Search results for: Shazia Anwer Bukhari
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 63

Search results for: Shazia Anwer Bukhari

33 Design of an Instrumentation Setup and Data Acquisition System for a GAS Turbine Engine Using Suitable DAQ Software

Authors: Syed Nauman Bin Asghar Bukhari, Mohtashim Mansoor, Mohammad Nouman

Abstract:

Engine test-Bed system is a fundamental tool to measure dynamic parameters, economic performance, and reliability of an aircraft Engine, and its automation and accuracy directly influences the precision of acquired and analysed data. In this paper, we present the design of digital Data Acquisition (DAQ) system for a vintage aircraft engine test bed that lacks the capability of displaying all the analyzed parameters at one convenient location (one panel-one screen). Recording such measurements in the vintage test bed is not only time consuming but also prone to human errors. Digitizing such measurement system requires a Data Acquisition (DAQ) system capable of recording these parameters and displaying them on one screen-one panel monitor. The challenge in designing upgrade to the vintage systems arises with a need to build and integrate digital measurement system from scratch with a minimal budget and modifications to the existing vintage system. The proposed design not only displays all the key performance / maintenance parameters of the gas turbine engines for operator as well as quality inspector on separate screens but also records the data for further processing / archiving.

Keywords: Gas turbine engine, engine test cell, data acquisition, instrumentation

Procedia PDF Downloads 96
32 Estimation of Carbon Sequestration and Air Quality of Terrestrial Ecosystems Using Remote Sensing Techniques

Authors: Kanwal Javid, Shazia Pervaiz, Maria Mumtaz, Muhammad Ameer Nawaz Akram

Abstract:

Forests and grasslands ecosystems play an important role in the global carbon cycle. Land management activities influence both ecosystems and enable them to absorb and sequester carbon dioxide (CO2). Similarly, in Pakistan, these terrestrial ecosystems are well known to mitigate carbon emissions and have a great source to supply a variety of services such as clean air and water, biodiversity, wood products, wildlife habitat, food, recreation and carbon sequestration. Carbon sequestration is the main agenda of developed and developing nations to reduce the impacts of global warming. But the amount of carbon storage within these ecosystems can be affected by many factors related to air quality such as land management, land-use change, deforestation, over grazing and natural calamities. Moreover, the long-term capacity of forests and grasslands to absorb and sequester CO2 depends on their health, productivity, resilience and ability to adapt to changing conditions. Thus, the main rationale of this study is to monitor the difference in carbon amount of forests and grasslands of Northern Pakistan using MODIS data sets and map results using Geographic Information System. Results of the study conclude that forests ecosystems are more effective in reducing the CO2 level and play a key role in improving the quality of air.

Keywords: carbon sequestration, grasslands, global warming, climate change.

Procedia PDF Downloads 157
31 Parabens, Paraben Metabolites and Triclocarban in Sediment Samples from the Trondheim Fjord, Norway

Authors: Kristine Vike-Jonas, Susana V. Gonzalez, Olav L. Bakkerud, Karoline S. Gjelstad, Shazia N. Aslam, Øyvind Mikkelsen, Alexandros Asimakopoulos

Abstract:

P-hydrobenzoic acid esters (parabens), paraben metabolites, and triclocarban (TCC) are a group of synthetic antimicrobials classified as endocrine disrupting chemicals (EDCs) and emerging pollutants. The aim of this study was to investigate the levels of these compounds in sediment near the effluent of a wastewater treatment plant (WWTP) in the Trondheim Fjord, Norway. Paraben, paraben metabolites, and TCC are high volume production chemicals that are found in a range of consumer products, especially pharmaceuticals and personal care products (PCPs). In this study, six parabens (methyl paraben; MeP, ethyl paraben; EtP, propyl paraben; PrP, butyl paraben; BuP, benzyl paraben; BezP, heptyl paraben; HeP), four paraben metabolites (4-hydroxybenzoic acid; 4-HB, 3,4-dihydroxybenzoic acid; 3,4-DHB, methyl protocatechuic acid; OH-MeP, ethyl protocatechuic acid; OH-EtP) and TCC were determined by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) in 64 sediment samples from 10 different locations outside Trondheim, Norway. Of these 11 target analytes, four were detected in 40 % or more of the samples. The sum of six parabens (∑Parabens), four paraben metabolites (∑Metabolites) and TCC in sediment ranged from 4.88 to 11.56 (mean 6.81) ng/g, 52.16 to 368.28 (mean 93.89) ng/g and 0.53 to 3.65 (mean 1.50) ng/g dry sediment, respectively. Pearson correlation coefficients indicated that TCC was positively correlated with OH-MeP, but negatively correlated with 4-HB. To the best of the author’s knowledge, this is the first time parabens, paraben metabolites and TCC have been reported in the Trondheim Fjord.

Keywords: parabens, liquid chromatography, sediment, tandem mass spectrometry

Procedia PDF Downloads 95
30 Sandwich Structure Composites: Effect of Kenaf on Mechanical Properties

Authors: Maizatulnisa Othman, Mohamad Bukhari, Zahurin Halim, Souad A. Muhammad, Khalisani Khalid

Abstract:

Sandwich structure composites produced by epoxy core and aluminium skin were developed as potential building materials. Interface bonding between core and skin was controlled by varying kenaf content. Five different weight percentage of kenaf loading ranging from 10 wt% to 50 wt% were employed in the core manufacturing in order to study the mechanical properties of the sandwich composite. Properties of skin aluminium with epoxy were found to be affected by drying time of the adhesive. Mechanical behavior of manufactured sandwich composites in relation with properties of constituent materials was studied. It was found that 30 wt% of kenaf loading contributed to increase the flexural strength and flexural modulus up to 102 MPa and 32 Gpa, respectively. Analysis were done on the flatwise and edgewise compression test. For flatwise test, it was found that 30 wt% of fiber loading could withstand maximum force until 250 kN, with compressive strength results at 96.94 MPa. However, at edgewise compression test, the sandwich composite with same fiber loading only can withstand 31 kN of the maximum load with 62 MPa of compressive strength results.

Keywords: sandwich structure composite, epoxy, aluminium, kenaf fiber

Procedia PDF Downloads 361
29 Nutritional Potential and Functionality of Whey Powder Influenced by Different Processing Temperature and Storage

Authors: Zarmina Gillani, Nuzhat Huma, Aysha Sameen, Mulazim Hussain Bukhari

Abstract:

Whey is an excellent food ingredient owing to its high nutritive value and its functional properties. However, composition of whey varies depending on composition of milk, processing conditions, processing method, and its whey protein content. The aim of this study was to prepare a whey powder from raw whey and to determine the influence of different processing temperatures (160 and 180 °C) on the physicochemical, functional properties during storage of 180 days and on whey protein denaturation. Results have shown that temperature significantly (P < 0.05) affects the pH, acidity, non-protein nitrogen (NPN), protein total soluble solids, fat and lactose contents. Significantly (p < 0.05) higher foaming capacity (FC), foam stability (FS), whey protein nitrogen index (WPNI), and a lower turbidity and solubility index (SI) were observed in whey powder processed at 160 °C compared to whey powder processed at 180 °C. During storage of 180 days, slow but progressive changes were noticed on the physicochemical and functional properties of whey powder. Reverse phase-HPLC analysis revealed a significant (P < 0.05) effect of temperature on whey protein contents. Denaturation of β-Lactoglobulin is followed by α-lacalbumin, casein glycomacropeptide (CMP/GMP), and bovine serum albumin (BSA).

Keywords: whey powder, temperature, denaturation, reverse phase, HPLC

Procedia PDF Downloads 270
28 Removal of Mixed Heavy Metals from Contaminated Clay Soils Using Pulsed Electrokinetic Process

Authors: Nuhu Dalhat Mu’azu, Abdullahi Usman, A. Bukhari, Muhammad Hussain Essa, Salihu Lukman

Abstract:

Electrokinetic remediation process was employed for the removal of four (4) heavy metals (Cr, Cu, Hg and Pb) from contaminated clay and bentonite soils under pulsed current supply mode. The effects of voltage gradient, pulse duty cycle and bentonite/clay ratio on the simultaneous removal efficiencies of the heavy metals were investigated. A total of thirteen experiments were designed and conducted according to factorial design with each experiment allowed to continuously ran for 3 weeks. Results obtained showed that increase in bentonite ratio decreased the removal efficiency of the heavy metals with no significant effect on the energy consumption. Conversely, increase in both voltage gradient and pulse duty cycle increased the heavy metals removal efficiencies with increased in energy consumption. Additionally, increase in voltage gradient increased the electrical conductivity and the soil pH due to due to continuous refill and replacement of process fluids as they decomposed under the induced voltage gradient. Under different operating conditions, the maximum removal efficiencies obtained for Cr, Cu, Hg, and Pb were 21.87, 83.2, 62.4, 78.06 and 16.65% respectively.

Keywords: clay, bentonite, soil remediation, mixed contaminants, heavy metals, and electrokinetic-adsorption

Procedia PDF Downloads 402
27 Revealing Potential Drug Targets against Proto-Oncogene Wnt10B by Comparative Molecular Docking

Authors: Shazia Mannan, Zunera Khalid, Hammad-Ul-Mubeen

Abstract:

Wingless type Mouse mammary tumor virus (MMTV) Integration site-10B (Wnt10B) is an important member of the Wnt protein family that functions as cellular messenger in paracrine manner. Aberrant Wnt10B activity is the cause of several abnormalities including cancers of breast, cervix, liver, gastric tract, esophagus, pancreas as well as physiological problems like obesity, and osteoporosis. The objective of this study was to determine the possible inhibitors against aberrant expression of Wnt10B in order to prevent and treat the physiological disorders associated with it. Wnt10B3D structure was predicted by using comparative modeling and then analyzed by PROCHECK, Verify3D, and Errat. The model having 84.54% quality value was selected and acylated to satisfy the hydrophobic nature of Wnt10B. For search of inhibitors, virtual screening was performed on Natural Products (NP) database. The compounds were filtered and ligand-based screening was performed using the antagonist for mouse Wnt-3A. This resulted in a library of 272 unique compounds having most potent drug like activities for Wnt-4. Out of the 271 molecules analyzed three small molecules ZINC35442871, ZINC85876388, and ZINC00754234 having activity against Wnt4 abbarent expression were found common through docking experiment of Wnt10B. It is concluded that the three molecules ZINC35442871, ZINC85876388, and ZINC00754234 can be considered as lead compounds for performing further drug designing experiments against aberrant Wnt expressions.

Keywords: Wnt10B inhibitors, comparative computational studies, proto-oncogene, molecular docking

Procedia PDF Downloads 131
26 Catastrophic Spending on Health: A Determinant of Access to Health Care by Migrant Slum Population

Authors: Saira Mehnaz, Ali Jafar Abedi, Shazia Farooq Fazli, Sakeena Mushfiq, Zulfia Khan, M. Athar Ansari

Abstract:

Introduction: Public health spending is a necessity in an underdeveloped country like India. The people are already suffering from poverty and that clubbed with out of pocket expenditure leads them to a very catastrophic situation, reducing the overall access to healthcare. Objectives: This study was designed to determine the usual source of medical care opted, the illness pattern, the expenditure incurred on illness and its source of procurement by the study population. It also intended to assess this expenditure as a determinant of access to health care. Methodology: Cities like Aligarh, which are classified as B grade cities in India are thought to be ripe sites for getting livelihood and hence are almost half filled with migrants living in urban slums. A cross sectional study was done to study the newer slum pockets. 3409 households with a population of 16,978 were studied with the help of pretested questionnaire; SPSS 20 was used for statistical analysis. Results and Conclusions: In our study, we found that almost all the households suffered from catastrophic health expenditure. The study population, which was already vulnerable owing to their low socio-economic and migrant status was further being forced with into poverty and indebtedness on account of expenditure on illness. This lead to a significant decrease in access to health. National health financing systems should be designed to protect households from financial catastrophe, by reducing out-of-pocket spending.

Keywords: access to healthcare, catastrophic health expenditure, new urban slums, out of pocket expenditure

Procedia PDF Downloads 175
25 A Cadaveric Study of Branching Pattern of Arch of Aorta and Its Clinical Significance in Nepalese Population

Authors: Gulam Anwer Khan, A. Gautam

Abstract:

Background: The arch of aorta is a large artery that arches over the root of the left lung and connects the ascending aorta and descending aorta. It is situated in the superior mediastinum behind the manubrium sterni. It gives off three major branches i.e. brachiocephalic trunk, left common carotid artery and left subclavian artery arising from the superior surface of arch of aorta from right to left. Material and Methods: This was a descriptive study. It was carried out in 44 cadavers, obtained during dissections for undergraduates of Department of Anatomy, Chitwan Medical College, Bharatpur, Chitwan, between March 2015 to October 2016. Cadavers of both sexes were included in the present study. The arch of aorta was dissected and exposed according to the methods described by Romanes in Cunningham’s manual of practical anatomy. Results: Out of 44 dissected cadavers, 35 (79.54%) were male and 9 (20.46%) were female cadavers. The normal branching pattern of the arch of aorta was encountered in 28 (63.64%) cadavers and the remaining 16 (36.36%) cadavers showed variations in the branching pattern of arch of aorta. Two different types of variations on the branching pattern of arch of aorta were noted in the present study, in which 12 (27.27%) cadavers had common trunk of the Arch of Aorta. In 3 (5.00%) male cadavers, we found the origin of the Thyroid ima artery. This variation was noted in 1(1.66%) female cadaver. Conclusion: The present study carried out on adult human cadavers’ revealed wide variations in the branching pattern of the arch of ao rta. These variations are of clinical significance and also very useful for the anatomists, radiologists, anesthesiologists, surgeons for practice during angiography, instrumentation, supra-aortic thoracic, head and neck surgery.

Keywords: arch of aorta, brachiocephalic trunk, left common carotid artery, left subclavian artery, Thyroidea ima artery

Procedia PDF Downloads 308
24 Self-Medicating Behavior of Urban Pakistani Population toward Psychotropic Agents and Its Correlates

Authors: M. Umar Hafeez, Furqan Khursheed Hashmi, Nadeem Irfan Bukhari, Shahzad Ali, Muzammil Ali

Abstract:

The trend of self-medication is increasing due to various factors and is associated with a large number of complications. A cross-sectional study was aimed to investigate self-medication trend in an urban community and its correlates such as level of education, gender and behavior of using psychoactive medicines. A validated questionnaire was used to collect the data from different locations of Lahore, provincial capital of Punjab, Pakistan. The trend of self-medication was noted in reference to difference in educational level and in gender. This study showed that total 110 respondents, all literate,were found to be self-medicating, and their educational status was as 73.13% primary, 63.15% secondary, 61.12% higher secondary and 62.15% university going. In this sample 74.99% were males and 48.00%were females. Twenty nine (26.36%) of the total sample were found to be using psychoactive agents without consulting the physician. The trend of self-medication was 10% higher in individuals having primary level education, whereas there was not much difference of self-medication trend in other levels of education. The main reasons involved in self-medication trend were socio-economic status, medicine accessibility, religious and cultural beliefs, lack of awareness about risks associated with medicine, non-prescription sale of medicines and previous medication experience. The trend of self-medication of psychotropic agents is quite significant.

Keywords: self-medication, educated community, psychotropic drugs, education levels

Procedia PDF Downloads 366
23 Investigating the Combined Medicinal Effects of Withania Somnifera (Ashwaghandha) and Murraya Koenigii (Curry Pata) in Vitro

Authors: Sadia Roshan, Kulsoom Sughra, Shazia Shamas, Shamaila Irum, Haleema Sadia

Abstract:

To evaluate synergistic medicinal effects of Withania somnifera (Ashwaghandha) and Murraya koenigii (Curry pata) in vitro. Antimicrobial activity was determined using the disc diffusion method against five bacterial and two fungal strains. The antioxidant activity was evaluated by the DPPH assay. The antidiabetic activity was evaluated by alpha-glucosidase inhibition assay and alpha-amylase inhibition assay. Synergistic antibacterial activity was observed against all the strains of bacteria, either Gram-positive or Gram-negative and fungi under study conditions. The maximum antibacterial activity was displayed by combined extract against E. coli i.e. 26±0.4mm. Maximum antifungal activity was shown by combined extract against Aspergillus niger, i.e., 17.3±0.5mm. The antioxidant activity of the combined extract was also significant. Alpha-glucosidase inhibition and alpha-amylase inhibition assays also showed synergism. Results indicate that Withania somnifera and Murraya koengii have medicinal properties. The combined extract of both plants is more potent than their individual extracts, suggesting that these can work in synergism. The research suggests that different plant extracts could be used in combination to increase their medicinal activities by many folds, thus giving an insight into future use of herbal medication.

Keywords: withania somnifera, murraya koenigii, antimicrobial activity, gram-positive bacetria, gram-negative bacteria

Procedia PDF Downloads 23
22 Assessing the Attitude and Belief towards Online Advertisement in Pakistan and China Mainland

Authors: Prih Bukhari

Abstract:

The purpose of the proposed paper is to determine if the perception of online advertisement formed due to attitude and belief vary among two different countries or not. Specifically, it seeks to find out how people from China and Pakistan perceive online advertisement. Public attitude and belief towards advertising have been a focus of attention to explore a path to a better strategy of advertising. The ‘belief’ factor was analyzed through 4 items, i.e., product information, entertainment, and increase in economy’ whereas, the ‘attitude’ factor was analyzed thorough questions based on 4 items, i.e. ‘overall, I consider online advertising a good thing’; 'overall, I like online advertising’; ‘'I consider online advertising very essential’; and 'I would describe my overall attitude toward online advertising very favorably’. As such, it provides theoretical basis to explain similarities and differences of beliefs and attitude towards advertising across the two countries. Given its mixed method approach, both quantitative and qualitative method is used to carry out research. A questionnaire-based survey and focus group interviews were conducted. The sample size was of 500 participants. For analysis survey copies were then collected from which 497 were received whereas focus group interviews were collected from both nations. The findings showed that the belief factor among both countries had no significant relation with the perception of online advertisement. However, the attitude had a significant relation with the perception about online advertisement. Also it was observed that despite of different backgrounds, perception about online advertisement based on beliefs and attitude were found largely to be similar. Implications and future studies are provided.

Keywords: attitude, belief, online advertisement, perception

Procedia PDF Downloads 120
21 Foliar Feeding of Methyl Jasmonate Induces Resistance in Normal and Salinity Stressed Tomato Plants, at Different Stages

Authors: Abdul Manan, Choudhary Muhammad Ayyub, Rashid Ahmad, Muhammad Adnan Bukhari

Abstract:

A project was designed to investigate the effect of foliar application of methyl jasmonate (MeJA) on physiological, biochemical and ionic attributes of salinity stressed and normal tomato plants at different stages. Salinity stress at every stage markedly reduced the net photosynthetic rate, stomatal conductance, transpiration rate, water relations parameters, protein contents, total free aminoacids and potassium (K+) contents. While, antioxidant enzymes (peroxidase (POX) and catalase (CAT)), sodium (Na+) contents and proline contents were increased substantially. Foliar application of MeJA ameliorated the drastic effects of salinity regime by recovery of physiological and biochemical attributes by enhanced production of antioxidant enzymes and osmoprotectants. The efficacy of MeJA at very initial stage (15 days after sowing (15 DAS)).proved effective for attenuating the deleterious effects of salinity stress than other stages (15 days after transplanting (15 DAT) and 30 days after transplanting (30 DAT)). To the best of our knowledge, different times of foliar feeding of MeJA was observed first time for amelioration of salinity stress in tomato plants that would be of pivotal significance for scientist to better understand the dynamics of physiological and biochemical processes in tomato.

Keywords: methyl jasmonate, osmoregulation, salinity stress, stress tolerance, tomato

Procedia PDF Downloads 281
20 Challenges Faced by the Visually Impaired Children and their Parents in Doing Homework Assignments Using Braille

Authors: Shazia Farooq Mirza

Abstract:

The purpose of this study was to explore the challenges faced by visually impaired children and their parents in doing homework assignments using Braille. This study had a quantitative approach and it was descriptive in nature. It took place in 6 public and special private schools of Lahore.177 visually impaired children of grades 4-10 and 153 parents of the visually impaired children were the volunteer participants of this study which were selected through a convenient sampling method. A survey method was adopted for the data collection. And for this purpose 2 self-developed validated questionnaires were used as instruments. The instruments were constructed by exploring the factors and sub-factors from the literature review. Thirty students with visual impairment and 30 parents of the students with visual impairment filled the questionnaires as a pilot study, and it ensured the reliability of the instruments. Data were analyzed using a statistical package of social sciences and it was completely interpreted. Findings revealed that the common challenges faced by the students with visual impairment were Physical Stress, Readiness, Braille Knowledge, Braille Skill and Communications. And the major challenges faced by the parents of the students with visual impairment were the Availability of the helping material, the Availability of the reading material, Braille Knowledge, Braille skills, School and family interactions, Behavior management and the Environment and equipment. Conclusions were drawn on the basis of the major findings. Future suggestions are given in light of the conclusions. This study will be beneficial for the children with visual impairment, the parents of the children with visual impairment, the special education teachers and for the policymakers of the special schools.

Keywords: challenges, visually impaired children, homework, parents, braille

Procedia PDF Downloads 82
19 GIS Based Public Transport Accessibility of Lahore using PTALs Model

Authors: Naveed Chughtai, Salman Atif, Azhar Ali Taj, Murtaza Asghar Bukhari

Abstract:

Accessible transport systems play a crucial role in infrastructure management and ease of access to destinations. Thus, the necessity of knowledge of service coverage and service deprived areas is a prerequisite for devising policies. Integration of PTALs model with GIS network analysis models (Service Area Analysis, Closest Facility Analysis) facilitates the analysis of deprived areas. In this research, models presented determine the accessibility. The empirical evidence suggests that current bus network system caters only 18.5% of whole population. Using network analysis results as inputs for PTALs, it is seen that excellent accessibility indexed bands cover a limited areas, while 78.8% of area is totally deprived of any service. To cater the unserved catchment, new route alignments are proposed while keeping in focus the Socio-economic characteristics, land-use type and net population density of the deprived area. Change in accessibility with proposed routes show a 10% increment in service delivery and enhancement in terms of served population is up to 20.4%. PTALs result shows a decrement of 60 Km2 in unserved band. The result of this study can be used for planning, transport infrastructure management, allocation of new route alignments in combination with future land-use development and for adequate spatial distribution of service access points.

Keywords: GIS, public transport accessibility, PTALs, accessibility index, service area analysis, closest facility analysis

Procedia PDF Downloads 406
18 Curvature Based-Methods for Automatic Coarse and Fine Registration in Dimensional Metrology

Authors: Rindra Rantoson, Hichem Nouira, Nabil Anwer, Charyar Mehdi-Souzani

Abstract:

Multiple measurements by means of various data acquisition systems are generally required to measure the shape of freeform workpieces for accuracy, reliability and holisticity. The obtained data are aligned and fused into a common coordinate system within a registration technique involving coarse and fine registrations. Standardized iterative methods have been established for fine registration such as Iterative Closest Points (ICP) and its variants. For coarse registration, no conventional method has been adopted yet despite a significant number of techniques which have been developed in the literature to supply an automatic rough matching between data sets. Two main issues are addressed in this paper: the coarse registration and the fine registration. For coarse registration, two novel automated methods based on the exploitation of discrete curvatures are presented: an enhanced Hough Transformation (HT) and an improved Ransac Transformation. The use of curvature features in both methods aims to reduce computational cost. For fine registration, a new variant of ICP method is proposed in order to reduce registration error using curvature parameters. A specific distance considering the curvature similarity has been combined with Euclidean distance to define the distance criterion used for correspondences searching. Additionally, the objective function has been improved by combining the point-to-point (P-P) minimization and the point-to-plane (P-Pl) minimization with automatic weights. These ones are determined from the preliminary calculated curvature features at each point of the workpiece surface. The algorithms are applied on simulated and real data performed by a computer tomography (CT) system. The obtained results reveal the benefit of the proposed novel curvature-based registration methods.

Keywords: discrete curvature, RANSAC transformation, hough transformation, coarse registration, ICP variant, point-to-point and point-to-plane minimization combination, computer tomography

Procedia PDF Downloads 400
17 Development and Validation of Employee Trust Scale: Factor Structure, Reliability and Validity

Authors: Chua Bee Seok, Getrude Cosmas, Jasmine Adela Mutang, Shazia Iqbal Hashmi

Abstract:

The aims of this study were to determine the factor structure and psychometric properties (i.e., reliability and convergent validity) of the employees trust scale, a newly created instrument by the researchers. The employees trust scale initially contained 82 items to measure employee’s trust toward their supervisors. A sample of 818 (343 females, 449 males) employees were selected randomly from public and private organization sectors in Kota Kinabalu, Sabah, Malaysia. Their ages ranged from 19 to 67 years old with the mean of 34.55 years old. Their average tenure with their current employer was 11.2 years (s.d. = 7.5 years). The respondents were asked to complete the employees trust scale, as well as a managerial trust questionnaire from Mishra. The exploratory factor analysis on employee’s trust toward their supervisor’s extracted three factors, labeled 'trustworthiness' (32 items), 'position status' (11 items) and 'relationship' (6 items) which accounted for 62.49% of the total variance. Trustworthiness factors were re-categorized into three sub factors: competency (11 items), benevolence (8 items) and integrity (13 items). All factors and sub factors of the scales demonstrated clear reliability with internal consistency of Cronbach’s Alpha above 0.85. The convergent validity of the Scale was supported by an expected pattern of correlations (positive and significant correlation) between the score of all factors and sub factors of the scale and the score on the managerial trust questionnaire which measured the same construct. The convergent validity of employees trust scale was further supported by the significant and positive inter correlation between the factors and sub factors of the scale. The results suggest that the employees trust scale is a reliable and valid measure. However, further studies need to be carried out in other groups of sample as to further validate the Scale.

Keywords: employees trust scale, psychometric properties, trustworthiness, position status, relationship

Procedia PDF Downloads 434
16 Conflict, Confusion or Compromise: Violence against Women, A Case Study of Pakistan

Authors: Farhat Jabeen, Syed Asfaq Hussain Bukhari

Abstract:

In the wake of the contemporary period the basic objective of the research paper points out that socio-cultural scenario of Pakistan reveals that gender-based violence is deep rooted in the society irrespective of language and ethnicity. This paper would reconnaissance the possibility reforms in Pakistan for diminishing of violence. Women are not given their due role, rights, and respect. Furthermore, they are treated as chattels. This presentation will cover the socio-customary practices in the context of discrimination, stigmatization, and violence against women. This paper envisages justice in a broader sense of recognition of rights for women, and masculine structure of society, socio-customary practices and discrimination against women are a very serious concern which needs to be understood as a multidimensional problem. The paper will specially focus on understanding the existing obstacles of women in Pakistan in the constitutional scenario. Women stumble across discrimination and human rights manipulations, voluptuous violation and manipulation including domestic viciousness and are disadvantaged by laws, strategies, and programming that do not take their concerns into considerations. This presentation examines the role of honour killings among Pakistani community. This affects their self-assurance and capability to elevation integrity campaign where gender inequalities and discrimination in social, legal domain are to be put right. This paper brings to light the range of practices, laws and legal justice regarding the status of women and also covers attitude towards compensations for murders/killings, domestic violence, rape, adultery, social behavior and recourse to justice.

Keywords: discrimination, cultural, women, violence

Procedia PDF Downloads 293
15 Between Fiction and Reality: Reading the Silences in Partition History

Authors: Shazia Salam

Abstract:

This paper focuses on studying the literary reactions of selected Muslim women writers to the event of Partition of India in the north western region. It aims to explore how Muslim women experienced the Partition and how that experience was articulated through their writing. There is a serious dearth of research on the experience of Muslim women who had to witness the momentous event of the subcontinent. Since scholars have often questioned the silence around the historiography related to the experiences of Muslim women, this paper aims to explore if literature could provide insights that may be less readily available in other modes of narration. Using literature as an archival source, it aims to delve into the arenas of history that have been cloistered and closed. Muslim women have been silent about their experiences of Partition which at the cost of essentializing could be attributed to patriarchal constraints, and taboos, on speaking of intimate matters. These silences have consigned the question of their experience to a realm of anonymity. The lack of ethnographic research has in a way been compensated in the realm of literature, mainly poetry and fiction. Besides reportage, literature remains an important source of social history about Partition and how Muslim women lived through it. Where traditional history fails to record moments of rupture and dislocation, literature serves the crucial purpose. The central premise in this paper is that there is a need to revise the history of partition owing to the gaps in historiography. It looks into if literature can serve as a ground for developing new approaches to history since the question of the representation always confronts us--between what a text represents and how it represents it since imagination of the writer plays a great role in the construction of any text. With this approach as an entry point, this paper aims to unpack the questions of representation, the coalescing of history /literature and the gendered nature of partition history. It concludes that the gaps in the narratives of Partition and the memory of Partition can be addressed by way of suing literary as a source to fill in the cracks and fissures.

Keywords: gender, history, literature, partition

Procedia PDF Downloads 178
14 Supply Chain of Energy Resources and Its Alternatives Due to the Arab Spring: The Case of Egyptian Natural Gas Flow to Jordan

Authors: Moh’d Anwer Al-Shboul

Abstract:

The year 2011 was a challenging year for Jordanian economy, which felt a variety of effects from the Arab Spring which took place in neighboring countries. Since February, 5th 2012, the Arab Gas Supply Pipeline, which carries natural gas from Egypt through the Sinai Peninsula and to Jordan and Israel, has been attacked more than 39 times. Jordan imported about 80 percent of its necessity of natural gas (about 250 million cubic feet of natural gas per day) from Egypt to generate particularly electricity, with the reminder of being produced locally. Jordan has utilized multiple alternatives to address the interruption of available natural gas supply from Egypt. The Jordanian distributed power plants now rely on the use of heavy fuel oil and diesel for electricity generation, in this case, it costs Jordan about four times than natural gas. The substitution of Egyptian natural gas supplies by fuel oil and diesel, coupled with the 32 percent rise in global fuel prices, has increased Jordan’s energy import bill by over 50 percent in 2011, reaching more than 16 percent of the 2011 GDP. The increase in the cost of electricity generation pushed the Jordanian economy to borrow from multiple internal and external resource channels, thus increasing the public debt. The Jordanian government’s short-term solution to the reduced natural gas supply from Egypt was alternatively purchasing the necessary quantities from some Gulf countries such as Qatar and/or Saudi Arabia, which can be imported with two possible methods. The first method is to rent a ship equipped with a liquefied natural gas (LNG) terminal, which is currently operating. The second method requires equipping the Aqaba port with an LNG terminal, which also currently is operating. In the long-term, a viable solution to depending on importing expensive and often unreliable natural gas supplies from surrounding countries is to depend more heavily on renewable supply energy, including solar, wind, and water energy.

Keywords: energy supply resources, Arab spring, liquefied natural gas, pipeline, Jordan

Procedia PDF Downloads 110
13 A Pilot Study Assessing the Effectiveness of a Virtual Reality Intervention for Alleviating Pain and Anxiety in the Pediatric Emergency Room

Authors: Muqadis Shazia Rajpar, Lawrence Mitelberg, Rubaiat S. Ahmed, Jemer Garrido, Rukhsana Hossain, Sergey M. Motov

Abstract:

Distraction techniques have been used as a means to reduce pain, anxiety, and stress in various healthcare settings to facilitate care and make visits less unpleasant. Using virtual reality (VR) in the pediatric emergency setting can be a valuable, effective, and safe non-pharmacological alternative to the current standard of care for pain and anxiety management in pediatric patients. Our pilot study aimed to evaluate the effectiveness of a VR-based intervention as an alternative distraction modality to alleviate pain and anxiety associated with pediatric emergency department (ED) visits and acute pain conditions. The pilot study period was from November 16 to December 9, 2022, for pediatric ED visits for pain, anxiety, or both. Patients were selected based on a novel VR protocol to receive the VR intervention with the administration of pre and post-intervention surveys concerning pain/anxiety ratings and pain scores (Wong-Baker FACES/NRS). Descriptive statistics, paired t-test, and a Fisher Exact Test were used for data analysis, assuming a p-value of 0.05 for significance. A total of 33 patients (21 females, 12 males), ages 5-20 (M = 10.5, SD = 3.43) participated in this study – 12 patients had pain, 2 patients had anxiety, and 19 patients had both pain and anxiety. There was a statistically significant decrease in post-intervention pain scores of less than one point on the rating scale (6.48 vs. 5.62, p < .001). There was a statistically significant reduction in the percentage of patients suffering from “considerable” or “great” pain after the VR intervention (51.6% to 42.3%, p < .001). Similarly, we noticed an increase in the number of patients with “slight” or “moderate” pain post–VR intervention (48.4% to 57.7%, p < .001). Lastly, we demonstrated a decrease in anxiety among patients after utilizing VR (63.6% vs. 36.4%, p < .001). To conclude, VR can alleviate pain and anxiety in pediatric patients and be a useful non-pharmacological tool in the emergency setting.

Keywords: anxiety, emergency room, pain management, pediatric emergency medicine, virtual reality

Procedia PDF Downloads 57
12 A Prototype of an Information and Communication Technology Based Intervention Tool for Children with Dyslexia

Authors: Rajlakshmi Guha, Sajjad Ansari, Shazia Nasreen, Hirak Banerjee, Jiaul Paik

Abstract:

Dyslexia is a neurocognitive disorder, affecting around fifteen percent of the Indian population. The symptoms include difficulty in reading alphabet, words, and sentences. This can be difficult at the phonemic or recognition level and may further affect lexical structures. Therapeutic intervention of dyslexic children post assessment is generally done by special educators and psychologists through one on one interaction. Considering the large number of children affected and the scarcity of experts, access to care is limited in India. Moreover, unavailability of resources and timely communication with caregivers add on to the problem of proper intervention. With the development of Educational Technology and its use in India, access to information and care has been improved in such a large and diverse country. In this context, this paper proposes an ICT enabled home-based intervention program for dyslexic children which would support the child, and provide an interactive interface between expert, parents, and students. The paper discusses the details of the database design and system layout of the program. Along with, it also highlights the development of different technical aids required to build out personalized android applications for the Indian dyslexic population. These technical aids include speech database creation for children, automatic speech recognition system, serious game development, and color coded fonts. The paper also emphasizes the games developed to assist the dyslexic child on cognitive training primarily for attention, working memory, and spatial reasoning. In addition, it talks about the specific elements of the interactive intervention tool that makes it effective for home based intervention of dyslexia.

Keywords: Android applications, cognitive training, dyslexia, intervention

Procedia PDF Downloads 269
11 Pharmacological Activities and Potential Uses of Cyperus Rotundus: A Review

Authors: Arslan Masood Pirzada, Muhammad Naeem, Hafiz Haider Ali, Muhammad Latif, Aown Sammar Raza, Asad Hussain Bukhari, Muhammad Saqib, Muhammad Ijaz

Abstract:

Cyperus rotundus (Cyperaceae), a medicinal herb, is being traditionally used as a home remedy for the treatment of various clinical conditions like diarrhea, diabetic, pyretic, inflammation, malaria, and for treating stomach and bowel disorders. Its current status is one of the most widespread, troublesome, and economically damaging agronomic weeds, growing wildly in various tropical and sub-tropical regions of the world. Tuber and rhizomes of Cyperus rotundus possess a higher concentration of active ingredients in the form of essential oils, phenolic acids, ascorbic acids and flavonoids, responsible for its remedial properties. Exploitation of any medicinal plant application depends on the crucial and comprehensive information about the therapeutic potential of a plant. Researchers have evaluated and characterized the significance of Cyperus rotundus as an anti-androgenic, anti-bacterial, anti-cancerous, anti-convulsant, anti-diabetic, anti-diarrheal, anti-genotoxic, anti-inflammatory, anti-lipidemic, anti-malarial, anti-mutagenic, anti-obesity, anti-oxidant, anti-uropathogenic, hepato-, cardio-, neuroprotective, and nootropic agent. This paper comprises a broad review to summarize the current state of knowledge about chemical constituents, potential economic uses and therapeutic aspects of Cyperus rotundus that will aid in the development of bioethanol and modern herbal medicine through latest technologies that will promote the ability of this plant in the cure of many clinical disorders.

Keywords: purple nutsedge, chemical composition, economic uses, therapeutic values, future directions

Procedia PDF Downloads 473
10 Ethno-Botanical Survey on the Rare and Endangered Medicinal Plants of Poonch District (Jammu and Kashmir)

Authors: Shazia Shamim, Pallavi Gautam

Abstract:

The present study describes the presence of rare or endangered plants from Poonch Dist., which spread over 1674 Km sq. located between latitude 330 25' N to 340 01' N and longitude 730 58' E to 740 35' E forming a part of the Northwest Himalaya in Jammu and Kashmir state of India, with the aim of suggesting the strategy for the conservation and promotion of cultivation of rare and endangered medicinal plants, as well as developing traditional knowledge of medicinal plants. The main threats to biodiversity and ecosystem are overexploitation, global climate change, habitat loss, fragmentation, pollution, and invasion of alien species and disturbance of community structure. Surveys were carried out during 2015-2016 throughout the Poonch valley. During the field survey, various criteria of International Union for the conservation of nature for categorizing threatened plants, extent of occurrence, area of occupancy, probability of extinction, etc. were measured. The rarity of species was determined by field study, visual estimations, and literature. During the collection, it was observed that few rare and endangered species which were present in the study area, are also mentioned in the prescribed red data book of Indian plants, International Union for conservation of nature, list of threatened species and list of Botanical Survey of India presented by its Northern Regional Centre. The study was based on extensive surveys of the study area and then concluded by preparing a list of plant species occurring in different seasons, the photographs of all these plant species were collected. Actual threats to the population of a selected plant species in a given area were recorded by direct observation. The present paper provides information about 22 rare and endangered medicinal plant species belonging to 18 families that are used by the native of these areas. Information provided includes botanical name, family name, local name, habitat, part used, ethno medicinal uses and brief preparation of the reported plant species is presented in the present work.

Keywords: biodiversity, traditional knowledge, International Union for Conservation of Nature, Botanical Survery of India

Procedia PDF Downloads 108
9 Ceratocystis manginecans Causal Agent of a Destructive Mangoes in Pakistan

Authors: Asma Rashid, Shazia Iram, Iftikhar Ahmad

Abstract:

Mango sudden death is an emerging problem in Pakistan. As its prevalence is observed in almost all mango growing areas and severity varied from 2-5% in Punjab and 5-10% in Sindh. Symptoms on affected trees include bark splitting, discoloration of the vascular tissue, wilting, gummosis and at the end rapid death. Total of n= 45 isolates were isolated from different mango growing areas of Punjab and Sindh. Pathogenicity of these fungal isolates was tested through artificial inoculation method on different hosts (potato tubers, detached mango leaves, detached mango twigs and mango plants) under controlled conditions and all were proved pathogenic with varying degree of aggressiveness in reference to control. The findings of the present study proved that out of these four methods, potato tubers inoculation method was the most ideal as this fix the inoculums on the target site. Increased fungal growth and spore numbers may be due to soft tissues of potato tubers from which Ceratocystis isolates can easily pass. Lesion area on potato tubers was in the range of 7.09-0.14 cm2 followed by detached mango twigs which were ranged from 0.48-0.09 cm2). All pathological results were proved highly significant at P<0.05 through ANOVA but isolate to isolate showed non-significant behaviour but they have the positive effect on lesion area. Re-isolation of respective fungi was achieved with 100 percent success which results in the verification of Koch’s postulates. DNA of fungal pathogens was successfully extracted through phenol chloroform method. Amplification was done through ITS, b-tubulin gene, and Transcription Elongation Factor (EF1-a) gene primers and the amplified amplicons were sequenced and compared from NCBI which showed 99-100 % similarity with Ceratocystis manginecans. Fungus Ceratocystis manginecans formed one of strongly supported sub-clades through phylogenetic tree. Results obtained through this work would be supportive in establishment of relation of isolates with their region and will give information about pathogenicity level of isolates that would be useful to develop the management policies to reduce the afflictions in orchards caused by mango sudden death.

Keywords: artificial inoculation, mango, Ceratocystis manginecans, phylogenetic, screening

Procedia PDF Downloads 220
8 Infusing Social Business Skills into the Curriculum of Higher Learning Institutions with Special Reference to Albukhari International University

Authors: Abdi Omar Shuriye

Abstract:

A social business is a business designed to address socio-economic problems to enhance the welfare of the communities involved. Lately, social business, with its focus on innovative ideas, is capturing the interest of educational institutions, governments, and non-governmental organizations. Social business uses a business model to achieve a social goal, and in the last few decades, the idea of imbuing social business into the education system of higher learning institutions has spurred much excitement. This is due to the belief that it will lead to job creation and increased social resilience. One of the higher learning institutions which have invested immensely in the idea is Albukhari International University; it is a private education institution, on a state-of-the-art campus, providing an advantageous learning ecosystem. The niche area of this institution is social business, and it graduates job creators, not job seekers; this Malaysian institution is unique and one of its kind. The objective of this paper is to develop a work plan, direction, and milestone as well as the focus area for the infusion of social business into higher learning institutions with special reference to Al-Bukhari International University. The purpose is to develop a prototype and model full-scale to enable higher learning education institutions to construct the desired curriculum fermented with social business. With this model, major predicaments faced by these institutions could be overcome. The paper sets forth an educational plan and will spell out the basic tenets of social business, focusing on the nature and implementational aspects of the curriculum. It will also evaluate the mechanisms applied by these educational institutions. Currently, since research in this area remains scarce, institutions adopt the process of experimenting with various methods to find the best way to reach the desired result on the matter. The author is of the opinion that social business in education is the main tool to educate holistic future leaders; hence educational institutions should inspire students in the classroom to start up their own businesses by adopting creative and proactive teaching methods. This proposed model is a contribution in that direction.

Keywords: social business, curriculum, skills, university

Procedia PDF Downloads 59
7 Ameliorative Effect of Curcuma Longa against Arsenic Induced Reproductive Toxicity in Charles Foster Rats

Authors: Shazia Naheed Akhter, Rekha Kumari

Abstract:

An estimated 70 million population are exposed to arsenic poisoning in India in recent times. Arsenic contamination in the groundwater has caused serious health hazards among the exposed population. In Bihar, the first district was Bhojpur, where arsenic causing health issues were reported in 2002. Presently, there are 18 districts that are reported arsenic poisoning in the groundwater. The exposed population is firstly diseased with various symptoms such as skin manifestations, loss of appetite, constipation, hormonal disorders, etc. The long duration exposure has led to cause infertility in the male subjects. The present study thus aims to develop the antidote against arsenic-induced male reproductive toxicity in animal models. The study was carried out on Charles Foster Rats after the approval from Institutional Animal Ethics Committee. A total of n=18 rats (12 weeks old) of an average weight of 160 ± 20 g were used for the study. The study group included n=6 control and n= 12 treated with sodium arsenite orally at the dose of 8mg/Kg b.w daily for 40 days. The n= 6 animals were dissected and the rest n=6 was administered orally with Curcuma longa rhizome ethanolic extract at the dose of 600mg/Kg b.w per day for 40 days. At the end of the entire experiment, all the animals were dissected out and their reproductive organs were taken out, especially epididymis for sperm counts, sperm motility, sperm mortality, sperm morphology. The blood samples were collected for the hormonal assay (testosterone and luteinizing hormone), as well as for hematological and biochemical analysis. The study showed a high magnitude of degeneration in the reproductive organs of the rats in the arsenic-treated group. There were degenerative fluctuations in the sperm counts, sperm motility, sperm mortality, sperm morphology and in the hormonal parameters, as well as in the hematological and biochemical parameters in the arsenic-treated rats. But, after the administration of Curcuma longa, there was significant amelioration in all these parameters. Therefore, the present study shows that Curcuma longa plays a vital role to combat arsenic-induced male reproductive toxicity.

Keywords: sodium arsenite, Charles foster rats, ethanolic rhizome extract of curcuma longa, male reproductive toxicity, amelioration

Procedia PDF Downloads 192
6 Adequate Dietary Intake to Improve Outcome of Urine: Urea Nitrogen with Balance Nitrogen and Total Lymphocyte Count

Authors: Mardiana Madjid, Nurpudji Astuti Taslim, Suryani As'ad, Haerani Rasyid, Agussalim Bukhari

Abstract:

The high level of Urine Urea Nitrogen (UUN) indicates hypercatabolism occurs in hospitalized patients. High levels of Total Lymphocyte Count (TLC) indicates the immune system condition, adequate wound healing, and limit complication. Adequate dietary intake affects to decrease of hypercatabolism status in treated patient’s hospitals. Nitrogen Balance (NB) is simply the difference between nitrogen (N₂) intake and output. If more N₂ intake than output, then positive NB or anabolic will occur. This study aims to evaluate the effect of dietary intake in influencing balance nitrogen and total lymphocyte count. Method: A total of 43 patients admitted to a Wahidin Sudirohusodo Hospital between 2018 and 2019 for 10 days' treats are included. The inclusion criteria were patients who were treated for 10 days and receives food from the hospital orally. Patients did not experience gastrointestinal disorders such as vomiting and diarrhea and experience impair kidney function and liver function and expressed approval to participate in this study. During hospitalization, food intake, UUN, albumin serum, balance nitrogen, and TLC was assessed twice on day 1 and day 10. There is no Physician Clinical Nutritional intervention to correct food intake. UUN is 24 hours of urine collected on the second day after admission and the tenth day. Statistical analysis uses SPSS 24 with observational cohort methods. Result: The Forty-three participants completed the follow-up (27 men and 18 women). The age of fewer than 4 years is 22 people, 45 to 60 years is 16 people, and over 60 years is 4 people. The result of the study on day 1 obtained SGA score A, SGA score B, SGA score C are 8, 32, 3 until day 10 are 8, 31, 4, respectively. According to 24h dietary recalls, the energy intake during observation was from 522.5 ± 400.4 to 1011.9 ± 545.1 kcal/day P < 0.05, protein intake from 20.07 ± 17.2 to 40.3 ± 27.3 g/day P < 0.05, carbohydrates from 92.5 ± 71.6 to 184.8 ± 87.4 g/day, and fat from 5.5 ± 3.86 to 13.9 ± 13.9 g/day. The UUN during the observation was from 6.6 ± 7.3 to 5.5 ± 3.9 g/day, TLC decreased from 1622.9 ± 897.2 to 1319.9 ± 636.3/mm³ value target 1800/mm³, albumin serum from 3.07 ± 0.76 to 2.9 ± 0.57 g/day, and BN from -7.5 ± 7.2 to -3.1 ± 4.86. Conclusion: The high level of UUN needs to correct adequate dietary intake to improve NB and TLC status on hospitalized patients.

Keywords: adequate dietary intake, balance nitrogen, total lymphocyte count, urine urea nitrogen

Procedia PDF Downloads 90
5 Cardiac Protective Effect of Olive Oil against Ischemia Reperfusion- Induced Cardiac Arrhythmias in Isolated Diabetic Rat Hearts

Authors: Ishfaq A. Bukhari, Bassem Yousef Sheikh, Abdulrahman Almotrefi, Osama Yousaf, Amer Mahmood

Abstract:

Olive oil is the primary source of fat in the Mediterranean diet which is associated with a low mortality for cardiovascular disease. Olive oil is rich in monounsaturated fatty acids, and has been reported for variety of beneficial cardiovascular effects including blood pressure lowering, anti-platelet, anti-diabetic and anti-inflammatory effects. Growing number evidences from preclinical and clinical studies have shown that olive oil improves insulin resistance, decrease vessels stiffness and prevent thromboembolism. We evaluated the effects of olive against streptozotocin-induced physiological disorders in the animal models of diabetes and ischemia and reperfusion (I/R)- induced cardiac arrhythmias. Diabetes was induced in male rats with a single intraperitoneal injection of streptozotocin (60 mg/kg), rats were treated for two months with olive oil (1 ml/kg p.o). Control animals received saline. Blood glucose, body weight were monitored every 14 days. At the end of the treatment rats were sacrificed hearts were isolated for mounting on langedorff’s apparatus. The blood glucose and body weight was not significantly different in the control and olive treated animals. The control diabetic animals exhibited 100% incidence of I/R –induced ventricular fibrillation which was reduced to 0% with olive oil, treatment. The duration of ventricular fibrillation reduced from 98.8± 2.3 (control) to 0 seconds in the olive oil treated group. Diltiazem, a calcium channel blocker (1 µm/L) showed similar results and protected the I/R-induced cardiac disorders. The biochemical analysis of the cardiac tissues showed that diabetes and I/R produce marked pathological changes in the cardiomyocytes including decreased glutathione (GSH) and increased oxidative stress (Malondialdehyde; MDA). Pretreatment of animals with olive oil (1 ml/kg p.o) increased GSH and MDA levels. Olive oil also improved the diabetic-induced histopathological changes in the cardiomyocytes. These finding indicates that olive possesses cardiac protective properties. Further studies are under way in our lab to explore the mechanism of the cardio-protective effect of olive oil.

Keywords: diabeties, ischemia-reperfusion, olive oil, rats heart

Procedia PDF Downloads 438
4 Opto-Thermal Frequency Modulation of Phase Change Micro-Electro-Mechanical Systems

Authors: Syed A. Bukhari, Ankur Goswmai, Dale Hume, Thomas Thundat

Abstract:

Here we demonstrate mechanical detection of photo-induced Insulator to metal transition (MIT) in ultra-thin vanadium dioxide (VO₂) micro strings by using < 100 µW of optical power. Highly focused laser beam heated the string locally resulting in through plane and along axial heat diffusion. Localized temperature increase can cause temperature rise > 60 ºC. The heated region of VO₂ can transform from insulating (monoclinic) to conducting (rutile) phase leading to lattice compressions and stiffness increase in the resonator. The mechanical frequency of the resonator can be tuned by changing optical power and wavelength. The first mode resonance frequency was tuned in three different ways. A decrease in frequency below a critical optical power, a large increase between 50-120 µW followed by a large decrease in frequency for optical powers greater than 120 µW. The dynamic mechanical response was studied as a function of incident optical power and gas pressure. The resonance frequency and amplitude of vibration were found to be decreased with increasing laser power from 25-38 µW and increased by1-2 % when the laser power was further increased to 52 µW. The transition in films was induced and detected by a single pump and probe source and by employing external optical sources of different wavelengths. This trend in dynamic parameters of the strings can be co-related with reversible Insulator to metal transition in VO₂ films which creates change in density of the material and hence the overall stiffness of the strings leading to changes in string dynamics. The increase in frequency at a particular optical power manifests a transition to a more ordered metallic phase which tensile stress onto the string. The decrease in frequency at higher optical powers can be correlated with poor phonon thermal conductivity of VO₂ in conducting phase. Poor thermal conductivity of VO₂ can force in-plane penetration of heat causing the underneath SiN supporting VO₂ which can result as a decrease in resonance frequency. This noninvasive, non-contact laser-based excitation and detection of Insulator to metal transition using micro strings resonators at room temperature and with laser power in few µWs is important for low power electronics, and optical switching applications.

Keywords: thermal conductivity, vanadium dioxide, MEMS, frequency tuning

Procedia PDF Downloads 90