameter is, the larger the working area of the cutter is, which leads to higher the cutting efficiency. In view of the high performance of the 22 mm-PDC cutters, which was applied to carry out full-scale bit field experiments. The result shows that the bit with 22mm-PDC cutters achieves a breakthrough improvement of ROP than that with conventional 16mm and 19mm cutters in offset well drilling.

Keywords: polycrystalline diamond compact, 22 mm-PDC cutters, cutting efficiency, mechanical specific energy

Procedia PDF Downloads 176

Authors: Lidimma Benjamin, Nimmyel Gwakzing, Wuyep Nanyi

Abstract:

Technical and Vocational Education and Training (TVET) has many stakeholders, each with their own values and interests. This study will focus on the diversity of the values and interests within and across groups of stakeholders by quantifying the value that stakeholders attached to several quality attributes of TVET, and also find out to what extent TVET stakeholders differ in their values. The quality of TVET therefore, depends on how well it aligns with the values and interests of these stakeholders. The five stakeholders are parents, students, teachers, policy makers, and work place training supervisors. The 9 attributes are employer appreciation of students, graduation rate, obtained computer skills of students, mentoring hours in workplace learning/Students Industrial Work Experience Scheme (SIWES), challenge, structure, students’ appreciation of teachers, schooling hours, and attention to civic education. 346 respondents (comprising Parents, Students, Teachers, Policy Makers, and Workplace Training Supervisors) were repeatedly asked to rank a set of 4 programs, each with a specific value on the nine quality indicators. Conjoint analysis was used to obtain the values that the stakeholders assigned to the 9 attributes when evaluating the quality of TVET programs. Rank-ordered logistic regression was the statistical/tool used for ranking the respondents values assign to the attributes. The similarities and diversity in values and interests of the different stakeholders will be of use by both Nigerian government and TVET colleges, to improve the overall quality of education and the match between vocational programs and their stakeholders simultaneous evaluation and combination of information in product attributes. Such approach models the decision environment by confronting a respondent with choices that are close to real-life choices. Therefore, it is more realistically than traditional survey methods.

Keywords: TVET, vignette study, conjoint analysis, quality perception, educational stakeholders

Procedia PDF Downloads 57

Authors: Nida Rizvi, Deeksha Katyal, Varun Joshi

Abstract:

River Hindon is an important river catering the demand of highly populated rural and industrial cluster of western Uttar Pradesh, India. Water quality of river Hindon is deteriorating at an alarming rate due to various industrial, municipal and agricultural activities. The present study aimed at identifying the pollution sources and quantifying the degree to which these sources are responsible for the deteriorating water quality of the river. Various water quality parameters, like pH, temperature, electrical conductivity, total dissolved solids, total hardness, calcium, chloride, nitrate, sulphate, biological oxygen demand, chemical oxygen demand and total alkalinity were assessed. Water quality data obtained from eight study sites for one year has been subjected to the two multivariate techniques, namely, principal component analysis and cluster analysis. Principal component analysis was applied with the aim to find out spatial variability and to identify the sources responsible for the water quality of the river. Three Varifactors were obtained after varimax rotation of initial principal components using principal component analysis. Cluster analysis was carried out to classify sampling stations of certain similarity, which grouped eight different sites into two clusters. The study reveals that the anthropogenic influence (municipal, industrial, waste water and agricultural runoff) was the major source of river water pollution. Thus, this study illustrates the utility of multivariate statistical techniques for analysis and elucidation of multifaceted data sets, recognition of pollution sources/factors and understanding temporal/spatial variations in water quality for effective river water quality management.

Keywords: cluster analysis, multivariate statistical techniques, river Hindon, water quality

Procedia PDF Downloads 436

Authors: Himanshu Rohela

Abstract:

BACKGROUND: Ewing sarcoma can arise in either bone or soft tissue. Extraskeletal Ewing sarcoma (EES) is an uncommon primary tumor of the soft tissues, accounting for 20 30% of all reported cases of ES. AIM: Was to investigate demographic distribution, survival analysis and factors affecting the survival and recurrence in patients of EES. METHODS: Retrospective study of 19 biopsy-proven EES was performed. Overall survival (OS) using log-rank test and factors affecting OS and local recurrence (LR) were evaluated for the entire cohort. RESULTS: Patients with EES had a mean age of 19.5 and it was more commonly seen in males (63%). Axial location (58%) and solitary presentation (84%) were more common. The average size was 11 cm, 3 of 19 were metastatic at presentation, with the lung beings the most common site for metastasis. 17 received NACT, 16 with VAC-IE regimen and 1 underwent a second line with GEM/DOCE regimen. Unplanned surgery was done in 2 of 19. 3 patients received definitive RT and 13 underwent surgical-wide local excision. 2 of 13 showed good response to NACT. 10 patients required readmission out of which 6 patients had chemotherapy-related complications, 2 had surgical site complications and one patient developed secondary AML post-completion of treatment. A total of 4 patients had a recurrence. One had local recurrence alone, one had distant recurrence alone and 2 patients had a distant and local recurrence both. Tumor size >10 cm, axial location, and previous unplanned surgery was associated with higher LR rate. The mean overall survival was 32 months (2.66 years), with higher rates seen in non-metastatic and non-recurrent settings. CONCLUSIONS: Early and accurate diagnosis is the key to the management of EES, with promising results seen via NACT and RO resection regimens. But further studies with larger study groups are needed to standardize the treatment protocol and evaluate its efficacy.

Keywords: Ewings, sarcoma, extraskeletal, chemotherapy

Procedia PDF Downloads 54

Authors: Simona Moravcova, Jiri Novotny, Zdenka Bendova

Abstract:

The pineal gland of the vertebrate brain is a circumventricular organ which serves as a major neuroendocrine gland with the primary function of rhythmic secretion of neurohormone melatonin under the control of the hypothalamic suprachiasmatic nucleus (SCN). Soon after the onset of the darkness, the activity of the key rate-limiting enzyme for melatonin synthesis, arylalkylamine N-acetyltransferase (AANAT), raises due to the increased release of norepinephrine from sympathetic neurons terminating on the parenchymal cells where it binds to β-adrenergic receptors. Melatonin codes the length of the night, and it is well recognized for its anti-inflammatory effects. However, to our knowledge, less is known about the effect of the immune system on the melatonin biosynthesis and the precise role of the STAT3 in the signaling pathway leading to the expression of AANAT. Lipopolysaccharide (LPS) is the essential component in the outer surface membrane of gram-negative bacteria and acts as a strong stimulator of natural and innate immunity. STAT3 acts as an important factor in immune response. Here we investigated the effect of LPS on the components of the melatonergic synthetic pathway in the pineal gland. The experiments were performed both in vivo and in vitro. The changes in AANAT activity were determined by radioenzymatic assay. PCR analyses were carried out to detect aa-nat, icer, spi-3 and stat3 gene expression. From our results, it is apparent that the high basal level of phosphorylated forms of STAT3 can be elevated after systemic as well as in vitro administration of LPS. Our experiments have shown that LPS reduces melatonin synthesis, nevertheless, the activity of AANAT was increased. Moreover, the basal level of phosphorylated STAT3 counteracts β-adrenergic receptor-mediated aa-nat gene expression and sustains its own and spi-3 gene expression. In conclusion, LPS can affect immunomodulators such as melatonin in the pineal gland.

Keywords: AANAT, lipopolysaccharide, pineal gland, rat, STAT3

Procedia PDF Downloads 145

Authors: Ejazulhaq Rahimi

Abstract:

The development of techniques evaluating deterioration on concrete structures is vital for structural health monitoring (SHM). One of the main reasons for reinforced concrete structure's deterioration is the corroding of embedded rebars. It is a natural process that begins when the rebar starts to rust. It occurs when the protective layer on the rebar is destroyed. The rebar in concrete is usually protected against corrosion by the high pH of the surrounding cement paste. However, there are chemicals that can destroy the protective layer, making it susceptible to corrosion. It is very destructive for the lifespan and durability of the concrete structure. Corrosion products which are 3 to 6 times voluminous than the rebar stress its surrounding concrete and lead to fracture as cracks even peeling off the cover concrete over the rebar. As is clear that concrete shows limit elastic behavior in its stress strain property, so corrosion product stresses can be detected as strains from the concrete surface. It means that surface strains have a relation with the situation and amount of corrosion products and related concrete fractures inside reinforced concrete. In this paper, a comparative study of surface strains due to corrosion products detected by strain gauges and acoustic emission (AE) testing under periodic accelerated corrosion in the salty environment with 3% NaCl is reported. From the results, three different stages of strains were clearly observed based on the type and rate of strains in each corrosion situation and related fracture types. AE parameters which mostly are related to fracture and their shapes, describe the same phases. It is confirmed that there is a great agreement to the result of each other and describes three phases as generation and expansion of corrosion products and initiation and propagation of corrosion-induced cracks, and surface cracks. In addition, the strain on the concrete surface was rapidly increased before the cracks arrived at the surface of the concrete.

Keywords: acoustic emission, monitoring, rebar corrosion, reinforced concrete, strain

Procedia PDF Downloads 156

Authors: Nadilla Saskia, Octoria Nur, Assegaf Zareeva

Abstract:

Mass transport infrastructures are essential to enhance the connectivity between regions and regional equity in Indonesia. Indonesia’s capital city, Jakarta, ranked the 10th highest congestion rate in the world based on the 2019 traffic index, contributing to air pollution and energy consumption. Other than that, the World Air Quality Report in 2019 depicted Jakarta’s air pollutant concentration at 49.4 mg, the 5th highest in the world. Issues of severe traffic congestion, lack of sufficient urban infrastructure in Jakarta, and greenhouse gas emissions have to be addressed through mass transportation. Indonesia’s government is currently constructing The Greater Jakarta LRT (Light Rapid Transit) as convenient, efficient, and environmentally friendly transportation connecting Jakarta with Bekasi and Cibubur areas and plans to serve the passengers in August 2023. Greater Jakarta LRT is operated with Grade of Automation (GoA) No.3, Driverless Train Operation (DTO). Hence, the automated technology used in rail infrastructure is anticipated to address these issues with greater results. The paper will be validated and establish the extent to which the automation system would increase energy efficiency, help reduce carbon emissions, and benefit the environment. Based on the calculated CO2 emissions and fuel consumption for the existing condition (2015) during the feasibility study of the LRT Project and the predicted condition in 2030, it is obtained that Greater Jakarta LRT with GoA3 operation will reduce the CO2 emissions and fuel consumption by more than 50% in 2030. In the bigger picture, Greater Jakarta LRT supports the government's goal of achieving Jakarta Net-Zero Emissions (NZE) 2050.

Keywords: LRT, Grade of Automation (GoA), energy efficiency, carbon emissions, railway infrastructure, DKI Jakarta

Procedia PDF Downloads 55

Authors: Leila Karshenas, Hamidreza Khodaei, Behnaz Mahdavi

Abstract:

Ovulation is a physiologic process with an inflammatory response that depends on a coordinated activity of gonadotropins and steroid hormones, as well as inflammatory mediators such as cytokines, prostaglandins, leptin, nitric oxide (NO), etc. Conjugated linoleic acid (CLA) is composed of polyunsaturated fatty acids (PUFA) found in dairy products, beef and lamb. There is strong evidence that dietary CLA affects mediators involved in ovulation. The aim of this study was to determine the effects of different doses of dietary CLA on systemic and local hormones and factors involved in ovulation. In this case-control study, 80 (50±2-day old) female mice were randomly divided into four groups (C as the controls and T1, T2 and T3 as the treatment groups). There were four replicates in each group and there were five mice in every replicate (20 mice, in total). The mice in the control group were fed with no CLA in their diet but the ones in the treatment group received 0.1, 0.3 and 0.5g/kg of CLA (replacing corn oil in the diet), respectively for 120 days. Later on, blood samples were obtained from the tails of animals that displayed estrus signs and estradiol (E2), progesterone (P4), LH, FSH, NO, leptin and TNFα were measured. Furthermore, the effects of CLA on the ovarian production of prostaglandins (PGs) and NO were investigated. The data were analyzed by SAS software.CLA significantly decreased serum levels of FSH (p<0.05), LH, estradiol, NO, leptin and TNFα (p<0.01). In addition, CLA decreased progesterone levels but this effect was statistically insignificant. The significantly negative effects of CLA were seen on the ovarian production of PGE2 and PGF2α (p<0.01).It seems that CLA may play an effective role in reducing the ovulation rate in mice as CLA adversely affected female reproduction and it had negative effects on systemic and local hormones involved in ovulation.

Keywords: conjugated linoleic acid, nitric oxide, ovary, ovulation, prostaglandin, gonadotropin

Procedia PDF Downloads 279

Authors: Mulue Girmay Gebreslasie

Abstract:

Entomopathogenic fungi are naturally safe and eco-friendly biological agents. Their potential of host specificity and ease handling made them appealing options to substitute synthetic pesticides in pest control programs. However, they are highly delicate and unstable under field conditions. Therefore, the current experiment was held to search out persistent fungal strains by defining the relationship between invitro heat tolerance and field persistence. Current results on leaf and soil persistence assay revealed that strains of Metarhizium species, M. pingshaense (F2685), M. pingshaense (MS2) and M. brunneum (F709) exhibit maximum cumulative CFUs count, relative survival rate and least percent of CFUs reductions showed significant difference at 7 days and 28 days post inoculations (dpi) in hot seasons from sampled soils and leaves and in cold season from soil samples. Whereas relative survival of B. brongniartii (TNO6) found significantly higher in cold weather leaf treatment application as compared to hot season and found as persistent as other fungal strains, while higher deterioration of fungal conidia seen with M. pingshaense (MS2). In the current study, strains of Beauveria brongniartii (TNO6) and Cordyceps javanica (Czy-LP) were relatively vulnerable in field condition with utmost colony forming units (CFUs) reduction and least survival rates. Further, the relationship of the two parameters (heat tolerance and field persistence) was seen with strong linear positive correlations elucidated that heat test could be used in selection of field persistent fungal strains for hot season applications.

Keywords: integrated pest management, biopesticides, Insect pathology and microbial control, entomology

Procedia PDF Downloads 62

Authors: Heroda Gebru, Berhanu Seyoum, Melake Damena, Gezahegn Tesfaye

Abstract:

Background: In Ethiopia there is a population policy aimed at reducing fertility and increasing contraceptive prevalence. Objective: To assess the fertility preference and contraceptive use status of married women who were living in Dire Dawa administrative city. Methods: Cross sectional study which included a sample size of 421 married women of reproductive age were performed. Data was collected using structured questionnaire during house to house survey and semi-structured questionnaire during in-depth interview. Data was processed and analyzed using SPSS version 16 computer software. Univariate, bi variate and multi variate analysis was employed. Results: A total of 421 married women of reproductive age group were interviewed having a response rate of 100 percent. More than half (58.2%) of the respondent have desire of more children. While 41.8% want no more children. Regarding contraceptive use 52.5% of the respondents were using contraceptive at the time of survey. Fertility preference and contraceptive use were significantly associated with age of the respondent, history of child death, number of living children, religion and age at first birth. Conclusions: Those women with younger age group, who had no child death history and women with lesser number of surviving children were more likely desire additional children. Women with older age at first birth and protestant in religion were more likely practiced contraceptive use. Strong information and education regarding contraceptive for younger age group should be provided, advocacy at level of religious leader is important, comprehensive family planning counselling and education should be available for the community, husbands, and religious leaders and the aim for increasing contraceptive use should focus on the practical aspect.

Keywords: fertility preference, contraceptive use, univariate analysis, family planning

Procedia PDF Downloads 347

Authors: Chun-Han Li, Tien-Fu Yang, Chen-Yu Chen, Wei-Mon Yan

Abstract:

The conventional dehumidification method in air-conditioning system mostly utilizes a cooling coil to remove the moisture in the air via cooling the supply air down below its dew point temperature. During the process, it needs to reheat the supply air to meet the set indoor condition that consumes a considerable amount of energy and affect the coefficient of performance of the system. If the processes of dehumidification and cooling are separated and operated respectively, the indoor conditions will be more efficiently controlled. Therefore, decoupling the dehumidification and cooling processes in heating, ventilation and air conditioning system is one of the key technologies as membrane dehumidification processes for the next generation. The membrane dehumidification method has the advantages of low cost, low energy consumption, etc. It utilizes the pore size and hydrophilicity of the membrane to transfer water vapor by mass transfer effect. The moisture in the supply air is removed by the potential energy and driving force across the membrane. The process can save the latent load used to condense water, which makes more efficient energy use because it does not involve heat transfer effect. In this work, the performance measurements including the permeability and selectivity of water vapor and air with the composite and commercial membranes were conducted. According to measured data, we can choose the suitable dehumidification membrane for designing the flow channel length and components of the planar dehumidifier. The vacuum membrane dehumidification system was set up to examine the effects of temperature, humidity, vacuum pressure, flow rate, the coefficient of performance and other parameters on the dehumidification efficiency. The results showed that the commercial Nafion membrane has better water vapor permeability and selectivity. They are suitable for filtration with water vapor and air. Meanwhile, Nafion membrane has promising potential in the dehumidification process.

Keywords: vacuum membrane dehumidification, planar membrane dehumidifier, water vapour and air permeability, air conditioning

Procedia PDF Downloads 119

Authors: Nkem Angela Udeani

Abstract:

Despite the widespread use of synthetic dyes, natural dyes are still exploited and used to enhance its inherent aesthetic qualities as a major material for the beautification of the body. Centuries before the discovery of synthetic dye, natural dyes were the only source of dye open to mankind. Dyes are extracted from plant - leaves, roots, and barks, insect secretions, and minerals. However, research findings have made it clear that of all, plant- leaves, roots, barks or flowers are the most explored and exploited. Henna (Lawsonia innermis) is one of those plants. The experiment has also shown that henna is used in body painting in conjunction with an alkaline (Ammonium Sulphate) as a fixing agent. This of course gives a clue that if colour derived from henna is properly investigated, it may not only be used as body decoration but possibly, may have affinity to fibre substrate. This paper investigates the dyeing potentials - dyeing ability and fastness qualities of henna dye extract on cotton and linen fibres using mordants like ammonium sulphate and other alkalies (hydrosulphate and caustic soda, potash, common salt and alum). Hot and cold water and ethanol solvent were used in the extraction of the dye to investigate the most effective method of extraction, dyeing ability and fastness qualities of these extracts under room temperature. The results of the experiment show that cotton have a high rate of dye intake than linen fibre. On a similar note, the colours obtained depend most on the solvent and or the mordant used. In conclusion, hot water extraction appear more effective. While the colours obtained from ethanol and both cold and hot method of extraction range from light to dark yellow, light green to army green, there are to some extent shades of brown hues.

Keywords: dye, fabrics, henna leaves, potential

Procedia PDF Downloads 446

Authors: Zebiri Saliha

Abstract:

Ochratoxin A (OTA) is a mycotoxin produced by certain species of the genera Aspergillus and Penicillium, primarily found in cereals, coffee, and grapevine products. Its accumulation in the body can lead to nephrotoxic, teratogenic, immunosuppressive, and carcinogenic effects. The objective of this study is to investigate the contamination of consumed wheat and its derivatives by toxic fungi in Algeria. For this purpose, an analysis of 200 samples was conducted, including 90 samples of durum wheat and common wheat and 110 samples of wheat derivatives collected from mills (semolina and flour manufacturers). The results revealed an average fungal contamination rate ranging from 60% to 100%. The identified fungal isolates primarily belonged to the genera Aspergillus (70%), Penicillium (27.5%), Alternaria (40%), and Mucor (19.4%). The density of the fungal flora was higher in products intended for animal consumption, such as durum wheat flour (2525 CFU/g), wheat scraps (3175 CFU/g), and wheat bran (2950 CFU/g). Conversely, low fungal density was observed in fine semolina (900 CFU/g) and flour (800 CFU/g) intended for human consumption. The genus Penicillium was isolated in 46% of the analyzed samples of durum wheat derivatives and in 62.7% of the analyzed samples of common wheat derivatives. The Aspergillus genus dominated the majority of the analyzed samples. Molecular identification of Aspergillus and Penicillium isolates by sequencing ITS1-5.8S-ITS2 regions of DNAr and a part of the calmodulin (CaM) gene indicated that the species involved in the production of OTA in wheat and its derivatives were mainly Aspergillus ochraceus, A. westerdijkia, A. alliaceus, A. carbonarius, and Penicillium islandicus. The amounts of OTA produced by these species were determined by HPLC-FLD and ranged between 0,8.9 and 3033μg/g. Given that food safety and quality are major concerns today, understanding the microbial biodiversity of wheat is crucial because it is a staple food in Algeria.

Keywords: wheat derivatives, Aspergillus, microbial biodiversity, OTA

Procedia PDF Downloads 19

Authors: Aliyu Shitu Said

Abstract:

One of the major setbacks of every society is the proliferation of crimes that results in the inducement of fear, destruction of properties and loss of lives of people. The rising incidence of crime and general insecurity rate in the society and the inability of the policing agencies to curtail the menace necessitated the introduction of community policing in order to have a collaborative effort with community members in addressing the problem of crime. Thus, this study assessed the impact of community policing in crime prevention and control in Fagge Local Government area, Kano State, Nigeria. The study also examined the elements, roles, and challenges of community policing in crime prevention and control in the study area. The study adopted Broken Window and Routine Activity theories as frame of analysis. Mixed methods of data collection (quantitative and qualitative) were utilized for the study. Multi stage and purposive sampling techniques were adopted in selection of the study population. A total of 308 respondents were sampled for the study. These include 300 members of the public who were sampled through a multi stage sampling for questionnaire administration and 8 other respondents who were purposively sampled for in-depth interview. Findings of the study revealed that community policing has significant impact on crime prevention and control in the study area. Findings of the study further revealed that the elements and roles of community policing are effective and fully utilized, and there is cordial relationship between the police and the community members in the study area. This study therefore recommends that government should provide adequate support to community policing programmes and give more awareness to public, so as to boost the morale of the community in having a collaborative effort with the police in crime prevention and control.

Keywords: community, policing, crime, prevention, control

Procedia PDF Downloads 42

Authors: Mahesh Kumar Jat, Manisha Choudhary

Abstract:

Rapid population and economic growth resulted in changes in large-scale land use land cover (LULC) changes. Changes in the biophysical properties of the Earth's surface and its impact on climate are of primary concern nowadays. Different approaches, ranging from location-based relationships or modelling earth surface - atmospheric interaction through modelling techniques like surface energy balance (SEB) have been used in the recent past to examine the relationship between changes in Earth surface land cover and climatic characteristics like temperature and precipitation. A remote sensing-based model i.e., Surface Energy Balance Algorithm for Land (SEBAL), has been used to estimate the surface heat fluxes over Mahi Bajaj Sagar catchment (India) from 2001 to 2020. Landsat ETM and OLI satellite data are used to model the SEB of the area. Changes in observed precipitation and temperature, obtained from India Meteorological Department (IMD) have been correlated with changes in surface heat fluxes to understand the relative contributions of LULC change in changing these climatic variables. Results indicate a noticeable impact of LULC changes on climatic variables, which are aligned with respective changes in SEB components. Results suggest that precipitation increases at a rate of 20 mm/year. The maximum and minimum temperature decreases and increases at 0.007 ℃ /year and 0.02 ℃ /year, respectively. The average temperature increases at 0.009 ℃ /year. Changes in latent heat flux and sensible heat flux positively correlate with precipitation and temperature, respectively. Variation in surface heat fluxes influences the climate parameters and is an adequate reason for climate change. So, SEB modelling is helpful to understand the LULC change and its impact on climate.

Keywords: remote sensing, GIS, object based, classification

Procedia PDF Downloads 95

Authors: G. Kaushik, A. Gupta, S. Lalwani, K. D. Soni, S. Kumar, S. Sagar

Abstract:

Objective: Alcohol is a leading risk factor associated with the disability and death due to RTI. Present study aims to demonstrate the demographic profile, injury pattern, physiological parameters of victims of trauma following alcohol consumption arriving in the emergency department (ED) and mortality in alcohol intoxicated trauma patients admitted to Apex Trauma Center in Delhi. Design and Methods: Present study was performed in randomly selected 182 alcohol breath analyzer tested RTI patients from the emergency department of Jai Prakash Narayan Apex Trauma Center (JPNATC), All India Institute of Medical Sciences, New Delhi for over a period of 3 months started from September 2013 to November 2013. Results: A total 182 RTI patients with blunt injury were selected between 30-40 years of age and equally distributed to male and female group. Of these, 93 (51%) were alcohol negative and 89 (49%) were alcohol positive. In 89 alcohol positive patients, 47 (53%) had Artificial Airway as compared to 17 (18%), (p < 0.001) in the other group. The Glasgow Coma Scale (GCS) score was lower (p < 0.001) and higher Injury Severity Score (ISS) was observed in alcohol positive group as compared to other group (p < 0.03). Increased number of patients (58%) were admitted to Intensive Care Unit (ICU), in alcohol positive group (p < 0.001) and they were in ICU for longer time compare to other group (p < 0.001). The alcohol positive patients were on ventilator support for longer duration as compared to non-alcoholic group (p < 0.001). Mortality rate was higher in alcohol intoxicated patients as compared to non-alcoholic RTI patients, however, the difference was not statistically significant. Conclusion: This study revealed that GCS, mean ISS, ICU stay, ventilation time etc. might have considerable impact on mortality in alcohol intoxicated patients as compared to non-alcoholic group.

Keywords: road traffic injuries, alcohol, trauma, emergency department

Procedia PDF Downloads 295

Authors: Yixin Yan, Miao Yan, Irini Angelidaki, Ioannis Fotidis

Abstract:

Ammonia, which derives from the degradation of urea and protein-substrates, is the major toxicant of the commercial anaerobic digestion reactors causing loses of up to 1/3 of their practical biogas production, which reflects directly on the overall revenue of the plants. The current experimental work is aiming to alleviate the ammonia inhibition in anaerobic digestion (AD) process by developing an innovative bioaugmentation method of ammonia tolerant methanogenic consortia. The ammonia tolerant consortia were cultured in batch reactors and immobilized together with biochar in agar (customized inocula). Three continuous stirred-tank reactors (CSTR), fed with the organic fraction of municipal solid waste at a hydraulic retention time of 15 days and operated at thermophilic (55°C) conditions were assessed. After an ammonia shock of 4 g NH4+-N L-1, the customized inocula were bioaugmented into the CSTR reactors to alleviate ammonia toxicity effect on AD process. Recovery rate of methane production and methanogenic activity will be assessed to evaluate the bioaugmentation performance, while 16s rRNA gene sequence will be used to reveal the difference of microbial community changes through bioaugmentation. At the microbial level, the microbial community structures of the four reactors will be analysed to find the mechanism of bioaugmentation. Changes in hydrogen formation potential will be used to predict direct interspecies electron transfer (DIET) between ammonia tolerant methanogens and syntrophic bacteria. This experimental work is expected to create bioaugmentation inocula that will be easy to obtain, transport, handled and bioaugment in AD reactors to efficiently alleviate the ammonia toxicity, without alternating any of the other operational parameters including the ammonia-rich feedstocks.

Keywords: artisanal fishing waste, acidogenesis, volatile fatty acids, pH, inoculum/substrate ratio

Procedia PDF Downloads 99

Authors: Vaibhav Budhiraja, Chandra Mouli Pandey

Abstract:

The ultrasonic synthesis of nanostructured conducting copolymer is an effective technique to synthesize polymer with desired chemical properties. This tailored nanostructure, shows tremendous improvement in sensitivity and stability to detect a variety of analytes. The present work reports ultrasonically synthesized nanostructured conducting poly(o-phenylenediamine)-co-poly(1-naphthylamine) (POPD-co-PNA). The synthesized material has been characterized using Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy, transmission electron microscopy, X-ray diffraction and cyclic voltammetry. FTIR spectroscopy confirmed random copolymerization, while UV-visible studies reveal the variation in polaronic states upon copolymerization. High crystallinity was achieved via ultrasonic synthesis which was confirmed by X-ray diffraction, and the controlled morphology of the nanostructures was confirmed by transmission electron microscopy analysis. Cyclic voltammetry shows that POPD-co-PNA has rather high electrochemical activity. This behavior was explained on the basis of variable orientations adopted by the conducting polymer chains. The synthesized material was electrophoretically deposited at onto indium tin oxide coated glass substrate which is used as cathode and parallel platinum plate as the counter electrode. The fabricated bioelectrode was further used for detection of glucose by crosslinking of glucose oxidase in the PODP-co-PNA film. The bioelectrode shows a surface-controlled electrode reaction with the electron transfer coefficient (α) of 0.72, charge transfer rate constant (ks) of 21.77 s⁻¹ and diffusion coefficient 7.354 × 10⁻¹⁵ cm²s⁻¹.

Keywords: conducting, electrophoretic, glucose, poly (o-phenylenediamine), poly (1-naphthylamine), ultrasonic

Procedia PDF Downloads 123

Authors: David Polcari, Samuel C. Perry, Loredano Pollegioni, Matthias Geissler, Janine Mauzeroll

Abstract:

ᴅ-serine acts as an endogenous co-agonist for N-methyl-ᴅ-aspartate receptors in neuronal synapses. This makes it a key component in the development and function of a healthy brain, especially given its role in several neurodegenerative diseases such as Alzheimer’s disease and dementia. Despite such clear research motivations, the primary site and mechanism of ᴅ-serine release is still currently unclear. For this reason, we are developing a biosensor for the detection of ᴅ-serine utilizing a microelectrode in combination with a ᴅ-amino acid oxidase enzyme, which produces stoichiometric quantities of hydrogen peroxide in response to ᴅ-serine. For the fabrication of a biosensor with good selectivity, we use a permselective poly(meta-phenylenediamine) film to ensure only the target molecule is reacted, according to the size exclusion principle. In this work, we investigated the effect of the electrodeposition conditions used on the biosensor’s response time and selectivity. Careful optimization of the fabrication process allowed for enhanced biosensor response time. This allowed for the real time sensing of ᴅ-serine in a bulk solution, and also provided in means to map the efflux of ᴅ-serine in real time. This was done using scanning electrochemical microscopy (SECM) with the optimized biosensor to measure localized release of ᴅ-serine from an agar filled glass capillary sealed in an epoxy puck, which acted as a model system. The SECM area scan simultaneously provided information regarding the rate of ᴅ-serine flux from the model substrate, as well as the size of the substrate itself. This SECM methodology, which provides high spatial and temporal resolution, could be useful to investigate the primary site and mechanism of ᴅ-serine release in other biological samples.

Keywords: ᴅ-serine, enzymatic biosensor, microelectrode, scanning electrochemical microscopy

Procedia PDF Downloads 209

Authors: Esraa Mohamed El-Fawal

Abstract:

A facile solvothermal procedure was applied to fabricate zinc ferrite nanoparticles (ZnFe₂O₄ NPs). Activated carbon (AC) derived from peanut shells is synthesized using a microwave through the chemical activation method. The ZnFe₂O₄-AC composite is then mixed with a cerium-based metal-organic framework (CeMOF) by solid-state adding to formulate ZnFe₂O₄-AC/CeMOF composite. The synthesized photo materials were tested by scanning/transmission electron microscope (SEM/TEM), Photoluminescence (PL), (XRD) X-Ray diffraction, (FTIR) Fourier transform infrared, (UV-Vis/DRS) ultraviolet-visible/diffuse reflectance spectroscopy. The prepared ZnFe₂O₄-AC/CeMOFphotomaterial shows significantly boosted efficiency for photodegradation of methyl orange /methylene blue (MO/MB) compared with the pristine ZnFe₂O₄ and ZnFe₂O₄-AC composite under the irradiation of visible-light. The favorable ZnFe₂O₄-AC/CeMOFphotocatalyst displays the highest photocatalytic degradation efficiency of MB/MO (R: 91.5-88.6%, consecutively) compared with the other as-prepared materials after 30 min of visible-light irradiation. The apparent reaction rate K: 1.94-1.31 min-1 is also calculated. The boosted photocatalytic proficiency is ascribed to the heterojunction at the interface of prepared photo material that assists the separation of the charge carriers. To reach optimization, statistical analysis using response surface methodology was applied. The effect of independent parameters (such as A (pH), B (irradiation time), and (c) initial pollutants concentration on the response function (%)photodegradation of MB/MO dyes (as examples of azodyes) was investigated via using central composite design. At the optimum condition, the photodegradation efficiency (%) of the MB/MO is 99.8-97.8%, respectively. ZnFe2O₄-AC/CeMOF hybrid reveals good stability over four consecutive cycles.

Keywords: azo-dyes, photo-catalysis, zinc ferrite, response surface methodology

Procedia PDF Downloads 143

Authors: Narottam Puri, Bishnu Panigrahi, Narayan Pendse

Abstract:

Background: Clinical Outcomes are the globally agreed upon, evidence-based measurable changes in health or quality of life resulting from the patient care. Reporting of outcomes and its continuous monitoring provides an opportunity for both assessing and improving the quality of patient care. In 2012, International Consortium Of HealthCare Outcome Measurement (ICHOM) was founded which has defined global Standard Sets for measuring the outcome of various treatments. Method: Monitoring of Clinical Outcomes was identified as a pillar of Fortis’ core value of Patient Centricity. The project was started as an in-house developed Clinical Outcomes Reporting Portal by the Fortis Medical IT team. Standard sets of Outcome measurement developed by ICHOM were used. A pilot was run at Fortis Escorts Heart Institute from Aug’13 – Dec’13.Starting Jan’14, it was implemented across 11 hospitals of the group. The scope was hospital-wide and major clinical specialties: Cardiac Sciences, Orthopedics & Joint Replacement were covered. The internally developed portal had its limitations of report generation and also capturing of Patient related outcomes was restricted. A year later, the company provisioned for an ICHOM Certified Software product which could provide a platform for data capturing and reporting to ensure compliance with all ICHOM requirements. Post a year of the launch of the software; Fortis Healthcare has become the 1st Healthcare Provider in Asia to publish Clinical Outcomes data for the Coronary Artery Disease Standard Set comprising of Coronary Artery Bypass Graft and Percutaneous Coronary Interventions) in the public domain. (Jan 2016). Results: This project has helped in firmly establishing a culture of monitoring and reporting Clinical Outcomes across Fortis Hospitals. Given the diverse nature of the healthcare delivery model at Fortis Network, which comprises of hospitals of varying size and specialty-mix and practically covering the entire span of the country, standardization of data collection and reporting methodology is a huge achievement in itself. 95% case reporting was achieved with more than 90% data completion at the end of Phase 1 (March 2016). Post implementation the group now has one year of data from its own hospitals. This has helped identify the gaps and plan towards ways to bridge them and also establish internal benchmarks for continual improvement. Besides the value created for the group includes: 1. Entire Fortis community has been sensitized on the importance of Clinical Outcomes monitoring for patient centric care. Initial skepticism and cynicism has been countered by effective stakeholder engagement and automation of processes. 2. Measuring quality is the first step in improving quality. Data analysis has helped compare clinical results with best-in-class hospitals and identify improvement opportunities. 3. Clinical fraternity is extremely pleased to be part of this initiative and has taken ownership of the project. Conclusion: Fortis Healthcare is the pioneer in the monitoring of Clinical Outcomes. Implementation of ICHOM standards has helped Fortis Clinical Excellence Program in improving patient engagement and strengthening its commitment to its core value of Patient Centricity. Validation and certification of the Clinical Outcomes data by an ICHOM Certified Supplier adds confidence to its claim of being leaders in this space.

Keywords: clinical outcomes, healthcare delivery, patient centricity, ICHOM

Procedia PDF Downloads 215

Authors: Gerardo Sanjuan Sanjuan, Ángel Enrique Chavéz Castellanos

Abstract:

The knowledge of the rheological behavior of partially solidified metal alloy is an important issue when modeling and simulation of die filling in semisolid processes. Many experiments for like steady state, the step change in shear rate tests, shear stress ramps have been carried out leading that semi-solid alloys exhibit shear thinning, thixotropic behavior and yield stress. More advanced investigation gives evidence some viscoelastic features can be observed. The viscoelastic properties of materials are determinate by transient or dynamic methods; unfortunately, sparse information exists about oscillation experiments. The aim of this present work is to use small amplitude oscillatory tests for knowledge properties such as G´ and G´´. These properties allow providing information about materials structure. For this purpose, we investigated tin-lead alloy (Sn-15%Pb) which exhibits a similar microstructure to aluminum alloys and is the classic alloy for semisolid thixotropic studies. The experiments were performed with parallel plates rheometer AR-G2. Initially, the liquid alloy is cooled down to the semisolid range, a specific temperature to guarantee a constant fraction solid. Oscillation was performed within the linear viscoelastic regime with a strain sweep. So, the loss modulus G´´, the storage modulus G´ and the loss angle (δ) was monitored. In addition a frequency sweep at a strain below the critical strain for characterized its structure. This provides more information about the interactions among solid particles on a liquid matrix. After testing, the sample was removed then cooled, sectioned and examined metallographically. These experiments demonstrate that the viscoelasticity is sensitive to the solid fraction, and is strongly influenced by the shape and size of particles solid.

Keywords: rheology, semisolid alloys, thixotropic, viscoelasticity

Procedia PDF Downloads 347

Authors: Saheed Ahmad Rufai

Abstract:

The growing nature of insurgencies in their various forms in the Muslim world is now of great concern to both the leadership and the citizenry. The high sense of insecurity occasioned by the unpleasant experience has in fact attained an alarming rate in the estimation of both Muslims and non-Muslims alike. Consequently, the situation began to attract contributions from scholars and researchers in security-related fields of humanities and social sciences. However, there is little evidence of contribution to the discourse and the scholarship involved by scholars in the field of education. The purpose of this proposed study is to contribute an education dimension to the growing scholarship on the subject. The study which is situated in the broad scholarship of curriculum making and grounded in both the philosophical and sociological foundations of the curriculum, employs a combination of curriculum criticism and creative synthesis, as methods, in reconstructing Muslim schools’ educational blueprint. The significance of the proposed study lies in its potential to contribute a useful addition to the scholarship of curriculum construction in the context of the Muslim world. The significance also lies in its potential to offer an ameliorative proposal over unnecessary insurgency or militancy thereby paving the way for the enthronement of a regime characterized by peaceful, harmonious and tranquil co-existence among people of diverse orientations and ideological persuasions in the Muslim world. The study is restricted to only the first two stages of curriculum making namely the formulation of philosophy which concerns the articulation of objectives, aims, purposes, goals, and principles, as well as the second stage which covers the translation of such principles to an anti-insurgency secondary school curriculum for the Muslim world.

Keywords: education for conflict resolution, anti-insurgency curriculum principles, peace education, anti-terrorist curriculum framework, curriculum for Muslim secondary schools

Procedia PDF Downloads 198

Authors: Pragathi Gurumurthy, Christina Hagen, Patricia Ulloa, Martin A. Koch, Thorsten M. Buzug

Abstract:

Obstructive sleep apnea (OSA) is a sleep disorder where the patient suffers a disturbed airflow during sleep due to partial or complete occlusion of the pharyngeal airway. Recently, numerical simulations have been used to better understand the mechanism of pharyngeal collapse. However, to gain confidence in the solutions so obtained, an experimental validation is required. Therefore, in this study an experimental validation of computational fluid dynamics (CFD) used for the study of human pharyngeal flow patterns during OSA is performed. A stationary incompressible Navier-Stokes equation solved using the finite element method was used to numerically study the flow patterns in a computed tomography-based human pharynx model. The inlet flow rate was set to 250 ml/s and such that a flat profile was maintained at the inlet. The outlet pressure was set to 0 Pa. The experimental technique used for the validation of CFD of fluid flow patterns is phase contrast-MRI (PC-MRI). Using the same computed tomography data of the human pharynx as in the simulations, a phantom for the experiment was 3 D printed. Glycerol (55.27% weight) in water was used as a test fluid at 25°C. Inflow conditions similar to the CFD study were simulated using an MRI compatible flow pump (CardioFlow-5000MR, Shelley Medical Imaging Technologies). The entire experiment was done on a 3 T MR system (Ingenia, Philips) with 108 channel body coil using an RF-spoiled, gradient echo sequence. A comparison of the axial velocity obtained in the pharynx from the numerical simulations and PC-MRI shows good agreement. The region of jet impingement and recirculation also coincide, therefore validating the numerical simulations. Hence, the experimental validation proves the reliability and correctness of the numerical simulations.

Keywords: computational fluid dynamics, experimental validation, phase contrast-MRI, obstructive sleep apnea

Procedia PDF Downloads 292

Authors: Ibrahim Magaji

Abstract:

WhatsApp messaging platform brings about new opportunities for users to participate in unique storytelling experiences and audience engagement, particularly to Students of Mass communication who receive training to report events and issues accurately and objectively in accordance with official controls. Also, the complex nature of society today made it possible to use the WhatsApp platform that revolutionizes the means of sharing information, ideas, and experiences. This paper examined the WhatsApp messaging platform and how it influenced the academic performance of students in the Department of Mass Communication, Abdu Gusau Polytechnic, Talata Mafara. It used in-depth interview techniques and focus group discussion with students, as well as the use of published materials as well as unpublished materials to gather related and relevant data. Also, the paper used procedures involved to analyze long interview content. This procedure includes observation of a useful utterance, development of expanded observation, the examination of the interconnection of observed comments, collective scrutiny of observation for patterns and themes, and review and analysis of the themes across all interviews for development of the thesis. The result revealed that the majority of students used WhatsApp messenger for making friends and chatting. Also, the students experienced negative effects such as poor grammar and spelling, less study time, and poor academic performance because of active participation in the use of WhatsApp messaging platform. Surprisingly, there was a high addiction rate among students in the usage of WhatsApp messenger. However, other students experienced an improvement in their readings skills as a result of participation in the use of the platform. Also, students shared ideas, discussed, and shared examination questions among themselves on WhatsApp messenger.

Keywords: WhatsApp messenger, students, participation, group

Procedia PDF Downloads 106

Authors: Boudraa Wahiba, Chettibi Farah, Lahlah Naouel, Bouslama Zihad, Houhamdi Moussa

Abstract:

The marsh of Boussedra (55 ha) is a peri-urban wetland, located in the city of El - Bouni, wilaya of Annaba (North-east of the Algeria). This city hosts every year, 53 species of waterfowl, belonging to 15 different families, of which the most represented family is the Anatidae with almost 12 species. The Glossy ibis (Plegadis falcinellus) is the only representative of the family of the threskiornithidae. After a total absence for almost a decade, this species has established in North Africa and started breeding since 2000. The Glossy ibis (plegadis falcinellus), breeds with low numbers in distant areas. At the wetland of Boussedra, the population of this species was observed with numbers approaching 160 individuals. During the breeding season of 2014 (between march and july), this species bred in mixed heronries (Cattle egret Bubulcus ibis , Little egret Egretta garzetta, The black-crowned night heron Nycticorax nycticorax , Squacco heron Ardeola ralloides and Little bittern Ixobrychus minutus), where a total of 120 nests were counted. This represents the largest colony observed in North Africa. The reproduction of the studied species took place on a Tamaricaceae (Tamarix gallica), where more than 2000 nest were constructed. During this breeding season, we have monitored the colony's installation and evolution and tried to characterize the reproduction, at the urban water plan of Boussedra (measurements of nests, measurements of eggs and monitoring the growing rate and weight gaining of the chicks, since their birth until their flight).

Keywords: glossy ibis, reproduction, peri-urban wetland, mixed heronry, Boussedra, Algeria

Procedia PDF Downloads 299

Authors: Musse Mohamud Ahmed, Tina Linda Achilles, Mohammad Kamrul Hasan

Abstract:

Deterioration of the mother nature is evident these day with clear danger of human catastrophe emanating from greenhouses (GHG) with increasing CO2 emissions to the environment. PV technology can help to reduce the dependency on fossil fuel, decreasing air pollution and slowing down the rate of global warming. The objective of this paper is to propose, develop and design the production of clean water supply to rural communities using an appropriate technology such as Internet of Things (IOT) that does not create any CO2 emissions. Additionally, maximization of solar energy power output and reciprocally minimizing the natural characteristics of solar sources intermittences during less presence of the sun itself is another goal to achieve in this work. The paper presents the development of critical automated control system for solar energy power output optimization using several new techniques. water pumping system is developed to supply clean water with the application of IOT-renewable energy. This system is effective to provide clean water supply to remote and off-grid areas using Photovoltaics (PV) technology that collects energy generated from the sunlight. The focus of this work is to design and develop a submersible solar water pumping system that applies an IOT implementation. Thus, this system has been executed and programmed using Arduino Software (IDE), proteus, Maltab and C++ programming language. The mechanism of this system is that it pumps water from water reservoir that is powered up by solar energy and clean water production was also incorporated using filtration system through the submersible solar water pumping system. The filtering system is an additional application platform which is intended to provide a clean water supply to any households in Sarawak State, Malaysia.

Keywords: IOT, automated production and control system, water filtration, automated submersible water pump, solar energy

Procedia PDF Downloads 59

Authors: Erich Ryan, Benjamin McDaniel, Dragoljub Kosanovic

Abstract:

Combined heat and power (CHP) plants are an efficient technology for meeting the heating and electric needs of large campus energy systems, but have come under greater scrutiny as the world pushes for emissions reductions and lower consumption of fossil fuels. The electrification of heating and cooling systems offers a great deal of potential for carbon savings, but these systems can be costly endeavors due to increased electric consumption and peak demand. Thermal energy storage (TES) has been shown to be an effective means of improving the viability of electrified systems, by shifting heating and cooling load to off-peak hours and reducing peak demand charges. In this study, we analyze the integration of an electrified heating and cooling system with thermal energy storage into a campus CHP plant, to investigate the potential of leveraging existing infrastructure and technologies with the climate goals of the 21st century. A TRNSYS model was built to simulate a ground source heat pump (GSHP) system with TES using measured campus heating and cooling loads. The GSHP with TES system is modeled to follow the parameters of industry standards and sized to provide an optimal balance of capital and operating costs. Using known CHP production information, costs and emissions were investigated for a unique large energy user rate structure that operates a CHP plant. The results highlight the cost and emissions benefits of a targeted integration of heat pump technology within the framework of existing CHP systems, along with the performance impacts and value of TES capability within the combined system.

Keywords: thermal energy storage, combined heat and power, heat pumps, electrification

Procedia PDF Downloads 73

Authors: Binod Shrestha, Sandrine Hoppe, Thierry Ghislain, Phillipe Marchal, Nicolas Brosse, Anthony Dufour

Abstract:

The thermochemical conversion of lignin has received an increasing interest in the frame of different biorefinery concepts for the production of chemicals or energy. It is needed to better understand the physical and chemical conversion of lignin for feeder and reactor designs. In-situ rheology reveals the viscoelastic behaviour of lignin upon thermal conversion. The softening, re-solidification (char formation), swelling and shrinking behaviours are quantified during pyrolysis in real-time [1]. The in-situ rheology of an alkali lignin (Protobind 1000) was conducted in high torque controlled strain rheometer from 35°C to 400°C with a heating rate of 5°C.min-1. The swelling, through glass phase transition overlapped with depolymerization, and solidification (crosslinking and “char” formation) are two main phenomena observed during lignin pyrolysis. The onset of temperatures for softening and solidification for this lignin has been found to be 141°C and 248°C respectively. An ex-situ characterization of lignin/char residues obtained at different temperatures after quenching in the rheometer gives a clear understanding of the pathway of lignin degradation. The lignin residues were sampled from the mid-point temperatures of the softening range and solidification range to study the chemical transformations undergoing. Elemental analysis, FTIR and solid state NMR were conducted after quenching the solid residues (lignin/char). The quenched solid was also extracted by suitable solvent and followed by acetylation and GPC-UV analysis. The combination of 13C NMR and GPC-UV reveals the depolymerization followed by crosslinking of lignin/char. NMR and FTIR provide the evolution of functional moieties upon temperature. Physical and chemical mechanisms occurring during lignin pyrolysis are accounted in this study. Thanks to all these complementary methods.

Keywords: pyrolysis, bio-chemicals, valorization, mechanism, softening, solidification, cross linking, rheology, spectroscopic methods

Procedia PDF Downloads 404