Search results for: lead Ion

Authors: Zahra Salehi Shahrbabaki, Zahra Chavoshzadeh, Fahimeh Abdollahimajd, Samin Sharafian, Tolue Mahdavi, Mahnaz Jamee

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Background: Inborn errors of immunity (IEIs) are monogenic diseases of the immune the system with broad clinical manifestations. Despite the increasing genetic advancements, the diagnosis of IEIs still leans on clinical diagnosis. Dermatologic manifestations are observed in a large number of IEI patients and can lead to proper approach, prompt intervention and improved prognosis. Methods: This cross-sectional study was carried out between 2018 and 2020 on IEIs at a Children's tertiary care center in Tehran, Iran. Demographic details (including age, sex, and parental consanguinity), age at onset of symptoms and family history of IEI with were recorded. Results :212 patients were included. Cutaneous findings were reported in (95 ,44.8%) patients. and 61 of 95 (64.2%) reported skin lesions as the first clinical presentation. Skin infection (69, 72.6%) was the most frequent cutaneous manifestation, followed by an eczematous rash (24, 25 %). Conclusions: Skin manifestations are common feature in IEI patients and can be readily recognizable by healthcare providers. This study tried to provide information on prognostic consequences.

Keywords: primary immuno deficiency, inborn errror of metabolism, skin manifestation, skin infection

Procedia PDF Downloads 97

Authors: Mouad Ouafi, Lahoucine Atourki, Larbi Laanab, Erika Vega, Miguel Mollar, Bernabe Marib, Boujemaa Jaber

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Despite the astonishing emergence of the methylammonium lead triiodide perovskite as a promising light harvester for solar cells, their physical properties in solution-processed MAPbI₃ are still crucial and need to be improved. The objective of this work is to investigate the hot airflow effect during the growth of MAPbI₃ films using the spin-coating process on their structural, optical and morphological proprieties. The experimental results show that many physical proprieties of the perovskite strongly depend on the air flow temperature and the optimization which has a beneficial effect on the perovskite quality. In fact, a clear improvement of the crystallinity and the crystallite size of MAPbI₃ perovskite is demonstrated by the XRD analyses, when the airflow temperature is increased up to 100°C. Alternatively, as far as the surface morphology is concerned, SEM micrographs show that significant homogenous nucleation, uniform surface distribution and pin holes free with highest surface coverture of 98% are achieved when the airflow temperature reaches 100°C. At this temperature, the improvement is also observed when considering the optical properties of the films. By contrast, a remarkable degradation of the MAPbI₃ perovskites associated to the PbI₂ phase formation is noticed, when the hot airflow temperature is higher than 100°C, especially 300°C.

Keywords: hot air flow, crystallinity, surface coverage, perovskite morphology

Procedia PDF Downloads 165

Authors: Narupon Kunbootsri, J. Kraipoj, K. Phandech, P. Sirasaporn

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Physiotherapy is one of the treatments for frozen shoulder but there was no data about the treatment of physiotherapy. Moreover, it is question about onset of symptom before physiotherapy program and obtaining physical modalities and delayed start physiotherapy program lead to delayed improvement. Thus the aim of this study was to investigate physiotherapy program for frozen shoulder on pain score, onset of symptom and obtaining physical modalities. A retrospective study design was conducted. 182 medical records of patients with frozen shoulder were reviewed. These frozen shoulders were treated at physiotherapy unit, department of Rehabilitation last 3 years (January, 2014- December, 2016). The data consist of onset of symptom, pain score and obtaining physical modalities were recorded. There was a statistically significant improve in pain score, pretreatment score mean 7.24±1.52 and the last follow up pain score mean 3.88± 1.0 [mean difference 3.18 with 95%CI were [2.45- 3.92]. In addition, the onset of symptoms was 145 days before obtaining physiotherapy program. The physical modalities used frequently were hot pack 14.8% and ultrasound diathermy 13.7%. In conclusion, the retrospective study show physiotherapy program including, hot pack and ultrasound diathermy seem to be useful for frozen shoulder in term of pain score. But onset of symptom is too long to start physiotherapy programs.

Keywords: frozen shoulder, physiotherapy, pain score, onset of symptom, physical modality

Procedia PDF Downloads 177

Authors: Merrick Lopez, Aashish Abraham, Melissa Egge, Marissa Hood, Jui Shah

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A 3 year old male with unknown medical history presented initially with encephalopathy, intubated for respiratory failure, and admitted to the pediatric intensive care unit (PICU) with refractory shock. During resuscitation in the emergency department, he was found to be in severe metabolic acidosis with a pH of 7.03 and escalated on vasopressor drips for hypotension. His initial sodium was 174. He was noted to have burn injuries to his scalp, forehead, right axilla, bilateral arm creases and lower legs. He had rhabdomyolysis (initial creatinine kinase 5,430 U/L with peak levels of 62,340 normal <335 U/L), cardiac injury (initial troponin 88 ng/L with peak at 145 ng/L, normal <15ng/L), hypernatremia (peak 174, normal 140), hypocalcemia, liver injury, acute kidney injury, and neuronal loss on magnetic resonance imaging (MRI). Soft restraints and a shock collar were found in the home. He was critically ill for 8 days, but was gradually weaned off drips, extubated, and started on feeds. Discussion Electrical injury, specifically lightning injury is an uncommon but devastating cause of injury in pediatric patients. This patient with suspected abusive use of a dog shock collar presented similar to a lightning strike. Common entrance points include the hands and head, similar to our patient with linear wounds on his forehead. When current enters, it passes through tissues with the least resistance. Nerves, blood vessels, and muscles, have high fluid and electrolyte content and are commonly affected. Exit points are extremities: our child who had circumferential burns around his arm creases and ankles. Linear burns preferentially follow areas of high sweat concentration, and are thought to be due to vaporization of water on the skin’s surface. The most common cause of death from a lightning strike is due to cardiopulmonary arrest. The massive depolarization of the myocardium can result in arrhythmias and myocardial necrosis. The patient presented in cardiogenic shock with evident cardiac damage. Electricity going through vessels can lead to vaporization of intravascular water. This can explain his severe hypernatremia. He also sustained other internal organ injuries (adrenal glands, pancreas, liver, and kidney). Electrical discharge also leads to direct skeletal muscle injury in addition to prolonged muscular spasm. Rhabdomyolysis, the acute damage of muscle, leads to release of potentially toxic components into the circulation which could lead to acute renal failure. The patient had severe rhabdomyolysis and renal injury. Early hypocalcemia has been consistently demonstrated in patients with rhabdomyolysis. This was present in the patient and led to increased vasopressor needs. Central nervous system injuries are also common which can include encephalopathy, hypoxic injury, and cerebral infarction. The patient had evidence of brain injury as seen on MRI. Conclusion Electrical injuries due to lightning strikes and abusive use of a dog shock collar are rare, but can both present in similar ways with respiratory failure, shock, hypernatremia, rhabdomyolysis, brain injury, and multiorgan damage. Although rare, it is essential for early identification and prompt management for acute and chronic complications in these children.

Keywords: cardiogenic shock, dog shock collar, lightning strike, rhabdomyolysis

Procedia PDF Downloads 90

Authors: Gautam Sharda

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The concept of right speech is the third stage of the noble eightfold path as prescribed by the Buddha and followed by millions of practicing Buddhists. The Buddha lays a lot of importance on the notion of right speech (Samma Vacca). In the Angutara Nikaya, the Buddha mentioned what constitutes right speech, which is basically four kinds of abstentions; namely abstaining from false speech, abstaining from slanderous speech, abstaining from harsh or hateful speech and abstaining from idle chatter. The Buddha gives reasons in support of his view as to why abstaining from these four kinds of speeches is favourable not only for maintaining the peace and equanimity within an individual but also within a society. It is a known fact that when we say something harsh or slanderous to others, it eventually affects our individual peace of mind too. We also know about the many examples of hate speeches which have led to senseless cases of violence and which are well documented within our country and the world. Also, indulging in false speech is not a healthy sign for individuals within a group as this kind of a social group which is based on falsities and lies cannot really survive for long and will eventually lead to chaos. Buddha also told us to refrain from idle chatter or gossip as generally we have seen that idle chatter or gossip does more harm than any good to the individual and the society. Hence, if most of us actually inculcate this third stage (namely, right speech) of the noble eightfold path of the Buddha in our daily life, it would be highly beneficial both for the individual and for the harmony of the society.

Keywords: Buddhism, speech, individual, society

Procedia PDF Downloads 266

Authors: Ali Akber Jaffri, Asad Naseem, Javeria Khan

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The purpose of this study is to determine safety stock, maximum inventory level, reordering point, and reordering quantity by rearranging lot sizes for supplier and customer in MRO (maintenance repair operations) warehouse of Engro Polymers & Chemicals. To achieve the aim, physical analysis method and excel commands were carried out to elicit the customer and supplier data provided by the company. Initially, we rearranged the current lot sizes and MOUs (measure of units) in SAP software. Due to change in lot sizes we have to determine the new quantities for safety stock, maximum inventory, reordering point and reordering quantity as per company's demand. By proposed system, we saved extra cost in terms of reducing the time of receiving from vendor and in issuance to customer, ease of material handling in MRO warehouse and also reduce human efforts. The information requirements identified in this study can be utilized in calculating Economic Order Quantity.

Keywords: carrying cost, economic order quantity, fast moving, lead time, lot size, MRO, maximum inventory, ordering cost, physical inspection, reorder point

Procedia PDF Downloads 240

Authors: M. Malekian, M. E. Heydari, M. Irani Estyar

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Human papillomavirus (HPV) is one of the most common sexually transmitted infection, which may lead to cervical cancer as the main cause of it. With early diagnosis and treatment in health care services, cervical cancer and its complications are considered to be preventable. This study was aimed to compare the efficiency, sensitivity, and specificity of Pap smear and polymerase chain reaction (PCR) in detecting HPV. A literature search was performed in Google Scholar, PubMed and SID databases using the keywords 'human papillomavirus', 'pap smear' and 'polymerase change reaction' to identify studies comparing Pap smear and PCR methods for the detection. No restrictions were considered.10 studies were included in this review. All samples that were positive by pop smear were also positive by PCR. However, there were positive samples detected by PCR which was negative by pop smear and in all studies, many positive samples were missed by pop smear technique. Although The Pap smear had high specificity, PCR based HPV detection was more sensitive method and had the highest sensitivity. In order to promote the quality of detection and high achievement of the maximum results, PCR diagnostic methods in addition to the Pap smear are needed and Pap smear method should be combined with PCR techniques according to the high error rate of Pap smear in detection.

Keywords: human papillomavirus, cervical cancer, pap smear, polymerase chain reaction

Procedia PDF Downloads 132

Authors: R. Reshma srilakshmi, S. Shalini, P. Yogeeswari, D. Sriram

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Lysine aminotransferase is a crucial enzyme for dormancy in M. tuberculosis. It is involved in persistence and antibiotic resistance. In present work, we attempted to develop benzthiazole derivatives as lysine aminotransferase inhibitors. In our attempts, we also unexpectedly arrived at an interesting compound 21 (E)-4-(5-(2-(benzo[d]thiazol-2-yl)-2-cyanovinyl)thiophen-2-yl)benzoic acid which even though has moderate activity against persistent phase of mycobacterium, it has significant potency against active phase. In the entire series compound 22 (E)-4-(5-(2-(benzo[d]thiazol-2-yl)-2-cyanovinyl)thiophen-2-yl)isophthalic acid emerged as potent molecule with LAT IC50 of 2.62 µM. It has a significant log reduction of 2.9 and 2.3 fold against nutrient starved and biofilm forming mycobacteria. It was found to be inactive in MABA assay and M.marinum induced zebra fish model. It is also devoid of cytotoxicity. Compound 22 was also found to possess bactericidal effect which is independent of concentration and time. It was found to be effective in combination with Rifampicin in 3D granuloma model. The results are very encouraging as the hit molecule shows activity against active as well as persistent forms of tuberculosis. The identified hit needs further more pharmacokinetic and dynamic screening for development as new drug candidate.

Keywords: benzothiazole, latent tuberculosis, LAT, nutrient starvation

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Authors: Naser Safdarian, Nader Jafarnia Dabanloo

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In this paper we used four features i.e. Q-wave integral, QRS complex integral, T-wave integral and total integral as extracted feature from normal and patient ECG signals to detection and localization of myocardial infarction (MI) in left ventricle of heart. In our research we focused on detection and localization of MI in standard ECG. We use the Q-wave integral and T-wave integral because this feature is important impression in detection of MI. We used some pattern recognition method such as Artificial Neural Network (ANN) to detect and localize the MI. Because these methods have good accuracy for classification of normal and abnormal signals. We used one type of Radial Basis Function (RBF) that called Probabilistic Neural Network (PNN) because of its nonlinearity property, and used other classifier such as k-Nearest Neighbors (KNN), Multilayer Perceptron (MLP) and Naive Bayes Classification. We used PhysioNet database as our training and test data. We reached over 80% for accuracy in test data for localization and over 95% for detection of MI. Main advantages of our method are simplicity and its good accuracy. Also we can improve accuracy of classification by adding more features in this method. A simple method based on using only four features which extracted from standard ECG is presented which has good accuracy in MI localization.

Keywords: ECG signal processing, myocardial infarction, features extraction, pattern recognition

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Authors: Fawad Ali, Muhammad Ateeq, Ikhtiar Khan

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

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

Procedia PDF Downloads 347

Authors: Tarek Aly

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Introduction: Maintenance of the length, providing rotational stability, and preserving functional range of forearm motion is the mainstay of both bone forearm fractures treatment. Conservative treatment in older children may lead to malunion with poor remodeling capacity. Recent studies emphasized that the rate of complications with IM nailing was obviously increased in old children. Open reduction and internal fixation have been criticized for the amount of soft tissue dissection and periosteal stripping needed for fixation and excessive scar formation. The aim of this study was to evaluate the anatomical and functional outcomes of hybrid fixation in the treatment of closed proximal radius and ulna fractures in adolescents between 12 and 17 years of age. Patients and Methods: 30 cases of diaphyseal both bone forearm fractures treated with hybrid fixation (Nail radius – Plate ulna) and were available for a follow-up period of fewer than 24 months. Results: Clinically, 72% of cases had an excellent function, 22% had a good function, 4% had a fair function, and 2% had a poor function. Radiologically, signs of the union had appeared in the radius 2weeks earlier than in the ulna in 55% of cases. Conclusion: A hybrid fixation technique in adolescent proximal both-bones forearm fractures could be a viable option in managing these injuries.

Keywords: hyprid fixation, both bones, forearm, fractures

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Authors: Abeer Amayri, Akif A. Bulgak

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Due to today’s globalization as well as outsourcing practices of the companies, the Supply Chain (SC) performances have become more dependent on the efficient movement of material among places that are geographically dispersed, where there is more chance for disruptions. One such disruption is the quality and delivery uncertainties of outsourcing. These uncertainties could lead the products to be unsafe and, as is the case in a number of recent examples, companies may have to end up in recalling their products. As a result of these problems, there is a need to develop a methodology for selecting suppliers globally in view of risks associated with low quality and late delivery. Accordingly, we developed a two-stage stochastic model that captures the risks associated with uncertainty in quality and delivery as well as a solution procedure for the model. The stochastic model developed simultaneously optimizes supplier selection and purchase quantities under price discounts over a time horizon. In particular, our target is the study of global organizations with multiple sites and multiple overseas suppliers, where the pricing is offered in suppliers’ local currencies. Our proposed methodology is applied to a case study for a US automotive company having two assembly plants and four potential global suppliers to illustrate how the proposed model works in practice.

Keywords: global supply chains, quality, stochastic programming, supplier selection

Procedia PDF Downloads 461

Authors: Jia Yin Tan, Daniel Rambei, Kate Mann, Samuel price, Ahmed Aboelela

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Introduction: Breastfeeding is a complex process, influenced by various factors. Tongue-tie may lead to breastfeeding difficulties due to an inability to suck effectively, causing sore nipples and poor infant weight gain. In the UK, most frenotomies on infants are performed by doctors, nurses, health visitors or midwives. Objectives: Evaluation of safety and efficacy of a multispecialty nurse-led rapid access tongue-tie service at Sheffield Children’s Hospital, run jointly by the ENT and paediatric surgery departments. Methodology: A retrospective observational study, including all patients attending the ENT and paediatric surgery nurse-led tongue tie clinics between 1/10/2021 and 30/09/2022. Results: During the study period there were 1135 referrals for frenotomy, with a mean of 15 days between referral to clinic episode. 86.8% of referred patients underwent frenotomy, with a complication rate of 0.1% and revision rate of 5.4%. Conclusions: Our findings suggest that our rapid access nurse-led outpatient tongue tie service is safe and efficacious, with low complication and revision rates. This suggests a potential for developing a community-based service, allowing safe and effective care closer to home.

Keywords: tongue tie, frenotomy, cost, nurse-led

Procedia PDF Downloads 113

Authors: Armin Rahimi

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The Gravity Recovery and Climate Experiment (GRACE) has been a very successful project in determining math redistribution within the Earth system. Large deformations caused by earthquakes are in the high frequency band. Unfortunately, GRACE is only capable to provide reliable estimate at the low-to-medium frequency band for the gravitational changes. In this study, we computed the gravity changes after the 2012 Mw8.6 Indian Ocean earthquake off-Sumatra using the GRACE Level-2 monthly spherical harmonic (SH) solutions released by the University of Texas Center for Space Research (UTCSR). Moreover, we calculated gravity changes using different fault models derived from teleseismic data. The model predictions showed non-negligible discrepancies in gravity changes. However, after removing high-frequency signals, using Gaussian filtering 350 km commensurable GRACE spatial resolution, the discrepancies vanished, and the spatial patterns of total gravity changes predicted from all slip models became similar at the spatial resolution attainable by GRACE observations, and predicted-gravity changes were consistent with the GRACE-detected gravity changes. Nevertheless, the fault models, in which give different slip amplitudes, proportionally lead to different amplitude in the predicted gravity changes.

Keywords: undersea earthquake, GRACE observation, gravity change, dislocation model, slip distribution

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Authors: Diana López-Soto, Soumaya Yacout, Francisco Ángel-Bello

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Although inventories are considered as stocks of money sitting on shelve, they are needed in order to secure a constant and continuous production. Therefore, companies need to have control over the amount of inventory in order to find the balance between excessive and shortage of inventory. The classification of items according to certain criteria such as the price, the usage rate and the lead time before arrival allows any company to concentrate its investment in inventory according to certain ranking or priority of items. This makes the decision making process for inventory management easier and more justifiable. The purpose of this paper is to present a new approach for the classification of new items based on the already existing criteria. This approach is called the Logical Analysis of Data (LAD). It is used in this paper to assist the process of ABC items classification based on multiple criteria. LAD is a data mining technique based on Boolean theory that is used for pattern recognition. This technique has been tested in medicine, industry, credit risk analysis, and engineering with remarkable results. An application on ABC inventory classification is presented for the first time, and the results are compared with those obtained when using the well-known AHP technique and the ANN technique. The results show that LAD presented very good classification accuracy.

Keywords: ABC multi-criteria inventory classification, inventory management, multi-class LAD model, multi-criteria classification

Procedia PDF Downloads 884

Authors: S. Larbi, R. Bensaada, S. Djebali, A. Bilek

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The manufacture of composite parts is a major issue in many industrial domains. Polymer composite materials are ideal for structural applications where high strength-to-weight and stiffness-to-weight ratios are required. However, exposition to extreme environment conditions (temperature, humidity) affects mechanical properties of organic composite materials and lead to an undesirable degradation. Aging mechanisms in organic matrix are very diverse and vary according to the polymer and the aging conditions such as temperature, humidity etc. This paper studies the hygrothermal aging effect on the mechanical properties of fiber reinforced plastics laminates at 40 °C in different environment exposure. Two composite materials are used to conduct the study (carbon fiber/epoxy and glass fiber/vinyl ester with two stratifications for both the materials [904/04] and [454/04]). The experimental procedure includes a mechanical characterization of the materials in a virgin state and exposition of specimens to two environments (seawater and demineralized water). Absorption kinetics for the two materials and both the stratifications are determined. Three-point bending test is performed on the aged materials in order to determine the hygrothermal effect on the mechanical properties of the materials.

Keywords: FRP laminates, hygrothermal aging, mechanical properties, theory of laminates

Procedia PDF Downloads 285

Authors: A. Brahma

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Drying is a phenomenon that accompanies the hardening of hydraulic materials. It can, if it is not prevented, lead to significant spontaneous dimensional variations, which the cracking is one of events. In this context, cracking promotes the transport of aggressive agents in the material, which can affect the durability of concrete structures. Drying shrinkage develops over a long period almost 30 years although most occurred during the first three years. Drying shrinkage stabilizes when the material is water balance with the external environment. The drying shrinkage of cementitious materials is due to the formation of capillary tensions in the pores of the material, which has the consequences of bringing the solid walls of each other. Knowledge of the shrinkage characteristics of concrete is a necessary starting point in the design of structures for crack control. Such knowledge will enable the designer to estimate the probable shrinkage movement in reinforced or prestressed concrete and the appropriate steps can be taken in design to accommodate this movement. This study is concerned the modelling of drying shrinkage of the hydraulic materials and the prediction of the rate of spontaneous deformations of hydraulic materials during hardening. The model developed takes in consideration the main factors affecting drying shrinkage. There was agreement between drying shrinkage predicted by the developed model and experimental results. In last we show that developed model describe the evolution of the drying shrinkage of high performances concretes correctly.

Keywords: drying, hydraulic concretes, shrinkage, modeling, prediction

Procedia PDF Downloads 339

Authors: Alirıza Kaleli, M. Akif Ceviz, Erdoğan Güner, Köksal Erentürk

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The cyclic variations in spark ignition engines occurring especially under specific engine operating conditions make the maximum pressure variable for successive in-cylinder pressure cycles. Minimization of cyclic variations has a great importance in effectively operating near to lean limit, or at low speed and load. The cyclic variations may reduce the power output of the engine, lead to operational instabilities, and result in undesirable engine vibrations and noise. In this study, spark timing is controlled in order to reduce the cyclic variations in spark ignition engines. Firstly, an ARMAX model has developed between spark timing and maximum pressure using system identification techniques. By using this model, the maximum pressure of the next cycle has been predicted. Then, self-tuning minimum variance controller has been designed to change the spark timing for consecutive cycles of the first cylinder of test engine to regulate the in-cylinder maximum pressure. The performance of the proposed controller is illustrated in real time and experimental results show that the controller has a reliable effect on cycle to cycle variations of maximum cylinder pressure when the engine works under low speed conditions.

Keywords: cyclic variations, cylinder pressure, SI engines, self tuning controller

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Authors: Dionisios Panagiotaras, Dimitrios Papoulis, Elias Stathatos

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Microfibrous palygorskite and tubular halloysite clay mineral combined with nanocrystalline TiO2 are incorporating in the preparation of nanocomposite films on glass substrates via sol-gel route at 450 °C. The synthesis is employing nonionic surfactant molecule as pore directing agent along with acetic acid-based sol-gel route without addition of water molecules. Drying and thermal treatment of composite films ensure elimination of organic material lead to the formation of TiO2 nanoparticles homogeneously distributed on the palygorskite or halloysite surfaces. Nanocomposite films without cracks of active anatase crystal phase on palygorskite and halloysite surfaces are characterized by microscopy techniques, UV-Vis spectroscopy, and porosimetry methods in order to examine their structural properties. The composite palygorskite-TiO2 and halloysite-TiO2 films with variable quantities of palygorskite and halloysite were tested as photocatalysts in the photo-oxidation of Basic Blue 41 azo dye in water. These nanocomposite films proved to be most promising photocatalysts and highly effective to dye’s decoloration in spite of small amount of palygorskite -TiO2 or halloysite- TiO2 catalyst immobilized onto glass substrates mainly due to the high surface area and uniform distribution of TiO2 on clay minerals avoiding aggregation.

Keywords: halloysite, palygorskite, photocatalysis, titanium dioxide

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Authors: A. Samer Ezeldin, Jwanda M. El Sarag

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Variation orders are of great importance in any construction project. Variation orders are defined as any change in the scope of works of a project that can be an addition omission, or even modification. This paper investigates the variation orders that occur during construction projects in Egypt. The literature review represents a comparison of causes of variation orders among Egypt, Tanzania, Nigeria, Malaysia and the United Kingdom. A classification of occurrence of variation orders due to owner related factors, consultant related factors and other factors are signified in the literature review. These classified events that lead to variation orders were introduced in a survey with 19 events to observe their frequency of occurrence, and their time and cost impacts. The survey data was obtained from 87 participants that included clients, consultants, and contractors and a database of 42 scenarios was created. A model is then developed to help assist project managers in predicting the frequency of variations and account for a budget for any additional costs and minimize any delays that can take place. Two experts with more than 25 years of experience were given the model to verify that the model was working effectively. The model was then validated on a residential compound that was completed in July 2016 to prove that the model actually produces acceptable results.

Keywords: construction, cost impact, Egypt, time impact, variation orders

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Authors: Ankur Chaudhuri, Sibani Sen Chakraborty

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In human, glutaminyl cyclase activity is highly abundant in neuronal and secretory tissues and is preferentially restricted to hypothalamus and pituitary. The N-terminal modification of β-amyloids (Aβs) peptides by the generation of a pyro-glutamyl (pGlu) modified Aβs (pE-Aβs) is an important process in the initiation of the formation of neurotoxic plaques in Alzheimer’s disease (AD). This process is catalyzed by glutaminyl cyclase (QC). The expression of QC is characteristically up-regulated in the early stage of AD, and the hallmark of the inhibition of QC is the prevention of the formation of pE-Aβs and plaques. A computer-aided drug design (CADD) process was employed to give an idea for the designing of potentially active compounds to understand the inhibitory potency against human glutaminyl cyclase (QC). This work elaborates the ligand-based and structure-based pharmacophore exploration of glutaminyl cyclase (QC) by using the known inhibitors. Three dimensional (3D) quantitative structure-activity relationship (QSAR) methods were applied to 154 compounds with known IC50 values. All the inhibitors were divided into two sets, training-set, and test-sets. Generally, training-set was used to build the quantitative pharmacophore model based on the principle of structural diversity, whereas the test-set was employed to evaluate the predictive ability of the pharmacophore hypotheses. A chemical feature-based pharmacophore model was generated from the known 92 training-set compounds by HypoGen module implemented in Discovery Studio 2017 R2 software package. The best hypothesis was selected (Hypo1) based upon the highest correlation coefficient (0.8906), lowest total cost (463.72), and the lowest root mean square deviation (2.24Å) values. The highest correlation coefficient value indicates greater predictive activity of the hypothesis, whereas the lower root mean square deviation signifies a small deviation of experimental activity from the predicted one. The best pharmacophore model (Hypo1) of the candidate inhibitors predicted comprised four features: two hydrogen bond acceptor, one hydrogen bond donor, and one hydrophobic feature. The Hypo1 was validated by several parameters such as test set activity prediction, cost analysis, Fischer's randomization test, leave-one-out method, and heat map of ligand profiler. The predicted features were then used for virtual screening of potential compounds from NCI, ASINEX, Maybridge and Chembridge databases. More than seven million compounds were used for this purpose. The hit compounds were filtered by drug-likeness and pharmacokinetics properties. The selective hits were docked to the high-resolution three-dimensional structure of the target protein glutaminyl cyclase (PDB ID: 2AFU/2AFW) to filter these hits further. To validate the molecular docking results, the most active compound from the dataset was selected as a reference molecule. From the density functional theory (DFT) study, ten molecules were selected based on their highest HOMO (highest occupied molecular orbitals) energy and the lowest bandgap values. Molecular dynamics simulations with explicit solvation systems of the final ten hit compounds revealed that a large number of non-covalent interactions were formed with the binding site of the human glutaminyl cyclase. It was suggested that the hit compounds reported in this study could help in future designing of potent inhibitors as leads against human glutaminyl cyclase.

Keywords: glutaminyl cyclase, hit lead, pharmacophore model, simulation

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Authors: Sudhir Kumar Sharma, Ramesh Jagannathan

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The interaction of organic and inorganic matrices of biological origin resulting in self-assembled structures with unique properties is well established. The development of such self-assembled nanostructures by synthetic and bio-inspired techniques is an established field of active research. Among bio-materials, nacre, a laminar stack of calcium carbonate nanosheets, which are interleaved with organic material, has long been focused research due to its unique mechanical properties. In this paper, we present the development of nacre-like lamellar structures made up of calcium carbonate via a wet chemical route. We used the binding affinity of carboxylate anions and calcium cations using poly (acrylic) acid (PAA) to lead CaCO₃ crystallization. In these experiments, we selected calcium acetate as the precursor molecule along with PAA (Mw ~ 8000 Da). We found that Ca⁺²/COO⁻ ratio provided a tunable control for the morphology and growth of CaCO₃ nanostructures. Drop casting one such formulation on a silicon substrate followed by calcination resulted in co-planner, molecular sheets of CaCO₃, separated by a spacer layer of carbon. The scope of our process could be expanded to produce unit cell thick molecular sheets of other important inorganic materials.

Keywords: self-assembled structures, bio-inspired materials, calcium carbonate, wet chemical route

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Authors: Sarma Binti Aralas

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The relationship between property rights and trade specialization is examined for developing and developed countries using panel data analysis. Property rights is measured using the international property rights index while trade specialization is measured using the comparative advantage index. Cross country differences in property rights are hypothesized to lead to differences in trade specialization. Based on the argument that a weak protection of natural resources implies greater trade in resource-intensive goods, developing countries with less defined property rights are hypothesized to have a comparative advantage in resource-based exports while countries with more defined property rights will not have an advantage in resource-intensive goods. Evidence suggests that developing countries with weaker environmental protection index but are rich in natural resources do specialize in the trade of resource-intensive goods. The finding suggests that institutional frameworks to increase the stringency of environmental protection of resources may be needed to diversify exports away from the trade of resource-intensive goods.

Keywords: environmental protection, panel data, renewable resources, trade specialization

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Authors: Sanjay Saraf

Abstract:

The oral cavity can be the site for early manifestations of mucocutaneous disorders (MD) or the only site for occurrence of these disorders. It can also exhibit oral lesions with simultaneous associated skin lesions. The MD involving the oral mucosa commonly presents with signs such as ulcers, vesicles and bullae. The unique environment of the oral cavity may modify these signs of the disease, thereby making the clinical diagnosis an arduous task. In addition to the unique environment of oral cavity, the overlapping of the signs of various mucocutaneous disorders, also makes the clinical diagnosis more intricate. The aim of this review is to present the oral signs of dermatological disorders having common oral involvement and emphasize their importance in early detection of the systemic disorders. The aim is also to highlight the necessity of oral examination by a dermatologist while examining the skin lesions. Prior to the oral examination, it must be imperative for the dermatologists and the dental clinicians to have the knowledge of oral anatomy. It is also important to know the impact of various diseases on oral mucosa, and the characteristic features of various oral mucocutaneous lesions. An initial clinical oral examination is may help in the early diagnosis of the MD. Failure to identify the oral manifestations may reduce the likelihood of early treatment and lead to more serious problems. This paper reviews the oral manifestations of immune mediated dermatological disorders with common oral manifestations.

Keywords: dermatological investigations, genodermatosis, histological features, oral examination

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Authors: Göksel Şimşek

Abstract:

Celebrities are admired, appreciated and imitated all over the world. As a natural result of this, today many brands choose to work with celebrities for their advertisements. It can be said that the more the brands include celebrities in their marketing communication strategies, the tougher the competition in this field becomes and they allocate a large portion of their marketing budget to this. Brands invest in celebrities who will represent them in order to build the image they want to create. This study aimed to bring under spotlight the perceptions of Turkish customers regarding the use of celebrities in advertisements and marketing communication and try to understand their possible effects on subsequent purchasing decisions. In addition, consumers’ reactions and perceptions were investigated in the context of the product-celebrity match, to what extent the celebrity conforms to the concept of the advertisement and the celebrity-target audience match. In order to achieve this purpose, a quantitative research was conducted as a case study concerning Mavi Jeans (textile company). Information was obtained through survey. The results from this case study are supported by relevant theories concerning the main subject. The most valuable result would be that instead of creating an advertisement around a celebrity in demand at the time, using a celebrity that fits the concept of the advertisement and feeds the concept rather than replaces it, that is celebrity endorsement, will lead to more striking and positive results.

Keywords: celebrity endorsement, product-celebrity match, advertising, social sciences

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Authors: Chol Min Yu, Sok Chol Ri

Abstract:

The optimization of formation and growth of metallic nuggets during self-reduction of coal composite briquette (CCB here) is essential to increase the yield of valuable metals. The formation of metallic nuggets was investigated theoretically and experimentally during the reduction of coal composite briquette made from stainless steel dust and coal. The formation of metallic nuggets is influenced by slag viscosity and interfacial tension between the liquid metal and the slag in the reduced product. Surface tensions of liquid metal and slag are rather strong, respectively, due to the high basicity of its slag. Strong surface tensions of them lead to increase of interfacial tension between the liquid metal and the slag to be favorable to the growth of metallic nuggets. The viscosity of slag and interfacial tension between the liquid metal and the slag depends on the temperature and composition of the slag. The formation and the growth of metallic nuggets depend on carbon to oxygen ratio FC/O and temperature.

Keywords: stainless steel dust, coal-composite briquette, temperature, high basicity, interfacial tension

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Authors: Duy Nhat Tran, Van Tien Pham, Quang Trung Trinh, Tien Hai Tran, Van Cong Bui

Abstract:

In recent years, artificial intelligence and the Internet of Things have experienced significant advancements. Collecting image data and real-time analysis and processing of tasks have become increasingly popular in various aspects of life. Optical scanning devices are widely used to observe and analyze different environments, whether fixed outdoors, mounted on mobile devices, or used in unmanned aerial vehicles. As a result, the interaction between the physical environment and these devices has become more critical in terms of safety. Two commonly used methods for addressing these challenges are active and passive approaches. Each method has its advantages and disadvantages, but combining both methods can lead to higher efficiency. One solution is to utilize direct-drive motors for position control and real-time feedback within the operational range to determine appropriate control parameters with high precision. If the maximum motor torque is smaller than the inertial torque and the rotor reaches the operational limit, the spring system absorbs the impact force. Numerous experiments have been conducted to demonstrate the effectiveness of device protection during operation.

Keywords: optical device, collision safety, collision absorption, precise mechanics

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Authors: A. Abdikian

Abstract:

Using the linearized quantum hydrodynamic model (QHD) and by considering the role of quantum parameter (Bohm’s potential) and electron exchange-correlation potential in conjunction with Maxwell’s equations, electromagnetic wave propagation in a single-walled carbon nanotubes was studied. The electronic excitations are described. By solving the mentioned equations with appropriate boundary conditions and by assuming the low-frequency electromagnetic waves, two general expressions of dispersion relations are derived for the transverse magnetic (TM) and transverse electric (TE) modes, respectively. The dispersion relations are analyzed numerically and it was found that the dependency of dispersion curves with the exchange-correlation effects (which have been ignored in previous works) in the low frequency would be limited. Moreover, it has been realized that asymptotic behaviors of the TE and TM modes are similar in single wall carbon nanotubes (SWCNTs). The results show that by adding the function of electron exchange-correlation potential lead to the phenomena and make to extend the validity range of QHD model. The results can be important in the study of collective phenomena in nanostructures.

Keywords: transverse magnetic, transverse electric, quantum hydrodynamic model, electron exchange-correlation potential, single-wall carbon nanotubes

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Authors: P.J. Jiji, B.V. Murlimanju, Latha V. Prabhu, Mangala M. Pai

Abstract:

Background: The lunate bone dislocation can lead to the compression of the median nerve and subsequent carpal tunnel syndrome. The dislocation can interrupt the vasculature and would cause avascular necrosis. The objective of the present study was to study the morphology and number of the nutrient foramina in the cadaveric dried lunate bones of the Indian population. Methods: The present study included 28 lunate bones (13 right sided and 15 left sided) which were obtained from the gross anatomy laboratory of our institution. The bones were macroscopically observed for the nutrient foramina and the data was collected with respect to their number. The tabulation of the data and analysis were done. Results: All of our specimens (100%) exhibited the nutrient foramina over the non-articular surfaces. The foramina were observed only over the palmar and dorsal surfaces of the lunate bones. The foramen ranged between 2 and 10. The foramina were more in number over the dorsal surface (average number 3.3) in comparison to the palmar surface (average number 2.4). Conclusion: We believe that the present study has provided important data about the nutrient foramina of the lunate bones. The data is enlightening to the orthopedic surgeon and would help in the hand surgeries. The morphological knowledge of the vasculature, their foramina of entry and their number is required to understand the concepts in the lunatomalacia and Kienbock’s disease.

Keywords: avascular necrosis, foramen, lunate, nutrient

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Authors: I. Nazari, B. Shaabani, P. Abaasifar

Abstract:

In small quantities certain heavy metals are nutritionally essential for a healthy life. The heavy metals linked most often to human poisoning are lead, mercury, arsenic, and cadmium. Other heavy metals including copper, zinc and chromium are actually required by the body in small quantity but can also be toxic in large doses. Nowadays, we have contamination to this heavy metals in some untreated industrial waste waters and even in several populated cities drinking waters around the world. The contamination of ground and underground water sources to heavy metals can be concentrated and travel up to food chain by drinking water and agricultural products. In recent years, the need for safe and economical methods for removal of heavy metals from contaminated water has necessitated research interest towards the finding low-cost alternatives. Bio-adsorbents have emerged as low-cost and efficient materials for the removal of heavy metals from waste and ground waters. The bio-adsorbents have an affinity for heavy metals ions to form metal complexes or chelates due to having functional groups including carboxyl, hydroxyl, imidazole, and etc. The objective of this study is to review researches in less expensive adsorbents and their utilization possibilities for various low-cost bio-adsorbents such as coffee beans, rice husk, and saw dust for the removal of heavy metals from contaminated waters.

Keywords: heavy metals, water pollution, bio-adsorbents, low cost adsorbents

Procedia PDF Downloads 357