Search results for: torque loss
Commenced in January 2007
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Paper Count: 3754

Search results for: torque loss

2914 Development of a Drive Cycle Based Control Strategy for the KIIRA-EV SMACK Hybrid

Authors: Richard Madanda, Paul Isaac Musasizi, Sandy Stevens Tickodri-Togboa, Doreen Orishaba, Victor Tumwine

Abstract:

New vehicle concepts targeting specific geographical markets are designed to satisfy a unique set of road and load requirements. The KIIRA-EV SMACK (KES) hybrid vehicle is designed in Uganda for the East African market. The engine and generator added to the KES electric power train serve both as the range extender and the power assist. In this paper, the design consideration taken to achieve the proper management of the on-board power from the batteries and engine-generator based on the specific drive cycle are presented. To harness the fuel- efficiency benefits of the power train, a specific control philosophy operating the engine and generator at the most efficient speed- torque and speed-power regions is presented. By using a suitable model developed in MATLAB using Simulink and Stateflow, preliminary results show that the steady-state response of the vehicle for a particular hypothetical drive cycle mimicking the expected drive conditions in the city and highway traffic is sufficient.

Keywords: control strategy, drive cycle, hybrid vehicle, simulation

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2913 Intelligent Minimal Allocation of Capacitors in Distribution Networks Using Genetic Algorithm

Authors: S. Neelima, P. S. Subramanyam

Abstract:

A distribution system is an interface between the bulk power system and the consumers. Among these systems, radial distributions system is popular because of low cost and simple design. In distribution systems, the voltages at buses reduces when moved away from the substation, also the losses are high. The reason for a decrease in voltage and high losses is the insufficient amount of reactive power, which can be provided by the shunt capacitors. But the placement of the capacitor with an appropriate size is always a challenge. Thus, the optimal capacitor placement problem is to determine the location and size of capacitors to be placed in distribution networks in an efficient way to reduce the power losses and improve the voltage profile of the system. For this purpose, in this paper, two stage methodologies are used. In the first stage, the load flow of pre-compensated distribution system is carried out using ‘dimension reducing distribution load flow algorithm (DRDLFA)’. On the basis of this load flow the potential locations of compensation are computed. In the second stage, Genetic Algorithm (GA) technique is used to determine the optimal location and size of the capacitors such that the cost of the energy loss and capacitor cost to be a minimum. The above method is tested on IEEE 9 and 34 bus system and compared with other methods in the literature.

Keywords: dimension reducing distribution load flow algorithm, DRDLFA, genetic algorithm, electrical distribution network, optimal capacitors placement, voltage profile improvement, loss reduction

Procedia PDF Downloads 390
2912 Physicochemical Characterization of Waste from Vegetal Extracts Industry for Use as Briquettes

Authors: Maíra O. Palm, Cintia Marangoni, Ozair Souza, Noeli Sellin

Abstract:

Wastes from a vegetal extracts industry (cocoa, oak, Guarana and mate) were characterized by particle size, proximate and ultimate analysis, lignocellulosic fractions, high heating value, thermal analysis (Thermogravimetric analysis – TGA, and Differential thermal analysis - DTA) and energy density to evaluate their potential as biomass in the form of briquettes for power generation. All wastes presented adequate particle sizes to briquettes production. The wastes showed high moisture content, requiring previous drying for use as briquettes. Cocoa and oak wastes had the highest volatile matter contents with maximum mass loss at 310 ºC and 450 ºC, respectively. The solvents used in the aroma extraction process influenced in the moisture content of the wastes, which was higher for mate due to water has been used as solvent. All wastes showed an insignificant loss mass after 565 °C, hence resulting in low ash content. High carbon and hydrogen contents and low sulfur and nitrogen contents were observed ensuring a low generation of sulfur and nitrous oxides. Mate and cocoa exhibited the highest carbon and lignin content, and high heating value. The dried wastes had high heating value, from 17.1 MJ/kg to 20.8 MJ/kg. The results indicate the energy potential of wastes for use as fuel in power generation.

Keywords: agro-industrial waste, biomass, briquettes, combustion

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2911 Prediction of the Torsional Vibration Characteristics of a Rotor-Shaft System Using Its Scale Model and Scaling Laws

Authors: Jia-Jang Wu

Abstract:

This paper presents the scaling laws that provide the criteria of geometry and dynamic similitude between the full-size rotor-shaft system and its scale model, and can be used to predict the torsional vibration characteristics of the full-size rotor-shaft system by manipulating the corresponding data of its scale model. The scaling factors, which play fundamental roles in predicting the geometry and dynamic relationships between the full-size rotor-shaft system and its scale model, for torsional free vibration problems between scale and full-size rotor-shaft systems are firstly obtained from the equation of motion of torsional free vibration. Then, the scaling factor of external force (i.e., torque) required for the torsional forced vibration problems is determined based on the Newton’s second law. Numerical results show that the torsional free and forced vibration characteristics of a full-size rotor-shaft system can be accurately predicted from those of its scale models by using the foregoing scaling factors. For this reason, it is believed that the presented approach will be significant for investigating the relevant phenomenon in the scale model tests.

Keywords: torsional vibration, full-size model, scale model, scaling laws

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2910 The Real Consignee: An Exploratory Study of the True Party who is Entitled to Receive Cargo under Bill of Lading

Authors: Mojtaba Eshraghi Arani

Abstract:

According to the international conventions for the carriage of goods by sea, the consignee is the person who is entitled to take delivery of the cargo from the carrier. Such a person is usually named in the relevant box of the bill of lading unless the latter is issued “To Order” or “To Bearer”. However, there are some cases in which the apparent consignee, as above, was not intended to take delivery of cargo, like the L/C issuing bank or the freight forwarder who are named as consignee only for the purpose of security or acceleration of transit process. In such cases as well as the BL which is issued “To Order”, the so-called “real consignee” can be found out in the “Notify Party” box. The dispute revolves around the choice between apparent consignee and real consignee for being entitled not only to take delivery of the cargo but also to sue the carrier for any damages or loss. While it is a generally accepted rule that only the apparent consignee shall be vested with such rights, some courts like France’s Cour de Cassation have declared that the “Notify Party”, as the real consignee, was entitled to sue the carrier and in some cases, the same court went far beyond and permitted the real consignee to take suit even where he was not mentioned on the BL as a “Notify Party”. The main argument behind such reasoning is that the real consignee is the person who suffered the loss and thus had a legitimate interest in bringing action; of course, the real consignee must prove that he incurred a loss. It is undeniable that the above-mentioned approach is contrary to the position of the international conventions on the express definition of consignee. However, international practice has permitted the use of BL in a different way to meet the business requirements of banks, freight forwarders, etc. Thus, the issue is one of striking a balance between the international conventions on the one hand and existing practices on the other hand. While the latest convention applicable for sea transportation, i.e., the Rotterdam Rules, dealt with the comparable issue of “shipper” and “documentary shipper”, it failed to cope with the matter being discussed. So a new study is required to propose the best solution for amending the current conventions for carriage of goods by sea. A qualitative method with the concept of interpretation of data collection has been used in this article. The source of the data is the analysis of domestic and international regulations and cases. It is argued in this manuscript that the judge is not allowed to recognize any one as real consignee, other than the person who is mentioned in the “Consingee” box unless the BL is issued “To Order” or “To Bearer”. Moreover, the contract of carriage is independent of the sale contract and thus, the consignee must be determined solely based on the facts of the BL itself, like “Notify Party” and not any other contract or document.

Keywords: real consignee, cargo, delivery, to order, notify the party

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2909 Rearrangement and Depletion of Human Skin Folate after UVA Exposure

Authors: Luai Z. Hasoun, Steven W. Bailey, Kitti K. Outlaw, June E. Ayling

Abstract:

Human skin color is thought to have evolved to balance sufficient photochemical synthesis of vitamin D versus the need to protect not only DNA but also folate from degradation by ultraviolet light (UV). Although the risk of DNA damage and subsequent skin cancer is related to light skin color, the effect of UV on skin folate of any species is unknown. Here we show that UVA irradiation at 13 mW/cm2 for a total exposure of 187 J/cm2 (similar to a maximal daily equatorial dose) induced a significant loss of total folate in epidermis of ex vivo white skin. No loss was observed in black skin samples, or in the dermis of either color. Interestingly, while the concentration of 5 methyltetrahydrofolate (5-MTHF) fell in white epidermis, a concomitant increase of tetrahydrofolic acid was found, though not enough to maintain the total pool. These results demonstrate that UVA indeed not only decreases folate in skin, but also rearranges the pool components. This could be due in part to the reported increase of NADPH oxidase activity upon UV irradiation, which in turn depletes the NADPH needed for 5-MTHF biosynthesis by 5,10-methylenetetrahydrofolate reductase. The increased tetrahydrofolic acid might further support production of the nucleotide bases needed for DNA repair. However, total folate was lost at a rate that could, with strong or continuous enough exposure to ultraviolet radiation, substantially deplete light colored skin locally, and also put pressure on total body stores for individuals with low intake of folate.

Keywords: depletion, folate, human skin, ultraviolet

Procedia PDF Downloads 385
2908 Erosion Influencing Factors Analysis: Case of Isser Watershed (North-West Algeria)

Authors: Chahrazed Salhi, Ayoub Zeroual, Yasmina Hamitouche

Abstract:

Soil water erosion poses a significant threat to the watersheds in Algeria today. The degradation of storage capacity in large dams over the past two decades, primarily due to erosion, necessitates a comprehensive understanding of the factors that contribute to soil erosion. The Isser watershed, located in the Northwestern region of Algeria, faces additional challenges such as recurrent droughts and the presence of delicate marl and clay outcrops, which amplify its susceptibility to water erosion. This study aims to employ advanced techniques such as Geographic Information Systems (GIS) and Remote Sensing (RS), in conjunction with the Canonical Correlation Analysis (CCA) method and Soil Water Assessment Tool (SWAT) model, to predict specific erosion patterns and analyze the key factors influencing erosion in the Isser basin. To accomplish this, an array of data sources including rainfall, climatic, hydrometric, land use, soil, digital elevation, and satellite data were utilized. The application of the SWAT model to the Isser basin yielded an average annual soil loss of approximately 16 t/ha/year. Particularly high erosion rates, exceeding 12 T/ha/year, were observed in the central and southern parts of the basin, encompassing 41% of the total basin area. Through Canonical Correlation Analysis, it was determined that vegetation cover and topography exerted the most substantial influence on erosion. Consequently, the study identified significant and spatially heterogeneous erosion throughout the study area. The impact of land topography on soil loss was found to be directly proportional, while vegetation cover exhibited an inverse proportional relationship. Modeling specific erosion for the Ladrat dam sub-basin estimated a rate of around 39 T/ha/year, thus accounting for the recorded capacity loss of 17.80% compared to the bathymetric survey conducted in 2019. The findings of this research provide valuable decision-support tools for soil conservation managers, empowering them to make informed decisions regarding soil conservation measures.

Keywords: Isser watershed, RS, CCA, SWAT, vegetation cover, topography

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2907 Thinking in a Foreign Language Overcomes the Developmental Reversal in Risky Decision-Making: The Foreign Language Effect in Risky Decision-Making

Authors: Rendong Cai, Bei Peng, Yanping Dong

Abstract:

In risk decision making, individuals are found to be susceptible to 'frames': people tend to be risk averse when the choice is described in terms of potential 'gains' (gain frame), whereas they tend to be risk seeking when the same choice is described in terms of potential 'losses' (loss frame); this effect is termed the framing effect. The framing effect has been well documented and some studies even find a developmental reversal in the framing effect: The more experience an individual has in a certain field, the easier for him to be influenced by the frame relevant to the field, resulting in greater decision inconsistency. Recent studies reported that using a foreign language can reduce the framing effect. However, it is not clear whether foreign language use can overcome the developmental reversal in the framing effect. The present study investigated three potential factors that may influence the developmental reversal in the framing effect: specialized knowledge of the participants, the language in which the problem is presented, and the types of problems. The present study examined the decision making behavior of 188 Chinese-English bilinguals who majored in Finance, with a group of 277 English majors as the control group. They were asked to solve a financial problem (experimental condition) and a life problem (control condition). Each problem was presented in one of the following four versions: native language-gain frame, foreign language-gain frame, native language-loss frame, and foreign language-loss frame. Results revealed that for the life problem, under the native condition, both groups were affected by the frame; but under the foreign condition, this framing effect disappeared for the financial majors. This confirmed that foreign language use modulates framing effects in general decision making, which served as an effective baseline. For the financial problem, under the native condition, only the financial major was observed to be influenced by the frame, which was a developmental reversal; under the foreign condition, however, this framing effect disappeared. The results provide further empirical evidence for the universal of the developmental reversal in risky decision making. More importantly, the results suggest that using a foreign language can overcome such reversal, which has implications for the reduction of decision biases in professionals. The findings also shed new light on the complex interaction between general decision-making and bilingualism.

Keywords: the foreign language effect, developmental reversals, the framing effect, bilingualism

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2906 Swastika Shape Multiband Patch Antenna for Wireless Applications on Low Cost Substrate

Authors: Md. Samsuzzaman, M. T. Islam, J. S. Mandeep, N. Misran

Abstract:

In this article, a compact simple structure modified Swastika shape patch multiband antenna on a substrate of available low cost polymer resin composite material is designed for Wi-Fi and WiMAX applications. The substrate material consists of an epoxy matrix reinforced by woven glass. The designed micro-strip line fed compact antenna comprises of a planar wide square slot ground with four slits and Swastika shape radiation patch with a rectangular slot. The effect of the different substrate materials on the reflection coefficients of the proposed antennas was also analyzed. It can be clearly seen that the proposed antenna provides a wider bandwidth and acceptable return loss value compared to other reported materials. The simulation results exhibits that the antenna has an impedance bandwidth with -10 dB return loss at 3.01-3.89 GHz and 4.88-6.10 GHz which can cover both the WLAN, WiMAX and public safety WLAN bands. The proposed swastika shape antenna was designed and analyzed by using a finite element method based simulator HFSS and designed on a low cost FR4 (polymer resin composite material) printed circuit board. The electrical performances and superior frequency characteristics make the proposed material antenna desirable for wireless communications.

Keywords: epoxy resin polymer, multiband, swastika shaped, wide slot, WLAN/WiMAX

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2905 Cortical and Subcortical Dementias: A Psychoneurolinguistic Perspective

Authors: Sadeq Al Yaari, Fayza Alhammadi, Ayman Al Yaari, Montaha Al Yaari, Aayah Al Yaari, Adham Al Yaari, Sajedah Al Yaari, Saleh Al Yami

Abstract:

Background: A rapidly increasing number of studies that focus on the relationship between language and cortical (CD) and subcortical dementias (SCD) have recently shown that such correlation is existent. Mounting evidence suggests that cognitive impairments should be investigated against language disorders. Aims: This study aims at investigating how language is associated with dementia diseases namely CD &SCD in light of psychoneurolinguistic approach. Method: Data from multiple sources (e.g., theses, dissertations, articles, research, medical records, direct testing, staff reports, and client observations) have been integrated to provide a detailed analysis of the relationship between language and CD&SCD. The researchers identified over 20 most of dementia types, and described them. Having collected and described data, the researchers then analyzed these data independently to see to what extent CD&SCD are involved in matters concerning language. Results: Results of the present study demonstrate that language and CD&SCD are undoubtedly correlated with each other. The loss of the ability of some organs to perform certain functions (due to any of the dementia diseases) results in no way to the loss of some language aspects and /or speech skills. In clearer terms, it is rare to find a patient with dementia who is not suffering from partial or complete linguistic difficulties. Many deficits run through the current interpretation of linguistic disorders: language disorders, speech disorders, articulation disorders, or voice disorders.

Keywords: cortical dementia, subcortical dementia, diseases, psychoneurolinguistics, language, impairments, relationship

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2904 Stimulation of NCAM1-14.3.3.ζδ-derived Peptide Interaction Fuels Angiogenesis and Osteogenesis in Ageing

Authors: Taha Kadir Yesin, Hanyu Liu, Zhangfan Ding, Amit Singh, Qi Tian, Yuheng Zhang, Biswajyoti Borah, Junyu Chen, Anjali P. Kusumbe

Abstract:

The skeletal structure and bone marrow endothelium collectively form a critical functional unit essential for bone development, health, and aging. At the core of osteogenesis and bone formation lies the dynamic process of angiogenesis. In this study, we reveal a potent endogenous anabolic NCAM1-14.3.3. ζδ-derived- Peptide interaction, which stimulates bone angiogenesis and osteogenesis during homeostasis, aging, and age-related bone diseases. Employing high-resolution imaging and inducible cell-specific mouse genetics, our results elucidate the pivotal role of the NCAM1-14.3.3.ζδ-derived-Peptide interaction in driving the expansion of Clec14a+ angiogenic endothelial cells. Notably, Clec14a+ endothelial cells express key osteogenic factors. The NCAM1-14.3.3.ζδ-derived-Peptide interaction in osteoblasts drives osteoblast differentiation, ultimately contributing to the genesis of bone. Moreover, the NCAM1-14.3.3.ζδ-derived-Peptide interaction leads to a reduction in bone resorption. In age-associated vascular and bone loss diseases, stimulating the NCAM1-14.3.3.ζδ-derived-Peptide interaction not only promotes angiogenesis but also reverses bone loss. Consequently, harnessing the endogenous anabolic potential of the NCAM1-14.3.3.ζδ-derived-Peptide interaction emerges as a promising therapeutic modality for managing age-related bone diseases.

Keywords: endothelial cell, NCAM1, Clec14a, 14.3.3.ζδ

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2903 The Effect of Vitamin "E" on the Peripheral Neurotoxicity of Antimony in Adult Male Albino Rat

Authors: Pymaneh Bairami Rad

Abstract:

The present work was planned with the aim to study the histological changes that might occur in the sciatic nerve of adult male albino rat following antimony trioxide exposure and to throw more light on the protective role of vitamin "E" on the peripheral neurotoxicity induced by this environmental toxin Sixty adult male albino rats, weighing 183 - 235 grams, were utilized in this work. The animals were divided into 3 groups; each of 20 rats: animals of group I served as control, animals of group II received antimony trioxide daily for 12 successive weeks , animals of group III received antimony trioxide and vitamin "E" daily for the same duration. Antimony trioxide was given in a daily dose of 500 mg/ kg body weight which represents 1/40 of the known LD50 and vitamin "E" was administered in a daily dose of 300 mg/kg body weight. Both antimony trioxide and vitamin "E" were given to the animals by gastric intubation. This research revealed many histological changes in the sciatic nerve, following exposure to antimony trioxide, including Wallerian degeneration in most myelinated nerve fibers with pleomorphic destruction, fragmentation, loss of normal lamination and rupture of myelin sheaths. The axoplasms of these nerve fibers were irregular, degenerated and contained myelin fragments with loss of neurofibrils. Obvious increase in endoneurium was also observed. Concomitant administration of vitamin "E" with antimony trioxide resulted in marked improvement in the histological changes observed in the sciatic nerve.

Keywords: neurotoxicity, antimony, vitamin e, anatomy, histology

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2902 The Utilisation of Storytelling as a Therapeutic Intervention by Educational Psychologists to Address Behavioural Challenges Relating to Grief of Adolescent Clients

Authors: Laila Jeebodh Desai

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Storytelling as a therapeutic intervention entails the narrating of events by externalising emotions, thoughts and responses to life-changing events such as loss and grief. This creates the opportunity for clients to engage with psychologists by projecting various beliefs and challenges, such as grief, through a range of therapeutic modalities. This study conducts an inquiry into the ways in which storytelling can be utilised by educational psychologists with adolescent clients to address behavioural challenges relating to grief. This qualitative study therefore aims to facilitate an understanding of the use and benefits of storytelling as a therapeutic intervention. This has been achieved by examining interviews with four educational psychologists who have utilised storytelling as a therapeutic intervention with adolescent clients to overcome challenges with grief. The participants (educational psychologists) discussed case studies during interviews, which provided evidence of their practical administration of storytelling as a therapeutic intervention incorporating integrated theoretical approaches through the use of blended therapeutic techniques. Behavioural challenges relating to grief were also predominant in the case study information provided by the participants. The participants further confirmed that the term ‘grief’ included different types of loss that were experienced among adolescent clients. The implications and recommendations of the findings encouraged the utilisation of storytelling as a therapeutic intervention with adolescent clients in addressing behavioural challenges related to grief, based on the outcome of the case studies discussed by the participants.

Keywords: storytelling, therapeutic intervention, adolescents, grief

Procedia PDF Downloads 496
2901 Human-Carnivore Interaction: Patterns, Causes and Perceptions of Local Herders of Hoper Valley in Central Karakoram National Park, Pakistan

Authors: Saeed Abbas, Rahilla Tabassum, Haider Abbas, Babar Khan, Shahid Hussain, Muhammad Zafar Khan, Fazal Karim, Yawar Abbas, Rizwan Karim

Abstract:

Human–carnivore conflict is considered to be a major conservation and rural livelihood concern because many carnivore species have been heavily victimized due to elevated conflict levels with communities. Like other snow leopard range countries, this situation prevails in Pakistan, where WWF is currently working under Asia High Mountain Project (AHMP) in Gilgit-Baltistan of Pakistan. To mitigate such conflicts requires a firm understanding of grazing and predation pattern including human-carnivore interaction. For this purpose we conducted a survey in Hoper valley (one of the AHMP project sites in Pakistan), during August, 2013 through a questionnaire based survey and unstructured interviews covering 647 households, permanently residing in the project area out of the total 900 households. The valley, spread over 409 km2 between 36°7'46" N and 74°49'2"E, at 2900m asl in Karakoram ranges is considered to be one of an important habitat of snow leopard and associated prey species such as Himalayan ibex. The valley is home of 8100 Brusho people (ancient tribe of Northern Pakistan) dependent on agro-pastoral livelihoods including farming and livestock rearing. The total number of livestock reported were (N=15,481) out of which 8346 (53.91%) were sheep, 3546 (22.91%) goats, 2193 (14.16%) cows, 903 (5.83%) yaks, 508 (3.28%) bulls, 28 (0.18%) donkeys, 27 (0.17%) zo/zomo (cross breed of yak and cow), and 4 (0.03%) horses. 83 percent respondent (n=542 households) confirmed loss of their livestock during the last one year July, 2012 to June, 2013 which account for 2246 (14.51%) animals. The major reason of livestock loss include predation by large carnivores such as snow leopards and wolf (1710, 76.14%) followed by diseases (536, 23.86%). Of the total predation cases snow leopard is suspected to kill 1478 animals (86.43%). Among livestock sheep were found to be the major prey of snow leopard (810, 55%) followed by goats (484, 32.7%) cows (151, 10.21%), yaks (15, 1.015%), zo/zomo (7, 0.5%) and donkey (1, 0.07%). The reason for the mass depredation of sheep and goats is that they tend to browse on twigs of bushes and graze on soft grass near cliffs. They are also considered to be very active as compared to other species in moving quickly and covering more grazing area. This makes them more vulnerable to snow leopard attack. The majority (1283, 75%) of livestock killed by predators occurred during the warm season (May-September) in alpine and sub-alpine pastures and remaining (427, 25%) occurred in the winter season near settlements in valley. It was evident from the recent study that Snow leopard kills outside the pen were (1351, 79.76%) as compared to inside pen (359, 20.24%). Assessing the economic loss of livestock predation we found that the total loss of livestock predation in the study area is equal to PKR 11,230,000 (USD 105,797), which is about PRK 17, 357 (USD 163.51) per household per year. Economic loss incurred by the locals due to predation is quite significant where the average cash income per household per year is PKR 85,000 (USD 800.75).

Keywords: carnivores, conflict, predation, livelihood, conservation, rural, snow leopard, livestock

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2900 Evaluating the Effectiveness of Mesotherapy and Topical 2% Minoxidil for Androgenic Alopecia in Females, Using Topical 2% Minoxidil as a Common Treatment

Authors: Hamed Delrobai Ghoochan Atigh

Abstract:

Androgenic alopecia (AGA) is a common form of hair loss, impacting approximately 50% of females, which leads to reduced self-esteem and quality of life. It causes progressive follicular miniaturization in genetically predisposed individuals. Mesotherapy -- a minimally invasive procedure, topical 2% minoxidil, and oral finasteride have emerged as popular treatment options in the realm of cosmetics. However, the efficacy of mesotherapy compared to other options remains unclear. This study aims to assess the effectiveness of mesotherapy when it is added to topical 2% minoxidil treatment on female androgenic alopecia. Mesotherapy, also known as intradermotherapy, is a technique that entails administering multiple intradermal injections of a carefully composed mixture of compounds in low doses, applied at various points in close proximity to or directly over the affected areas. This study involves a randomized controlled trial with 100 female participants diagnosed with androgenic alopecia. The subjects were randomly assigned to two groups: Group A used topical 2% minoxidil twice daily and took Finastride oral tablet. For Group B, 10 mesotherapy sessions were added to the prior treatment. The injections were administered every week in the first month of treatment, every two weeks in the second month, and after that the injections were applied monthly for four consecutive months. The response assessment was made at baseline, the 4th session, and finally after 6 months when the treatment was complete. Clinical photographs, 7-point Likert scale patient self-evaluation, and 7-point Likert scale assessment tool were used to measure the effectiveness of the treatment. During this evaluation, a significant and visible improvement in hair density and thickness was observed. The study demonstrated a significant increase in treatment efficacy in Group B compared to Group A post-treatment, with no adverse effects. Based on the findings, it appears that mesotherapy offers a significant improvement in female AGA over minoxidil. Hair loss was stopped in Group B after one month and improvement in density and thickness of hair was observed after the third month. The findings from this study provide valuable insights into the efficacy of mesotherapy in treating female androgenic alopecia. Our evaluation offers a detailed assessment of hair growth parameters, enabling a better understanding of the treatments' effectiveness. The potential of this promising technique is significantly enhanced when carried out in a medical facility, guided by appropriate indications and skillful execution. An interesting observation in our study is that in areas where the hair had turned grey, the newly regrown hair does not retain its original grey color; instead, it becomes darker. The results contribute to evidence-based decision-making in dermatological practice and offer different insights into the treatment of female pattern hair loss.

Keywords: androgenic alopecia, female hair loss, mesotherapy, topical 2% minoxidil

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2899 Effect of Modified Atmosphere Packaging and Storage Temperatures on Quality of Shelled Raw Walnuts

Authors: M. Javanmard

Abstract:

This study was aimed at analyzing the effects of packaging (MAP) and preservation conditions on the packaged fresh walnut kernel quality. The central composite plan was used for evaluating the effect of oxygen (0–10%), carbon dioxide (0-10%), and temperature (4-26 °C) on qualitative characteristics of walnut kernels. Also, the response level technique was used to find the optimal conditions for interactive effects of factors, as well as estimating the best conditions of process using least amount of testing. Measured qualitative parameters were: peroxide index, color, decreased weight, mould and yeast counting test, and sensory evaluation. The results showed that the defined model for peroxide index, color, weight loss, and sensory evaluation is significant (p < 0.001), so that increase of temperature causes the peroxide value, color variation, and weight loss to increase and it reduces the overall acceptability of walnut kernels. An increase in oxygen percentage caused the color variation level and peroxide value to increase and resulted in lower overall acceptability of the walnuts. An increase in CO2 percentage caused the peroxide value to decrease, but did not significantly affect other indices (p ≥ 0.05). Mould and yeast were not found in any samples. Optimal packaging conditions to achieve maximum quality of walnuts include: 1.46% oxygen, 10% carbon dioxide, and temperature of 4 °C.

Keywords: shelled walnut, MAP, quality, storage temperature

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2898 High Motivational Salient Face Distractors Slowed Target Detection: Evidence from Behavioral Studies

Authors: Rashmi Gupta

Abstract:

Rewarding stimuli capture attention involuntarily as a result of an association process that develops quickly during value learning, referred to as the reward or value-driven attentional capture. It is essential to compare reward with punishment processing to get a full picture of value-based modulation in visual attention processing. Hence, the present study manipulated both valence/value (reward as well as punishment) and motivational salience (probability of an outcome: high vs. low) together. Series of experiments were conducted, and there were two phases in each experiment. In phase 1, participants were required to learn to associate specific face stimuli with a high or low probability of winning or losing points. In the second phase, these conditioned stimuli then served as a distractor or prime in a speeded letter search task. Faces with high versus low outcome probability, regardless of valence, slowed the search for targets (specifically the left visual field target) and suggesting that the costs to performance on non-emotional cognitive tasks were only driven by motivational salience (high vs. loss) associated with the stimuli rather than the valence (gain vs. loss). It also suggests that the processing of motivationally salient stimuli is right-hemisphere biased. Together, results of these studies strengthen the notion that our visual attention system is more sensitive to affected by motivational saliency rather than valence, which termed here as motivational-driven attentional capture.

Keywords: attention, distractors, motivational salience, valence

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2897 Leaching Losses of Fertilizer Nitrogen as Affected by Sulfur and Nitrification Inhibitor Applications

Authors: Abdel Khalek Selim, Safaa Mahmoud

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Experiments were designed to study nitrogen loss through leaching in soil columns treated with different nitrogen sources and elemental sulfur. The soil material (3 kg alluvial or calcareous soil) were packed in Plexiglas columns (10 cm diameter). The soil columns were treated with 2 g N in the form of Ca(NO3)2, urea, urea + inhibitor (Nitrapyrin), another set of these treatments was prepared to add elemental sulfur. During incubation period, leaching was performed by applying a volume of water that allows the percolation of 250-ml water throughout the soil column. The leachates were analyzed for NH4-N and N03-N. After 10 weeks, soil columns were cut into four equal segments and analyzed for ammonium, nitrate, and total nitrogen. Results indicated the following: Ca(NO3)2 treatment showed a rapid NO3 leaching, especially in the first 3 weeks, in both clay and calcareous soils. This means that soil texture did not play any role in this respect. Sulfur addition also did not affect the rate of NO3 leaching. In urea treatment, there was a steady increase of NH4- and NO3–N from one leachate to another. Addition of sulfur with urea slowed down the nitrification process and decreased N losses. Clay soil contained residual N much more than calcareous soil. Almost one-third of added nitrogen might have been immobilized by soil microorganisms or lost through other loss paths. Nitrification inhibitor can play a role in preserving added nitrogen from being lost through leaching. Combining the inhibitor with elemental sulfur may help to stabilize certain preferred ratio of NH4 to NO3 in the soil for the benefit of the growing plants.

Keywords: alluvial soil, calcareous soil, elemental sulfur, nitrate leaching

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2896 Correlations between Wear Rate and Energy Dissipation Mechanisms in a Ti6Al4V–WC/Co Sliding Pair

Authors: J. S. Rudas, J. M. Gutiérrez Cabeza, A. Corz Rodríguez, L. M. Gómez, A. O. Toro

Abstract:

The prediction of the wear rate of rubbing pairs has attracted the interest of many researchers for years. It has been recently proposed that the sliding wear rate can be inferred from the calculation of the energy rate dissipated by the tribological pair. In this paper some of the dissipative mechanisms present in a pin-on-disc configuration are discussed and both analytical and numerical calculations are carried out. Three dissipative mechanisms were studied: First, the energy release due to temperature gradients within the solid; second, the heat flow from the solid to the environment, and third, the energy loss due to abrasive damage of the surface. The Finite Element Method was used to calculate the dynamics of heat transfer within the solid, with the aid of commercial software. Validation the FEM model was assisted by virtual and laboratory experimentation using different operating points (sliding velocity and geometry contact). The materials for the experiments were Ti6Al4V alloy and Tungsten Carbide (WC-Co). The results showed that the sliding wear rate has a linear relationship with the energy dissipation flow. It was also found that energy loss due to micro-cutting is relevant for the system. This mechanism changes if the sliding velocity and pin geometry are modified though the degradation coefficient continues to present a linear behavior. We found that the less relevant dissipation mechanism for all the cases studied is the energy release by temperature gradients in the solid.

Keywords: degradation, dissipative mechanism, dry sliding, entropy, friction, wear

Procedia PDF Downloads 502
2895 Comparative Survival Rates of Yeasts during Freeze-Drying, Traditional Drying and Spray Drying

Authors: Latifa Hamoudi-Belarbi, L'Hadi Nouri, Khaled Belkacemi

Abstract:

The effect of three methods of drying (traditional drying, freeze-drying and spray-drying) on the survival of concentrated cultures of Geotrichum fragrans and Wickerhamomyces anomalus was studied. The survival of yeast cultures was initially compared immediately after freeze-drying using HES 12%(w/v)+Sucrose 7% (w/v) as protectant, traditional drying in dry rice cakes and finally spray-drying with whey proteins. The survival of G. fragrans and W. anomalus was studied during 4 months of storage at 4°C and 25°C, in the darkness, under vacuum and at 0% relative humidity. The results demonstrated that high survival was obtained using traditional method of preservation in rice cakes (60% for G. fragrans and 65% for W. anomalus) and freeze-drying in (68% for G. fragrans and 74% for W. anomalus). However, poor survival was obtained by spray-drying method in whey protein with 20% for G. fragrans and 29% for W. anomalus. During storage at 25°C, yeast cultures of G. fragrans and W. anomalus preserved by traditional and freeze-drying methods showed no significant loss of viable cells up to 3 months of storage. Spray-dried yeast cultures had the greatest loss of viable count during the 4 months of storage at 25°C. During storage at 4°C, preservation of yeasts cultures using traditional method of preservation provided better survival than freeze-drying. This study demonstrated the effectiveness of the traditional method to preserve yeasts cultures compared to the high cost methods like freeze-drying and spray-drying.

Keywords: freeze-drying, traditional drying, spray drying, yeasts

Procedia PDF Downloads 488
2894 Coupled Spacecraft Orbital and Attitude Modeling and Simulation in Multi-Complex Modes

Authors: Amr Abdel Azim Ali, G. A. Elsheikh, Moutaz Hegazy

Abstract:

This paper presents verification of a modeling and simulation for a Spacecraft (SC) attitude and orbit control system. Detailed formulation of coupled SC orbital and attitude equations of motion is performed in order to achieve accepted accuracy to meet the requirements of multitargets tracking and orbit correction complex modes. Correction of the target parameter based on the estimated state vector during shooting time to enhance pointing accuracy is considered. Time-optimal nonlinear feedback control technique was used in order to take full advantage of the maximum torques that the controller can deliver. This simulation provides options for visualizing SC trajectory and attitude in a 3D environment by including an interface with V-Realm Builder and VR Sink in Simulink/MATLAB. Verification data confirms the simulation results, ensuring that the model and the proposed control law can be used successfully for large and fast tracking and is robust enough to keep the pointing accuracy within the desired limits with considerable uncertainty in inertia and control torque.

Keywords: attitude and orbit control, time-optimal nonlinear feedback control, modeling and simulation, pointing accuracy, maximum torques

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2893 Role of Physical Properties of Maize Grains Towards Resistance to Sitotroga Cerealella (OLIV.) (Gelechiidae: Lepidoptera) in No Choice

Authors: Sohail Ahmed, Ahmad Raza

Abstract:

Physical properties of maize grains were correlated with levels of the life history of Sitotroga cerealella (Oliv.) (Gelechiidae: Lepidoptera) in no choice test to find out relative resistance in different varieties. Eight maize varieties /lines (EV-6089, Sahiwal-2002, Golden, 34N43, EV-1098, Sultan, China-1, EV-20) including seven yellow and one white were obtained from Maize and Millet Research Institute, Yousaf Wala, Sahiwal, Punjab, Pakistan. Freshly laid eggs (one day old) of S. cerealella were obtained and cultured on a susceptible maize variety for two generations for later on shifting to test varieties. Results showed that maximum moth emergence (10.33), fecundity (35.66), hatching (87.66%), moth weight (5.05 mg), development time (36.0 days) damage (93.35%) and grain weight loss (38.84%) was found in varieties, 34N43 and Golden, Sultan, Sahiwal 2002, 34N43, EV-6089, 34N43 and EV-1089, respectively. Varieties had significant difference with other varieties in these parameters (P<0.05). The varieties had positive as well as negative correlation between hardness index, grain weight and bulk density with the biological parameters of S. cerealella, percent grain damage and weight loss. Possible involvement of these grain properties in the resistance of maize grains towards S. cerealella is discussed.

Keywords: sitotroga cerealella, hardness index, grain damage, maize, varieties

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2892 Loss of Control Eating as a Key Factor of the Psychological Symptomatology Related to Childhood Obesity

Authors: L. Beltran, S. Solano, T. Lacruz, M. Blanco, M. Rojo, M. Graell, A. R. Sepulveda

Abstract:

Introduction and Objective: Given the difficulties of assessing Binge Eating Disorder during childhood, episodes of Loss of Control (LOC) eating can be a key symptom. The objective is to know the prevalence of food psychopathology depending on the type of evaluation and find out which psychological characteristics differentiate overweight or obese children who present LOC from those who do not. Material and Methods: 170 children from 8 to 12 years of age with overweight or obesity (P > 85) were evaluated through the Primary Care Centers of Madrid. Sociodemographic data and psychological measures were collected through the Kiddie-Schedule for Affective Disorders & Schizophrenia, Present & Lifetime Version (K-SADS-PL) diagnostic interview and self-applied questionnaires: Children's eating attitudes (ChEAT), depressive symptomatology (CDI), anxiety (STAIC), general self-esteem (LAWSEQ), body self-esteem (BES), perceived teasing (POTS) and perfectionism (CAPS). Results: 15.2% of the sample exceeded the ChEAT cut-off point, presenting a risk of pathological eating; 5.88% presented an Eating Disorder through the diagnostic interview (2.35% Binge Eating disorder), and 33.53% had LOC episodes. No relationship was found between the presence of LOC and clinical diagnosis of eating disorders according to DSM-V; however, the group with LOC presented a higher risk of eating psychopathology using the ChEAT (p < .02). Significant differences were found in the group with LOC (p < .02): higher z-BMI, lower body self-esteem, greater anxious symptomatology, greater frequency of teasing towards weight, and greater effect of teasing both towards weight and competitions; compared to their peers without LOC. Conclusion: According to previous studies in samples with overweight children, in this Spanish sample of children with obesity, we found a prevalence of moderate eating disorder and a high presence of LOC episodes, which is related to both eating and general psychopathology. These findings confirm that the exclusion of LOC episodes as a diagnostic criterion can underestimate the presence of eating psychopathology during this developmental stage. According to these results, it is highly recommended to promote school context programs that approach LOC episodes in order to reduce associated symptoms. This study is included in a Project funded by the Ministry of Innovation and Science (PSI2011-23127).

Keywords: childhood obesity, eating psychopathology, loss-of-control eating, psychological symptomatology

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2891 Transition Pay vs. Liquidity Holdings: A Comparative Analysis on Consumption Smoothing using Bank Transaction Data

Authors: Nora Neuteboom

Abstract:

This study investigates household financial behaviors during unemployment spells in the Netherlands using high-frequency transaction data through a event study specification integrating propensity score matching. In our specification, we contrasted treated individuals, who underwent job loss, with non-treated individuals possessing comparable financial characteristics. The initial onset of unemployment triggers a substantial surge in income, primarily attributed to transition payments, but swiftly drops post-unemployment, with unemployment benefits covering slightly over half of former salary earnings. Despite a re-employment rate of around half within six months, the treatment group experiences a persistent average monthly earnings reduction of approximately 600 EUR by month. Spending patterns fluctuate significantly, surging before unemployment due to transition payments and declining below non-treated individuals post-unemployment, indicating challenges to fully smooth consumption after job loss. Furthermore, our study disentangles the effects of transition payments and liquidity holdings on spending, revealing that transition payments exert a more pronounced and prolonged impact on consumption smoothing than liquidity holdings. Transition payments significantly stimulate spending, particularly in pin and iDEAL categories, contrasting a much smaller relative spending impact of liquidity holdings.

Keywords: household consumption, transaction data, big data, propensity score matching

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2890 Control of a Wind Energy Conversion System Works in Tow Operating Modes (Hyper Synchronous and Hypo Synchronous)

Authors: A. Moualdia, D. J. Boudana, O. Bouchhida, A. Medjber

Abstract:

Wind energy has many advantages, it does not pollute and it is an inexhaustible source. However, the cost of this energy is still too high to compete with traditional fossil fuels, especially on sites less windy. The performance of a wind turbine depends on three parameters: the power of wind, the power curve of the turbine and the generator's ability to respond to wind fluctuations. This paper presents a control chain conversion based on a double-fed asynchronous machine and flow-oriented. The supply system comprises of two identical converters, one connected to the rotor and the other one connected to the network via a filter. The architecture of the device is up by three commands are necessary for the operation of the turbine control extraction of maximum power of the wind to control itself (MPPT) control of the rotor side converter controlling the electromagnetic torque and stator reactive power and control of the grid side converter by controlling the DC bus voltage and active power and reactive power exchanged with the network. The proposed control has been validated in both modes of operation of the three-bladed wind 7.5 kW, using Matlab/Simulink. The results of simulation control technology study provide good dynamic performance and static.

Keywords: D.F.I.G, variable wind speed, hypersynchrone, energy quality, hyposynchrone

Procedia PDF Downloads 366
2889 A Dual Debrief-Based Co-Autoethnography of a Humanitarian Delegation Member: Supporting Ukraine Refugee Mothers through Ambiguous Loss

Authors: Bilha Paryente, Rivi Frei Landau

Abstract:

Autoethnography - a combination of autobiography and ethnography - focuses on the intersection of personal experiences and the culture in which they take place and is considered a viable method for exploring human experiences. The Russo-Ukrainian war has resulted in millions of forcibly displaced asylum-seeking refugees facing ambiguous loss. Whereas much is known about refugees' support needs, little is known about the needs and experiences of the humanitarian delegation members (HDM) who assist them. Through a debrief-based co-autoethnographic account of a female HDM who supported Ukrainian refugee mothers and children on the Polish borders, we explored the lived experiences involved in such a mission. Specifically, we conducted a transnational dyadic autoethnography debrief-based co-autoethnography which included both verbal and photo-based debriefing (8 two-hour sessions) alongside a reflexive (10-day) field diary analysis. Content analysis revealed cognitive dilemmas, emotional struggles, and practical adaptations occurring within the HDM's three identity-related domains: personal, professional (psychologist), and ethnic. The methodology presented and demonstrated in this paper enhances our theoretical understanding of the challenges faced by HDMs and may contribute to better future design of HDM training. Practically, the findings of the current study suggest the need for a three-stage accompaniment for HDMs relating to their personal, professional, and ethnic identities and considering their cognitive, emotional, and adaptive aspects. First, before leaving, HDMs should be briefed on personal and professional aspects of their experiences and ways of coping with them, as well as ethnic and religious affiliation issues. Second, while volunteering every evening their dilemmas, emotional struggles, and ways of adapting should be addressed for the three layers of identities. And finally, shortly after their return, there should be a final meeting to discuss all aspects of their identities and layers of personality. In this way, HDMs can become more effective in the important mission they fulfill. We hope that future HDMs and the bodies that send them on humanitarian missions of paramount importance will adopt these recommendations and generate proactive insights for members of future delegations.

Keywords: autoethnography, refugees, humanitarian delegation, ambiguous loss, Russo-Ukraine War, parenting

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2888 “Congratulations, I Am Sorry for Your Loss”. A Qualitative Study to Help Healthcare Providers Search for Words When a Baby Dies

Authors: Liesbeth Van Kelst, Jozefiene Jansens

Abstract:

Background: All care providers within mother and child care are confronted, at some point in their career, with the care for parents who (will) lose or have lost a baby. Obtaining the correct attitude and communicating well during these difficult moments are aspects that many healthcare provides continue to struggle with. Parents still encounter well-intentioned but inappropriate communication from healthcare providers. Aim: To study how communication, both verbal and non-verbal, around the death of a baby during pregnancy, birth, or in the first ten days postnatal was experienced by parents and healthcare providers. Methods: A qualitative study using grounded theory principles was conducted. Data were collected through 22 individual face-to-face in-depth interviews with parents who had lost a baby (n = 12) and intramural caregivers, such as midwives, nurses, gynecologists and neonatologists (n=10). In the first phase, data were analyzed within each group separately (parents and healthcare providers) and in the second phase, findings from both groups were compared and analyzed according to meta-synthesis principles. Results: The themes that emerged from the data demonstrated congruent experiences between the group of the parents and the health care providers. Both strengths and weaknesses in current care were named and suggestions for appropriate communication were formulated. Conclusion: Since most health care providers only occasionally care for parents with a deceased baby, a communication tool can optimize communication between healthcare professionals and parents who lose a baby. This is very important as the words which are said at this difficult period last a lifetime in the heads of parents.

Keywords: communication, death, perinatal loss, stillbirth

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2887 Macular Ganglion Cell Inner Plexiform Layer Thinning

Authors: Hye-Young Shin, Chan Kee Park

Abstract:

Background: To compare the thinning patterns of the ganglion cell-inner plexiform layer (GCIPL) and peripapillary retinal nerve fiber layer (pRNFL) as measured using Cirrus high-definition optical coherence tomography (HD-OCT) in patients with visual field (VF) defects that respect the vertical meridian. Methods: Twenty eyes of eleven patients with VF defects that respect the vertical meridian were enrolled retrospectively. The thicknesses of the macular GCIPL and pRNFL were measured using Cirrus HD-OCT. The 5% and 1% thinning area index (TAI) was calculated as the proportion of abnormally thin sectors at the 5% and 1% probability level within the area corresponding to the affected VF. The 5% and 1% TAI were compared between the GCIPL and pRNFL measurements. Results: The color-coded GCIPL deviation map showed a characteristic vertical thinning pattern of the GCIPL, which is also seen in the VF of patients with brain lesions. The 5% and 1% TAI were significantly higher in the GCIPL measurements than in the pRNFL measurements (all P < 0.01). Conclusions: Macular GCIPL analysis clearly visualized a characteristic topographic pattern of retinal ganglion cell (RGC) loss in patients with VF defects that respect the vertical meridian, unlike pRNFL measurements. Macular GCIPL measurements provide more valuable information than pRNFL measurements for detecting the loss of RGCs in patients with retrograde degeneration of the optic nerve fibers.

Keywords: brain lesion, macular ganglion cell, inner plexiform layer, spectral-domain optical coherence tomography

Procedia PDF Downloads 336
2886 The Relationship between Vitamin D and Vitamin B12 Concentrations in Cataract Patients (Senile vs Diabetic)

Authors: Ali Showail Ali Alasmari

Abstract:

Introduction: Cataract is the loss of transparency of the lens inside the eye. It is the most common cause of visual loss and blindness worldwide. This study provides a systemic review of the recent findings on the association of vitamin D, and vitamin B12, and their possible role in preventing cataracts in senile (S) and diabetic mellitus (DM) patient groups. Objective: This study was intended to establish and investigate if there is any role between vitamin D and vitamin B12? Secondly, the connection between serum level of vitamin D and vitamin B12 in cataract incidence senile (s) vs. diabetic mellitus (DM) cataract patient groups. Furthermore, to evaluate and analyze cataract occurrence regarding vitamin D and vitamin B12 levels with other risk factors. Finally, to evaluate lens opacities pre and post treatment with vitamin D and vitaminB12 linked to age and visual acuity loss in both senile(S) and diabetic mellitus (DM) cataract patients’ groups. Methods: This study conducted at the ophthalmology clinic at Muhyail General Hospital. Select a prospective case-control to study the effect of vitamin D and Vit B12 on senile(S) cataracts that caused by age and diabetic mellitus (DM)cataract patients; then we compare these two groups. This study prospectively enrolled a total of 50 samples, 25 with senile cataract and 25 with diabetic cataract, from ophthalmology clinic at Muhyail General Hospital. Measuring 25-hydroxy vitamin D and vitamin B12 level concentrations in the assigned samples. Analyses were performed using SAS (statistical analysis software) program. Results: The most important finding in this study was that the senile(s) cataract patients’ group greatly benefited by the combination therapy of vitamin D, and Vitamin B12 reached (28.5±1.50 and 521.1±21.10) respectively; on the contrary, the diabetic cataract patient group hardly shows any significant improvement (21.5 ± 1.00 and 197.2 ± 7.20) respectively. This is because of the Metformin, the first line drug for treating diabetes, has been reported to potentially decrease vitamin B-12 status. This epigenetic modification was correlated with the diabetic mellitus (DM) cataract patients’ group not responding. Vitamin B12 deficiency also leads to an impairment of the conversion of methylmalonyl-CoA to succinyl-CoA, which has been associated with insulin resistance. There was no significant difference between the age, body mass index (BMI), the mean of Vit-D pre-treatments, and the mean values of Hemoglobin A1C of both senile (S) and diabetic mellitus (DM) cataract patient groups. On other hand, there was a highly significant difference between the mean values of glucose levels in both senile (S) and diabetic mellitus (DM) cataract patient groups. Conclusion: Here we conclude that diabetic mellitus (DM) cataract patient group hardly benefited from this combination therapy vitamin D and vitamin B12; on the other hand senile patient group (s) benefited a lot from the therapy.

Keywords: cataract patients, senile, diabetes mellitus, vitamin B12, vitamin D, Muhyail General Hospital, Saudi Arabia

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2885 Greatly Improved Dielectric Properties of Poly'vinylidene fluoride' Nanocomposites Using Ag-BaTiO₃ Hybrid Nanoparticles as Filler

Authors: K. Silakaew, P. Thongbai

Abstract:

There is an increasing need for high–permittivity polymer–matrix composites (PMC) owing to the rapid development of the electronics industry. Unfortunately, the dielectric permittivity of PMC is still too low ( < 80). Moreover, the dielectric loss tangent is usually high (tan > 0.1) when the dielectric permittivity of PMC increased. In this research work, the dielectric properties of poly(vinylidene fluoride) (PVDF)–based nanocomposites can be significantly improved by incorporating by silver–BaTiO3 (Ag–BT) ceramic hybrid nanoparticles. The Ag–BT/PVDF nanocomposites were fabricated using various volume fractions of Ag–BT hybrid nanoparticles (fAg–BT = 0–0.5). The Ag–BT/PVDF nanocomposites were characterized using several techniques. The main phase of Ag and BT can be detected by the XRD technique. The microstructure of the Ag–BT/PVDF nanocomposites was investigated to reveal the dispersion of Ag–BT hybrid nanoparticles because the dispersion state of a filler can have an effect on the dielectric properties of the nanocomposites. It was found that the filler hybrid nanoparticles were well dispersed in the PVDF matrix. The phase formation of PVDF phases was identified using the XRD and FTIR techniques. We found that the fillers can increase the polar phase of a PVDF polymer. The fabricated Ag–BT/PVDF nanocomposites are systematically characterized to explain the dielectric behavior in Ag–BT/PVDF nanocomposites. Interestingly, largely enhanced dielectric permittivity (>240) and suppressed loss tangent (tan<0.08) over a wide frequency range (102 – 105 Hz) are obtained. Notably, the dielectric permittivity is slightly dependent on temperature. The greatly enhanced dielectric permittivity was explained by the interfacial polarization between the Ag and PVDF interface, and due to a high permittivity of BT particles.

Keywords: BaTiO3, PVDF, polymer composite, dielectric properties

Procedia PDF Downloads 191