Colloidal behavior of aqueous montmorillonite suspensions in the presence of non-ionic polymer

In this paper we characterized at first, the rheological behavior of the bentonite suspensions and the aqueous solutions of polyethylene oxide (PEO), then we were investigated the influence of this polymer in a water-based drilling fluid model (6% of bentonite suspension). The objective is to exhibit how the non ionic polymer with molecular weight 6×103 g/mol. of varying concentration mass (0.7%, 1%, 2% et 3%) significantly alter the rheological properties (yield stress, viscosity, loss and elastic modulus) of the bentonite suspensions. The rheological measurements made in simple shear and in dynamic on the mixture (water-bentonite-PEO), showed rheological properties of bentonite suspensions both in the presence and absence of non-ionic polymer. The PEO presents an affinity for the bentonite particles slowing down their kinetic aggregation. The analysis by X-rays diffraction also allowed understanding the structure of this mixture. It had revealed the intercalation between of the clay platelets on one hand, and the links bridges assured by the chains of polymer between bentonite particles beyond a critical concentration in PEO on the other hand. The Herschel- Bulkley rheological model is used for the correlation of our experimental result

NUMERICAL EXPERIMENT ON EFFECT OF SURFACE ROUGHNESS FOR HEAT AND FLOW AROUND TWO CONTACTING PARTICLES

The aim of the present work is to establish a model of heat transfer between particles by using the numerical simulation that can be incorporated in the discrete element method (DEM). The contact heat transfer between particles can be regarded as a contact thermal resistance problem. In the thermal resistance model, the local characteristics, e.g. exact contact area and heat flux distribution on particle surface, are important. However, it is difficult to measure such factors in detail. Accordingly, the authors utilized a numerical simulation. The thermal resistance was modeled by placing a small solid block between the contacting areas in the simulation. The small solid thickness represents the surface roughness and the width represents the contact force. The simulated temperature profile along the center line through two particle’s centers well agreed with measured one

Knowledge of Risk Factors, Symptoms and Barriers to Seeking Medical Help for Cervical Cancer among Omani Women Attending Sultan Qaboos University Hospital

Objectives: This study aimed to assess knowledge and attitudes among Omani woman regarding cervical cancer risk factors and symptoms as well as barriers to them seeking medical help. Methods: This cross-sectional study was conducted between December 2017 and March 2018 at the Sultan Qaboos University Hospital (SQUH) in Muscat, Oman. A validated Arabic-language version of the Cervical Cancer Awareness Measure questionnaire was used to collect data from 550 Omani women visiting SQUH during the study period. Results: A total of 490 women participated (response rate: 89.1%) in this study. Overall, the women demonstrated low levels of knowledge of cervical cancer risk factors and symptoms (28.5% and 45.0%, respectively). The most frequently recognised risk factor was having many children (36.1%), while the most recognised symptom was unexplained vaginal bleeding (69.8%). Women reported that being too scared was the greatest barrier to seeking medical help (68.0%). Various factors were significantly associated with greater knowledge of cervical cancer signs and symptoms including education level (odds ratio [OR] = 2.85; 95% confidence interval [CI]: 1.0–8.22; P <0.05), income (OR = 4.34; 95% CI: 1.70–11.12; P <0.05), parity (OR = 3.59; 95% CI: 1.38–9.36; P <0.05) and a family history of cancer (OR = 1.71; CI: 1.0–2.90; P <0.05). Conclusion: Overall, Omani women demonstrated poor knowledge with regards to cervical cancer; in addition, they identified several emotional barriers to seeking medical help. Healthcare practitioners should reassure female patients to encourage care-seeking behaviour. A national screening programme is also recommended to increase awareness and early diagnosis of cervical cancer in Oman.Keywords: Cervical Cancer; Knowledge; Awareness; Risk Factors; Health Care Seeking Behavior; Women; Oman

EFEKTIVITAS PEMBELAJARAN PENDIDIKAN AGAMA ISLAM MELALUI DARING DI SEKOLAH MENENGAH PERTAMA NEGERI 9 KECAMATAN MARO SEBO ULU KABUPATEN BATANGHARI

Skripsi ini membahas tentang efektivitas pembelajaran Pendidikan Agama Islam melalui Daring di SMP Negeri 9 Batanghari. Penelitian ini berbentuk deskriptif kualitatif yang dilihat melalui sudut pandang pendidikan, sedangkan pengumpulan data dilakukan dengan wawancara, observasi dan dokumentasi. Penelitian ini menemukan bahwa pembelajaran Pendidikan Agama Islam melalui daring di SMP Negeri 9 Batanghari diakukan dengan menyiapkan perangkat mengajar daring sesuai keadaan siswa dan guru dan kurikulum 2013, melaksanakan pembelajaran daring melalui peragkat classroom dan whatsapp group dan sms, dengan memberika tugas-tugas harian dan mingguan. Pada tahap evaluasi dari setiap hari dalam bentuk tugas-tugas yang dikirimkan secara berkala melalui whatsapp group untuk memantu kemajuan belajar siswa, lalu siswa mengumpulkan tugas secara daring pula.. Kendala pembelajaran Pendidikan Agama Islam melalui daring di SMP Negeri 9 Batanghari dimana guru dan tidak bisa menggunakan metode melalui classroom dan whatsapp group setiap saat signal dan kemampuan finansial orang tua dalam menyediakan perangkat daringnya. Efektivitas pembelajaran Pendidikan Agama Islam melalui daring di SMP Negeri 9 Batanghari belum tercapai kemampuan guru dan siswa tentang melalui classroom dan whatsapp group tidak sama dan sejumlah aspek lain yang tidak mendukung seperti sinyal dan jelek dan kedisiplinan siswa yang tidak sama setiap waktu saat mengikuti pembelajaran daring

Clinical Spectrum of Hereditary Spastic Paraplegia in Children : A study of 74 cases

Objectives: The aim of the study was to explore the spectrum of hereditary spastic paraplegia (HSP) in children in Oman. Methods: This retrospective study was carried out between January 1994 and August 2011 on children with delayed development, gait disorders and motor handicaps, with signs of symmetrical pyramidal tract involvement. A detailed perinatal and family history, including the age of onset of symptoms, was recorded. The children were labelled as having either the pure or complicated form of HSP based on the established diagnostic criteria. In families with more than one affected child, parents and all other siblings were also examined. Results: Within the study, 74 children from 31 families were diagnosed with HSP. Parental consanguinity was seen in 91% of cases, with 44 children (59.4%) experiencing onset of the disease under one year of age. Complicated HSP was the most common type, seen in 81.1%. Speech involvement, mental retardation, and epilepsy were the most common associated abnormalities. Nonspecific white matter changes and corpus callosum abnormalities were noted in 24.3% of cases on magnetic resonance imaging. Conclusion: The study described clinical features of 74 children with HSP. Autosomal recessive complicated HSP was seen in 81.1% of cases.

Simulation Of Cascading LNA And RF Amplifier For Front-End Direct-Conversion Receiver At 5.8 GHz

In this paper, a simulation of cascaded LNA and RF amplifier for front-end direct conversion receiver at 5.8-GHz frequency band is presented. By using direct conversion architecture, the image rejection performance is improved, lower complexity and the component is reduced. The cascading LNA and RF amplifier has 27 dB gain and 2.17 dB noise figure. The LNA and RF amplifier is simulated using Ansoft Designer software and fabricated with Duroid 5880 as the microstrip material

Awareness and Attitude Towards the Premarital Screening Programme Among High School Students in Muscat, Oman

Objectives: This study aimed to explore high school students’ awareness and attitude towards premarital screening (PMS). Methods: This cross-sectional study was conducted in 10 public high schools in Muscat, Oman from May to July 2016. A three-part self-administered questionnaire was used to collect data from grade 12 students. The first part focused on respondents’ sociodemographic characteristics, while the second part dealt with awareness of the national PMS programme and the third part explored attitudes towards the national PMS programme. Results: A total of 1,541 participants (response rate: 91.1%) completed the questionnaire. Most participants (78.1%) were aware of the availability of the PMS programme and their main source of information was family and friends (34.3%). The majority of students (87.4%) believed that PMS is important and most students (87.2%) indicated that they would undergo PMS. Over half of the students (55.3%) agreed that PMS should be mandatory before marriage and approximately one-third (38.3%) were in favour of having laws and regulations to prevent consanguineous marriages. Females were significantly more in favour of making PMS mandatory (P = 0.002) and enforcing PMS laws (P = 0.010) compared to males. Conclusion: Most respondents had good levels of knowledge about the PMS programme and half thought it is important to be tested. However, some students were not in favour of PMS. Increasing awareness about Oman’s PMS programme is important and motivating students could contribute significantly to increasing the utilisation of the PMS programme and to limiting genetic blood disorders.Keywords: Awareness; Knowledge; Attitude; Secondary School; Students; Premarital Examinations; Genetic Carrier Screening; Oman

Effects of lean combustion on bioethanol-gasoline blends using turbocharged spark ignition engine

Liquid alternative fuels have been utilised as engine fuel since the 19th century. For several alternative fuels, bioethanol is well-known as the most suited friendly, alternative-product based and renewable for use in spark-ignition (SI) engines. In addition, it is well known that bioethanol has higher evaporation of heat, research octane number and flammability of temperature; therefore, it has a greater influence on performance and lower emission. In this study, the effect of gasoline fuel RON95 (G) was blended into bioethanol fuel (E10, E20 and E30) to investigate the engine combustion, performance and emission. The engine used was 1.8L Mitsubishi, four-cylinder, four-stroke, multipoint port injection and turbocharger SI. The engine speed used was 1000-3000 rpm at 10-40% load with wide-open throttle (WOT). The results showed that bioethanol addition to gasoline increases the brake torque at a higher load. The mass fraction burn (MFB) and coefficient of variation (COV) blend fuel and main fuel are comparable to each other. The brake specific fuel consumption (BSFC) significantly increases when engine speed increases. The emission of nitrogen oxide (NOx), carbon monoxide (CO), and hydrocarbon (HC) emissions reduced dramatically compared to gasoline fuel. Indeed, bioethanol-gasoline fuel allows the engine utilised in low proportion to increase engine performance and lower engine emission