Search results for: plate-stiffener combination and hard corner
Commenced in January 2007
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Edition: International
Paper Count: 4136

Search results for: plate-stiffener combination and hard corner

3806 Microstructure and Mechanical Properties of Nb: Si: (a-C) Thin Films Prepared Using Balanced Magnetron Sputtering System

Authors: Sara Khamseh, Elahe Sharifi

Abstract:

321 alloy steel is austenitic stainless steel with high oxidation resistance and is commonly used to fabricate heat exchangers and steam generators. However, the low hardness and weak tribological performance can cause dangerous failures during industrial operations. The well-designed protective coatings on 321 alloy steel surfaces with high hardness and good tribological performance can guarantee their safe applications. The surface protection of metal substrates using protective coatings showed high efficiency in prevailing these problems. Carbon-based multicomponent coatings, such as metal-added amorphous carbon coatings, are crucially necessary because of their remarkable mechanical and tribological performances. In the current study, (Nb: Si: a-C) multicomponent coatings (a-C: amorphous carbon) were coated on 321 alloys using a balanced magnetron (BM) sputtering system at room temperature. The effects of the Si/Nb ratio on microstructure, mechanical and tribological characteristics of (Nb: Si: a-C) composite coatings were investigated. The XRD and Raman analysis results showed that the coatings formed a composite structure of cubic diamond (C-D), NbC, and graphite-like carbon (GLC). The NbC phase's abundance decreased when the C-D phase's affluence increased with an increasing Si/Nb ratio. The coatings' indentation hardness and plasticity index (H³/E² ratio) increased with an increasing Si/Nb ratio. The better mechanical properties of the coatings with higher Si content can be attributed to the higher cubic diamond (C-D) content. The cubic diamond (C-D) is a challenging phase and can positively affect the mechanical performance of the coatings. It is well documented that in hard protective coatings, Si encourages amorphization. In addition, THE studies showed that Nb and Mo can act as a catalyst for nucleation and growth of hard cubic (C-D) and hexagonal (H-D) diamond phases in a-C coatings. In the current study, it seems that fully arranged nanocomposite coatings contain hard C-D and NbC phases that embedded in the amorphous carbon (GLC) phase is formed. This unique structure decreased grain boundary density and defects and resulted in high hardness and H³/E² ratio. Moreover, the COF and wear rate of the coatings decreased with increasing Si/Nb ratio. This can be attributed to the good mechanical properties of the coatings and the formation of graphite-like carbon (GLC) structure with lamellae arrangement in the coatings. The complex and self-lubricant coatings are successfully formed on the surface of 321 alloys. The results of the present study clarified that Si addition to (Nb: a-C) coatings improve the mechanical and tribological performance of the coatings on 321 alloy.

Keywords: COF, mechanical properties, microstructure, (Nb: Si: a-C) coatings, Wear rate

Procedia PDF Downloads 58
3805 Understanding Factors that Affect the Prior Knowledge of Deaf and Hard of Hearing Students and their Relation to Reading Comprehension

Authors: Khalid Alasim

Abstract:

The reading comprehension levels of students who are deaf or hard of hearing (DHH) are low compared to those of their hearing peers. One possible reason for this low reading levels is related to the students’ prior knowledge. This study investigated the potential factors that might affected DHH students’ prior knowledge, including their degree of hearing loss, the presence or absence of family members with a hearing loss, and educational stage (elementary–middle school). The study also examined the contribution of prior knowledge in predicting DHH students’ reading comprehension levels, and investigated the differences in the students’ scores based on the type of questions, including text-explicit (TE), text-implicit (TI), and script-implicit (SI) questions. Thirty-one elementary and middle-school students completed a demographic form and assessment, and descriptive statistics and multiple and simple linear regressions were used to answer the research questions. The findings indicated that the independent variables—degree of hearing loss, presence or absence of family members with hearing loss, and educational stage—explained little of the variance in DHH students’ prior knowledge. Further, the results showed that the DHH students’ prior knowledge affected their reading comprehension. Finally, the result demonstrated that the participants were able to answer more of the TI questions correctly than the TE and SI questions. The study concluded that prior knowledge is important in these students’ reading comprehension, and it is also important for teachers and parents of DHH children to use effective ways to increase their students’ and children’s prior knowledge.

Keywords: reading comprehension, prior knowledge, metacognition, elementary, self-contained classrooms

Procedia PDF Downloads 73
3804 A High Linear and Low Power with 71dB 35.1MHz/4.38GHz Variable Gain Amplifier in 180nm CMOS Technology

Authors: Sina Mahdavi, Faeze Noruzpur, Aysuda Noruzpur

Abstract:

This paper proposes a high linear, low power and wideband Variable Gain Amplifier (VGA) with a direct current (DC) gain range of -10.2dB to 60.7dB. By applying the proposed idea to the folded cascade amplifier, it is possible to achieve a 71dB DC gain, 35MHz (-3dB) bandwidth, accompanied by high linearity and low sensitivity as well. It is noteworthy that the proposed idea can be able to apply on every differential amplifier, too. Moreover, the total power consumption and unity gain bandwidth of the proposed VGA is 1.41mW with a power supply of 1.8 volts and 4.37GHz, respectively, and 0.8pF capacitor load is applied at the output nodes of the amplifier. Furthermore, the proposed structure is simulated in whole process corners and different temperatures in the region of -60 to +90 ºC. Simulations are performed for all corner conditions by HSPICE using the BSIM3 model of the 180nm CMOS technology and MATLAB software.

Keywords: variable gain amplifier, low power, low voltage, folded cascade, amplifier, DC gain

Procedia PDF Downloads 73
3803 Quantifying Individual Performance of Pakistani Cricket Players

Authors: Kasif Khan, Azlan Allahwala, Moiz Ali, Hasan Lodhi, Umer Amjad

Abstract:

The number of runs scored by batsmen and wickets taken by bowlers serves as a natural way of quantifying the performance of a cricketer. Traditionally the batsmen and bowlers are rated on their batting or bowling average respectively. However, in a game like Cricket, it is not sufficient to evaluate performance on the basis of average. The biasness in selecting batsman and bowler on the basis of their past performance. The objective is to predict the best player and comparing their performance on the basis of venue, opponent, weather, and particular position. On the basis of predictions and analysis, and comparison the best team is selected for next upcoming series of Pakistan. The system is based and will be built to aid analyst in finding best possible team combination of Pakistan for a particular match and by providing them with advisories so that they can select the best possible team combination. This will also help the team management in identifying a perfect batting order and the bowling order for each match.

Keywords: data analysis, Pakistan cricket players, quantifying individual performance, cricket

Procedia PDF Downloads 273
3802 Devotional Informant and Diagenetic Alterations, Influences of Facies and Fine Kaolinite Formation Migration on Sandstone’ Reservoir Quality, Sarir Formation, Sirt

Authors: Faraj M. Elkhatri, Hana Ellafi

Abstract:

In recent years, there has been a growing recognition of the potential of marine-based functional foods and combination therapies in promoting a healthy lifestyle and exploring their effectiveness in preventing or treating diseases. The combination of marine bioactive compounds or extracts offers synergistic or enhancement effects through various mechanisms, including multi-target actions, improved bioavailability, enhanced bioactivity, and mitigation of potential adverse effects. Both the green-lipped mussel (GLM) and fucoidan derived from brown seaweed are rich in bioactivities. These two, mussel and fucoidan, have not been previously formulated together. This study aims to combine GLM oil from Perna canaliculus with low molecular weight fucoidan (LMWF) extracted from Undaria pinnatifida to investigate the unique mixture’s anti-inflammatory and antioxidant properties. The cytotoxicity of individual compounds and combinations was assessed using the MTT assay in (THP-1 and RAW264.7) cell lines. The anti-inflammatory activity of mussel-fucoidan was evaluated by treating LPS-stimulated human monocyte and macrophage (THP1-1) cells. Subsequently, the inflammatory cytokines released into the supernatant of these cell lines were quantified via ELISA. Antioxidant activity was determined by using the free radical scavenging assay (DPPH). DPPH assay demonstrated that the radical scavenging activity of the combinations, particularly at concentrations exceeding 1 mg/ml, showed a significantly higher percentage of inhibition when compared to the individual component. This suggests an enhancement effect when the two compounds are combined, leading to increased antioxidant activity. In terms of immunomodulatory activity, the individual compounds exhibited distinct behaviors. GLM oil displayed a higher ability to suppress the cytokine TNF- compared to LMWF. Interestingly, the LMWF fraction, when used individually, did not demonstrate TNF- suppression. However, when combined with GLM, the TNF- suppression (anti-inflammatory) activity of the combination was better than GLM or LWMF alone. This observation underscores the potential for enhancement interactions between the two components in terms of anti-inflammatory properties. This study revealed that each individual compound, LMWF, and GLM, possesses unique and notable bioactivity. The combination of these two individual compounds results in an enhancement effect, where the bioactivity of each is enhanced, creating a superior combination. This suggests that the combination of LMWF and GLM has the potential to offer a more potent and multifaceted therapeutic effect, particularly in the context of antioxidant and anti-inflammatory activities. These findings hold promise for the development of novel therapeutic interventions or supplements that harness the enhancement effects.

Keywords: formation damage, porosity loses, pore throat, quartz cement

Procedia PDF Downloads 37
3801 A Rare Neck Trauma by Bicycle Handlebar in Road Traffic Accident

Authors: Parthasarathi Pramanik

Abstract:

Paediatric blunt abdominal trauma associated with superficial bruise, hematoma, or laceration and internal organ damage secondary to bicycle handlebar is widely documented in the literature. In this article, we have presented a case of bicycle handlebar inflicted fatal neck laceration in a road accident. The deceased sustained a horizontally placed laceration injury over the front and both sides of the middle third of neck (13 cm x 5-8 cm x 2-3.5 cm).The margins of the wound were irregular and focally abraded. The right corner of the injury was pointed whereas the left one was ended with a skin flap. Multiple graze abrasions, contusions and lacerations were found on different parts of body. Autopsy findings and other circumstantial evidences revealed that the victim died due to exsanguination because of severance of carotid artery and jugular vein of both sides. Analysis of the wound suggests the decease sustained the wound by the revolving bicycle handle bar while he had lost the balance.

Keywords: bicycle handle bar, neck injury, lacerated injury, road acident

Procedia PDF Downloads 291
3800 Corporate Social Responsibility Practices and Financial Performance: The Case of French Unlisted SMEs

Authors: Zineb Abidi, Marc-Arthur Diaye

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There exists a large empirical literature concerning the relationship between corporate social responsibility (CSR) and corporate financial performance. This literature, however, applies mainly to large corporations and/or listed firms. To the best of our knowledge, the question of whether meeting CSR requirements impacts the financial performance of small and medium-sized unlisted SMEs has not so far been analyzed. This paper aims to analyze, for the first time, the effect of CSR on the financial performance of SMEs. Using an original database including 5,257 French SMEs, we show that adopting CSR practices has a positive but weak effect on a firm’s financial performance. To develop this further, we analyzed CSR practices interactions assessing the best combination of CSR components that positively influence SME financial performance. Our results show that French SMEs benefit more from their pro-social behavior when they choose a combination of CSR components best adapted to their individual characteristics.

Keywords: corporate social responsibility, financial performance, unlisted firms, SMEs

Procedia PDF Downloads 138
3799 Childhood Trauma and Borderline Personality: An Analysis of the Root Causes and Treatment Plans

Authors: Sidika McNeil

Abstract:

Borderline personality disorder (BPD) is a personality disorder that has been found to have strong origins in childhood trauma. One of the key symptoms of BPD is an association with irregular moods swings, as well as suicidal ideation (SI). Owing to the typically severe trauma patients experience during childhood, it is hard for them to control their emotions and thus makes it hard to emotionally regulate. It is then very common for those suffering from BPD to turn to unhealthy coping mechanisms, such as substance use, unhealthy relationships, and more, often unsuccessfully creating experiences that facilitate safety which leads to further negative experiences. With the high suicide rating among children, adolescents, and teens, and an ever-increasing number of children being diagnosed with BPD, it is very important that more research is done to find further treatments for patients who are currently suffering. Methods: Utilizing data found in prior studies, this paper will analyze the literature to focus on a comprehensive treatment plan for those with DBT. It is currently suggested that with the use of dialectical behavioral therapy (DBT), a therapy that focuses on changing negative thinking patterns and pushes for more positive ones is helpful for treatment for those with BPD. Though this therapy is not a cure to BPD, it does help mitigate the risk; this essay will explore other options that can further the treatment process, such as cognitive analytical therapy (CAT), which focuses on delving into the past to find the root causes of an issue to create coping strategies and harm reduction, a type of therapy used to aid patients in lowering the use of substances without complete cessation. Results: The research provides enough evidence to link between the treatment of BPD with the utilization of CAT.

Keywords: borderline personality disorder, cognitive analytical therapy, dialectical behavioral therapy, harm reduction, suicidal ideation

Procedia PDF Downloads 151
3798 The Effect of Irgafos 168 in the Thermostabilization of High Density Polyethylene

Authors: Mahdi Almaky

Abstract:

The thermostabilization of High Density Polyethylene (HDPE) is realized through the action of primary antioxidant such as phenolic antioxidants and secondary antioxidants as aryl phosphates. The efficiency of two secondary antioxidants, commercially named Irgafos 168 and Weston 399, was investigated using different physical, mechanical, spectroscopic, and calorimetric methods. The effect of both antioxidants on the processing stability and long term stability of HDPE produced in Ras Lanuf oil and gas processing Company were measured and compared. The combination of Irgafos 168 with Irganox 1010, as used in smaller concentration, results in a synergetic effect against thermo-oxidation and protect better than the combination of Weston 399 with Irganox 1010 against the colour change at processing temperature and during long term oxidation process.

Keywords: thermostabilization, high density polyethylene, primary antioxidant, phenolic antioxidant, Irgafos 168, Irganox 1010, Weston 399

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3797 Combined Effect of High Curing Temperature and Crack Width on Chloride Migration in Reinforced Concrete Beams

Authors: Elkedrouci Lotfi, Diao Bo, Pang Sen, Li Yi

Abstract:

Deterioration of reinforced concrete structures is a serious concern in the construction engineering, largely due to chloride induced corrosion of reinforcement. Chloride penetration is markedly influenced by one or several major factors at the same time such as cuing in combination with different crack widths which have spectacular effect on reinforced concrete structures. This research presents the results of an experimental investigation involving reinforced concrete beams with three different crack widths ranging from 0 to 0.2mm, curing temperatures of 20°C or 40°C and water-to-cement of 0.5. Chloride content profiles were determined under non-steady state diffusion at 20°C. Based on the obtained results, higher chloride content was obtained under condition of high curing temperature in combination with large crack more than 0.1mm and there are no significant differences between narrow crack width (less than 0.1 mm) and beams without crack (0mm).

Keywords: crack width, high curing temperature, rapid chloride migration, reinforced concrete beam

Procedia PDF Downloads 178
3796 Between a Rock and a Hard Place: The Possible Roles of Eternity Clauses in the Member States of the European Union

Authors: Zsuzsa Szakaly

Abstract:

Several constitutions have explicit or implicit eternity clauses in the European Union, their classic roles were analyzed so far, albeit there are new possibilities emerging in relation to the identity of the constitutions of the Member States. The aim of the study is to look at the practice of the Constitutional Courts of the Member States in detail regarding eternity clauses where limiting constitutional amendment has practical bearing, and to examine the influence of such practice on Europeanization. There are some states that apply explicit eternity clauses embedded in the text of the constitution, e.g., Italy, Germany, and Romania. In other states, the Constitutional Court 'unearthed' the implicit eternity clauses from the text of the basic law, e.g., Slovakia and Croatia. By using comparative analysis to examine the explicit or implicit clauses of the concerned constitutions, taking into consideration the new trends of the judicial opinions of the Member States and the fresh scientific studies, the main questions are: How to wield the double-edged sword of eternity clauses? To support European Integration or to support the sovereignty of the Member State? To help Europeanization or to act against it? Eternity clauses can easily find themselves between a rock and a hard place, the law of the European Union and the law of a Member State, with more possible interpretations. As more and more Constitutional Courts started to declare elements of their Member States’ constitutional identities, these began to interfere with the eternity clauses. Will this trend eventually work against Europeanization? As a result of the research, it can be stated that a lowest common denominator exists in the practice of European Constitutional Courts regarding eternity clauses. The chance of a European model and the possibility of this model influencing the status quo between the European Union and the Member States will be examined by looking at the answers these courts have found so far.

Keywords: constitutional court, constitutional identity, eternity clause, European Integration

Procedia PDF Downloads 117
3795 Effects of Organic Chromium and Propylene Glycol on Milk Yield and Some Serum Biochemical Parameters of Early Lactation Dairy Cows

Authors: Cangir Uyarlar, Ismail Bayram, Ibrahim Sadi Cetingul, Mustafa Kabu, Eyup Eren Gultepe

Abstract:

This study was conducted to determine the effects of organic chromium and organic chromium+propylene glycol on milk yield and some blood parameters related with liver fatty acid metabolism in early lactation dairy cows. Thirty multiparous Holstein dairy cows were used as study material. Cows assigned to three groups as control (C), chromium (Cr) and chromium+propylene glycol (CP). Live weight, parity and body condition score were used as covariates for statistical analyses. The study began at calving and finished at 3 weeks after calving. All cows were consumed same diet. Organic chromium and organic chromium+propylene glycol were orally administrated to cows in treatment groups shortly after the morning milking. Blood samples were collected from all cows on 0 (calving), 3rd, 6th, 9th, 12th, 15th, 18th, 21th days after calving. Then, samples were analyzed for BHBA (Betahydroxybutiric acids), NEFA (Non Esterified Fatty Acids), urea, total protein (TP) and glucose concentrations. Weekly milk yields were calculated from daily milk data on farm. Organic chromium treatment had no significant differences on serum biochemical parameters and milk yields. However, administration of organic chromium and propylene glycol combination decreased serum urea and total protein concentration, helped to protection from subclinical metabolic diseases via decreasing serum NEFA and BHBA concentrations. Also, this combination decreased serum glucose levels of cows. Neither only chromium nor chromium and propylene glycol combination did not affect milk yield throughout the study. These findings were suggested that orally administrations of chromium and propylene glycol combination improved liver glucose and fatty acid metabolism, decreased serum parameters which are representing subclinical diseases in early lactation dairy cows.

Keywords: chromium, early lactation dairy cows, propylene glycol, milk yield

Procedia PDF Downloads 463
3794 Synthesis and Functionalization of Gold Nanostars for ROS Production

Authors: H. D. Duong, J. I. Rhee

Abstract:

In this work, gold nanoparticles in star shape (called gold nanostars, GNS) were synthesized and coated by N-(3-aminopropyl) methacrylamide hydrochloride (PA) and mercaptopropionic acid (MPA) for functionalizing their surface by amine and carboxyl groups and then investigated for ROS production. The GNS with big size and multi-tips seem to be superior in singlet oxygen production as compared with that of small GNS and less tips. However, the functioned GNS in small size could also enhance efficiency of singlet oxygen production about double as compared with that of the intact GNS. In combination with methylene blue (MB+), the functioned GNS could enhance the singlet oxygen production of MB+ after 1h of LED750 irradiation and no difference between small size and big size in this reaction was observed. In combination with 5-aminolevulinic acid (ALA), only GNS coated PA could enhance the singlet oxygen production of ALA and the small size of GNS coated PA was a little higher effect than that of the bigger size. However, GNS coated MPA with small size had strong effect on hydroxyl radical production of ALA.

Keywords: 5-aminolevulinic acid, gold nanostars, methylene blue, ROS production

Procedia PDF Downloads 324
3793 Wear Resistance and Thermal Stability of Tungsten Boride Layers Deposited by Magnetron Sputtering

Authors: Justyna Chrzanowska, Jacek Hoffman, Dariusz Garbiec, Łukasz Kurpaska, Piotr Denis, Tomasz Moscicki, Zygmunt Szymanski

Abstract:

Tungsten and boron compounds belong to the group of superhard materials and its hardness could exceed 40 GPa. In this study, the properties of the tungsten boride (WB) layers deposited in magnetron sputtering process are investigated. The sputtering process occurred from specially prepared targets that were composed of boron and tungsten mixed in molar ratio of 2.5 or 4.5 and sintered in spark plasma sintering process. WB layers were deposited on silicon (100) and stainless steel 304 substrates at room temperature (RT) or in 570 °C. Layers deposited in RT and in elevated temperature varied considerably. Layers deposited in RT are amorphous and have low adhesion. In contrast, the layers deposited in 570 °C are crystalline and have good adhesion. All deposited layers have a hardness about 40 GPa. Moreover, the friction coefficient of crystalline layers is 0.22 and wear rate is about 0.67•10-6 mm3N-1m-1. After material characterization the WB layers were annealed in argon atmosphere in 1000 °C for 1 hour. On the basis of X-Ray Diffraction analysis, it has been noted that the crystalline layers are thermally stable and do not change their phase composition, whereas the amorphous layers change their phase composition. Moreover, after annealing, on the surface of WB layers some cracks were observed. It is probably connected with the differences of the thermal expansion between the layer and the substrate. Despite of the presence of cracks, the wear resistance of annealed layers is still higher than the wear resistance of uncoated substrate. The analysis of the structure and properties of tungsten boride layers lead to the discussion about the application area of this material.

Keywords: hard coatings, hard materials, magnetron sputtering, mechanical properties, tungsten boride

Procedia PDF Downloads 255
3792 Effect of Early Therapeutic Intervention for the Children with Autism Spectrum Disorders: A Quasi Experimental Design

Authors: Sultana Razia

Abstract:

The purpose of this study was to investigate the effect of early therapeutic intervention on children with an autism spectrum disorder. Participants were 140 children with autism spectrum disorder from Autism Corner in a selected rehabilitation center of Bangladesh. This study included children who are at aged of 18-month to 36-month and who were taking occupational therapy and speech and language therapy from the autism center. They were primarily screened using M-CHAT; however, children with other physical disabilities or medical conditions were excluded. 3-months interventions of 6 sessions per week are a minimum of 45-minutes long per session, one to one interaction followed by parent-led structured home-based therapy were provided. The results indicated that early intensive therapeutic intervention improves understanding, social skills and sensory skills. It can be concluded that therapeutic early intervention has a positive effect on diminishing symptoms of Autism Spectrum Disorder.

Keywords: autism, m-chat, reciprocal social behavior, CRP

Procedia PDF Downloads 89
3791 Lithium and Sodium Ion Capacitors with High Energy and Power Densities based on Carbons from Recycled Olive Pits

Authors: Jon Ajuria, Edurne Redondo, Roman Mysyk, Eider Goikolea

Abstract:

Hybrid capacitor configurations are now of increasing interest to overcome the current energy limitations of supercapacitors entirely based on non-Faradaic charge storage. Among them, Li-ion capacitors including a negative battery-type lithium intercalation electrode and a positive capacitor-type electrode have achieved tremendous progress and have gone up to commercialization. Inexpensive electrode materials from renewable sources have recently received increased attention since cost is a persistently major criterion to make supercapacitors a more viable energy solution, with electrode materials being a major contributor to supercapacitor cost. Additionally, Na-ion battery chemistries are currently under development as less expensive and accessible alternative to Li-ion based battery electrodes. In this work, we are presenting both lithium and sodium ion capacitor (LIC & NIC) entirely based on electrodes prepared from carbon materials derived from recycled olive pits. Yearly, around 1 million ton of olive pit waste is generated worldwide, of which a third originates in the Spanish olive oil industry. On the one hand, olive pits were pyrolized at different temperatures to obtain a low specific surface area semigraphitic hard carbon to be used as the Li/Na ion intercalation (battery-type) negative electrode. The best hard carbon delivers a total capacity of 270mAh/g vs Na/Na+ in 1M NaPF6 and 350mAh/g vs Li/Li+ in 1M LiPF6. On the other hand, the same hard carbon is chemically activated with KOH to obtain high specific surface area -about 2000 m2g-1- activated carbon that is further used as the ion-adsorption (capacitor-type) positive electrode. In a voltage window of 1.5-4.2V, activated carbon delivers a specific capacity of 80 mAh/g vs. Na/Na+ and 95 mAh/g vs. Li/Li+ at 0.1A /g. Both electrodes were assembled in the same hybrid cell to build a LIC/NIC. For comparison purposes, a symmetric EDLC supercapacitor cell using the same activated carbon in 1.5M Et4NBF4 electrolyte was also built. Both LIC & NIC demonstrates considerable improvements in the energy density over its EDLC counterpart, delivering a maximum energy density of 110Wh/Kg at a power density of 30W/kg AM and a maximum power density of 6200W/Kg at an energy density of 27 Wh/Kg in the case of NIC and a maximum energy density of 110Wh/Kg at a power density of 30W/kg and a maximum power density of 18000W/Kg at an energy density of 22 Wh/Kg in the case of LIC. In conclusion, our work demonstrates that the same biomass waste can be adapted to offer a hybrid capacitor/battery storage device overcoming the limited energy density of corresponding double layer capacitors.

Keywords: hybrid supercapacitor, Na-Ion capacitor, supercapacitor, Li-Ion capacitor, EDLC

Procedia PDF Downloads 176
3790 Extracting the Failure Criterion to Evaluate the Strength of Cracked Drills under Torque Caused by Drilling

Authors: A. Falsafi, M. Dadkhah, S. Shahidi

Abstract:

The destruction and defeat of drill pipes and drill rigs in oil wells often combined with a combination of shear modulus II and III. In such a situation, the strength and load bearing capacity of the drill are evaluated based on the principles of fracture mechanics and crack growth criteria. In this paper, using the three-dimensional stress equations around the Turkish frontier, the relations of the tense-tense criterion (MTS) are extracted for the loading of the combined II and III modulus. It is shown that in crisp deflection under loading of combination II and III, the level of fracture is characterized by two different angles: the longitudinal angle of deflection θ and the angle of the deflection of the alpha. Based on the relationships obtained from the MTS criterion, the failure criteria, the longitudinal angle of the theta failure and the lateral angle of the failure of the alpha are presented. Also, the role of Poisson's coefficient on these parameters is investigated in these graphs.

Keywords: most tangential tension criterion, longitudinal angle of failure, side angle of fracture, drills crack

Procedia PDF Downloads 109
3789 Τhe Importance of Previous Examination Results, in Futural Differential Diagnostic Procedures and Especially in the Era of Covid-19

Authors: Angelis P. Barlampas

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Purpose or Learning Objective It is well known that previous examinations play a major role in futural diagnosis, thus avoiding unnecessary new exams that cost in time and money both for the patient and the health system. A case is presented in which past patient’s results, in combination with the least needed new tests, give an easy final diagnosis. Methods or Background A middle aged man visited the emergency department complaining of hard controlled, persisting fever for the last few days. Laboratory tests showed an elevated number of white blood cells with neutrophil shift and abnormal CRP. The patient was admitted to hospital a month ago for continuing lungs symptomatology after a recent covid-19 infection. Results or Findings Computed tomography scanning showed a solid mass with spiculating margins in right lower lobe. After intravenous iodine contrast administration, there was mildly peripheral enhancement and eccentric non enhancing area. A pneumonic cancer was suspected. Comparison with the patient’s latest computed tomography revealed no mass in the area of interest but only signs of recent post covid-19 lung parenchyma abnormalities. Any new mass that appears in a month’s time span can not be a cancer but a benign lesion. It was obvious that an abscess was the most suitable explanation. The patient was admitted to hospital, and antibiotic therapy was given, with very good results. After a few days, the patient was afebrile and in good condition. Conclusion In this case , a PET scan or a biopsy was avoided, thanks to the patient’s medical history and the availability of previous examinations. It is worthy encouraging the patients to keep their medical records and organizing more efficiently the health system with the current technology of archiving the medical examinations, too.

Keywords: covid-19, chest ct, cancer, abscess, fever

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3788 The Energy Efficient Water Reuse by Combination of Nano-Filtration and Capacitive Deionization Processes

Authors: Youngmin Kim, Jae-Hwan Ahn, Seog-Ku Kim, Hye-Cheol Oh, Bokjin Lee, Hee-Jun Kang

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The high energy consuming processes such as advanced oxidation and reverse osmosis are used as a reuse process. This study aims at developing an energy efficient reuse process by combination of nanofiltration (NF) and capacitive deionization processes (CDI) processes. Lab scale experiments were conducted by using effluents from a wastewater treatment plant located at Koyang city in Korea. Commercial NF membrane (NE4040-70, Toray Ltd.) and CDI module (E40, Siontech INC.) were tested in series. The pollutant removal efficiencies were evaluated on the basis of Korean water quality criteria for water reuse. In addition, the energy consumptions were also calculated. As a result, the hybrid process showed lower energy consumption than conventional reverse osmosis process even though its effluent did meet the Korean standard. Consequently, this study suggests that the hybrid process is feasible for the energy efficient water reuse.

Keywords: capacitive deionization, energy efficient process, nanofiltration, water reuse

Procedia PDF Downloads 161
3787 Assessment of E-learning Facilities and Information Need by Open and Distance Learning Students in Jalingo, Nigeria

Authors: R. M. Bashir, Sabo Elizabeth

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Electronic learning is an increasingly popular learning approach in higher educational institutions due to vast growth of internet technology. An investigation on the assessment of e-learning facilities and information need by open and distance learning students in Jalingo, Nigeria was conducted. Structured questionnaires were administered to 70 students of the university. Information sourced from the respondents covered demographic, economic and institutional variables. Data collected for demographic variables were computed as frequency count and percentages. Information on assessment of e-learning facilities and information need among open and distance learning students was computed on a three or four point Likert Rating Scale. Findings indicated that there are more men compared to women, a large proportion of the respondents are married and there are more matured students. A high proportion of the students obtained qualifications higher than the secondary school certificate. The proportion of computer literate students was higher compared with those students that owned a computer. Inadequate e-books and reference materials, internet gadgets and inadequate books (hard copies) and reference material are factors that limit utilization of e-learning facilities. Inadequate computer facilities caused delay in examination schedule at the study center. Open and distance learning students required to a high extent information on university timetable and schedule of activities, books (hard and e-books) and reference materials and contact with course coordinators via internet for better learning and academic performance.

Keywords: open and distance learning, information required, electronic books, internet gadgets, Likert scale test

Procedia PDF Downloads 262
3786 Flame Acceleration of Premixed Natural Gas/Air Explosion in Closed Pipe

Authors: H. Mat Kiah, Rafiziana M. Kasmani, Norazana Ibrahim, Roshafima R. Ali, Aziatul N.Sadikin

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An experimental study has been done to investigate the flame acceleration in a closed pipe. A horizontal steel pipe, 2m long and 0.1 m in diameter (L/D of 20), was used in this work. For tests with 90 degree bends, the bend had a radius of 0.1 m and thus, the pipe was lengthened 1 m (based on the centreline length of the segment). Ignition was affected one end of the vessel while the other end was closed. Only stoichiometric concentration (Ф, = 1.0) of natural gas/air mixtures will be reported in this paper. It was demonstrated that bend pipe configuration gave three times higher in maximum over-pressure (5.5 bars) compared to straight pipe (2.0 bars). From the results, the highest flame speed of 63 m s-1 was observed in a gas explosion with bent pipe, greater by a factor of ~3 as compared with straight pipe (23 m s-1). This occurs because bending acts similar to an obstacle, in which this mechanism can induce more turbulence, initiating combustion in an unburned pocket at the corner region and causing a high mass burning rate which increases the flame speed.

Keywords: bending, gas explosion, bending, flame acceleration, over-pressure

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3785 Modulation of Tamoxifen-Induced Cytotoxicity in Breast Cancer Cell Lines by 3-Bromopyruvate

Authors: Yasmin M. Attia, Hanan S. El-Abhar, Mahmoud M. Al Marzabani, Samia A. Shouman

Abstract:

Background: Tamoxifen (TAM) is the most commonly used hormone therapy for the treatment of early and metastatic breast cancer. Although it significantly decreases the tumor recurrence rate and provides an overall benefit, as much as 20–30% of women still relapse during or after long-term therapy. 3-Bromopyruvate (3-BP) is a promising agent with impressive antitumor effects in several models of animal tumors and cell lines. Aim: This study was designed to investigate the combined effect of (TAM) and (3-BP) in breast cancer cells and to explore their molecular interaction via assessment of apoptotic, angiogenic, and metastatic markers. Methods: In vitro cytotoxicity study was carried out for both compounds to determine the combination regimen producing a synergistic effect and mechanistic pathways were studied using RT-PCR and western techniques. Moreover, the anti-oncolytic and anti-angiogenic potentials were assessed in mice bearing solid Ehrlich carcinoma (SEC). Results: The combined treatment significantly increased the expressions and protein levels of caspase 7, 9, and 3 and decreased of angiogenic markers VEGF, HIF-1α, and HK2 compared to cells treated with either drug individually. However, there were no significant changes in MMP-2 and MMP-9 protein levels. Interestingly, the in vivo results supported the in vitro findings; there was a decrease in the tumor volume and VEFG using immunohistochemistry in the combination-treated groups compared to either TAM or 3-BP treated one. Conclusion: 3-BP synergizes the cytotoxic effect of TAM by increasing apoptosis and decreasing angiogenesis which makes this combination a promising regimen to be applied clinically.

Keywords: tamoxifen, 3-bromopyruvate, breast cancer, cytotoxicity, angiogenesis

Procedia PDF Downloads 207
3784 Investigation of Active Modified Atmosphere and Nanoparticle Packaging on Quality of Tomatoes

Authors: M. Ghasemi-Varnamkhasti, S. H. Yoosefian, A. Mohammad-Razdari

Abstract:

This study investigated the effects of Ag nanoparticle polyethylene film and active modified atmosphere on the postharvest quality of tomatoes stored at 6 ºC. The atmosphere composition used in the packaging was 7% O2 + 7% CO2 + 86% N2, and synthetic air (control). The variables measured were weight loss, firmness, color and respiration rate over 21 days. The results showed that the combination of Ag nanoparticle polyethylene film and modified atmosphere could extend the shelf life of tomatoes to 21 days and could influence the postharvest quality of tomatoes. Also, existence of Ag nanoparticles caused preventing from increasing weight loss, a*, b*, Chroma, Hue angle and reducing firmness and L*. As well as, tomatoes at Ag nanoparticle polyethylene films had lower respiration rate than Polyethylene and paper bags to 13.27% and 23.50%, respectively. The combination of Ag nanoparticle polyethylene film and active modified atmosphere was effective with regard to delaying maturity during the storage period, and preserving the quality of tomatoes.

Keywords: ag nanoparticles, modified atmosphere, polyethylene film, tomato

Procedia PDF Downloads 250
3783 Simultaneous Determination of Proposed Anti-HIV Combination Comprising of Elvitegravir and Quercetin in Rat Plasma Using the HPLC–ESI-MS/MS Method: Drug Interaction Study

Authors: Lubna Azmi, Ila Shukla, Shyam Sundar Gupta, Padam Kant, C. V. Rao

Abstract:

Elvitegravir is the mainstay of anti-HIV combination therapy in most endemic countries presently. However, it cannot be used alone owing to its long onset time of action. 2-(3,4-dihydroxyphenyl)-3,5,7-trihydroxychromen-4-one (Quercetin: QU) is a polyphenolic compound obtained from Argeria speciosa Linn (Family: Convolvulaceae), an anti-HIV candidate. In the present study, a sensitive, simple and rapid high-performance liquid chromatography coupled with positive ion electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method was developed for the simultaneous determination elvitegravir and Quercetin, in rat plasma. The method was linear over a range of 0.2–500 ng/ml. All validation parameters met the acceptance criteria according to regulatory guidelines. LC–MS/MS method for determination of Elvitegravir and Quercetin was developed and validated. Results show the potential of drug–drug interaction upon co-administration this marketed drugs and plant derived secondary metabolite.

Keywords: anti-HIV resistance, extraction, HPLC-ESI-MS-MS, validation

Procedia PDF Downloads 319
3782 Access to Sexual Reproductive Health (SRH) Education and Services to Deaf Adolescents in Wakiso, Uganda - The Ugandan Perspective

Authors: Racheal Ayanga, Nancy Katumba Muwangala, Jane Babirye, Harriet Kivumbi

Abstract:

Background: Deaf adolescents are vulnerable. Deafness limits their access to resources that are accessed by their hearing peers. There is minimal attention placed on the SRH needs of persons with disabilities, especially in developing countries. We sought to assess barriers to access of SRH education and services for deaf adolescents in Uganda. Methods: We performed a cross sectional study using a questionnaire on knowledge of and access to SRH education and services from a selected sample of deaf adolescents aged 13-19 years at Wakiso Secondary school for the deaf. A consecutive sample of eligible participants was asked to join the study after obtaining informed consent until the target sample size was reached. Results: From 01 Jul 2022 to 30 Jan 2023, 70 quantitative interviews were conducted. Participants’ mean age was 17 years, and 66% were female. 89% had heard about several components of SRH. 99% reported a need for education and services but had challenges with access 85% of the time. 54% reported receipt of education and services from government or private facilities, and the rest from friends, parents, siblings, teachers and the internet. Conclusion: Government needs to look into availing tailored, sustainable SRH education/services to deaf adolescents at health facilities and teach health workers sign language. SRH education to parents, teachers and communities of deaf adolescents improves access in hard-to-reach areas. Integration of services into routine health care is key in creating and improving models of access to wider communities of persons with disabilities to improve their mental health.

Keywords: sexual and reproductive health, deaf, adolescents, education, services, disabilities, mental health, hard-to-reach areas

Procedia PDF Downloads 52
3781 Structure and Magnetic Properties of Low-Temperature Synthesized M-W Hexaferrite Composites

Authors: Young-Min Kang

Abstract:

M-type Sr-hexaferrites (SrFe12O19) is one of the most utilized materials in permanent magnets due to their low price, outstanding chemical stability, and appropriate hard magnetic properties. For a M-type Sr-hexaferrite with a saturation magnetization (MS) of ~74.0 emu/g the practical limits of remanent flux density (Br) and maximum energy product (BH) max are ~4.6 kG and ~5.3 MGOe. Meanwhile, W-type hexaferrite (SrFe18O27) with higher MS ~81emu/g can be a good candidate for the development of enhanced ferrite magnet. However the W-type hexaferrite is stable at the temperature over 1350 ºC in air, and thus it is hard to control grain size and the coercivity. We report here high-MS M-W composite hexaferrites synthesized at 1250 ºC in air by doping Ca, Co, Mn, and Zn into the hexaferrite structures. The hexaferrites samples of stoichiometric SrFe12O19 (SrM) and Ca-Co-Mn-Zn doped hexaferrite (Sr0.7Ca0.3Fen-0.6Co0.2Mn0.2Zn0.2Oa) were prepared by conventional solid state reaction process with varying Fe content (10 ≤ n ≤ 17). Analysis by x-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) were performed for phase identification and microstructural observation respectively. Magnetic hysteresis curves were measured using vibrating sample magnetometer (VSM) at room temperature (300 K). Single M-type phase could be obtained in the non-doped SrM sample after calcinations at the range of 1200 ºC ~ 1300 ºC, showing MS in the range of 72 ~ 72.6 emu/g. The Ca-Co-Mn-Zn doped SrM with Fe content, 10 ≤ n ≤ 13, showed both M and W-phases peaks in the XRD after respective calcinations at 1250 ºC. The sample with n=13 showed the MS of 70.7, 75.3, 78.0 emu/g, respectively, after calcination at 1200, 1250, 1300 ºC. The high MS over that of non-doped SrM (~72 emu/g) is attributed to the volume portion of W-phase. It is also revealed that the high MS W-phase could not formed if only one of the Ca, Co, Zn is missed in the substitution. These elements are critical to form the W-phase at the calcinations temperature of 1250 ºC, which is 100 ºC lower than the calcinations temperature for non-doped Sr-hexaferrites.

Keywords: M-type hexaferrite, W-type hexaferrite, saturation magnetization, low-temperature synthesis

Procedia PDF Downloads 147
3780 Researching International PhD Algerian Students’ Communication Challenges in Speaking When Discussing and Interacting with Their British Peers: A Researcher’s Interpretive Perspective through the Use of Semi-Structured Interview

Authors: H. Maita

Abstract:

This paper addresses the issue of the speaking challenges that the Algerian PhD students experience during their studies abroad, particularly in UK territory; more specifically, this study describes how these students may deal with such challenges and whether the cultural differences is one core reason in such dilemma or not. To this end, an understanding and interpretation of what actually encompasses both linguistic interference and cultural differences are required. Throughout the paper there is an attempt to explain the theoretical basis of the interpretive research and to theoretically discuss the pivotal use of the interview, as a data collection tool, in interpretive research. Thus, the central issue of this study is to frame the theoretical perspective of the interpretive research through the discussion of PhD Algerian’s communication and interaction challenges in the EFL context. This study is a corner stone for other research studies to further investigate the issue related to communication challenges because no specific findings will be pointed out in this research.

Keywords: communication, EFL, interaction, linguistic interference

Procedia PDF Downloads 108
3779 Combining Work and Study: A Solution for Stronger University-Industry Linkage

Authors: Payam Najafi, Behnam Ebrahimi, Hamid Montazerolghaem, Safoura Akbari-Alavijeh, Rasoul Tarkesh Esfahani

Abstract:

The combination of work and study has been recently gained lots of attention due to the crucial demand of industries to skillfully trained youth. Nevertheless, the distance between university and industry makes this combination challenging. According to the OECD (2012), in most countries, there is a limited link between students’ field of study and their area of work while studying. On the other hand, high unemployment rates among the specialized workforce, which is common in developing countries, highlights the need to strengthen this relationship. Innovative Center of Isfahan Chamber of Commerce has defined a project called 'POUYESH', which helps students to find related work opportunities to their field of study as well as supporting industries to supply their needed workforce. The present research is sought to explore the effect of the running project as a model of combining work and study on the university-industry linkage.

Keywords: work and study, university-industry linkage, POUYESH project, field of study

Procedia PDF Downloads 158
3778 Strategies for Arctic Greenhouse Farming: An Energy and Technology Survey of Greenhouse Farming in the North of Sweden

Authors: William Sigvardsson, Christoffer Alenius, Jenny Lindblom, Andreas Johansson, Marcus Sandberg

Abstract:

This article covers a study focusing on a subarctic greenhouse located in Nikkala, Sweden. Through a visit and the creation of a CFD model, the study investigates the differences in energy demand with high pressure sodium (HPS) lights and light emitting diode (LED) lights in combination with an air-carried and water-carried heating system accordingly. Through an IDA ICE model, the impact of insulating the parts of the greenhouse without active cultivation was also investigated. This, with the purpose of comparing the current system in the greenhouse to state-of-the-art alternatives and evaluating if an investment in either a water-carried heating system in combination with LED lights and insulating the non-cultivating parts of the greenhouse could be considered profitable. Operating a greenhouse in the harsh subarctic climate found in the northern parts of Sweden is not an easy task and especially if the operation is year-round. With an average temperature of under -5 °C from November through January, efficient growing techniques are a must to ensure a profitable business. Today the most crucial parts of a greenhouse are the heating system, lighting system, dehumidifying measures, as well as thermal screen, and the impact of a poorly designed system in a sub-arctic could be devastating as the margins are slim. The greenhouse studied uses a pellet burner to power their air- carried heating system which is used. The simulations found the resulting savings amounted to just under 14 800 SEK monthly or 18 % of the total cost of energy by implementing the water-carrying heating system in combination with the LED lamps. Given this, a payback period of 3-9 years could be expected given different scenarios, including specific time periods, financial aids, and the resale price of the current system. The insulation of the non-cultivating parts of the greenhouse was found to have possible savings of 25 300 SEK annually or 46 % of the current heat demand resulting in a payback period of just over 1-2 years. Given the possible energy savings, a reduction in emitted CO2 equivalents of almost 1,9 tonnes could be achieved annually. It was concluded that relatively inexpensive investments in modern greenhouse equipment could make a significant contribution to reducing the energy consumption of the greenhouse resulting in a more competitive business environment for sub-arctic greenhouse owners. New parts of the greenhouse should be built with the water-carried heating system in combination with state-of-the-art LED lights, and all parts which are not housing active cultivation should be insulated. If the greenhouse in Nikkala is eligible for financial aid or finds a resale value in the current system, an investment should be made in a new water-carried heating system in combination with LED lights.

Keywords: energy efficiency, sub-arctic greenhouses, energy measures, greenhouse climate control, greenhouse technology, CFD

Procedia PDF Downloads 47
3777 Tree Species Classification Using Effective Features of Polarimetric SAR and Hyperspectral Images

Authors: Milad Vahidi, Mahmod R. Sahebi, Mehrnoosh Omati, Reza Mohammadi

Abstract:

Forest management organizations need information to perform their work effectively. Remote sensing is an effective method to acquire information from the Earth. Two datasets of remote sensing images were used to classify forested regions. Firstly, all of extractable features from hyperspectral and PolSAR images were extracted. The optical features were spectral indexes related to the chemical, water contents, structural indexes, effective bands and absorption features. Also, PolSAR features were the original data, target decomposition components, and SAR discriminators features. Secondly, the particle swarm optimization (PSO) and the genetic algorithms (GA) were applied to select optimization features. Furthermore, the support vector machine (SVM) classifier was used to classify the image. The results showed that the combination of PSO and SVM had higher overall accuracy than the other cases. This combination provided overall accuracy about 90.56%. The effective features were the spectral index, the bands in shortwave infrared (SWIR) and the visible ranges and certain PolSAR features.

Keywords: hyperspectral, PolSAR, feature selection, SVM

Procedia PDF Downloads 391