Multiwavelength fiber laser in four mode fiber

Multiwavelength fiber laser is a nonlinear phenomenon that has a great potential for optical communication system. A stable triple-wavelength fiber laser in four mode fiber had been demonstrated experimentally by employing Sagnac filter in a simple close loop laser cavity. The Sagnac loop filter configuration was constructed using a 2 m of polarization maintaining fiber (PMF), a 3 dB coupler and a polarization controller. The laser is able to sustain triple-wavelength laser generation at 13.1 dBm output power of Erbium-Doped Fiber Amplifier (EDFA) as all laser wavelengths produced less than 0.25 nm fluctuation for over 20 min of unstoppable lasing operation. This laser configuration also has flexibility to perform single, dual and triple wavelength laser by controlling the EDFA output power

Risk management among mountain bikers in selected clubs in Malaysia

Mountain biking is the best pedal sport on road and off road trails. The element of adventure in this sport make many people like to join this challenging sports. This study examined the risk among mountain bikers in selected clubs in Malaysia. The main objective of this study is to reveal injuries among mountain bikers during their cycling session. All data in this study will be shown descriptively. Survey forms were distributed via active cycling clubs in Perak states. The respondents need to testify their previous injuries during their previous activities. The data shows the age of the mountain bikers, their experiences and abilities. From a total of 225, only 192 repondents experienced and had an injury during the activities. The result showed only 43.2% seeked medical attention and went to the hospital or clinic after experiencing an injury. Mountain biking activities require the cyclist to be physically and mentally fit and the equipment, which is the bike itself. Best practice and proper skill trainingshelp them to avoid accident during the activities. The new discipline called ‘down hill’ is getting more popular and can be one of the future studies because this new discipline is more risky.Keywords: mountain biking, risk management, event management, Malaysi

Motivational Factors that Influence Student Work Attitude

Employers look for employees who have positive work attitudes besides technical knowledge and related skills. Students, therefore, should have positive work attitudes to be successful in the workplace. This study is an attempt to identify the motivational factors that may be associated with work attitudes of students at Universiti Pertanian Malaysia. The motivational factors include: (1) educational aspirations, (2) occupational aspirations, (3) reason for entering the programme, (4) religiosity, and (5) student perception of parental work values. A cluster random sampling was used to determine the sample of respondents. The sample consisted of686 diploma programme students. The results indicated that the reason for entering the programme, religiosity and student perception of parental work values were related to work attitude. These variables were further analyzed to determine the semi-partial multiple regression coefficients. The findings showed that reason for entering the programme did not account for a significant unique proportion of the variance in work attitude. However, religiosity and student perceptions of parental work values accounted for a significant unique proportion of the variance in work attitude. These two variables were used in the stepwise multiple regression analysis. It was found that the two variables were the best predictors of the work attitude of diploma programme students at the Universiti Pertanian Malaysia

Preferences of contexts for learning mathematics expressed by students in rural secondary school environments of Zimbabwe

A ZJER journal article on how students could be assisted to appreciate Mathematics, as an academic subject, in the rural areas of the Zimbabwe educational system.The study aimed at identifying situations for learning Mathematics that could contribute to increasing student motivation for learning that subject in Zimbabwean rural secondary school settings. We asked how student preferences of contexts for learning Mathematics relates to schooling year, Form level and gender in rural secondary school environments. Judgmental and systematic sampling procedures were used to select 450 students from 5 out of about 30 rural secondary schools. Participants consisted of 225 boys and 225 girls all in the 13-17 age range and in their 8th, 9th, and 1ffh years of schooling. Data were collected by asking the ^students to express their interest levels in selected contexts for learning using a “Relevance of School Mathematics Education” (ROSME) instrument (Julie, 2005; 2006). Kendall's W mean ranks, medians, modes, clustered bar graphs, and Chi Square were used to describe the trends. The results indicate that learning situations related to science and technology were associated more with boys than with girls, while contexts for learning that have connotations of care-giving were associated more with girls in a rural secondary school setting. The results also suggest that generally higher levels of preferences of contexts for learning can be associated with Form 2 students— who are typically older than their Form 1 counterparts. While these results contradict a literature-based observation that interest with Mathematics diminishes overtime (i.e., with age), they probably show that the younger students could be carrying more restricted views of situations deemed to have potential for facilitating development of Mathematical concepts

Microembossing of ultrafine grained Al: microstructural analysis and finite element modelling

Ultra fine grained (UFG) Al-1050 processed by equal channel angular pressing (ECAP) and UFG Al-Mg-Cu-Mn processed by high pressure torsion (HPT) were embossed at both room temperature and 300 °C, with the aim of producing micro-channels. The behaviour of Al alloys during the embossing process was analysed using finite element (FE) modelling. The cold embossing of both Al alloys is characterised by a partial pattern transfer, a large embossing force, channels with oblique sidewalls and a large failure rate of the mould. The hot embossing is characterised by straight channel sidewalls, fully transferred patterns and reduced loads which decrease the failure rate of the mould. Hot embossing of UFG Al-Mg-Cu-Mn produced by HPT shows a potential of fabrication of microelectromechanical system (MEMS) components with micro channels

1,1′-Fc(4-C6H4CO2Et)2and its unusual salt derivative withZ′ = 5,catena-[Na+]2[1,1′-Fc(4-C6H4CO2−)2]·0.6H2O [1,1′-Fc = (η5-(C5H4)2Fe]

The neutral diethyl 4,4'-(ferrocene-1,1'-diyl)dibenzoate, Fe[[eta]5-(C5H4)(4-C6H4CO2Et)]2 (I), yields (II) (following base hydrolysis) as the unusual complex salt poly[disodium bis[diethyl 4,4'-(ferrocene-1,1'-diyl)dibenzoate] 0.6-hydrate] or [Na+]2[Fe{[eta]5-(C5H4)-4-C6H4CO_2^-}2]·0.6H2O with Z' = 5. Compound (I) crystallizes in the triclinic system, space group P\bar 1, with two molecules having similar geometry in the asymmetric unit (Z' = 2). The salt complex (II) crystallizes in the orthorhombic system, space group Pbca, with the asymmetric unit comprising poly[decasodium pentakis[diethyl 4,4'-(ferrocene-1,1'-diyl)dibenzoate] trihydrate] or [Na+]10[Fe{[eta]5-(C5H4)-4-C6H4CO_2^-}2]5·3H2O. The five independent 1,1'-Fc[(4-C6H4CO2)-]2 dianions stack in an offset ladder (stepped) arrangement with the ten benzoates mutually oriented cisoid towards and bonded to a central layer comprising the ten Na+ ions and three water molecules [1,1'-Fc = [eta]5-(C5H4)2Fe]. The five dianions differ in the cisoid orientations of their pendant benzoate groups, with four having their -C6H4- groups mutually oriented at interplanar angles from 0.6 (3) to 3.2 (3)° (as [pi]...[pi] stacked C6 rings) and interacting principally with Na+ ions. The fifth dianion is distorted and opens up to an unprecedented -C6H4- interplanar angle of 18.6 (3)° through bending of the two 4-C6H4CO2 groups and with several ionic interactions involving the three water molecules (arranged as one-dimensional zigzag chains in the lattice). Overall packing comprises two-dimensional layers of Na+ cations coordinated mainly by the carboxylate O atoms, and one-dimensional water chains. The non-polar Fc(C6H4)2 groups are arranged perpendicular to the layers and mutually interlock through a series of efficient C-H...[pi] stacking contacts in a herringbone fashion to produce an overall segregation of polar and non-polar entities

Surgical management of posterior fossa metastases

The diagnosis of brain metastases is associated with a poor prognosis reflecting uncontrolled primary disease that has spread to the relative sanctuary of the central nervous system. 20 % of brain metastases occur in the posterior fossa and are associated with significant morbidity. The risk of acute hydrocephalus and potential for sudden death means these metastases are often dealt with as emergency cases. This approach means a full pre-operative assessment and staging of underlying disease may be neglected and a proportion of patients undergo comparatively high risk surgery with little or no survival benefit. This study aimed to assess outcomes in patients to identify factors that may assist in case selection. We report a retrospective case series of 92 consecutive patients operated for posterior fossa metastases between 2007 and 2012. Routine demographic data was collected plus data on performance status, primary cancer site, details of surgery, adjuvant treatment and survival. The only independent positive prognostic factors identified on multivariate analysis were good performance status (if Karnofsky performance score >70, hazard ratio (HR) for death 0.36, 95 % confidence interval (CI) 0.18–0.69), adjuvant whole brain radiotherapy (HR 0.37, 95 % CI 0.21–0.65) and adjuvant chemotherapy where there was extracranial disease and non-synchronous presentation (HR 0.51, 95 % CI 0.31–0.82). Patients presenting with posterior fossa metastases may not be investigated as thoroughly as those with supratentorial tumours. Staging and assessment is essential however, and in the meantime emergencies related to tumour mass effect should be managed with steroids and cerebrospinal fluid diversion as required

Ultrasonographic imaging on the progress of wound healing after abdominal surgery in dogs

The present study has been carried out with the aim of evaluating the progress of abdominal wound healing after abdominal surgery and to detect any changes that might occur during the reparative phase using B-mode ultrasound. Five dogs of different breeds, sex and age were used in this study. The dogs had undergone ventral abdominal surgery for various reasons. A real-time B-mode ultrasound machine (Capasee TOSHIBA) connected with a 7.5 MHz linear array transducer was used in this study. The ultrasonographic examination was done transversely across the ventral abdominal midline (wound) from cranial to caudal and longitudinal scan was done along the wound (incision site) from cranial to caudal. Initial scanning was carried out on day one (approximately 24 hours) post-operation. Subsequent scans were carried out on the basis of one day apart while the animal was still in the hospital. The ultrasonographic appearance of wound (surgical site) at the early stage was ill-defined hypoechoic with acoustic shadowing artefact. With time the wound appeared hypoechoic with some degree of an echogenic centre and casting acoustic shadowing artefact. By day 11 post-operation, the wound was found to have a disorganized echogenic structure with acoustic shadowing artefact. By day 13 post-operation, the wound appeared as disorganized hyperechoic with acoustic shadowing artefact due to the presence of fibrous tissue formation. Results from this study also demonstrate that the wound could be evaluated in both transverse and longitudinal scans. However, the transverse scan seems to be easier than the longitudinal scan in evaluation of the surgical wound