Search results for: good
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 6441

Search results for: good

5961 Physiological Regulation of Lignin-Modifying Enzymes Synthesis by Selected Basidiomycetes

Authors: Ana Tsokilauri

Abstract:

The uppermost factor in the regulation of lignin-cellulose activity of decaying white rot or free rot are the substances serving as carbon and nitrogen nutrition of microorganisms and are considered as the most important factor of generative activity of white rot. The research object was Basidiomycete Fungi, peculiar and common in Georgia, and the separation of 10 of them as pure crops. The unidentified pure crops have tasted in order to be determined the potential of synthesis of lignin-degrading enzymes and the substrate of optimal lignocellulose growth. One of the most important aspects of the research conducted on Basidiomycetes was the use of specific lignocellulosic residues for selecting Fungi as a substrate of their growth. In order to increase lignocellulose with the help of substrate, crops were selected from the screening stage that showed good laccase activity. (Dusheti 1; Dusheti 10; Fshavi 5; Fshavi1; Fshavi 8; Fshavi 32; Manglisi 26; Sabaduri20; Dusheti 7; Sabaduri 1 ), Among the selected cultures, the crops with good laccase activity against the following substances, in particular: Dusheti 1- in this case, the rate of enzymatic activity on bran substrate was -105,6 u/ml, mandarin-96,4 u/ml. In case of corn - 102,9 u/ml. In case of Dusheti 7- the indicators were as follows: bananas-121,7 u/ml, mandarin-125,4 u/ml, corn - 117,1 u/ml. In the case of Sanaduri 32, the laccase activity was as follows: pomegranate- 101,2 u/ml. As a result of conducted experiments, the synthesis and activity rates of enzymes depending on plant substrates varied within a fairly wide range, which is still being under research.

Keywords: Lignocellulosic substrate, Basidiomycetes, white-rot basidiomycetes, Laccase

Procedia PDF Downloads 196
5960 A Novel Environmentally Benign Positive Electrode Material with Improved Energy Density for Lithium Ion Batteries

Authors: Wassima El Mofid, Svetlozar Ivanov, Andreas Bund

Abstract:

The increasing requirements for high power and energy lithium ion batteries have led to the development of several classes of positive electrode materials. Among those one promising material is LiNixMnyCo1−x−yO2 due to its high reversible capacity and remarkable cycling performance. Further structural stabilization and improved electrochemical performance of this class of cathode materials can be achieved by cationic substitution to a transition metal such as Al, Mg, Cr, etc. The current study discusses a novel NMC type material obtained by simultaneous cationic substitution of the cobalt which is a toxic element, with aluminum and iron. A compound with the composition LiNi0.6Mn0.2Co0.15Al0.025Fe0.025O2 (NMCAF) was synthesized by the self-combustion method using sucrose as fuel. The material has a layered α-NaFeO2 type structure with a good hexagonal ordering. Rietveld refinement analysis of the XRD patterns revealed a very low cationic mixing compared to the non-substituted material LiNi0.6Mn0,2Co0.2O2 suggesting a structural stabilization. Galvanostatic cycling measurements indicate improved electrochemical performance after the metal substitution. An initial discharge capacity of about 190 mAh.g−1 at slow rate (C/20), and a good cycling stability even at moderately faster rates (C/5 and C) have been observed. The long term cycling displayed a capacity retention of about 90% after 10 cycles.

Keywords: cationic substitution, lithium ion batteries, positive electrode material, self-combustion synthesis method

Procedia PDF Downloads 416
5959 Corporate Social Responsibility and Firm Performance: The Mediating Role of Reputation

Authors: Yosra Makni, Mariam Dammak, Dhouha Abed

Abstract:

Purpose: This paper investigates the mediating role of corporate reputation on the relationship between corporate social responsibility and financial performance. Design/Methodology/Approach: Based on a sample of 4329 drawn from 33 developed and developing countries and over a period of eight-year ranging from 2009 to 2016, we apply an Ordinary Least Squares regression (OLS) regressions to test our hypotheses. Findings: The authors find that there is a positive association between Corporate Social Responsibility (CSR) engagement and the financial performance of a company. They also document that there is a positive association between CSR engagement and a company's reputation and the company's reputation mediates the relationship between engagement in CSR activities and financial performance. Originality Value: This study contributes to the literature in the following ways. First, our research advances the understanding of the link between corporate social responsibility and financial performance by responding to the requests of several researchers to study the mechanisms of mediation between these two concepts given the scarcity relative to currently available research. So we include the most important predicted advantage of CSR, namely reputation, by developing and testing a more complex relationship. Secondly, these relationships have been investigated using an international sample drawn from a large number of countries with a high reputation. Using Judy and Kenny's method, we have confirmed that the company's reputation can play the role of a mediating variable on the relationship between CSR's commitment to operations and the financial performance of the company. More specifically, the more the company is engaged in the activities of CSR, the more it can have a good reputation, more than it has a good financial performance.

Keywords: corporate social responsibility, company's reputation, financial performance, mediating variable

Procedia PDF Downloads 168
5958 The Role of Satisfaction on Performance among Afe Babalola University Team Sports

Authors: B. O. Diyaolu

Abstract:

Viability and competency during competition is the dream of every team sports so as to have a good result. But it seems factors abound which deter the performance of even a good sports team. Different individuals with different state of mind all come together to perform in team sports with different degree of satisfaction. This study investigated the role of satisfaction on performance among Afe Babalola University team sports. Descriptive survey research design was used and the population consists of all male and female athletes in the team sports that participated in the last 2019 Ekiti State Higher Institution games (ESHIGA). Total enumeration technique was used for the three team sports; football (44), basketball (24) and volleyball (24). A total of 92 participants were involved in the research. The instrument used for the study was a modified Athlete Satisfaction Scale (ASS). The questionnaire was divided into two sections. The Cronbach’s Alpha reliability coefficient of 0.71 was obtained. The hypotheses were tested at 0.05 significant levels. The completed questionnaire was collated, coded, and analyzed using descriptive statistics of frequency counts and percentage and inferential statistics of chi-square (X2). Findings of this study revealed that satisfaction significantly influences team sports performance among Athletes of Afe Babalola University. The responsibility of satisfying athlete lies on the coaches, fans, sports administrators as well as organizers of such event, as it is not only financial reward that gives satisfaction. The performance of a team sports is quiet important and its being determined by the degree of satisfaction of each individual that make up the team. All effort must be made to satisfy athlete in order to guarantee optimum performance.

Keywords: athlete satisfaction, optimum achievement, optimum performance, sports performance and team sports

Procedia PDF Downloads 149
5957 High Sensitive Graphene-Based Strain Sensors for SHM of Composite Laminates

Authors: A. Rinaldi, A. Proietti, C. Aquarelli, F. Marra, A. Tamburrano, M. Ciminello, M. S. Sarto

Abstract:

A new type of high sensitive piezoresistive sensors based on graphene was developed within the SARISTU project for application on Structural Health Monitoring (SHM). The new sensor consists of a graphene-based film, obtained through the spray deposition of a colloidal suspension of Multi-Layer Graphene (MLGs) nano platelets over a substrate. MLGs are produced by liquid exfoliation of thermally expanded Graphite Intercalation Compound. An array of 8 sensors is produced by spray deposition over an aeronautical CFRC plate of dimensions 550 mm (length) × 550 mm (width) × 3 mm (thickness). Electromechanical tests were performed in order to assess the sensitivity of the new piezoresistive sensors, which are characterized by an isotropic response. In the quasi-static characterizations, the CFRC plate was clamped on one side and loaded on the opposite one. The local strain map of the plate was then obtained from displacement measurements and numerical analysis. The dynamic tests were performed lying the plate over an anti-vibration table and actuating a piezoelectric element located in the middle of the sensing array. The obtained experimental results demonstrated that the sensors possess a good repeatability and a high constant gauge factor (~200) in the applied strain range 0.001%-0.02%. Moreover, they can follow dynamics up to 400 kHz and for this reason they are good candidates for Lamb-wave analysis.

Keywords: graphene, strain sensor, spray deposition, lamb-wave analysis

Procedia PDF Downloads 431
5956 Quantitative Method of Measurement for the Rights and Obligations of Contracting Parties in Standard Forms of Contract in Malaysia: A Case Study

Authors: Sim Nee Ting, Lan Eng Ng

Abstract:

Standard forms of contract in Malaysia are pre-written, printed contractual documents drafted by recognised authoritative bodies in order to describe the rights and obligations of the contracting parties in all construction projects in Malaysia. Studies and form revisions are usually conducted in a relatively random and qualitative manner, but the search of contractual documents idealization remains. It is not clear how these qualitative findings could be helpful for contractual documents improvements and re-drafting. This study aims to quantitatively and systematically analyse and evaluate the rights and obligations of the contracting parties as stated in the standard forms of contract. The Institution of Engineers Malaysia (IEM) published a new standard form of contract in 2012 with a total of 63 classes but the improvements and changes in the newly revised form that are yet to be analysed. IEM form will be used as the case study for this study. Every clause in this said form were interpreted and analysed according to the involved parties including contractor, engineer and employer. Modified from Matrix Method and Likert Scale, the result analysis were conducted based on a scale from 0 to 1 with five ratings namely “Very Unbalance”, “Unbalance”, “Balance”, “Good Balance” and “Very Good Balance”. It is hoped that quantitative method of form study can be used for future form revisions and any new forms drafting so to reduce on any subjectivity in standard forms of contract studies.

Keywords: contracting parties, Malaysia, obligations, quantitative measurement, rights, standard form of contract

Procedia PDF Downloads 265
5955 Good Governance in Perspective: An Example of Transition from Corruption towards Integrity within a Developing Country (Pakistan)

Authors: Saifullah Khalid

Abstract:

Governance and good governance are among the main topics in international discussions about the success factors for social and economic development. The image of developing countries as for example Pakistan in this respect is bad (in TI Corruption Index nr. among countries). Additionally, the police are among the sectors and organizations which are seen as most corrupt in many countries. However, in case of Pakistan there seem to be exceptions to the rule, and improvement can be brought in specific police departments. This paper represents the findings of Islamabad traffic police (ITP). In Pakistan, the police, in general, have been stigmatized for being the most corrupt department in the country. However, the few recent examples of Motorway police and its replicated model of Islamabad traffic police changed the perception about police and policing. These police forces have shown that Policing in Pakistan can be changed for better. In this paper, the research question that is addressed is: How corrupt are (traffic) police forces in Pakistan and what factors influence corruption within that police force? And What lessons can be learned from that to improve police integrity? Both qualitative and quantitative tools are utilized for data collection. The overall picture of the factors is not so easy to interpret and summarise. Nevertheless paying a better salary does not seem to limit integrity violations, neither does recruitment and selection and leadership, while supervision and control, training and stimulating the positive and limiting the negative elements of culture appear to be important in curbing (sometimes specific) integrity violations in the context of Pakistani police forces. The study also leads to a number of suggestions for curbing corruption and other integrity violations in the Pakistan police.

Keywords: corruption control, governance, integrity violations, Islamabad traffic police, Pakistan

Procedia PDF Downloads 216
5954 Tofu Flour as a Protein Sources

Authors: Dicky Eka Putra, S. P. Nadia Chairunissa, Lidia Paramita, Roza Hartati, Ice Yolanda Puri

Abstract:

Background: Soy bean and the products such as tofu, tempeh and soy milk are famous in the community. Moreover, another product is tofu flour which is not familiar in Indonesia yet and it is well known as Okara. There are massive differences of energy, protein and carbohydrate between them which is know as good for protein sources as well. Unfortunately, it is seldom used as food variety. Basically, it can be benefit in order to create many products for example cakes, snacks and some desserts. Aim: the study was in order to promote the benefit of tofu flour as school feeding of elementary school and baby porridge and also to compare the nutrient. Method: Soy pulp was filtered and steamed approximately 30 minutes. Then, it was put at a plate under sunrise or barked on the oven for 10 hours at 800C. When it have dried and milling and tofu flour is ready to be used. Result: Tofu flour could be used as substitute of flour and rice flour when people want to cook some foods. In addition, some references said that soy bean is good for a specific remedy for the proper functioning of the heart, liver, kidneys, stomach, and bowels, constipation, as a stimulant for the lungs, for eradication of poison from the system, improving the complexion by cleaning the skin of impurities, and stimulating the growth and appearance of the hair. Discussion: Comparing between soy bean, tofu and tofu flour which has difference amount of nutrients. For example energy 382 kcal, 79 kcal and 393 kcal respectively and also protein 30.2 kcal, 7.8 kcal, and 17.4 kcal. In addition, carbohydrate of soy pulp was high than soy bean and tofu (30.1 kcal). Finally, local should replace flour, rice and gelatin rice flour with tofu flour.

Keywords: tofu flour, protein, soy bean, school feeding

Procedia PDF Downloads 378
5953 Barrier Characteristics of Molecular Semiconductor-Based Organic/Inorganic Au/C₄₂H₂₈/n-InP Hybrid Junctions

Authors: Bahattin Abay

Abstract:

Thin film of polycyclic aromatic hydrocarbon rubrene, C₄₂H₂₈ (5,6,11,12-tetraphenyltetracene), has been surfaced on Moderately Doped (MD) n-InP substrate as an interfacial layer by means of spin coating technique for the electronic modification of Au/MD n-InP structure. Ex situ annealing has been carried out at 150 °C for three minutes under a brisk flow of nitrogen for the better adhesion of the deposited film with the substrate surface. Room temperature electrical characterization has been performed on the C₄₂H₂₈/MD n-InP hybrid junctions by current-voltage (I-V) and capacitance-voltage (C-V) measurement in the dark. It has been seen that the C₄₂H₂₈/MD n-InP structure demonstrated extraordinary rectifying behavior. An effective barrier height (BH) as high as 0.743 eV, along with an ideality factor very close to unity (n=1.203), has been achieved for C₄₂H₂₈/n-InP organic/inorganic device. A thin C₄₂H₂₈ interfacial layer between Au and MD n-InP also reduce the reverse leakage current by almost four orders of magnitude and enhance the BH about 0.278 eV. This good performance of the device is ascribed to the passivation effect of organic interfacial layer between Au and n-InP. By using C-V measurement, in addition, the value of BH of the C₄₂H₂₈/n-InP organic/inorganic hybrid junctions have been obtained as 0.796 eV. It has been seen that both of the BH value (0.743 and 0.796 eV) for the organic/inorganic hybrid junction obtained I-V and C-V measurement, respectively are significantly larger than that of the conventional Au/n-InP structure (0.465 and 0.503 eV). It was also seen that the device had good sensitivity to the light under 100 mW/cm² illumination conditions. The obtained results indicated that modification of the interfacial potential barrier for Metal/n-InP junctions might be attained using polycyclic aromatic hydrocarbon thin interlayer C₄₂H₂₈.

Keywords: I-V and C-V measurements, heterojunction, n-InP, rubrene, surface passivation

Procedia PDF Downloads 162
5952 Treatment Outcome Of Corneal Ulcers Using Levofloxacin Hydrate 1.5% Ophthalmic Solution And Adjuvant Oral Ciprofloxacin, A Treatment Strategy Applicable To Primary Healthcare

Authors: Celine Shi Ying Lee, Jong Jian Lee

Abstract:

Background: Infectious keratitis is one of the leading causes of blindness worldwide. Prompt treatment with effective medication will control the infection early, preventing corneal scarring and visual loss. fluoroquinolones ophthalmic medication is used because of its broad-spectrum properties, potency, good intraocular penetration, and low toxicity. The study aims to evaluate the treatment outcome of corneal ulcers using Levofloxacin 1.5% ophthalmic solution (LVFX) with adjuvant oral ciprofloxacin when indicated and apply this treatment strategy in primary health care as first-line treatment. Methods: Patients with infective corneal ulcer treated in an eye center were recruited. Inclusion criteria includes Corneal infection consistent with bacterial keratitis, single or multiple small corneal ulcers. Treatment regime: LVFX hourly for the first 2 days, 2 hourly from the 3rd day, and 3 hourly on the 5th day of review. Adjuvant oral ciprofloxacin 500mg BD was administered for 5 days if there were multiple corneal ulcers or when the location of the cornea ulcer was central or paracentral. Results: 47 subjects were recruited. There were 16 (34%) males and 31 (66%) females. 40 subjects (85%) were contact lens (CL) related to corneal ulcer, and 7 subjects (15%) were non-contact lens related. 42 subjects (89%) presented with one ulcer, of which 20 of them (48%) needed adjuvant therapy. 5 subjects presented with 2 or 3 ulcers, of which 3 needed adjuvant therapy. A total of 23 subjects (49%) was given adjuvant therapy (oral ciprofloxacin 500mg BD for 5 days).21 of them (91%) were CL related. All subjects recovered fully, and the average duration of treatment was 3.7 days, with 49% of the subjects resolved on the 3rd day, 38% on the 5thday of and 13% on the 7thday. All subjects showed symptoms of relief of pain, light-sensitivity, and redness on the 3rd day with full visual recovery post-treatment. No adverse drug reactions were recorded. Conclusion: Our treatment regime demonstrated good clinical outcome as first-line treatment for corneal ulcers. A corneal ulcer is a common eye condition in Singapore, mainly due to CL wear. Pseudomonas aeruginosa is the most frequent and potentially sight-threatening pathogen involved in CL related corneal ulcer. Coagulase-negative Staphylococci, Staphylococcus aureus, and Streptococcus Pneumoniae were seen in non-CL users. All these bacteria exhibit good sensitivity rates to ciprofloxacin and levofloxacin. It is therefore logical in our study to use LVFX Eyedrops and adjuvant ciprofloxacin oral antibiotics when indicated as first line treatment for most corneal ulcers. Our study of patients, both CL related and non-CL related, have shown good clinical response and full recovery using the above treatment strategy. There was also a full restoration of visual acuity in all the patients. Eye-trained primary Healthcare practitioners can consider adopting this treatment strategy as first line treatment in patients with corneal ulcers. This is relevant during the COVID pandemic, where hospitals are overwhelmed with patients and in regions with limited access to specialist eye care. This strategy would enable early treatment with better clinical outcome.

Keywords: corneal ulcer, levofloxacin hydrate, treatment strategy, ciprofloxacin

Procedia PDF Downloads 175
5951 A Novel Cold Asphalt Concrete Mixture for Heavily Trafficked Binder Course

Authors: Anmar Dulaimi, Hassan Al Nageim, Felicite Ruddock, Linda Seton

Abstract:

Cold bituminous asphalt mixture (CBEM) provide a sustainable, cost effective and energy efficiency alternative to traditional hot mixtures. However, these mixtures have a comparatively low initial strength and as it is considered as evolutionary materials, mainly in the early life where the initial cohesion is low and builds up slowly. On the other hand, asphalt concrete is, by far, the most common mixtures in use as binder course and base in road pavement in the UK having a continuous grade offer a good aggregate interlock results in this material having very good load-spreading properties as well as a high resistance to permanent deformation. This study aims at developing a novel fast curing cold asphalt concrete binder course mixtures by using Ordinary Portland Cement (OPC) as a replacement to conventional mineral filler (0%-100%) while new by-product material (LJMU-A2) was used as a supplementary cementitious material. With this purpose, cold asphalt concrete binder course mixtures with cationic emulsions were studied by means of stiffness modulus whereas water sensitivity was approved by assessing the stiffness modulus ratio before and after sample conditioning. The results indicate that a substantial enhancement in the stiffness modulus and a considerable improvement of water sensitivity resistance by adding of LJMU-A2 to the cold asphalt mixtures as a supplementary cementitious material. Moreover, the addition of LJMU-A2 to those mixtures leads to stiffness modulus after 2- day curing comparable to those obtained with Portland cement after 7-day curing.

Keywords: cold mix asphalt, binder course, cement, stiffness modulus, water sensitivity

Procedia PDF Downloads 311
5950 Slovenia in the Heart of Europe

Authors: M. Žibert, T. Špindler, S. Uhan, A. Lisec

Abstract:

We can find Slovenia in the heart of Europe and has really good geographical location. With same slogan are promoted Switzerland, Montenegro, Greece and probably many others. However, from anatomic point of view, injustice is being made to someone because the heart is placed only in left part of chest cavity and there we can`t find place for the entire territory from Switzerland to the south of Balkan.

Keywords: Ljubljana, logistics, Slovenia, tourism

Procedia PDF Downloads 374
5949 Excision and Reconstruction of a Hypertrophic and Functional Bleb with Bovine Pericardium (Tutopatch®) and Amniotic Membrane: A Case Report

Authors: Blanca Fatela Cantillo, Silvia Iglesias Cerrato, Guadalupe Garrido Ceca

Abstract:

Purpose: Bleb dysfunction is a late complication following glaucoma filtration surgery. We describe our surgical technique for excision and reconstruction of a hypertrophic bleb complication using bovine pericardium patch graft (Tutopatch®) and amniotic membrane. Material and methods: The case report presents a hypertrophic bleb over the cornea with good intraocular pressure control. The hanging bleb without leak caused dysesthesia and high irregular astigmatism. Bleb reconstruction involved the excision of corneal fibrous material and avascular conjunctiva, preserving the original scleral and tennon. Bovine pericardium patch graft (Tutopatch®) was sited over these with fixed sutures, reinforcing the underlying scleral, and the conjunctiva advanced. The superior epithelium corneal defect was covered using an amniotic membrane. Conclusion: Repair of bleb dysfunction with varied techniques has been reported, including conjunctival advancement, use of scleral patch graft, dural patch graft, or pericardium. Additional use of amniotic membrane promotes epithelialization and exhibits anti-fibrotic and anti-inflammatory features. Reconstruction with bovine pericardium patch graft and amniotic membrane resulted in pain relief, visual rehabilitation, and good aesthetic results, with preservation of bleb function.

Keywords: reconstruction, hypertrophic bleb, bovine pericardium, amniotic membrane, dysesthesia of the bleb

Procedia PDF Downloads 78
5948 Prognostic and Predictive Value of Tumor: Infiltrating Lymphocytes in Triple Negative Breast Cancer

Authors: Wooseok Byon, Eunyoung Kim, Junseong Kwon, Byung Joo Song, Chan Heun Park

Abstract:

Background/Purpose: Previous preclinical and clinical data suggest that increased lymphocytic infiltration would be associated with good prognosis and benefit from immunogenic chemotherapy especially in triple-negative breast cancer (TNBC). We investigated a single-center experience of TNBC and relationship with lymphocytic infiltration. Methods: From January 2004 to December 2012, at the Department of Surgery, Kangbuk Samsung Hospital, Sungkyunkwan University, School of Medicine, we retrospectively reviewed 897 breast cancer patients-clinical outcomes, clinicopathological characteristics, breast cancer subtypes. And we reviewed lymphocytic infiltration of TNBC specimens by two pathologists. Statistical analysis of risk factors associated with recurrence was performed. Results: A total of 897 patients, 76 were TNBC (8.47%). Mean age of TNBC patients were 50.95 (SD10.42) years, mean follow-up periods was 40.06 months. We reviewed 49 slides, and there were 8 recurrent breast cancer patients (16.32%), and 4 patients were expired (8.16%). There were 9 lymphocytic predominant breast cancers (LPBC)-carcinomas with either intratumoral lymphocytes in >60% of tumor cell nests. 1 patient of LPBC was recurred and 8 were not. In multivariate logistic regression, the odds ratio of lymphocytic infiltration was 0.59 (p=0.643). Conclusion: In a single-center experience of TNBC, the lymphocytic infiltration in tumor cell nest might be a good trend on the prognosis but there was not statistically significant.

Keywords: tumor-infiltrating lymphocytes, triple negative breast cancer, medical and health sciences

Procedia PDF Downloads 408
5947 Thermochemical Modelling for Extraction of Lithium from Spodumene and Prediction of Promising Reagents for the Roasting Process

Authors: Allen Yushark Fosu, Ndue Kanari, James Vaughan, Alexandre Changes

Abstract:

Spodumene is a lithium-bearing mineral of great interest due to increasing demand of lithium in emerging electric and hybrid vehicles. The conventional method of processing the mineral for the metal requires inevitable thermal transformation of α-phase to the β-phase followed by roasting with suitable reagents to produce lithium salts for downstream processes. The selection of appropriate reagent for roasting is key for the success of the process and overall lithium recovery. Several researches have been conducted to identify good reagents for the process efficiency, leading to sulfation, alkaline, chlorination, fluorination, and carbonizing as the methods of lithium recovery from the mineral.HSC Chemistry is a thermochemical software that can be used to model metallurgical process feasibility and predict possible reaction products prior to experimental investigation. The software was employed to investigate and explain the various reagent characteristics as employed in literature during spodumene roasting up to 1200°C. The simulation indicated that all used reagents for sulfation and alkaline were feasible in the direction of lithium salt production. Chlorination was only feasible when Cl2 and CaCl2 were used as chlorination agents but not NaCl nor KCl. Depending on the kind of lithium salt formed during carbonizing and fluorination, the process was either spontaneous or nonspontaneous throughout the temperature range investigated. The HSC software was further used to simulate and predict some promising reagents which may be equally good for roasting the mineral for efficient lithium extraction but have not yet been considered by researchers.

Keywords: thermochemical modelling, HSC chemistry software, lithium, spodumene, roasting

Procedia PDF Downloads 159
5946 Pattern of Refractive Error, Knowledge, Attitude and Practice about Eye Health among the Primary School Children in Bangladesh

Authors: Husain Rajib, K. S. Kishor, D. G. Jewel

Abstract:

Background: Uncorrected refractive error is a common cause of preventable visual impairment in pediatric age group which can be lead to blindness but early detection of visual impairment can reduce the problem that will have good effective in education and more involve in social activities. Glasses are the cheapest and commonest form of correction of refractive errors. To achieve this, patient must exhibit good compliance to spectacle wear. Patient’s attitude and perception of glasses and eye health could affect compliance. Material and method: A Prospective community based cross sectional study was designed in order to evaluate the knowledge, attitude and practices about refractive errors and eye health amongst the primary school going children. Result: Among 140 respondents, 72 were males and 68 were females. We found 50 children were myopic and out of them 26 were male and 24 were female, 27 children were hyperopic and out of them 14 were male and 13 were female. About 63 children were astigmatic and out of them 32 were male and 31 were female. The level of knowledge, attitude was satisfactory. The attitude of the students, teachers and parents was cooperative which helps to do cycloplegic refraction. Practice was not satisfactory due to social stigma and information gap. Conclusion: Knowledge of refractive error and acceptance of glasses for the correction of uncorrected refractive error. Public awareness program such as vision screening program, eye camp, and teachers training program are more beneficial for wearing and prescribing spectacle.

Keywords: refractive error, stigma, knowledge, attitude, practice

Procedia PDF Downloads 264
5945 Policy to Improve in vitro Fertilization Outcome in Women with Poor Ovarian Response: Frozen Embryo Transfer (ET) of Accumulated Vitrified Embryos vs. Frozen ET of Accumulated Vitrified Embryos plus Fresh ET

Authors: Hwang Kwon

Abstract:

Objective: To assess the efficacy of embryo transfer (ET) of accumulated vitrified embryos and compare pregnancy outcomes between ET of thawed embryos following accumulation of vitrified embryos (frozen ET) and ET of fresh and thawed frozen embryos following accumulation of vitrified embryos (fresh ET + frozen ET). Study design: Patients were poor ovarian responders defined according to the Bologna criteria as well as a subgroup of women whose previous IVF-ET cycle through controlled ovarian stimulation (COS) yielded one or no embryos. Sixty-four frozen ETs were performed following accumulation of vitrified embryos (ACCE )(ACCE Frozen) and 51 fresh + frozen ETs were performed following accumulation of vitrified embryos (ACCE Fresh + Frozen). Positive βhCG rate, clinical pregnancy rate, ongoing pregnancy rate, and good quality embryos (%, ±SD) were compared between two groups. Results: There were more good quality embryos in the ACCE Fresh + Frozen group than in the ACCE Frozen group: 60±34.7 versus 42.9±28.9, respectively (p=0.03). Positive βhCG rate [18/64(28.2%) vs. 13/51(25.5%); p=0.75] and clinical pregnancy rate [12/64 (18.8%) vs. 11/51 (10.9%); p=0.71] were comparable between the two groups. Conclusion: Accumulation of vitrified embryos is an effective method in patients with poor ovarian response who fulfill the Bologna criteria. Pregnancy outcomes were comparable between the two groups.

Keywords: accumulation of embryos, frozen embryo transfer, poor responder, Bologna criteria

Procedia PDF Downloads 229
5944 Determining the Relationship Between Maternal Stress and Depression and Child Obesity: The Mediating Role of Maternal Self-efficacy

Authors: Alireza Monzavi Chaleshtori, Mahnaz Aliakbari Dehkordi, Maryam Aliakbari, Solmaz Seyed Mostafaii

Abstract:

Objective: Considering the growing obesity among children and the role of mother's psychological factors as well as the need to prevent childhood obesity, this study aimed to investigate the mediating role of mother's self-efficacy in the relationship between mother's stress and depression and child obesity. Method: For this purpose, in a descriptive-correlation study, 222 mothers and children aged 1 to 5 years in Tehran, who had the opportunity to answer an online questionnaire, were selected by random sampling and to the depression scales of the Kroenke and Spitzer Patient Health Questionnaire, Cohen's stress and Self-efficacy of Berkeley mothers answered. Pearson correlation test and path analysis were used for data analysis. Findings: The findings showed that maternal depression had an indirect and significant effect on child obesity, and the effect of stress and depression on child obesity was indirect and non-significant. Therefore, the model has a good fit with the research data, and stress and depression indirectly predicted child obesity with the mediating role of self-efficacy. Conclusion: The hypothesized model tested based on mother's stress and depression with the mediating role of mother's self-efficacy was a good model in explaining the prediction of child obesity. Based on the findings of this research, a practical framework can be provided to explain the psychological factors of the mother in relation to child obesity and its treatment.

Keywords: stress, self-efficacy, child obesity, depression

Procedia PDF Downloads 71
5943 A Study of Patriotism through History Education in Primary School

Authors: Abdul Razak Bin Ahmad, Mohd Mahzan Awang

Abstract:

Appreciation of patriotism value is important for every student to be able to become a quality citizen and good for the country. Realizing this situation, Malaysia has introduced history education for primary school students since 2014. One of the aims is to provide basic knowledge on patriotism as well as to promote patriotic behaviour among school pupils. In order to examine the relationship between the students’ knowledge and their behaviour, a survey study was carried out. A set of questionnaire was designed and developed based prior studies on history education and patriotism. The sample of this survey was 153 primary school students aged 12 years old (Standard Six). Data collected and analysed using SPSS (Statistical Package for The Social Science 20.0). The results showed that the level of knowledge and patriotism practise at the moderate levels. Inferential statistic results revealed that there is no significant difference between genders with regards to patriotism knowledge and patriotism practice through history education subject. Results also demonstrated that there is a significant relationship between knowledge and the practice of patriotism values among the students. This means that knowledge on patriotism is important for promoting patriotic behaviour and practice in primary schools. This study implies that teaching students to understand and comprehend the concept of patriotism is vital to promote patriotic behaviour among students. Therefore, teachers should master pedagogical skills and good content knowledge on patriotism as mechanisms to promote effective learning in history education subjects. creativity in teaching history education subjects is also needed.

Keywords: history education, knowledge, primary school, patriotism values, teachers

Procedia PDF Downloads 382
5942 Evaluation of Antioxidants in Medicinal plant Limoniastrum guyonianum

Authors: Assia Belfar, Mohamed Hadjadj, Messaouda Dakmouche, Zineb Ghiaba

Abstract:

Introduction: This study aims to phytochemical screening; Extracting the active compounds and estimate the effectiveness of antioxidant in Medicinal plants desert Limoniastrum guyonianum (Zeïta) from South Algeria. Methods: Total phenolic content and total flavonoid content using Folin-Ciocalteu and aluminum chloride colorimetric methods, respectively. The total antioxidant capacity was estimated by the following methods: DPPH (1.1-diphenyl-2-picrylhydrazyl radical) and reducing power assay. Results: Phytochemical screening of the plant part reveals the presence of phenols, saponins, flavonoids and tannins. While alkaloids and Terpenoids were absent. The acetonic extract of L. guyonianum was extracted successively with ethyl acetate and butanol. Extraction of yield varied widely in the L. guyonianum ranging from (0.9425 %to 11.131%). The total phenolic content ranged from 53.33 mg GAE/g DW to 672.79 mg GAE/g DW. The total flavonoid concentrations varied from 5.45 to 21.71 mg/100g. IC50 values ranged from 0.02 ± 0.0004 to 0.13 ± 0.002 mg/ml. All extracts showed very good activity of ferric reducing power, the higher power was in butanol fraction (23.91 mM) more effective than BHA, BHT and VC. Conclusions: Demonstrated this study that the acetonic extract of L. guyonianum contain a considerable quantity of phenolic compounds and possess a good antioxidant activity. Can be used as an easily accessible source of Natural Antioxidants and as a possible food supplement and in the pharmaceutical industry.

Keywords: limoniastrum guyonianum, phenolics compounds, flavonoid compound, antioxidant activity

Procedia PDF Downloads 348
5941 The Relevance of the U-Shaped Learning Model to the Acquisition of the Difference between C'est and Il Est in the English Learners of French Context

Authors: Pooja Booluck

Abstract:

A U-shaped learning curve entails a three-step process: a good performance followed by a bad performance followed by a good performance again. U-shaped curves have been observed not only in language acquisition but also in various fields such as temperature face recognition object permanence to name a few. Building on previous studies of the curve child language acquisition and Second Language Acquisition this empirical study seeks to investigate the relevance of the U-shaped learning model to the acquisition of the difference between cest and il est in the English Learners of French context. The present study was developed to assess whether older learners of French in the ELF context follow the same acquisition pattern. The empirical study was conducted on 15 English learners of French which lasted six weeks. Compositions and questionnaires were collected from each subject at three time intervals (after one week after three weeks after six weeks) after which students work were graded as being either correct or incorrect. The data indicates that there is evidence of a U-shaped learning curve in the acquisition of cest and il est and students did follow the same acquisition pattern as children in regards to rote-learned terms and subject clitics. This paper also discusses the need to introduce modules on U-shaped learning curve in teaching curriculum as many teachers are unaware of the trajectory learners undertake while acquiring core components in grammar. In addition this study also addresses the need to conduct more research on the acquisition of rote-learned terms and subject clitics in SLA.

Keywords: child language acquisition, rote-learning, subject clitics, u-shaped learning model

Procedia PDF Downloads 293
5940 Extraction of Scandium (Sc) from an Ore with Functionalized Nanoporous Silicon Adsorbent

Authors: Arezoo Rahmani, Rinez Thapa, Juha-Matti Aalto, Petri Turhanen, Jouko Vepsalainen, Vesa-PekkaLehto, Joakim Riikonen

Abstract:

Production of Scandium (Sc) is a complicated process because Sc is found only in low concentrations in ores and the concentration of Sc is very low compared with other metals. Therefore, utilization of typical extraction processes such as solvent extraction is problematic in scandium extraction. The Adsorption/desorption method can be used, but it is challenging to prepare materials, which have good selectivity, high adsorption capacity, and high stability. Therefore, efficient and environmentally friendly methods for Sc extraction are needed. In this study, the nanoporous composite material was developed for extracting Sc from an Sc ore. The nanoporous composite material offers several advantageous properties such as large surface area, high chemical and mechanical stability, fast diffusion of the metals in the material and possibility to construct a filter out of the material with good flow-through properties. The nanoporous silicon material was produced by first stabilizing the surfaces with a silicon carbide layer and then functionalizing the surface with bisphosphonates that act as metal chelators. The surface area and porosity of the material were characterized by N₂ adsorption and the morphology was studied by scanning electron microscopy (SEM). The bisphosphonate content of the material was studied by thermogravimetric analysis (TGA). The concentration of metal ions in the adsorption/desorption experiments was measured with inductively coupled plasma mass spectrometry (ICP-MS). The maximum capacity of the material was 25 µmol/g Sc at pH=1 and 45 µmol/g Sc at pH=3, obtained from adsorption isotherm. The selectivity of the material towards Sc in artificial solutions containing several metal ions was studied at pH one and pH 3. The result shows good selectivity of the nanoporous composite towards adsorption of Sc. Scandium was less efficiently adsorbed from solution leached from the ore of Sc because of excessive amounts of iron (Fe), aluminum (Al) and titanium (Ti) which disturbed the adsorption process. For example, the concentration of Fe was more than 4500 ppm, while the concentration of Sc was only three ppm, approximately 1500 times lower. Precipitation methods were developed to lower the concentration of the metals other than Sc. Optimal pH for precipitation was found to be pH 4. The concentration of Fe, Al and Ti were decreased by 99, 70, 99.6%, respectively, while the concentration of Sc decreased only 22%. Despite the large reduction in the concentration of other metals, more work is needed to further increase the relative concentration of Sc compared with other metals to efficiently extract it using the developed nanoporous composite material. Nevertheless, the developed material may provide an affordable, efficient and environmentally friendly method to extract Sc on a large scale.

Keywords: adsorption, nanoporous silicon, ore solution, scandium

Procedia PDF Downloads 146
5939 The Role of Public Management Development in Enhancing Public Service Delivery in the South African Local Government

Authors: Andrew Enaifoghe

Abstract:

The study examined the role of public management development in enhancing public service delivery in the South African local government. The study believes that the ultimate empowerment of the third tier sphere of governments in South Africa remains the instrument required to enhance both national and continental development. This over the year has been overwhelmed with problems and imbalance related to ethical practice, accountability and the functional local government system and the machinery itself. The study finds that imbalances are being strengthened by a lack of understanding and unanimity as to what a public management development in a democratic system is and how it should work to achieve the dividends of democracy in delivering public goods. Studies indicated that the magnitudes are widespread corruption and misrepresentations of government priorities; both of which weaken the ability of governments to enhance broad-based economic growth and social well-being of the people. This study addressed the problem of public management and accountable local government. The study indicates the need for citizens’ participation in the decision-making process in delivering public service in South Africa and how its accountability mechanism supports good governance. The study concludes that good and ethical watersheds in South Africa have since reached such proportions that social pressure, the pressure from the government and various institutions have to re-consider where they stand regarding ethics, ethical behaviour, accountability and professionalism in delivering public goods to the people at the local municipal government.

Keywords: accountability, development, democratic system, South Africa

Procedia PDF Downloads 125
5938 A Questionnaire Survey Reviewing Radiographers' Knowledge of Computed Tomography Exposure Parameters

Authors: Mohammad Rawashdeh, Mark McEntee, Maha Zaitoun, Mostafa Abdelrahman, Patrick Brennan, Haytham Alewaidat, Sarah Lewis, Charbel Saade

Abstract:

Despite the tremendous advancements that have been generated by Computed Tomography (CT) in the field of diagnosis, concerns have been raised about the potential cancer induction risk from CT because of the exponentially increased use of it in medicine. This study aims at investigating the application and knowledge of practicing radiographers in Jordan about CT radiation. In order to collect the primary data of this study, a questionnaire was designed and distributed by social media using a snow-balling sampling method. The respondents (n=54) have answered 36 questions including the questions about their demographic information, knowledge about Diagnostic Reference Levels (DRLs), CT exposure and adaptation of pediatric patients exposure. The educational level of the respondents was either at a diploma degree (35.2%) or bachelor (64.8%). The results of this study have indicated a good level of general knowledge between radiographers about the relationship between image quality, exposure parameters, and patient dose. The level of knowledge related to DRL was poor where less than 7.4 percent of the sample members were able to give specific values for a number of common anatomical fields, including abdomen, brain, and chest. Overall, Jordanian radiographers need to gain more knowledge about the expected levels of the dose when applying good practice. Additional education on DRL or DRL inclusion in educational programs is highlighted.

Keywords: computed tomography, CT scan, DRLs, exposure parameters, image quality, radiation dose

Procedia PDF Downloads 144
5937 Influence of Hearing Aids on Non-medically Treatable Deafness

Authors: Donatien Niragira

Abstract:

The progress of technology creates new expectations for patients. The world of deafness is no exception. In recent years, there have been considerable advances in the field of technologies aimed at assisting failing hearing. According to the usual medical vocabulary, hearing aids are actually orthotics. They do not replace an organ but compensate for a functional impairment. The Amplifier Hearing amplification is useful for a large number of people with hearing loss. Hearing aids restore speech audibility. However, their benefits vary depending on the quality of residual hearing. The hearing aid is not a "cure" for deafness. It cannot correct all affected hearing abilities. It should be considered as an aid to communication. The urge to judge from the audiogram alone should be resisted here, as audiometry only indicates the ability to detect non-verbal sounds. To prevent hearing aids from ending up in the drawer, it is important to ensure that the patient's disability situations justify the use of this type of orthosis. If the problems of receptive Pre-fitting counseling are crucial: the person with hearing loss must be informed of the advantages and disadvantages of amplification in his or her case. Their expectations must be realistic. They also need to be aware that the adaptation process requires a good deal of patience and perseverance. They should be informed about the various models and types of hearing aids, including all the aesthetic, functional and financial considerations. If the person's motivation "survives" pre-fitting counseling, we are in the presence of a good candidate for amplification. In addition to its relevance, it shows that the results found in this study significantly improve the quality of audibility in the patient, from where this technology must be made accessible everywhere in the world.

Keywords: auditives protheses, hearing, aids, no medicaly treatable deafnes

Procedia PDF Downloads 57
5936 Clinical Outcome after in Vitro Fertilization in Women Aged 40 Years and Above: Reasonable Cut-Off Age for Successful Pregnancy

Authors: Eun Jeong Yu, Inn Soo Kang, Tae Ki Yoon, Mi Kyoung Koong

Abstract:

Advanced female age is associated with higher cycle cancelation rates, lower clinical pregnancy rate, increased miscarriage and aneuploidy rates in IVF (In Vitro Fertilization) cycles. This retrospective cohort study was conducted at a Cha Fertility Center, Seoul Station. All fresh non-donor IVF cycles performed in women aged 40 years and above from January 2016 to December 2016 were reviewed. Donor/recipient treatment, PGD/PGS (Preimplantation Genetic Diagnosis/ Preimplantation Genetic Screening) were excluded from analysis. Of the 1,166 cycles from 753 women who completed ovulation induction, 1,047 were appropriate for the evaluation according to inclusion and exclusion criterion. IVF cycles were categorized according to age and grouped into the following 1-year age groups: 40, 41, 42, 43, 44, 45 and > 46. The mean age of patients was 42.4 ± 1.8 years. The median AMH (Anti-Mullerian Hormone) level was 1.2 ± 1.5 ng/mL. The mean number of retrieved oocytes was 4.9 ± 4.3. The clinical pregnancy rate and live birth rate in women > 40 years significantly decreased with each year of advancing age (p < 0.001). The clinical pregnancy rate decreased from 21% at the age of 40 years to 0% at ages above 45 years. Live birth rate decreased from 12.3% to 0%, respectively. There were no clinical pregnancy outcomes among 95 patients aged above 45 years of age. The overall miscarriage rate was 40.7% (range, 36.7%-70%). The transfer of at least one good quality embryo was associated with about 4-9% increased chance of a clinical pregnancy rate. Therefore, IVF in old age women less than 46 had a reasonable chance for successful pregnancy outcomes especially when good quality embryo is transferred.

Keywords: advanced maternal age, in vitro fertilization, pregnancy rate, live birth rate

Procedia PDF Downloads 144
5935 Application of RS and GIS Technique for Identifying Groundwater Potential Zone in Gomukhi Nadhi Sub Basin, South India

Authors: Punitha Periyasamy, Mahalingam Sudalaimuthu, Sachikanta Nanda, Arasu Sundaram

Abstract:

India holds 17.5% of the world’s population but has only 2% of the total geographical area of the world where 27.35% of the area is categorized as wasteland due to lack of or less groundwater. So there is a demand for excessive groundwater for agricultural and non agricultural activities to balance its growth rate. With this in mind, an attempt is made to find the groundwater potential zone in Gomukhi river sub basin of Vellar River basin, TamilNadu, India covering an area of 1146.6 Sq.Km consists of 9 blocks from Peddanaickanpalayam to Villupuram fall in the sub basin. The thematic maps such as Geology, Geomorphology, Lineament, Landuse, and Landcover and Drainage are prepared for the study area using IRS P6 data. The collateral data includes rainfall, water level, soil map are collected for analysis and inference. The digital elevation model (DEM) is generated using Shuttle Radar Topographic Mission (SRTM) and the slope of the study area is obtained. ArcGIS 10.1 acts as a powerful spatial analysis tool to find out the ground water potential zones in the study area by means of weighted overlay analysis. Each individual parameter of the thematic maps are ranked and weighted in accordance with their influence to increase the water level in the ground. The potential zones in the study area are classified viz., Very Good, Good, Moderate, Poor with its aerial extent of 15.67, 381.06, 575.38, 174.49 Sq.Km respectively.

Keywords: ArcGIS, DEM, groundwater, recharge, weighted overlay

Procedia PDF Downloads 444
5934 A Prediction Model Using the Price Cyclicality Function Optimized for Algorithmic Trading in Financial Market

Authors: Cristian Păuna

Abstract:

After the widespread release of electronic trading, automated trading systems have become a significant part of the business intelligence system of any modern financial investment company. An important part of the trades is made completely automatically today by computers using mathematical algorithms. The trading decisions are taken almost instantly by logical models and the orders are sent by low-latency automatic systems. This paper will present a real-time price prediction methodology designed especially for algorithmic trading. Based on the price cyclicality function, the methodology revealed will generate price cyclicality bands to predict the optimal levels for the entries and exits. In order to automate the trading decisions, the cyclicality bands will generate automated trading signals. We have found that the model can be used with good results to predict the changes in market behavior. Using these predictions, the model can automatically adapt the trading signals in real-time to maximize the trading results. The paper will reveal the methodology to optimize and implement this model in automated trading systems. After tests, it is proved that this methodology can be applied with good efficiency in different timeframes. Real trading results will be also displayed and analyzed in order to qualify the methodology and to compare it with other models. As a conclusion, it was found that the price prediction model using the price cyclicality function is a reliable trading methodology for algorithmic trading in the financial market.

Keywords: algorithmic trading, automated trading systems, financial markets, high-frequency trading, price prediction

Procedia PDF Downloads 184
5933 Managers' Awareness of Employees' Mental Health in Small- and Medium-Sized Enterprises in Underpopulated Mountainous Areas

Authors: Susumu Fukita, Hiromi Kawasaki, Satoko Yamasaki, Kotomi Yamashita, Tomoko Iki

Abstract:

The increase in the number of workers with mental health problems has become an issue. Many workers work in small- and medium-sized enterprises, which often support local employment and economy, especially in underpopulated mountainous areas. It is important for managers to take mental health measures for employees since there is no budget to hire health staff in small- and medium-sized enterprises. It is necessary to understand the manager's attitude toward the mental health of employees and to publicly support the manager in promoting mental health measures for employees. The purpose of this study was to study the awareness of managers of small- and medium-sized enterprises regarding the mental health of employees and to consider support for managers to take measures for the mental health of employees. Semi-structured interviews were conducted with six managers of small- and medium-sized enterprises in underpopulated mountainous areas in November 2019. Managers were asked about their awareness of the mental health of their employees. Qualitative descriptive analysis was used, and subcategories and categories were extracted. Four categories emerged. Regarding the mental health of employees, the managers acknowledged that if the appearance and behavior of the employees do not interfere with their lives, the manager judges that the employees’ mental health is normal. It was also found that the managers acknowledged that there is a comfortable working environment due to the characteristics of the underpopulated mountainous area. On the other hand, the managers acknowledged that employees are dissatisfied with salaries and management systems. In addition, it was found the manager acknowledged that some employees retire due to mental health problems. Although managers recognized that employees may be dissatisfied with salaries, they also recognized that there was a comfortable working environment due to the characteristics of the areas, with good interpersonal relationships. Economic challenges are difficult to solve in underpopulated mountainous areas. It is useful to consider measures that take advantage of the characteristics of the areas where it is easy to work because of good relations with each other, for example, to create a family-like workplace culture where managers and employees can engage in daily conversation. The managers judged that the employees were in good health if there was no interference with their lives. However, it is too late to take measures at the stage when it becomes an obstacle to life. Therefore, it is necessary to provide training for managers to learn observation techniques by which they quickly notice changes in the situation of employees and give appropriate responses; and to set up a contact point for managers to consult. Local governments should actively provide public support such as training for managers and establishing consultation desks to maintain valuable employment and local economics in underpopulated mountainous areas.

Keywords: employer, mental health, small- and medium- sized enterprises, underpopulated areas

Procedia PDF Downloads 145
5932 Optimization of Mechanical Properties of Alginate Hydrogel for 3D Bio-Printing Self-Standing Scaffold Architecture for Tissue Engineering Applications

Authors: Ibtisam A. Abbas Al-Darkazly

Abstract:

In this study, the mechanical properties of alginate hydrogel material for self-standing 3D scaffold architecture with proper shape fidelity are investigated. In-lab built 3D bio-printer extrusion-based technology is utilized to fabricate 3D alginate scaffold constructs. The pressure, needle speed and stage speed are varied using a computer-controlled system. The experimental result indicates that the concentration of alginate solution, calcium chloride (CaCl2) cross-linking concentration and cross-linking ratios lead to the formation of alginate hydrogel with various gelation states. Besides, the gelling conditions, such as cross-linking reaction time and temperature also have a significant effect on the mechanical properties of alginate hydrogel. Various experimental tests such as the material gelation, the material spreading and the printability test for filament collapse as well as the swelling test were conducted to evaluate the fabricated 3D scaffold constructs. The result indicates that the fabricated 3D scaffold from composition of 3.5% wt alginate solution, that is prepared in DI water and 1% wt CaCl2 solution with cross-linking ratios of 7:3 show good printability and sustain good shape fidelity for more than 20 days, compared to alginate hydrogel that is prepared in a phosphate buffered saline (PBS). The fabricated self-standing 3D scaffold constructs measured 30 mm × 30 mm and consisted of 4 layers (n = 4) show good pore geometry and clear grid structure after printing. In addition, the percentage change of swelling degree exhibits high swelling capability with respect to time. The swelling test shows that the geometry of 3D alginate-scaffold construct and of the macro-pore are rarely changed, which indicates the capability of holding the shape fidelity during the incubation period. This study demonstrated that the mechanical and physical properties of alginate hydrogel could be tuned for a 3D bio-printing extrusion-based system to fabricate self-standing 3D scaffold soft structures. This 3D bioengineered scaffold provides a natural microenvironment present in the extracellular matrix of the tissue, which could be seeded with the biological cells to generate the desired 3D live tissue model for in vitro and in vivo tissue engineering applications.

Keywords: biomaterial, calcium chloride, 3D bio-printing, extrusion, scaffold, sodium alginate, tissue engineering

Procedia PDF Downloads 111