Search results for: chemical education

Authors: Muhammad Jamil, Ning He, Aqib Mashood Khan, Munish Kumar Gupta

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Ti-6Al-4V has numerous applications in the medical, automobile, and aerospace industries due to corrosion resistivity, structural stability, and chemical inertness to most fluids at room temperature. These peculiar characteristics are beneficial for their application and present formidable challenges during machining. Machining of Ti-6Al-4V produces an elevated cutting temperature above 1000oC at dry conditions. This accelerates tool wear and reduces product quality. Therefore, there is always a need to employ sustainable/effective coolant/lubricant when machining such alloy. In this study, Finite Element Modeling (FEM) and experimental analysis when cutting Ti-6Al-4V under a distinctly developed dry ice mixed hybrid lubri-coolant are presented. This study aims to model the milling process of Ti-6Al-4V under a proposed novel hybrid lubri-coolant using different cutting speeds and feed per tooth DEFORM® software package was used to conduct the FEM and the numerical model was experimentally validated. A comparison of experimental and simulation results showed a maximum error of no more than 6% for all experimental conditions. In a nutshell, it can be said that the proposed model is effective in predicting the machining temperature precisely.

Keywords: friction coefficient, heat transfer, finite element modeling (FEM), milling Ti-6Al-4V

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Authors: Amir Amiri, Naghmeh Morakabati

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During the recent years the six-fold growth of cancer in Iran has led the production of healthy products to become a challenge in the food industry. Due to the young population in the country, the consumption of fast foods is growing. The chemical cancer-causing preservatives are used to produce these products more than the standard; so using an appropriate alternative seems to be important. On the one hand, the plant essential oils show the high antimicrobial potential against pathogenic and spoilage microorganisms and on the other hand they are highly volatile and decomposed under the processing conditions. The study aims to produce the loaded chitosan nanoparticles with different concentrations of savory essential oil to improve the anti-microbial property and increase the resistance of essential oil to oxygen and heat. The encapsulation efficiency was obtained in the range of 32.07% to 39.93% and the particle size distribution of the samples was observed in the range of 159 to 210 nm. The range of Zeta potential was obtained between -11.9 to -23.1 mV. The essential oil loaded in chitosan showed stronger antifungal activity against Rhizopus stolonifer. The results showed that the antioxidant property is directly related to the concentration of loaded essential oil so that the antioxidant property increases by increasing the concentration of essential oil. In general, it seems that the savory essential oil loaded in chitosan particles can be used as a food processor.

Keywords: chitosan, encapsulation, essential oil, nanogel

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Authors: Sakul Jaariyachamsit, Kevin Wongleedee

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The objectives of this research were to study five perceptions of service quality from international tourists who visited Bangkok, Thailand. The independent variables included gender, age, levels of education, occupation, and income while the dependent variables included their opinion on the service provided by employees in Thai tourism. An accidental random sampling method was utilized to get 215 respondents. The respondents were both male and female in the same proportion and most were between 21-40 years old. Most were married and had a graduate degree. The average income of the respondents was between $20,000-40,000. The findings revealed that the majority of respondents came to Thailand for the first time and spent about 6-8 days in Thailand and preferred to travel in small groups with no children. The five service perceptions of employees in tourism by the international tourists in descending order according to mean were reliable employees, neat and clean employees, polite employees, timely employees, and competent employees.

Keywords: experience, international tourists, service quality, Thailand

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Authors: Rozh Abdulrahman Kareem

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The displacement of individuals has become a common interest for international players. Mostly occurs in Islamic states, as religion is considered the most common cause of this form of displacement. Therefore, this thesis aims to depict the reality of the situations of the refugees, particularly in KRI, illustrating how they are treated and protected and if the treatment merits the protection clause as envisaged in the 1951 Refugee Convention. Overall, the aim is to touch on the issue of protection by non-governmental organizations and government towards the refugees here. In light of this, it focused on the adequate protection of refugees in relation to the refugee law. In the Middle East, including Iraq, there have been multiple reports on violations of these refugee laws and human rights. Protection involves providing physical security to the concerned parties, functional administration with legal structures, and infrastructural setup that could help citizens exercise rights. The KRI has provided the refugees with various benefits, including education, access to residency, and employment. It also provided transitionary in various social dimensions like gender-based violence. The Convention on Status of Refugees 1951 tried to resolve this problem, whereby the principle of ‘nonrefoulement’ under Article 33 was passed. The ‘nonrefoulement’, an exceptional reference, was enacted to protect refugees from forcible return to their countries of the original. However, the convention never addressed an unusual scenario regarding the application of this principle, ‘Extradition Treaties.’ Even though some scholarly article exists regarding the problems of refugees, the topic of interplay between Nonrefoulement and Extradition Treaties has never been explained in detail in the available books on refugee laws and practices. Each year, millions of refugees seek protection from foreign countries for fear of being tortured, victimized, or executed. People seeking international protection are susceptible and insecure. The main objective of the prevention is to provide security to citizens susceptible to inhuman treatment, distress, oppression, or other human rights defilements when they arrive back in their own countries. The refugee situation may get worse in the near future. Just like several nations within the Middle East, Iraq is not a signatory to the globally acknowledged legal structure for the protection of refugees. The first law of 1971 in Iraq was issued only for military or political causes. This law also establishes benefits such as the right to education and health services and the right to acquire employment just as the Iraqi nationals. The other legislative instrument is the 21st law from the ministry of migration of Iraq widened the description of an immigrant to incorporate the definition from the refugee resolution. Nonetheless, there is a lack of overall consistency in the protection provided under these legislations regarding rights and entitlement. A Memorandum of Understanding was signed in October 2016 by the UNHCR and the Iraq government to develop the protection of refugees. Under the term of this MoU, the Iraqi Government is obligated to provide identity documents to asylum seekers beside that UNHCR provides more guidance.

Keywords: law, refugee, protection, Kurdistan

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Authors: Zafar Iqbal, Eugene Chan, Fareed Ahmed, Mohamed Jama, Avez Rizvi

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Advancements in Ultrasound Technology have enabled machines to capture 3D and 4D images with intricate features of the growing fetus. Sonographers can now capture clear 3D images and 4D videos of the fetus, especially of the face. Fetal faces are often seen on the ultrasound scan of the third trimester where anatomical features become more defined. Parents often want 3D/4D images and videos of their ultrasounds, and particularly image that capture the child’s face. Sidra Medicine developed a patient education mobile app called 10 Moons to improve care and provide useful information during the length of their pregnancy. In addition to general information, we built the ability to send ultrasound images directly from the modality to the mobile application, allowing expectant mothers to easily store and share images of their baby. 10 Moons represent the length of the pregnancy on a lunar calendar, which has both cultural and religious significance in the Middle East. During the third trimester scan, sonographers can capture 3D pictures of the fetus. Ultrasound machines are connected with a local 10 Moons Server with a Digital Imaging and Communications in Medicine (DICOM) application running on it. Sonographers are able to send images directly to the DICOM server by a preprogrammed button on the ultrasound modality. Mothers can also request which pictures they would like to be available on the app. An internally built DICOM application receives the image and saves the patient information from DICOM header (for verification purpose). The application also anonymizes the image by removing all the DICOM header information and subsequently converts it into a lossless JPEG. Finally, and the application passes the image to the mobile application server. On the 10 Moons mobile app – patients enter their Medical Record Number (MRN) and Date of Birth (DOB) to receive a One Time Password (OTP) for security reasons to view the images. Patients can also share the images anonymized images with friends and family. Furthermore, patients can also request 3D printed mementos of their child through 10 Moons. 10 Moons is unique patient education and information application where expected mothers can also see 3D ultrasound images of their children. Sidra Medicine staff has the added benefit of a full content management administrative backend where updates to content can be made. The app is available on secure infrastructure with both local and public interfaces. The application is also available in both English and Arabic languages to facilitate most of the patients in the region. Innovation is at the heart of modern healthcare management. With Innovation being one of Sidra Medicine’s core values, our 10 Moons application provides expectant mothers with unique educational content as well as the ability to store and share images of their child and purchase 3D printed mementos.

Keywords: patient educational mobile application, ultrasound images, digital imaging and communications in medicine (DICOM), imaging informatics

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Authors: Anita Vidacs, Robert Rajko, Csaba Vagvolgyi, Judit Krisch

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With the optimization of a new disinfectant the number of tests could be decreased and the cost of processing too. Good sanitizers are eco-friendly and allow no resistance evolvement of bacteria. The essential oils (EOs) are natural antimicrobials, and most of them have the Generally Recognized As Safe (GRAS) status. In our study, the effect of the EOs cinnamon, marjoram, and thyme was investigated against mixed species bacterial biofilms of Escherichia coli, Listeria monocytogenes, Pseudomonas putida, and Staphylococcus aureus. The optimal concentration of EOs, disinfection time and level of pH were evaluated with the aid of Response Surface Box-Behnken Design (RSD) on 1 day and 7 days old biofilms on metal, plastic, and wood surfaces. The variable factors were in the range of 1-3 times of minimum bactericide concentration (MBC); 10-110 minutes acting time and 4.5- 7.5 pH. The optimized EO disinfectant was compared to industrial used chemicals (HC-DPE, Hypo). The natural based disinfectants were applicable; the acting time was below 30 minutes. EOs were able to eliminate the biofilm from the used surfaces except from wood. The disinfection effect of the EO based natural solutions was in most cases equivalent or better compared to chemical sanitizers used in food industry.

Keywords: biofilm, Box-Behnken design, disinfectant, essential oil

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Authors: Mohammad Jamil Abd AlGhani

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The natural native antioxidants N,N-P-methyl phenyl acetone and N,N-phenyl acetone were isolated from the Iraqi crude oil region of Kirkuk by ion exchange and their structure was characterized by spectral and chemical analysis methods. Tetraline was used as a liquid hydrocarbon to detect the efficiency of isolated molecules at elevated temperature (393 K) that it has physicochemical specifications and structure closed to hydrocarbons fractionated from crude oil. The synthesized universal antioxidant 2,6-ditertiaryisobutyl-p-methyl phenol (Unol) with known stochiometric coefficient of inhibition equal to (2) was used as a model for comparative evaluation at the same conditions. Modified chemiluminescence method was used to find the amount of absorbed oxygen and the induction periods in and without the existence of isolated antioxidants molecules. The results of induction periods and quantity of absorbed oxygen during the oxidation process were measured by manometric installation. It was seen that at specific equal concentrations of N,N-phenyl acetone and N, N-P-methyl phenyl acetone in comparison with Unol at 393 K were with (2) and (2.5) times efficient than do Unol. It means that they had the ability to inhibit the formation of new free radicals and prevent the chain reaction to pass from the propagation to the termination step rather than decomposition of formed hydroperoxides.

Keywords: antioxidants, chemiluminescence, inhibition, Unol

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Authors: Marium Shaikh, Tahira M. Ali, Abid Hasnain

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Physical and sensory properties of white sauces prepared from native and chemically modified corn and pearl millet starches were compared. Interestingly, no syneresis was observed in hydroxypropylated corn and pearl millet starch containing white sauce even after nine days of cold storage (4 °C), while other modifications also reduced the syneresis significantly in comparison to their native counterparts. White sauce containing succinylated corn starch showed least oil separation due to its greater emulsion stability. Light microscopy was used to visualize the size and shape of fat globules, and it was found that they were most homogenously distributed in succinylated and hydroxypropylated samples. Sensory results revealed that chemical modification of corn and pearl millet starch improved the consistency, thickness and overall acceptability of white sauces. Viscosity profiles showed that pasting parameters of native pearl millet starch are almost similar to native corn starch suggesting pearl millet starch as an alternative of corn starch. Also, white sauce prepared from modified pearl millet starch showed better cold storage stability in terms of various textural attributes like hardness, cohesiveness, chewiness, and springiness.

Keywords: corn starch, pearl millet, hydroxypropylation, succinylation, white sauce

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Authors: Dilay Akgun Giray

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Basic insuffiency spaces of ASD diagnosed individuals can be grouped as cognitive and academic characteristics, communicational characteristics, social characteristics and emotional characteristics. Referring to the features that children with ASD exhibit on social events, it is clear they have limitations for several social skills. One of the evidence based practices which has been developed and used for the limitations of definite social skills for individuals with autism is “Social Story Method”. Social stories was designed and applied for the first time in 1991, a special education teacher, in order to acquire social skills and improve the existing social skills for children with ASD. Many studies have revealed the effectiveness of social stories for teaching the social skills to individuals with ASD. In this study, three social skills that the child ,who was diagnosed ASD, is going to need primarily will be studied with smart board. This study is multiple probe across-behavior design which is one of the single subject research models.

Keywords: authism spectrum disorders, social skills, social story, smart board

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Authors: Narges Solaymani

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Definition of Nurse: Nurse: A person who is educated and skilled in the field of scientific principles and professional skills of health care, treatment, and medical training of patients. Nursing is a very important profession in the societies of the world. Although in the past, all caregivers of the sick and disabled were called nurses, nowadays, a nurse is a person who has a university education in this field. There are nurses in bachelor's, master's, and doctoral degrees in nursing. New courses have been launched in the master's degree based on duty-oriented nurses. A nurse cannot have an independent treatment center but is a member of the treatment team in established treatment centers such as hospitals, clinics, or offices. Nurses can establish counseling centers and provide nursing services at home. According to the standards, the number of nurses should be three times the number of doctors or twice the number of hospital beds, or there should be three nurses for every thousand people. Also, international standards show that in the internal and surgical department, every 4 to 6 patients should have a nurse.

Keywords: nurse, intensive care, CPR, bandage

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Authors: Juliana Guimarães Faria

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The article focus on social networks and deaf people. It aims to analyze the studies done about this topic published in journals, as well as the ones done through dissertations and theses. It also aims to identify the thematic focus of the studies produced and to identify how the deaf relates to social networks, more specifically, trying to identify, starting with those productions, what are the benefits, or not, of social networks for the deaf and if there is some reflection about the way the deaf community has been organizing politically in search of bilingual education and inclusion, making use of the softwares of social networks. After reading, description and analysis of the eleven works identified about social networks and the deaf, we detected three thematic groups: four studies presented discussions about social networks and the socialization of the deaf; four works presented discussions about the contribution of social networks to the linguistic and cognitive development of the deaf; and three works presented discussions about the political bias of the use of social networks in favor of the deaf. We also identified that the works presented an optimistic view of social networks.

Keywords: social networks, deaf, internet, Brazil

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Authors: Yasar N. Kavil, Yasser A. Shaban, Radwan K. Al Farawati, Mohamed I. Orif, Shahed U. M. Khanc

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Photocatalytic way of reduction of CO₂ in polluted seawater into chemical fuel, methanol, was successfully gained over Cu/C-co-doped TiO₂ nanoparticles under UV and natural sunlight. A homemade stirred batch annular reactor was used to carry out the photocatalytic reduction experiments. Photocatalysts with various Cu loadings (0, 0.5, 1, 3, 5 and 7 wt.%) were synthesized by the sol-gel procedure and were characterized by XRD, SEM, UV–Vis, FTIR, and XPS. The photocatalytic production of methanol was promoted by the co-doping with C and Cu into TiO₂. This improvement was attributed to the modification of bandgap energy and the hindrance of the charges recombination. The polluted seawater showing the yield depended on its background hydrographic parameters. We assessed two types of polluted seawater system, the observed yield was 2910 and 990 µmol g⁻¹ after 5 h of illumination under UV and natural sunlight respectively in system 1 and the corresponding yield in system 2 was 2250 and 910 µmol g⁻¹ after 5 h of illumination. The production of methanol in the case of oxygen-depleted water was low, this is mainly attributed to the competition of methanogenic bacteria over methanol production. The results indicated that the methanol yield produced by Cu-C/TiO₂ was much higher than those of carbon-modified titanium oxide (C/TiO₂) and Degussa (P25-TiO₂). Under the current experimental condition, the optimum loading was achieved by the doping of 3 wt % of Cu. The highest methanol yield was obtained over 1 g L-1 of 3wt% Cu/C-TiO₂.

Keywords: CO₂ photoreduction, copper, Cu/C-co-doped TiO₂, methanol, seawater

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Authors: Won-Seok Kim, Hyung-Ik Shin

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Self-rated health (SRH) is a subjective assessment of individual health and has been identified as a strong predictor for mortality and morbidity. However few studies have been directed to the factors associated with SRH in persons with disabilities (PWD). We used data of 7th Korean national survey for 5307 PWD in 2008. Multiple logistic regression analysis was performed to find out independent risk factors for poor SRH in PWD. As a result, indicators of physical condition (poor instrumental ADL), socioeconomic disadvantages (poor education, economically inactive, low self-rated social class, medicaid in health insurance, presence of unmet need for hospital use) and social participation and networks (no use of internet service) were selected as independent risk factors for poor SRH in final model. Findings in the present study would be helpful in making a program to promote the health and narrow the gap of health status between the PWD.

Keywords: disabilities, risk factors, self-rated health, socioeconomic disadvantages, social networks

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Authors: Autjira Songjan, Poramatdha Chutimant

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This research is intended to study the operational quality assurance of private schools in Bangkok according to the opinions of administrators and teachers. Second is comparing the opinions of administrators and teachers about operating quality assurance process by gender, job and work experience. The sample include administrators and teachers of private schools in the Education School in Bangkok by using a proportion random technic. The questionnaire are used as query operations quality assurance to collect the data of private schools, the statistics that are used to analyze the data using the percentage, mean, standard deviation and Test the difference value and test of variance. The research found that the administrators and teachers have different sex, positions and duties have the different opinions about quality assurance in different statistically insignificant level 0.05 in the elements of performance management and the quality of the service that provided to students in the school.

Keywords: educational quality assurance, performance management, private schools in Bangkok, quality of the service

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Authors: Fawad Ali, Muhammad Ateeq, Ikhtiar Khan

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Ground water, a major source of drinking water supply in Peshawar has been severely contaminated by leather tanning industry. Effluents from the tanneries contain high concentration of chromium besides several other chemical species. Release of untreated effluents from the tanning industry has severely damaged surface and ground water, agriculture soil as well as vegetables and crops. Chromium is a well-known carcinogenic and mutagenic agent. Once in the human food chain, it causes multiple problems to the exposed population including various types of cancer, skin dermatitis, and DNA damage. In order to assess the extent of chromium and other heavy metals contamination, water samples were analyzed for heavy metals using Graphite Furnace Atomic Absorption Spectrometer (GFAAS, Analyst 700, Perkin Elmer). Total concentration of chromium was above the permissible limit (0.048 mg/l) in 85% of the groundwater (drinking water) samples. The concentration of cobalt, manganese, cadmium, nickel, lead, zinc and iron was also determined in the ground water, surface water, agriculture soil, and vegetables samples from the affected area.

Keywords: heavy metals, soil, groundwater, tannery effluents, food chain

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Authors: Karwan Khudhir

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A cross-sectional study was carried out to determine the prevalence of musculoskeletal disorders (MSDs) and psychosocial factors associated with it, among Kurdistan nursing professionals. Simple random sampling was used to select 220 nurses and data were collected by self-administrative questionnaire. Results of the study showed that the overall prevalence of MSDs among Kurdistan nurses was 74% in different body regions and, by body regions, neck pain was reported to be the highest complaint of twelve-month MSDs (48.4%) compared to other body parts. Logistic regression analysis indicated 6 variables that are significantly associated with musculoskeletal disorders: smoking (OR=19.472, 95% CI: 5.396, 70.273), BMI (OR= 5.106, 95% CI: 1.735, 15.025), physical activity (OR=8.639, 95% CI: 3.075, 24.271), psychological demand (OR=6.685, 95% CI: 3.318, 13.468), social support (OR=3.143, 95% CI: 1.202, 4.814) and job satisfaction (OR=2.44, 95% CI: 1.04, 5.63). Prevention strategies and health education which emphasizes on psychosocial risk factors and how to improve working conditions should be introduced.

Keywords: Kurdistan Region, Iraq, musculoskeletal disorders, nurses, psycho-social factors

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Authors: Mikel W. Cole, Stephanie M. Madison, Adam Henze

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Since 2004, the U.S. immigrant detention system has imprisoned more than five million people. President John F. Kennedy famously dubbed this country a “Nation of Immigrants.” Like many of the nation’s imagined ideals, the historical record finds its practices have never lived up to the tenets championed as defining qualities.The United Nations High Commission on Refugees argues the educational needs of people in carceral spaces, especially those in immigrant detention centers, are urgent and supported by human rights guarantees. However, there is a genuine dearth of literacy research in immigrant detention centers, compounded by a general lack of access to these spaces. Denying access to literacy education in detention centers is one way the history of xenophobic immigration policy persists. In this conceptual exploration, first-hand accounts from detained individuals, their families, and the organizations that work with them have been shared with the authors. In this paper, the authors draw on experiences, reflections, and observations from serving as volunteers to develop a conceptual framework for the ways in which literacy practices are enacted in detention centers. Literacy is an essential tool for accessing those detained in immigrant detention centers and a critical tool for those being detained to access legal and other services. One of the most striking things about the detention center is how to behave; gaining access for a visit is neither intuitive nor straightforward. The men experiencing detention are also at a disadvantage. The lack of access to their own documents is a profound barrier to men navigating the complex immigration process. Literacy is much more than a skill for gathering knowledge or accessing carceral spaces; literacy is fundamentally a source of personal empowerment. Frequently men find a way to reclaim their sense of dignity through work on their own terms by exchanging their literacy services for products or credits at the commissary. They write cards and letters for fellow detainees, read mail, and manage the exchange of information between the men and their families. In return, the men who have jobs trade items from the commissary or transfer money to the accounts of the men doing the reading, writing, and drawing. Literacy serves as a form of resistance by providing an outlet for productive work. At its core, literacy is the exchange of ideas between an author and a reader and is a primary source of human connection for individuals in carceral spaces. Father’s Day and Christmas are particularly difficult at detention centers. Men weep when speaking about their children and the overwhelming hopelessness they feel by being separated from them. Yet card-writing campaigns have provided these men with words of encouragement as thousands of hand-written cards make their way to the detention center. There are undoubtedly more literacies being practiced in the immigrant detention center where we work and at other detention centers across the country, and these categories are early conceptions with which we are still wrestling.

Keywords: detention centers, education, immigration, literacy

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Authors: Ching-Sung Lee, Wei-Chou Hsu, Han-Yin Liu, Hung-Hsi Huang, Si-Fu Chen, Yun-Jung Yang, Bo-Chun Chiang, Yu-Chuang Chen, Shen-Tin Yang

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AlGaN/GaN high electron mobility transistors (HEMTs) have been intensively studied due to their intrinsic advantages of high breakdown electric field, high electron saturation velocity, and excellent chemical stability. They are also suitable for ultra-violet (UV) photodetection due to the corresponding wavelengths of GaN bandgap. To improve the optical responsivity by decreasing the dark current due to gate leakage problems and limited Schottky barrier heights in GaN-based HEMT devices, various metal-oxide-semiconductor HEMTs (MOS-HEMTs) have been devised by using atomic layer deposition (ALD), molecular beam epitaxy (MBE), metal-organic chemical vapor deposition (MOCVD), liquid phase deposition (LPD), and RF sputtering. The gate dielectrics include MgO, HfO2, Al2O3, La2O3, and TiO2. In order to provide complementary circuit operation, enhancement-mode (E-mode) devices have been lately studied using techniques of fluorine treatment, p-type capper, piezoneutralization layer, and MOS-gate structure. This work reports an Al2O3-dielectric Al0.25Ga0.75N/GaN E-mode MOS-HEMT design by using a cost-effective ozone water oxidization technique. The present ozone oxidization method advantages of low cost processing facility, processing simplicity, compatibility to device fabrication, and room-temperature operation under atmospheric pressure. It can further reduce the gate-to-channel distance and improve the transocnductance (gm) gain for a specific oxide thickness, since the formation of the Al2O3 will consume part of the AlGaN barrier at the same time. The epitaxial structure of the studied devices was grown by using the MOCVD technique. On a Si substrate, the layer structures include a 3.9 m C-doped GaN buffer, a 300 nm GaN channel layer, and a 5 nm Al0.25Ga0.75N barrier layer. Mesa etching was performed to provide electrical isolation by using an inductively coupled-plasma reactive ion etcher (ICP-RIE). Ti/Al/Au were thermally evaporated and annealed to form the source and drain ohmic contacts. The device was immersed into the H2O2 solution pumped with ozone gas generated by using an OW-K2 ozone generator. Ni/Au were deposited as the gate electrode to complete device fabrication of MOS-HEMT. The formed Al2O3 oxide thickness 7 nm and the remained AlGaN barrier thickness is 2 nm. A reference HEMT device has also been fabricated in comparison on the same epitaxial structure. The gate dimensions are 1.2 × 100 µm 2 with a source-to-drain spacing of 5 μm for both devices. The dielectric constant (k) of Al2O3 was characterized to be 9.2 by using C-V measurement. Reduced interface state density after oxidization has been verified by the low-frequency noise spectra, Hooge coefficients, and pulse I-V measurement. Improved device characteristics at temperatures of 300 K-450 K have been achieved for the present MOS-HEMT design. Consequently, Al2O3-dielectric Al0.25Ga0.75N/GaN E-mode MOS-HEMTs by using the ozone water oxidization method are reported. In comparison with a conventional Schottky-gate HEMT, the MOS-HEMT design has demonstrated excellent enhancements of 138% (176%) in gm, max, 118% (139%) in IDS, max, 53% (62%) in BVGD, 3 (2)-order reduction in IG leakage at VGD = -60 V at 300 (450) K. This work is promising for millimeter-wave integrated circuit (MMIC) and three-terminal active UV photodetector applications.

Keywords: MOS-HEMT, enhancement mode, AlGaN/GaN, passivation, ozone water oxidation, gate leakage

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Authors: N. Boukabcha, Y. Megrouss, N. Benhalima, S. Yahiaoui, A. Chouaih, F. Hamzaoui

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We present the electron density analysis of organic compound 4-methyl-N-[(5- nitrothiophen-2-ylmethylidene)] aniline with chemical formula C12H10N2O2S. Indeed, determining the electrostatic properties of nonlinear optical organic compounds requires knowledge of the distribution of the electron density with high precision. On the other hand, a structural analysis is performed. Two methods are used to obtain the structure, X-ray diffraction and theoretical calculation with density functional theory (DFT). The electron density study is performed using the Mopro program1503 based on the multipolar model of Hansen and Coppens. Electron density analysis allows determination of the value and orientation of the dipole moment. The net atomic charges, electrostatic potential and the molecular dipole moment have been determined in order to understand the nature of inter- and intramolecular charge transfer. The study reveals the nature of intermolecular interactions including charge transfer and hydrogen bonds in the title compound. Crystallographic data: monoclinic system - space group P21 / n. Celle parameters: a = 4.7606 (4) Å, b = 22.415 (2) Å, c = 10.7008 (15) Å, β = 92.566 (13) 0, V = 1140.7 (2) Å3, Z = 4, R = 0.0034 for 2693 observed reflections.

Keywords: electron density, dipole moment, electrostatic potential, DFT, Mopro

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Authors: Kanmanas Muensak, Somphoom Saweangkun

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The objectives of this research were to study the consumer behavior that affects the customer loyalty of CP Fresh Mart in Bangkok province. The sample of the study comprised 400 consumers over 15 years old who made the purchase through CP Fresh Mart in Bangkok. The questionnaires were used as the data gathering instrument, and the data were analyzed applying Percentage, Mean, Standard Deviation, Independent Sample t-test, Two- Way ANOVA, and Least Significant Difference, and Pearson’s Correlation Coefficient also. The result of hypothesis testing showed that the respondents of different gender, age, level of education, income, marital status and occupation had differences in consumer behavior through customer loyalty of CP Fresh Mart and the factors on customer loyalty in the aspects of re-purchase, word of mouth and price sensitive, promotion, process, and personnel had positive relationship with the consumer behavior through of CP Fresh Mart in Bangkok as well as.

Keywords: consumers in Bangkok, consumer behavior, customer loyalty, CP Fresh Mart, operating budget

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Authors: M. S. Mrudula, M. R. Gopinathan Nair

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In order to utilize the natural rubber for developing new green polymeric materials for specialty applications, we have prepared natural rubber and polyethylene oxide based polymeric networks by two shot method. The polymeric networks thus formed have been used as chelating exchanger for metal ion binding. Chelating exchangers are, in general, coordinating copolymers containing one or more electron donor atoms such as N, S, O, and P that can form coordinate bonds with metals. Hydrogels are water- swollen network of hydrophilic homopolymer or copolymers. They acquire a great interest due to the facility of the incorporation of different chelating groups into the polymeric networks. Such polymeric hydrogels are promising materials in the field of hydrometallurgical applications and water purification due to their chemical stability. The current study discusses the swelling response of the polymeric networks as a function of time, temperature, pH and [NaCl] and sorption studies. Equilibrium swelling has been observed to depend on both structural aspects of the polymers and environmental factors. Metal ion sorption shows that these polymeric networks can be used for removal, separation, and enrichment of metal ions from aqueous solutions and can play an important role for environmental remediation of municipal and industrial wastewater.

Keywords: block copolymer, adsorption, chelating exchanger, swelling study, polymer, metal complexes

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Authors: Imam Wierawansyah Eltara, Iftitah, Agus Ismail

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In the present work, cellulose nanowhiskers (CNW) extracted from coconut husk fibers, were incorporated in polylactide (PLA)-based composites. Prior to the blending, PLA chains were chemically grafted on the surface of CNW to enhance the compatibilization between CNW and the hydrophobic polyester matrix. Ring-opening polymerization of L-lactide was initiated from the hydroxyl groups available at the CNW surface to yield CNW-g-PLA nanohybrids. PLA-based nanocomposites were prepared by melt blending to ensure a green concept of the study thereby limiting the use of organic solvents. The influence of PLA-grafted cellulose nanoparticles on the mechanical and thermal properties of the ensuing nanocomposites was deeply investigated. The thermal behavior and mechanical properties of the nanocomposites were determined using differential scanning calorimetry (DSC) and dynamical mechanical and thermal analysis (DMTA), respectively. In theory, evidenced that the chemical grafting of CNW enhances their compatibility with the polymeric matrix and thus improves the final properties of the nanocomposites. Large modification of the crystalline properties such as the crystallization half-time was evidenced according to the nature of the PLA matrix and the content of nanofillers.

Keywords: cellulose nanowhiskers, nanocomposites, coconut husk fiber, ring opening polymerization

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Authors: Hesham Shaalan

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Senior design projects teach students many important skills. One of the major goals is to prepare students to apply effective problem-solving techniques to a problem that represents a real-world situation. This includes the ability to define the problem, compare alternative solutions, identify the best solution, and design the system. This paper describes the design of a shipboard power plant as a senior project in the Marine Engineering program at the U.S. Merchant Marine Academy. The design project was supervised by faculty members who guided a multidisciplinary group of seniors. The research project was sponsored by the Office of Naval Research. Each group of seniors focused on one of the main design aspects of the project, including the electric power system, nuclear power plant, ship hull design, and economics.

Keywords: senior design project, shipboard power system, engineering education, marine engineering

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Authors: Raziyeh Teimouri, Sadasivam Karuppannan, Alpana Sivam, Ning Gu

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Urban Green Space (UGS) is one of the most critical components of urban systems to create sustainable cities. UGS has valuable social benefits that closely correlate with people's life quality. Studying social sustainability factors that can be achieved by green spaces is required for optimal UGS planning to increase urban social sustainability. This paper aims to identify key factors that enhance urban social sustainability through UGS planning. To reach the goal of the study international experts’ survey has been conducted. According to the results of the survey analysis, factors of proper distribution, links to public transportation, walkable access, sense of place, social interactions, public education, safety and security, walkability and cyclability, physical activity and recreational facilities, suitability for all ages, disabled people, women, and children are among the key factors that should consider in UGS planning programs to promote urban social sustainability.

Keywords: UGS, planning, social sustainability, key factors

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Authors: Seyed Hassan Moosa-kazemi, Hassan Vatandoost

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Malaria, Dirofilaria immitis (dog heart worm), and D. repens (dirofilariasis), which are transmitted by mosquitoes, have been reported in Iran. The Iranian mosquito fauna includes seven genera, 65 species, and three subspecies. Aedes albopictus has been reported since. West Nile, Sindbis, Dengue, Japanese encephalitis viruses, and the nematode Setaria (setariasis) has been reported in the country but there are no information about their vectors in Iran. Iran is malaria elimination phase. Insecticides residual spraying (IRS), distributed of insecticides long lasting treated nets (ITNs), fogging, release of larvivours fishes and Bacillus thuringiensis, chemical larviciding, as well as case finding and manipulation and modification of breeding places carried out thought the IVM program in the country. Prolonged exposure to insecticides over several generations of the vectors, develop resistance, a capacity to survive contact with insecticides. However, use of insecticides in agriculture has often been implicated as contributing to resistance in mosquito’s vectors. Resistance of mosquitoes to some insecticides has been documented just within a few years after the insecticides were introduced. Some enzymes such as monooxygenases, esterases and glutathione S-transferases have been considered as a reason for resistance to pyrethroid insecticides. In conclusion, regarding to documented resistance and tolerance of mosquitoes vectors to some insecticides, resistance management is suggested by using new insecticide with novel mode of action.

Keywords: control, Iran, resistance, vector

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Authors: Shehryar Afzal

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Gender is one of the organizing principles of the society. Gender relations are based on the ideology of sexual division of labors. Consequently, women tend to have a lower level of education, vocational and professional skills then men in a conservative area. In Swabi women, overall take part in their daily work, either it is home management. I-e cooking, sewing. Their Economic roles are selling daily used commodities I-e poultry, embroidery Selling, etc. Their Social roles are participation in traditional ceremonies’ like Death, marriages, etc. The aim is to introduce the Society a new range of communal and recreational spaces acting as a community center for women and children, while developing plans for the community women and children, Providing recreational and communal activities for which the community strive and urge, having a sense of freedom and openness. Already interacting spaces are present where they have a social and communal gathering, but there is no such facilities to celebrate these activities.

Keywords: social sitting, communal spaces, tradition, freedom

Procedia PDF Downloads 217

Authors: Camille Perréard, Yoann Ladner, Fanny D'Orlyé, Stéphanie Descroix, Vélan Taniga, Anne Varenne, Cédric Guyon, Michael. Tatoulian, Frédéric Kanoufi, Cyrine Slim, Sophie Griveau, Fethi Bedioui

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The development of micro total analysis systems is of major interest for contaminant and biomarker analysis. As a lab-on-chip integrates all steps of an analysis procedure in a single device, analysis can be performed in an automated format with reduced time and cost, while maintaining performances comparable to those of conventional chromatographic systems. Moreover, these miniaturized systems are either compatible with field work or glovebox manipulations. This work is aimed at developing an analytical microsystem for trace and ultra trace quantitation in complex matrices. The strategy consists in the integration of a sample pretreatment step within the lab-on-chip by a confinement zone where selective ligands are immobilized for target extraction and preconcentration. Aptamers were chosen as selective ligands, because of their high affinity for all types of targets (from small ions to viruses and cells) and their ease of synthesis and functionalization. This integrated target extraction and concentration step will be followed in the microdevice by an electrokinetic separation step and an on-line detection. Polymers consisting of cyclic olefin copolymer (COC) or fluoropolymer (Dyneon THV) were selected as they are easy to mold, transparent in UV-visible and have high resistance towards solvents and extreme pH conditions. However, because of their low chemical reactivity, surface treatments are necessary. For the design of this miniaturized diagnostics, we aimed at modifying the microfluidic system at two scales : (1) on the entire surface of the microsystem to control the surface hydrophobicity (so as to avoid any sample wall adsorption) and the fluid flows during electrokinetic separation, or (2) locally so as to immobilize selective ligands (aptamers) on restricted areas for target extraction and preconcentration. We developed different novel strategies for the surface functionalization of COC and Dyneon, based on plasma, chemical and /or electrochemical approaches. In a first approach, a plasma-induced immobilization of brominated derivatives was performed on the entire surface. Further substitution of the bromine by an azide functional group led to covalent immobilization of ligands through “click” chemistry reaction between azides and terminal alkynes. COC and Dyneon materials were characterized at each step of the surface functionalization procedure by various complementary techniques to evaluate the quality and homogeneity of the functionalization (contact angle, XPS, ATR). With the objective of local (micrometric scale) aptamer immobilization, we developed an original electrochemical strategy on engraved Dyneon THV microchannel. Through local electrochemical carbonization followed by adsorption of azide-bearing diazonium moieties and covalent linkage of alkyne-bearing aptamers through click chemistry reaction, typical dimensions of immobilization zones reached the 50 µm range. Other functionalization strategies, such as sol-gel encapsulation of aptamers, are currently investigated and may also be suitable for the development of the analytical microdevice. The development of these functionalization strategies is the first crucial step in the design of the entire microdevice. These strategies allow the grafting of a large number of molecules for the development of new analytical tools in various domains like environment or healthcare.

Keywords: alkyne-azide click chemistry (CuAAC), electrochemical modification, microsystem, plasma bromination, surface functionalization, thermoplastic polymers

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Authors: Charles Owenda Omulo

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This study examines Occupational Health and Safety implications in flower farms in Central Uganda. An exploratory sequential mixed method design and methodology was employed, with multiple data collection methods, including interviews, focus group discussions, and surveys. The findings show that occupational health and safety issues remain a major problem in flower farms. While the majority of workers agreed that the farms provided them with protective equipment, the data collected from the workers point to either the improper use or ineffectiveness of this equipment. A number of workers reported skin irritations, sore and painful eyes, stiff necks, back pains, and occasional headaches that were presumably argued to have arisen from their work environment. The study also found that farms have been adjusting in an attempt to correct some of these anomalies. These included the use of biological approaches to control pests and diseases and restricting the use of some chemical formulations that are deemed to be harmful to applicators and the environment. Alongside these efforts, the study recommends increased vigilance by the flower farm owners in the provision of personal protective equipment to workers.

Keywords: flower farms, personal protective equipment, agrochemicals, rural communities, occupational health and safety

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Authors: M. S. Tajul Islam, Md. Zahangir Alam

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To enhance biogas production through anaerobic digestion, the application of various type of pre-treatment method has some limitations in terms of sustainable environmental management. Many studies on pretreatments especially chemical and physical processes are carried out to evaluate the anaerobic digestion for enhanced biogas production. Among the pretreatment methods acid and alkali pre-treatments gained the highest importance. Previous studies have showed that although acid and alkali pretreatment has significant effect on degradation of biomass, these methods have some negative impact on environment due to their hazard in nature while enzymatic pre-treatment is environmentally friendly. One of the constrains to use of enzyme in pretreatment process for biogas production is high cost which is currently focused to reduce cost through fermentation of waste-based media. As such palm oil mill effluent (POME) as an abundant resource generated during palm oil processing at mill is being used a potential fermentation media for enzyme production. This low cost of enzyme could be an alternative to biogas pretreatment process. This review is to focus direct application of enzyme as enzymatic pre-treatment on POME to enhanced production of biogas.

Keywords: POME, enzymatic pre-treatment, biogas, lignocellulosic biomass, anaerobic digestion

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Authors: I. M. Sujaul, M. A. Sobahan, A. A. Edriyana, F. M. Yahaya, R. M. Yunus

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This study was carried out to investigate the adverse effect of industrial waste water on surface water quality in Gebeng industrial estate, Pahang, Malaysia. Surface water was collected from 6 sampling stations. Physico-chemical parameters were characterized based on in-situ and ex-situ analysis according to standard methods by American Public Health Association (APHA). Selected heavy metals were determined by using Inductively Coupled Plasma Mass Spectrometry (ICP MS). The result reveled that the concentration of heavy metals such as Pb, Cu, Cd, Cr and Hg were high in samples. The result showed that the value of Pb and Hg were higher in the wet season in comparison to dry season. According to Malaysia National Water Quality Standard (NWQS) and Water Quality Index (WQI) all the sampling station were categorized as class IV (highly polluted). The present study reveled that the adverse effects of careless disposal of wastes and directly discharge of effluents affected on surface water quality. Therefore, the authorities should implement the laws to ensure the proper practices of waste water management for environmental sustainability around the study area.

Keywords: water, heavy metals, water quality index, Gebeng

Procedia PDF Downloads 362